func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            let diff = numbers[j] - numbers[i]
            if diff.abs <= threshold {
                return true
            }
        }
    }
    return false
}

```swift
// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            let diff = numbers[j] - numbers[i]
            if diff.abs <= threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            let diff = numbers[j] - numbers[i]
            if diff.abs <= threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            let diff = numbers[j] - numbers[i]
            if diff.abs <= threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            let diff = numbers[j] - numbers[i]
            if diff.abs <= threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            let diff = numbers[j] - numbers[i]
            if diff.abs <= threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            let diff = numbers[j] - numbers[i]
            if diff.abs <= threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements

func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            let diff = numbers[i] - numbers[j]
            if diff.abs <= threshold {
                return true
            }
        }
    }
    return false
}

```swift
// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            let diff = numbers[i] - numbers[j]
            if diff.abs <= threshold {
                return true
            }
        }
    }
    return false
}

// Test cases
print(hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5)) // false
print(hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3)) // true
```

func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if numbers[i] - numbers[j] < threshold {
                return true
            }
        }
    }
    return false
}

```swift
// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if numbers[i] - numbers[j] < threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if numbers[i] - numbers[j] < threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if numbers[i] - numbers[j] < threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if numbers[i] - numbers[j] < threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if numbers[i] - numbers[j] < threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if numbers[i] - numbers[j] < threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.

func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            let diff = numbers[i] - numbers[j]
            if diff.abs <= threshold {
                return true
            }
        }
    }
    return false
}

```swift
// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            let diff = numbers[i] - numbers[j]
            if diff.abs <= threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            let diff = numbers[i] - numbers[j]
            if diff.abs <= threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            let diff = numbers[i] - numbers[j]
            if diff.abs <= threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            let diff = numbers[i] - numbers[j]
            if diff.abs <= threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            let diff = numbers[i] - numbers[j]
            if diff.abs <= threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            let diff = numbers[i] - numbers[j]
            if diff.abs <= threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements

func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            let diff = numbers[i] - numbers[j]
            if diff.abs <= threshold {
                return true
            }
        }
    }
    return false
}

```swift
// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            let diff = numbers[i] - numbers[j]
            if diff.abs <= threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            let diff = numbers[i] - numbers[j]
            if diff.abs <= threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            let diff = numbers[i] - numbers[j]
            if diff.abs <= threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            let diff = numbers[i] - numbers[j]
            if diff.abs <= threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            let diff = numbers[i] - numbers[j]
            if diff.abs <= threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            let diff = numbers[i] - numbers[j]
            if diff.abs <= threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements

func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if numbers[i] - numbers[j] < threshold {
                return true
            }
        }
    }
    return false
}

```swift
// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if numbers[i] - numbers[j] < threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if numbers[i] - numbers[j] < threshold {
                return true
            }
        }
    }
    return false
}
```

func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            let diff = numbers[j] - numbers[i]
            if diff.abs <= threshold {
                return true
            }
        }
    }
    return false
}

```swift
// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            let diff = numbers[j] - numbers[i]
            if diff.abs <= threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            let diff = numbers[j] - numbers[i]
            if diff.abs <= threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            let diff = numbers[j] - numbers[i]
            if diff.abs <= threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            let diff = numbers[j] - numbers[i]
            if diff.abs <= threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            let diff = numbers[j] - numbers[i]
            if diff.abs <= threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            let diff = numbers[j] - numbers[i]
            if diff.abs <= threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements

func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if numbers[i] - numbers[j] < threshold {
                return true
            }
        }
    }
    return false
}

```swift
// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if numbers[i] - numbers[j] < threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if numbers[i] - numbers[j] < threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if numbers[i] - numbers[j] < threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if numbers[i] - numbers[j] < threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if numbers[i] - numbers[j] < threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if numbers[i] - numbers[j] < threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.

func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if numbers[i] - numbers[j] < threshold {
                return true
            }
        }
    }
    return false
}

```swift
// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if numbers[i] - numbers[j] < threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if numbers[i] - numbers[j] < threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if numbers[i] - numbers[j] < threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if numbers[i] - numbers[j] < threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if numbers[i] - numbers[j] < threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if numbers[i] - numbers[j] < threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.

func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if numbers[i] - numbers[j] < threshold {
                return true
            }
        }
    }
    return false
}

```swift
// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if numbers[i] - numbers[j] < threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if numbers[i] - numbers[j] < threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if numbers[i] - numbers[j] < threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if numbers[i] - numbers[j] < threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if numbers[i] - numbers[j] < threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.0, 4.0, 5.0, 2.0], threshold: 0.3) == true
func hasCloseElements(numbers: [Double], threshold: Double) -> Bool {
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if numbers[i] - numbers[j] < threshold {
                return true
            }
        }
    }
    return false
}

// Check if in given array of numbers, are any two numbers closer to each other than
// given threshold.
// hasCloseElements(numbers: [1.0, 2.0, 3.0], threshold: 0.5) == false
// hasCloseElements(numbers: [1.0, 2.8, 3.

func separateParenGroups(parenString: String) -> [String] {
    var result = [String]()
    var stack = [String]()
    var openParenCount = 0
    var closeParenCount = 0
    var currentGroup = String()
    for i in 0..<parenString.count {
        var char = parenString[i]
        if char == '(' {
            openParenCount += 1
        } else if char == ')' {
            closeParenCount += 1
        }
        currentGroup += char
        if openParenCount == closeParenCount {
            result.append(currentGroup)
            currentGroup = String()
            openParenCount = 0
            closeParenCount = 0
        }
    }
    return result
}

```swift
// Input to this function is a string containing multiple groups of nested parentheses. Your goal is to
// separate those group into separate strings and return the array of those.
// Separate groups are balanced (each open brace is properly closed) and not nested within each other
// Ignore any spaces in the input string.
// separateParenGroups(parenString: "( ) (( )) (( )( ))") == ["()", "(())", "(()())"]
func separateParenGroups(parenString: String) -> [String] {
    var result = [String]()
    var stack = [String]()
    var openParenCount = 0
    var closeParenCount = 0
    var currentGroup = String()
    for i in 0..<parenString.count {
        var char = parenString[i]
        if char == '(' {
            openParenCount += 1
        } else if char == ')' {
            closeParenCount += 1
        }
        currentGroup += char
        if openParenCount == closeParenCount {
            result.append(currentGroup)
            currentGroup = String()
            openParenCount = 0
            closeParenCount = 0
        }
    }
    return result
}

// Input to this function is a string containing multiple groups of nested parentheses. Your goal is to
// separate those group into separate strings and return the array of those.
// Separate groups are balanced (each open brace is properly closed) and not nested within each other
// Ignore any spaces in the input string.
// separateParenGroups(parenString: "( ) (( )) (( )( ))") == ["()", "(())", "(()())"]
func separateParenGroups(parenString: String) -> [String] {
    var result = [String]()
    var stack = [String]()
    var openParenCount = 0
    var closeParenCount = 0
    var currentGroup = String()
    for i in 0..<parenString.count {
        var char = parenString[i]
        if char == '(' {
            openParenCount += 1
        } else if char == ')' {
            closeParenCount += 1
        }
        currentGroup += char
        if openParenCount == closeParenCount {
            result.append(currentGroup)
            currentGroup = String()
            openParenCount = 0
            closeParenCount = 0
        }
    }
    return result
}

// Input to this function is a string containing multiple groups of nested parentheses. Your goal is to
// separate those group into separate strings and return the array of those.
// Separate groups are balanced (each open brace is properly closed) and not nested within each other
// Ignore any spaces in the input string.
// separateParenGroups(parenString: "( ) (( )) (( )( ))") == ["()", "(())", "(()())"]
func separateParenGroups(parenString: String) -> [String] {
    var result = [String]()
    var stack = [String]()
    var openParenCount = 0
    var closeParenCount = 0
    var currentGroup = String()
    for i in 0..<parenString.count {
        var char = parenString[i]
        if char == '(' {
            openParenCount += 1
        } else if char == ')' {
            closeParenCount += 1
        }
        currentGroup += char
        if openParenCount == closeParenCount {
            result.append(currentGroup)
            currentGroup = String()
            openParenCount = 0
            closeParenCount = 0
        }
    }
    return result
}

// Input to this function is a string containing multiple groups of nested parentheses. Your goal is to
// separate those group into separate strings and return the array of those.
// Separate groups are balanced (each open brace is properly closed) and not nested within each other
// Ignore any spaces in the input string.
// separateParenGroups(parenString: "( ) (( )) (( )( ))") == ["()", "(())", "(()())"]
func separateParenGroups(parenString: String) -> [String] {
    var result = [String]()
    var stack = [String]()
    var openParenCount = 0
    var closeParenCount = 0
    var currentGroup = String()
    for i in 0..<parenString.count {
        var char = parenString[i]
        if char == '(' {
            openParenCount += 1
        } else if char == ')' {
            closeParenCount += 1
        }
        currentGroup += char
        if openParenCount == closeParenCount {
            result.append(currentGroup)
            currentGroup = String()
            openParenCount = 0
            closeParenCount = 0
        }
    }
    return result
}

// Input to this function is a string containing multiple groups of nested parentheses. Your goal is to
// separate those group into separate strings and return the array of those.
// Separate groups are balanced (each open brace is properly closed) and not nested within each other

```swift
// Input to this function is a string containing multiple groups of nested parentheses. Your goal is to
// separate those group into separate strings and return the array of those.
// Separate groups are balanced (each open brace is properly closed) and not nested within each other
// Ignore any spaces in the input string.
// separateParenGroups(parenString: "( ) (( )) (( )( ))") == ["()", "(())", "(()())"]
func separateParenGroups(parenString: String) -> [String] {
    var result = [String]()
    var stack = [String]()
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var currentGroup = ""
    var currentGroupIndex = 0
    var currentGroupLength = 0
    var currentGroupStart = 0
    var currentGroupEnd = 0
    var currentGroupStartFound = false
    var currentGroupEndFound = false
    var currentGroupStartFoundIndex = 0
    var currentGroupEndFoundIndex = 0
    var currentGroupStartFoundCount = 0
    var currentGroupEndFoundCount = 0
    var currentGroupStartFoundCountIndex = 0
    var currentGroupEndFoundCountIndex = 0
    var currentGroupStartFoundCountLength = 0
    var currentGroupEndFoundCountLength = 0
    var currentGroupStartFoundCountLengthIndex = 0
    var currentGroupEndFoundCountLengthIndex = 0
    var currentGroupStartFoundCountLengthCount = 0
    var currentGroupEndFoundCountLengthCount = 0
    var currentGroupStartFoundCountLengthCountIndex = 0
    var currentGroupEndFoundCountLengthCountIndex = 0
    var currentGroupStartFoundCountLengthCountLength = 0
    var currentGroupEndFoundCountLengthCountLength = 0
    var currentGroupStartFoundCountLengthCountLengthIndex = 0
    var currentGroupEndFoundCountLengthCountLengthIndex = 0
    var currentGroupStartFoundCountLengthCountLengthCount = 0
    var currentGroupEndFoundCountLengthCountLengthCount = 0
    var currentGroupStartFoundCountLengthCountLengthCountIndex = 0
    var currentGroupEndFoundCountLengthCountLengthCountIndex = 0
    var currentGroupStartFoundCountLengthCountLengthCountLength = 0
    var currentGroupEndFoundCountLengthCountLengthCountLength = 0
    var currentGroupStartFoundCountLengthCountLengthCountLength = 0
    var currentGroupEndFoundCountLengthCountLengthCountLength = 0
    var currentGroupStartFoundCountLengthCountLengthCountLengthCount = 0
    var currentGroupEndFoundCountLengthCountLengthCountLengthCount = 0
    var currentGroupStartFoundCountLengthCountLengthCountLengthCountIndex = 0
    var currentGroupEndFoundCountLengthCountLengthCountLengthCountIndex = 0
    var currentGroupStartFoundCountLengthCountLengthCountLengthCountLength = 0
    var currentGroupEndFoundCountLengthCountLengthCountLengthCountLength = 0
    var currentGroupStartFoundCountLengthCountLengthCountLengthCountLength = 0
    var currentGroupEndFoundCountLengthCountLengthCountLengthCountLengthCount = 0
    var currentGroupStartFoundCountLengthCountLengthCountLengthCountLengthCountIndex = 0
    var currentGroupEndFoundCountLengthCountLengthCountLengthCountLengthCountIndex = 0
    var currentGroupStartFoundCountLengthCountLengthCountLengthCountLengthCountLength = 0
    var currentGroupEndFoundCountLengthCountLengthCountLengthCountLengthCountLength = 0
    var currentGroupStartFoundCountLengthCountLengthCountLengthCountLengthCountLengthIndex = 0
    var currentGroupEndFoundCountLengthCountLengthCountLengthCountLengthCountLengthIndex = 0
    var currentGroupStartFoundCountLengthCountLengthCountLengthCountLengthCountLengthLength = 0
    var currentGroupEndFoundCountLengthCountLengthCountLengthCountLengthCountLengthLength = 0
    var currentGroupStartFoundCountLengthCountLengthCountLengthCountLengthCountLengthLengthIndex = 0
    var currentGroupEndFoundCountLengthCountLengthCountLengthCountLengthCountLengthLengthIndex = 0
    var currentGroupStartFoundCountLengthCountLengthCountLengthCountLengthCountLengthLengthLength = 0
    var currentGroupEndFoundCountLengthCountLengthCountLengthCountLengthCountLengthLengthLength = 0
    var currentGroupStartFoundCountLengthCountLengthCountLengthCountLengthCountLengthLengthLengthIndex = 0
    var currentGroupEndFoundCountLengthCountLengthCountLengthCountLengthCountLengthLengthLengthIndex = 0
    var currentGroupStartFoundCountLengthCountLengthCountLengthCountLengthCountLengthLengthLengthLength = 0
    var currentGroupEndFoundCountLengthCountLengthCountLengthCountLengthCountLengthLengthLengthLengthIndex = 0
    var currentGroupStartFoundCountLengthCountLengthCountLengthCountLengthCountLengthLengthLengthLengthLength = 0
    var currentGroupEndFoundCountLengthCountLengthCountLengthCountLengthCountLengthLengthLengthLengthLengthIndex = 0
    var currentGroupStartFoundCountLengthCountLengthCountLengthCountLengthCountLengthLength

```swift
// Input to this function is a string containing multiple groups of nested parentheses. Your goal is to
// separate those group into separate strings and return the array of those.
// Separate groups are balanced (each open brace is properly closed) and not nested within each other
// Ignore any spaces in the input string.
// separateParenGroups(parenString: "( ) (( )) (( )( ))") == ["()", "(())", "(()())"]
func separateParenGroups(parenString: String) -> [String] {
    var result = [String]()
    var stack = [String]()
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenStack = [Int]()
    var closeParenStack = [Int]()
    var openParenStackIndex = 0
    var closeParenStackIndex = 0
    var openParen = '('
    var closeParen = ')'
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenStackIndex = 0
    var closeParenStackIndex = 0
    var openParenStack = [Int]()
    var closeParenStack = [Int]()
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenStack = [Int]()
    var closeParenStack = [Int]()
    var openParenStackIndex = 0
    var closeParenStackIndex = 0
    var openParen = '('
    var closeParen = ')'
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenStack = [Int]()
    var closeParenStack = [Int]()
    var openParenStackIndex = 0
    var closeParenStackIndex = 0
    var openParen = '('
    var closeParen = ')'
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenStack = [Int]()
    var closeParenStack = [Int]()
    var openParenStackIndex = 0
    var closeParenStackIndex = 0
    var openParen = '('
    var closeParen = ')'
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenStack = [Int]()
    var closeParenStack = [Int]()
    var openParenStackIndex = 0
    var closeParenStackIndex = 0
    var openParen = '('
    var closeParen = ')'
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenStack = [Int]()
    var closeParenStack = [Int]()
    var openParenStackIndex = 0
    var closeParenStackIndex = 0
    var openParen = '('
    var closeParen = ')'
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenStack = [Int]()
    var closeParenStack = [Int]()
    var openParenStackIndex = 0
    var closeParenStackIndex = 0
    var openParen = '('
    var closeParen = ')'
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenStack = [Int]()
    var closeParenStack = [Int]()
    var openParenStackIndex = 0
    var closeParenStackIndex = 0
    var openParen = '('
    var closeParen = ')'
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenStack = [Int]()
    var closeParenStack = [Int]()
    var openParenStackIndex = 0
    var closeParenStackIndex = 0
    var openParen = '('
    var closeParen = ')'
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenStack = [Int]()
    var closeParenStack = [Int]()
    var openParenStackIndex = 0
    var closeParenStackIndex = 0
    var openParen = '('
    var closeParen = ')'
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenStack = [Int]()
    var closeParenStack = [Int]()
    var openParenStackIndex = 0
    var closeParenStackIndex = 0
    var openParen = '('
    var closeParen = ')'
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenStack = [Int]()
    var closeParenStack = [Int]()
    var openParenStackIndex = 0
    var closeParenStackIndex = 0
    var openParen = '('
    var closeParen = ')'
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenStack = [Int]()
    var closeParenStack = [Int]()
    var openParenStackIndex = 0
    

```swift
// Input to this function is a string containing multiple groups of nested parentheses. Your goal is to
// separate those group into separate strings and return the array of those.
// Separate groups are balanced (each open brace is properly closed) and not nested within each other
// Ignore any spaces in the input string.
// separateParenGroups(parenString: "( ) (( )) (( )( ))") == ["()", "(())", "(()())"]
func separateParenGroups(parenString: String) -> [String] {
    var result = [String]()
    var stack = [String]()
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var currentGroup = ""
    var currentGroupIndex = 0
    var currentGroupLength = 0
    var currentGroupStart = 0
    var currentGroupEnd = 0
    var currentGroupCount = 0
    var currentGroupCountIndex = 0
    var currentGroupCountStart = 0
    var currentGroupCountEnd = 0
    var currentGroupCountLength = 0
    var currentGroupCountLengthIndex = 0
    var currentGroupCountLengthStart = 0
    var currentGroupCountLengthEnd = 0
    var currentGroupCountLengthCount = 0
    var currentGroupCountLengthCountIndex = 0
    var currentGroupCountLengthCountStart = 0
    var currentGroupCountLengthCountEnd = 0
    var currentGroupCountLengthCountLength = 0
    var currentGroupCountLengthCountLengthIndex = 0
    var currentGroupCountLengthCountLengthStart = 0
    var currentGroupCountLengthCountLengthEnd = 0
    var currentGroupCountLengthCountLengthCount = 0
    var currentGroupCountLengthCountLengthCountIndex = 0
    var currentGroupCountLengthCountLengthCountStart = 0
    var currentGroupCountLengthCountLengthCountEnd = 0
    var currentGroupCountLengthCountLengthCountCount = 0
    var currentGroupCountLengthCountLengthCountCountIndex = 0
    var currentGroupCountLengthCountLengthCountCountStart = 0
    var currentGroupCountLengthCountLengthCountCountEnd = 0
    var currentGroupCountLengthCountLengthCountCountCount = 0
    var currentGroupCountLengthCountLengthCountCountCountIndex = 0
    var currentGroupCountLengthCountLengthCountCountCountStart = 0
    var currentGroupCountLengthCountLengthCountCountCountEnd = 0
    var currentGroupCountLengthCountLengthCountCountCountCount = 0
    var currentGroupCountLengthCountLengthCountCountCountCountIndex = 0
    var currentGroupCountLengthCountLengthCountCountCountCountStart = 0
    var currentGroupCountLengthCountLengthCountCountCountCountEnd = 0
    var currentGroupCountLengthCountLengthCountCountCountCountCount = 0
    var currentGroupCountLengthCountLengthCountCountCountCountCountIndex = 0
    var currentGroupCountLengthCountLengthCountCountCountCountCountStart = 0
    var currentGroupCountLengthCountLengthCountCountCountCountCountEnd = 0
    var currentGroupCountLengthCountLengthCountCountCountCountCountCount = 0
    var currentGroupCountLengthCountLengthCountCountCountCountCountCountIndex = 0
    var currentGroupCountLengthCountLengthCountCountCountCountCountCountStart = 0
    var currentGroupCountLengthCountLengthCountCountCountCountCountCountEnd = 0
    var currentGroupCountLengthCountLengthCountCountCountCountCountCountCount = 0
    var currentGroupCountLengthCountLengthCountCountCountCountCountCountCountIndex = 0
    var currentGroupCountLengthCountLengthCountCountCountCountCountCountCountStart = 0
    var currentGroupCountLengthCountLengthCountCountCountCountCountCountCountEnd = 0
    var currentGroupCountLengthCountLengthCountCountCountCountCountCountCountCount = 0
    var currentGroupCountLengthCountLengthCountCountCountCountCountCountCountCountIndex = 0
    var currentGroupCountLengthCountLengthCountCountCountCountCountCountCountCountStart = 0
    var currentGroupCountLengthCountLengthCountCountCountCountCountCountCountCountEnd = 0
    var currentGroupCountLengthCountLengthCountCountCountCountCountCountCountCountCount = 0
    var currentGroupCountLengthCountLengthCountCountCountCountCountCountCountCountCountIndex = 0
    var currentGroupCountLengthCountLengthCountCountCountCountCountCountCountCountCountStart = 0
    var currentGroupCountLengthCountLengthCountCountCountCountCountCountCountCountCountEnd = 0
    var currentGroupCountLengthCountLengthCountCountCountCountCountCountCountCountCountCount = 0
    var currentGroupCountLengthCountLengthCountCountCountCountCountCountCountCountCountCountIndex = 0
    var currentGroupCountLengthCountLengthCountCountCountCountCountCountCountCountCountCountStart = 0
    var currentGroupCountLengthCountLengthCountCountCountCountCountCountCountCountCountCountEnd = 0
    var currentGroupCountLengthCountLengthCountCountCountCountCountCountCountCountCountCount

func separateParenGroups(parenString: String) -> [String] {
    var result = [String]()
    var stack = [String]()
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var currentGroup = ""
    var isGroupOpen = false
    
    for i in 0..<parenString.length {
        var char = parenString[i]
        
        if char == '(' {
            openParenCount += 1
            currentGroup += char
            isGroupOpen = true
            openParenIndex = i
        } else if char == ')' {
            closeParenCount += 1
            currentGroup += char
            isGroupOpen = false
            closeParenIndex = i
            
            if openParenCount == closeParenCount {
                result.append(currentGroup)
                currentGroup = ""
                openParenCount = 0
                closeParenCount = 0
                isGroupOpen = false
            }
        } else {
            currentGroup += char
        }
    }
    
    return result
}

```swift
// Input to this function is a string containing multiple groups of nested parentheses. Your goal is to
// separate those group into separate strings and return the array of those.
// Separate groups are balanced (each open brace is properly closed) and not nested within each other
// Ignore any spaces in the input string.
// separateParenGroups(parenString: "( ) (( )) (( )( ))") == ["()", "(())", "(()())"]
func separateParenGroups(parenString: String) -> [String] {
    var result = [String]()
    var stack = [String]()
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var currentGroup = ""
    var isGroupOpen = false
    
    for i in 0..<parenString.length {
        var char = parenString[i]
        
        if char == '(' {
            openParenCount += 1
            currentGroup += char
            isGroupOpen = true
            openParenIndex = i
        } else if char == ')' {
            closeParenCount += 1
            currentGroup += char
            isGroupOpen = false
            closeParenIndex = i
            
            if openParenCount == closeParenCount {
                result.append(currentGroup)
                currentGroup = ""
                openParenCount = 0
                closeParenCount = 0
                isGroupOpen = false
            }
        } else {
            currentGroup += char
        }
    }
    
    return result
}

// Input to this function is a string containing multiple groups of nested parentheses. Your goal is to
// separate those group into separate strings and return the array of those.
// Separate groups are balanced (each open brace is properly closed) and not nested within each other
// Ignore any spaces in the input string.
// separateParenGroups(parenString: "( ) (( )) (( )( ))") == ["()", "(())", "(()())"]
func separateParenGroups(parenString: String) -> [String] {
    var result = [String]()
    var stack = [String]()
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var currentGroup = ""
    var isGroupOpen = false
    
    for i in 0..<parenString.length {
        var char = parenString[i]
        
        if char == '(' {
            openParenCount += 1
            currentGroup += char
            isGroupOpen = true
            openParenIndex = i
        } else if char == ')' {
            closeParenCount += 1
            currentGroup += char
            isGroupOpen = false
            closeParenIndex = i
            
            if openParenCount == closeParenCount {
                result.append(currentGroup)
                currentGroup = ""
                openParenCount = 0
                closeParenCount = 0
                isGroupOpen = false
            }
        } else {
            currentGroup += char
        }
    }
    
    return result
}

// Input to this function is a string containing multiple groups of nested parentheses. Your goal is to
// separate those group into separate strings and return the array of those.
// Separate groups are balanced (each open brace is properly closed) and not nested within each other
// Ignore any spaces in the input string.
// separateParenGroups(parenString: "( ) (( )) (( )( ))") == ["()", "(())", "(()())"]
func separateParenGroups(parenString: String) -> [String] {
    var result = [String]()
    var stack = [String]()
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var currentGroup = ""
    var isGroupOpen = false
    
    for i in 0..<parenString.length {
        var char = parenString[i]
        
        if char == '(' {
            openParenCount += 1
            currentGroup += char
            isGroupOpen = true
            openParenIndex = i
        } else if char == ')' {
            closeParenCount += 1
            currentGroup += char
            isGroupOpen = false
            closeParenIndex = i
            
            if openParenCount == closeParenCount {
                result.append(currentGroup)
                currentGroup = ""
                openParenCount = 0
                closeParenCount = 0
                isGroupOpen = false
            }
        } else {
            currentGroup += char
        }
    }
    
    return result
}

// Input to this function is a string containing multiple groups of nested parentheses. Your goal is to
// separate those group into separate strings and return the array of those.
// Separate groups are balanced (each open brace is properly closed) and not nested within each other
// Ignore any spaces in the input string.
// separateParenGroups(parenString

func separateParenGroups(parenString: String) -> [String] {
    var result = [String]()
    var stack = [String]()
    var openParenCount = 0
    var closeParenCount = 0
    var currentGroup = String()
    var i = 0
    while i < parenString.count {
        var char = parenString[i]
        if char == '(' {
            openParenCount += 1
            stack.append(currentGroup)
            currentGroup = String()
        } else if char == ')' {
            closeParenCount += 1
            if openParenCount > 0 {
                currentGroup = stack.pop() + char
                openParenCount -= 1
            }
        } else {
            currentGroup += char
        }
        i += 1
    }
    if openParenCount > 0 {
        currentGroup = stack.pop()
    }
    if currentGroup.count > 0 {
        result.append(currentGroup)
    }
    return result
}

```swift
// Input to this function is a string containing multiple groups of nested parentheses. Your goal is to
// separate those group into separate strings and return the array of those.
// Separate groups are balanced (each open brace is properly closed) and not nested within each other
// Ignore any spaces in the input string.
// separateParenGroups(parenString: "( ) (( )) (( )( ))") == ["()", "(())", "(()())"]
func separateParenGroups(parenString: String) -> [String] {
    var result = [String]()
    var stack = [String]()
    var openParenCount = 0
    var closeParenCount = 0
    var currentGroup = String()
    var i = 0
    while i < parenString.count {
        var char = parenString[i]
        if char == '(' {
            openParenCount += 1
            stack.append(currentGroup)
            currentGroup = String()
        } else if char == ')' {
            closeParenCount += 1
            if openParenCount > 0 {
                currentGroup = stack.pop() + char
                openParenCount -= 1
            }
        } else {
            currentGroup += char
        }
        i += 1
    }
    if openParenCount > 0 {
        currentGroup = stack.pop()
    }
    if currentGroup.count > 0 {
        result.append(currentGroup)
    }
    return result
}

// Input to this function is a string containing multiple groups of nested parentheses. Your goal is to
// separate those group into separate strings and return the array of those.
// Separate groups are balanced (each open brace is properly closed) and not nested within each other
// Ignore any spaces in the input string.
// separateParenGroups(parenString: "( ) (( )) (( )( ))") == ["()", "(())", "(()())"]
func separateParenGroups(parenString: String) -> [String] {
    var result = [String]()
    var stack = [String]()
    var openParenCount = 0
    var closeParenCount = 0
    var currentGroup = String()
    var i = 0
    while i < parenString.count {
        var char = parenString[i]
        if char == '(' {
            openParenCount += 1
            stack.append(currentGroup)
            currentGroup = String()
        } else if char == ')' {
            closeParenCount += 1
            if openParenCount > 0 {
                currentGroup = stack.pop() + char
                openParenCount -= 1
            }
        } else {
            currentGroup += char
        }
        i += 1
    }
    if openParenCount > 0 {
        currentGroup = stack.pop()
    }
    if currentGroup.count > 0 {
        result.append(currentGroup)
    }
    return result
}

// Input to this function is a string containing multiple groups of nested parentheses. Your goal is to
// separate those group into separate strings and return the array of those.
// Separate groups are balanced (each open brace is properly closed) and not nested within each other
// Ignore any spaces in the input string.
// separateParenGroups(parenString: "( ) (( )) (( )( ))") == ["()", "(())", "(()())"]
func separateParenGroups(parenString: String) -> [String] {
    var result = [String]()
    var stack = [String]()
    var openParenCount = 0
    var closeParenCount = 0
    var currentGroup = String()
    var i = 0
    while i < parenString.count {
        var char = parenString[i]
        if char == '(' {
            openParenCount += 1
            stack.append(currentGroup)
            currentGroup = String()
        } else if char == ')' {
            closeParenCount += 1
            if openParenCount > 0 {
                currentGroup = stack.pop() + char
                openParenCount -= 1
            }
        } else {
            currentGroup += char
        }
        i += 1
    }
    if openParenCount > 0 {
        currentGroup = stack.pop()
    }
    if currentGroup.count > 0 {
        result.append(currentGroup)
    }
    return result
}

// Input to this function is a string containing multiple groups of nested parentheses. Your goal is to
// separate those group into separate strings and return the array of those.
// Separate groups are balanced (each open brace is properly closed) and not nested within each other
// Ignore any spaces in the input string.
// separateParenGroups(parenString: "( ) (( )) (( )( ))") == ["()", "(())", "(()())"]
func separateParenGroups(parenString: String) -> [String] {
    var result = [String]()
    var stack = [String]()
    var openParenCount = 0
    var closeParenCount

func separateParenGroups(parenString: String) -> [String] {
    var result = [String]()
    var stack = [String]()
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var currentGroup = ""
    var i = 0
    while i < parenString.length {
        if parenString[i] == '(' {
            openParenCount++
            if openParenCount == 1 {
                openParenIndex = i
            }
        } else if parenString[i] == ')' {
            closeParenCount++
            if closeParenCount == 1 {
                closeParenIndex = i
            }
        }
        if openParenCount > 0 && closeParenCount > 0 && openParenCount == closeParenCount {
            currentGroup = parenString[openParenIndex + 1:closeParenIndex]
            result.append(currentGroup)
            stack.append(currentGroup)
            openParenCount = 0
            closeParenCount = 0
            currentGroup = ""
        }
        i++
    }
    return result
}

```swift
// Input to this function is a string containing multiple groups of nested parentheses. Your goal is to
// separate those group into separate strings and return the array of those.
// Separate groups are balanced (each open brace is properly closed) and not nested within each other
// Ignore any spaces in the input string.
// separateParenGroups(parenString: "( ) (( )) (( )( ))") == ["()", "(())", "(()())"]
func separateParenGroups(parenString: String) -> [String] {
    var result = [String]()
    var stack = [String]()
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var currentGroup = ""
    var i = 0
    while i < parenString.length {
        if parenString[i] == '(' {
            openParenCount++
            if openParenCount == 1 {
                openParenIndex = i
            }
        } else if parenString[i] == ')' {
            closeParenCount++
            if closeParenCount == 1 {
                closeParenIndex = i
            }
        }
        if openParenCount > 0 && closeParenCount > 0 && openParenCount == closeParenCount {
            currentGroup = parenString[openParenIndex + 1:closeParenIndex]
            result.append(currentGroup)
            stack.append(currentGroup)
            openParenCount = 0
            closeParenCount = 0
            currentGroup = ""
        }
        i++
    }
    return result
}

// Input to this function is a string containing multiple groups of nested parentheses. Your goal is to
// separate those group into separate strings and return the array of those.
// Separate groups are balanced (each open brace is properly closed) and not nested within each other
// Ignore any spaces in the input string.
// separateParenGroups(parenString: "( ) (( )) (( )( ))") == ["()", "(())", "(()())"]
func separateParenGroups(parenString: String) -> [String] {
    var result = [String]()
    var stack = [String]()
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var currentGroup = ""
    var i = 0
    while i < parenString.length {
        if parenString[i] == '(' {
            openParenCount++
            if openParenCount == 1 {
                openParenIndex = i
            }
        } else if parenString[i] == ')' {
            closeParenCount++
            if closeParenCount == 1 {
                closeParenIndex = i
            }
        }
        if openParenCount > 0 && closeParenCount > 0 && openParenCount == closeParenCount {
            currentGroup = parenString[openParenIndex + 1:closeParenIndex]
            result.append(currentGroup)
            stack.append(currentGroup)
            openParenCount = 0
            closeParenCount = 0
            currentGroup = ""
        }
        i++
    }
    return result
}

// Input to this function is a string containing multiple groups of nested parentheses. Your goal is to
// separate those group into separate strings and return the array of those.
// Separate groups are balanced (each open brace is properly closed) and not nested within each other
// Ignore any spaces in the input string.
// separateParenGroups(parenString: "( ) (( )) (( )( ))") == ["()", "(())", "(()())"]
func separateParenGroups(parenString: String) -> [String] {
    var result = [String]()
    var stack = [String]()
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var currentGroup = ""
    var i = 0
    while i < parenString.length {
        if parenString[i] == '(' {
            openParenCount++
            if openParenCount == 1 {
                openParenIndex = i
            }
        } else if parenString[i] == ')' {
            closeParenCount++
            if closeParenCount == 1 {
                closeParenIndex = i
            }
        }
        if openParenCount > 0 && closeParenCount > 0 && openParenCount == closeParenCount {
            currentGroup = parenString[openParenIndex + 1:closeParenIndex]
            result.append(currentGroup)
            stack.append(currentGroup)
            openParenCount = 0
            closeParenCount = 0
            currentGroup = ""
        }
        i++
    }
    return result
}

// Input to this function is a string containing multiple groups of nested parentheses. Your goal is to
// separate those group into separate strings and return the array of those.
// Separate groups are balanced (each

```swift
// Input to this function is a string containing multiple groups of nested parentheses. Your goal is to
// separate those group into separate strings and return the array of those.
// Separate groups are balanced (each open brace is properly closed) and not nested within each other
// Ignore any spaces in the input string.
// separateParenGroups(parenString: "( ) (( )) (( )( ))") == ["()", "(())", "(()())"]
func separateParenGroups(parenString: String) -> [String] {
    var result = [String]()
    var stack = [String]()
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var currentGroup = ""
    var currentGroupIndex = 0
    var currentGroupLength = 0
    var currentGroupStart = 0
    var currentGroupEnd = 0
    var currentGroupStartCount = 0
    var currentGroupEndCount = 0
    var currentGroupStartCountIndex = 0
    var currentGroupEndCountIndex = 0
    var currentGroupStartCountLength = 0
    var currentGroupEndCountLength = 0
    var currentGroupStartCountLengthIndex = 0
    var currentGroupEndCountLengthIndex = 0
    var currentGroupStartLength = 0
    var currentGroupEndLength = 0
    var currentGroupStartLengthIndex = 0
    var currentGroupEndLengthIndex = 0
    var currentGroupStartLengthLength = 0
    var currentGroupEndLengthLength = 0
    var currentGroupStartLengthLengthIndex = 0
    var currentGroupEndLengthLengthIndex = 0
    var currentGroupStartLengthLengthLength = 0
    var currentGroupEndLengthLengthLength = 0
    var currentGroupStartLengthLengthLengthIndex = 0
    var currentGroupEndLengthLengthLengthIndex = 0
    var currentGroupStartLengthLengthLengthLength = 0
    var currentGroupEndLengthLengthLengthLength = 0
    var currentGroupStartLengthLengthLengthLengthIndex = 0
    var currentGroupEndLengthLengthLengthLengthIndex = 0
    var currentGroupStartLengthLengthLengthLengthLength = 0
    var currentGroupEndLengthLengthLengthLengthLength = 0
    var currentGroupStartLengthLengthLengthLengthLengthIndex = 0
    var currentGroupEndLengthLengthLengthLengthLengthIndex = 0
    var currentGroupStartLengthLengthLengthLengthLengthLength = 0
    var currentGroupEndLengthLengthLengthLengthLengthLength = 0
    var currentGroupStartLengthLengthLengthLengthLengthLengthIndex = 0
    var currentGroupEndLengthLengthLengthLengthLengthLengthIndex = 0
    var currentGroupStartLengthLengthLengthLengthLengthLengthLength = 0
    var currentGroupEndLengthLengthLengthLengthLengthLengthLength = 0
    var currentGroupStartLengthLengthLengthLengthLengthLengthLengthIndex = 0
    var currentGroupEndLengthLengthLengthLengthLengthLengthLengthIndex = 0
    var currentGroupStartLengthLengthLengthLengthLengthLengthLengthLength = 0
    var currentGroupEndLengthLengthLengthLengthLengthLengthLengthLength = 0
    var currentGroupStartLengthLengthLengthLengthLengthLengthLengthLengthIndex = 0
    var currentGroupEndLengthLengthLengthLengthLengthLengthLengthLengthIndex = 0
    var currentGroupStartLengthLengthLengthLengthLengthLengthLengthLengthLength = 0
    var currentGroupEndLengthLengthLengthLengthLengthLengthLengthLengthLengthIndex = 0
    var currentGroupStartLengthLengthLengthLengthLengthLengthLengthLengthLengthIndex = 0
    var currentGroupEndLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthIndex = 0
    var currentGroupStartLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthIndex = 0
    var currentGroupEndLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthIndex = 0
    var currentGroupStartLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthIndex = 0
    var currentGroupEndLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthIndex = 0
    var currentGroupStartLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthIndex = 0
    var currentGroupEndLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthIndex = 0
    var currentGroupStartLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthIndex = 0
    var currentGroupEndLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthIndex = 0
    var currentGroupStartLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthIndex = 0
    var currentGroupEndLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthIndex = 0
    var currentGroupStartLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthIndex = 0
    var currentGroupEndLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthLengthIndex = 0
    var currentGroupStartLengthLengthLengthLength

```swift
// Input to this function is a string containing multiple groups of nested parentheses. Your goal is to
// separate those group into separate strings and return the array of those.
// Separate groups are balanced (each open brace is properly closed) and not nested within each other
// Ignore any spaces in the input string.
// separateParenGroups(parenString: "( ) (( )) (( )( ))") == ["()", "(())", "(()())"]
func separateParenGroups(parenString: String) -> [String] {
    var result = [String]()
    var stack = [String]()
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParen = "("
    var closeParen = ")"
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var open

```swift
// Input to this function is a string containing multiple groups of nested parentheses. Your goal is to
// separate those group into separate strings and return the array of those.
// Separate groups are balanced (each open brace is properly closed) and not nested within each other
// Ignore any spaces in the input string.
// separateParenGroups(parenString: "( ) (( )) (( )( ))") == ["()", "(())", "(()())"]
func separateParenGroups(parenString: String) -> [String] {
    var result = [String]()
    var stack = [String]()
    var openParenCount = 0
    var closeParenCount = 0
    var openParenIndex = 0
    var closeParenIndex = 0
    var openParenIndexArray = [Int]()
    var closeParenIndexArray = [Int]()
    var openParenIndexArrayIndex = 0
    var closeParenIndexArrayIndex = 0
    var openParenIndexArrayIndex2 = 0
    var closeParenIndexArrayIndex2 = 0
    var openParenIndexArrayIndex3 = 0
    var closeParenIndexArrayIndex3 = 0
    var openParenIndexArrayIndex4 = 0
    var closeParenIndexArrayIndex4 = 0
    var openParenIndexArrayIndex5 = 0
    var closeParenIndexArrayIndex5 = 0
    var openParenIndexArrayIndex6 = 0
    var closeParenIndexArrayIndex6 = 0
    var openParenIndexArrayIndex7 = 0
    var closeParenIndexArrayIndex7 = 0
    var openParenIndexArrayIndex8 = 0
    var closeParenIndexArrayIndex8 = 0
    var openParenIndexArrayIndex9 = 0
    var closeParenIndexArrayIndex9 = 0
    var openParenIndexArrayIndex10 = 0
    var closeParenIndexArrayIndex10 = 0
    var openParenIndexArrayIndex11 = 0
    var closeParenIndexArrayIndex11 = 0
    var openParenIndexArrayIndex12 = 0
    var closeParenIndexArrayIndex12 = 0
    var openParenIndexArrayIndex13 = 0
    var closeParenIndexArrayIndex13 = 0
    var openParenIndexArrayIndex14 = 0
    var closeParenIndexArrayIndex14 = 0
    var openParenIndexArrayIndex15 = 0
    var closeParenIndexArrayIndex15 = 0
    var openParenIndexArrayIndex16 = 0
    var closeParenIndexArrayIndex16 = 0
    var openParenIndexArrayIndex17 = 0
    var closeParenIndexArrayIndex17 = 0
    var openParenIndexArrayIndex18 = 0
    var closeParenIndexArrayIndex18 = 0
    var openParenIndexArrayIndex19 = 0
    var closeParenIndexArrayIndex19 = 0
    var openParenIndexArrayIndex20 = 0
    var closeParenIndexArrayIndex20 = 0
    var openParenIndexArrayIndex21 = 0
    var closeParenIndexArrayIndex21 = 0
    var openParenIndexArrayIndex22 = 0
    var closeParenIndexArrayIndex22 = 0
    var openParenIndexArrayIndex23 = 0
    var closeParenIndexArrayIndex23 = 0
    var openParenIndexArrayIndex24 = 0
    var closeParenIndexArrayIndex24 = 0
    var openParenIndexArrayIndex25 = 0
    var closeParenIndexArrayIndex25 = 0
    var openParenIndexArrayIndex26 = 0
    var closeParenIndexArrayIndex26 = 0
    var openParenIndexArrayIndex27 = 0
    var closeParenIndexArrayIndex27 = 0
    var openParenIndexArrayIndex28 = 0
    var closeParenIndexArrayIndex28 = 0
    var openParenIndexArrayIndex29 = 0
    var closeParenIndexArrayIndex29 = 0
    var openParenIndexArrayIndex30 = 0
    var closeParenIndexArrayIndex30 = 0
    var openParenIndexArrayIndex31 = 0
    var closeParenIndexArrayIndex31 = 0
    var openParenIndexArrayIndex32 = 0
    var closeParenIndexArrayIndex32 = 0
    var openParenIndexArrayIndex33 = 0
    var closeParenIndexArrayIndex33 = 0
    var openParenIndexArrayIndex34 = 0
    var closeParenIndexArrayIndex34 = 0
    var openParenIndexArrayIndex35 = 0
    var closeParenIndexArrayIndex35 = 0
    var openParenIndexArrayIndex36 = 0
    var closeParenIndexArrayIndex36 = 0
    var openParenIndexArrayIndex37 = 0
    var closeParenIndexArrayIndex37 = 0
    var openParenIndexArrayIndex

func truncateNumber(number: Double) -> Double {
    return number - Int(number)
}

func truncateNumber(number: Double) -> Double {
    return Int(number)
}

```swift
// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the decimal part of the number.
// truncateNumber(number: 3.5) == 0.5
func truncateNumber(number: Double) -> Double {
    return number - Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}
```

func truncateNumber(number: Double) -> Double {
    return number - Int(number)
}

func truncateInteger(number: Double) -> Double {
    return Int(number)
}

func truncateNumber(number: Double) -> Double {
    return Int(number)
}

```swift
// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the decimal part of the number.
// truncateNumber(number: 3.5) == 0.5
func truncateNumber(number: Double) -> Double {
    return number - Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateInteger(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(

func truncateNumber(number: Double) -> Double {
    return number - Int(number)
}

func truncateNumber(number: Double) -> Double {
    return Int(number)
}

```swift
// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the decimal part of the number.
// truncateNumber(number: 3.5) == 0.5
func truncateNumber(number: Double) -> Double {
    return number - Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}
```

func truncateNumber(number: Double) -> Double {
    return number - Int(number)
}

func truncateInteger(number: Double) -> Double {
    return Int(number)
}

func truncate(number: Double) -> Double {
    return Int(number)
}

```swift
// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the decimal part of the number.
// truncateNumber(number: 3.5) == 0.5
func truncateNumber(number: Double) -> Double {
    return number - Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateInteger(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncate(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncate(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncate(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncate(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncate(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncate(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncate(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncate(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncate(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncate(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3

func truncateNumber(number: Double) -> Double {
    return number - Int(number)
}

func truncateInteger(number: Double) -> Double {
    return Int(number)
}

```swift
// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the decimal part of the number.
// truncateNumber(number: 3.5) == 0.5
func truncateNumber(number: Double) -> Double {
    return number - Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateInteger(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateInteger(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateInteger(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateInteger(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateInteger(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateInteger(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateInteger(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateInteger(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateInteger(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateInteger(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateInteger(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(

func truncateNumber(number: Double) -> Double {
    return number - Int(number)
}

func truncateInteger(number: Double) -> Double {
    return Int(number)
}

func truncateNumber(number: Double) -> Double {
    return Int(number)
}

```swift
// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the decimal part of the number.
// truncateNumber(number: 3.5) == 0.5
func truncateNumber(number: Double) -> Double {
    return number - Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateInteger(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(

func truncateNumber(number: Double) -> Double {
    return number - Int(number)
}

func truncateInteger(number: Double) -> Double {
    return Int(number)
}

```swift
// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the decimal part of the number.
// truncateNumber(number: 3.5) == 0.5
func truncateNumber(number: Double) -> Double {
    return number - Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateInteger(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateInteger(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateInteger(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateInteger(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateInteger(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateInteger(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateInteger(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateInteger(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateInteger(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateInteger(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateInteger(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(

func truncateNumber(number: Double) -> Double {
    return number - Int(number)
}

func truncateNumber(number: Double) -> Double {
    return Int(number)
}

```swift
// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the decimal part of the number.
// truncateNumber(number: 3.5) == 0.5
func truncateNumber(number: Double) -> Double {
    return number - Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(

func truncateNumber(number: Double) -> Double {
    return number - Int(number)
}

func truncateNumber(number: Double) -> Double {
    return Int(number)
}

```swift
// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the decimal part of the number.
// truncateNumber(number: 3.5) == 0.5
func truncateNumber(number: Double) -> Double {
    return number - Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(

func truncateNumber(number: Double) -> Double {
    return number - Int(number)
}

func truncateNumber(number: Double) -> Double {
    return Int(number)
}

```swift
// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the decimal part of the number.
// truncateNumber(number: 3.5) == 0.5
func truncateNumber(number: Double) -> Double {
    return number - Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}

// Given a positive floating point number, it can be decomposed into
// and integer part (largest integer smaller than given number) and decimals
// (leftover part always smaller than 1).
// Return the integer part of the number.
// truncateNumber(number: 3.5) == 3
func truncateNumber(number: Double) -> Double {
    return Int(number)
}
```

func belowZero(operations: [Int]) -> Bool {
    var balance = 0
    for operation in operations {
        balance += operation
        if balance < 0 {
            return true
        }
    }
    return false
}

```swift
// You're given an array of deposit and withdrawal operations on a bank account that starts with
// zero balance. Your task is to detect if at any point the balance of account fallls below zero, and
// at that point function should return true. Otherwise it should return false.
// belowZero(operations: [1, 2, 3]) == false
// belowZero(operations: [1, 2, -4, 5]) == true
func belowZero(operations: [Int]) -> Bool {
    var balance = 0
    for operation in operations {
        balance += operation
        if balance < 0 {
            return true
        }
    }
    return false
}
```

func belowZero(operations: [Int]) -> Bool {
    var balance = 0
    for operation in operations {
        balance += operation
        if balance < 0 {
            return true
        }
    }
    return false
}

```swift
// You're given an array of deposit and withdrawal operations on a bank account that starts with
// zero balance. Your task is to detect if at any point the balance of account fallls below zero, and
// at that point function should return true. Otherwise it should return false.
// belowZero(operations: [1, 2, 3]) == false
// belowZero(operations: [1, 2, -4, 5]) == true
func belowZero(operations: [Int]) -> Bool {
    var balance = 0
    for operation in operations {
        balance += operation
        if balance < 0 {
            return true
        }
    }
    return false
}
```

func belowZero(operations: [Int]) -> Bool {
    var balance = 0
    for operation in operations {
        balance += operation
        if balance < 0 {
            return true
        }
    }
    return false
}

```swift
// You're given an array of deposit and withdrawal operations on a bank account that starts with
// zero balance. Your task is to detect if at any point the balance of account fallls below zero, and
// at that point function should return true. Otherwise it should return false.
// belowZero(operations: [1, 2, 3]) == false
// belowZero(operations: [1, 2, -4, 5]) == true
func belowZero(operations: [Int]) -> Bool {
    var balance = 0
    for operation in operations {
        balance += operation
        if balance < 0 {
            return true
        }
    }
    return false
}
```

func belowZero(operations: [Int]) -> Bool {
    var balance = 0
    for operation in operations {
        balance += operation
        if balance < 0 {
            return true
        }
    }
    return false
}

```swift
// You're given an array of deposit and withdrawal operations on a bank account that starts with
// zero balance. Your task is to detect if at any point the balance of account fallls below zero, and
// at that point function should return true. Otherwise it should return false.
// belowZero(operations: [1, 2, 3]) == false
// belowZero(operations: [1, 2, -4, 5]) == true
func belowZero(operations: [Int]) -> Bool {
    var balance = 0
    for operation in operations {
        balance += operation
        if balance < 0 {
            return true
        }
    }
    return false
}
```

func belowZero(operations: [Int]) -> Bool {
    var balance = 0
    for operation in operations {
        balance += operation
        if balance < 0 {
            return true
        }
    }
    return false
}

```swift
// You're given an array of deposit and withdrawal operations on a bank account that starts with
// zero balance. Your task is to detect if at any point the balance of account fallls below zero, and
// at that point function should return true. Otherwise it should return false.
// belowZero(operations: [1, 2, 3]) == false
// belowZero(operations: [1, 2, -4, 5]) == true
func belowZero(operations: [Int]) -> Bool {
    var balance = 0
    for operation in operations {
        balance += operation
        if balance < 0 {
            return true
        }
    }
    return false
}
```

func belowZero(operations: [Int]) -> Bool {
    var balance = 0
    for operation in operations {
        balance += operation
        if balance < 0 {
            return true
        }
    }
    return false
}

```swift
// You're given an array of deposit and withdrawal operations on a bank account that starts with
// zero balance. Your task is to detect if at any point the balance of account fallls below zero, and
// at that point function should return true. Otherwise it should return false.
// belowZero(operations: [1, 2, 3]) == false
// belowZero(operations: [1, 2, -4, 5]) == true
func belowZero(operations: [Int]) -> Bool {
    var balance = 0
    for operation in operations {
        balance += operation
        if balance < 0 {
            return true
        }
    }
    return false
}
```

func belowZero(operations: [Int]) -> Bool {
    var balance = 0
    for operation in operations {
        balance += operation
        if balance < 0 {
            return true
        }
    }
    return false
}

func sum(numbers: [Int]) -> Int {
    var sum = 0
    for number in numbers {
        sum += number
    }
    return sum
}

```swift
// You're given an array of deposit and withdrawal operations on a bank account that starts with
// zero balance. Your task is to detect if at any point the balance of account fallls below zero, and
// at that point function should return true. Otherwise it should return false.
// belowZero(operations: [1, 2, 3]) == false
// belowZero(operations: [1, 2, -4, 5]) == true
func belowZero(operations: [Int]) -> Bool {
    var balance = 0
    for operation in operations {
        balance += operation
        if balance < 0 {
            return true
        }
    }
    return false
}

// You're given an array of integers. Your task is to find the sum of all integers in the array.
// sum([1, 2, 3]) == 6
// sum([1, 2, -3]) == 0
// sum([1, 2, -3, 4]) == 6
func sum(numbers: [Int]) -> Int {
    var sum = 0
    for number in numbers {
        sum += number
    }
    return sum
}

// You're given an array of integers. Your task is to find the sum of all integers in the array.
// sum([1, 2, 3]) == 6
// sum([1, 2, -3]) == 0
// sum([1, 2, -3, 4]) == 6
func sum(numbers: [Int]) -> Int {
    var sum = 0
    for number in numbers {
        sum += number
    }
    return sum
}

// You're given an array of integers. Your task is to find the sum of all integers in the array.
// sum([1, 2, 3]) == 6
// sum([1, 2, -3]) == 0
// sum([1, 2, -3, 4]) == 6
func sum(numbers: [Int]) -> Int {
    var sum = 0
    for number in numbers {
        sum += number
    }
    return sum
}

// You're given an array of integers. Your task is to find the sum of all integers in the array.
// sum([1, 2, 3]) == 6
// sum([1, 2, -3]) == 0
// sum([1, 2, -3, 4]) == 6
func sum(numbers: [Int]) -> Int {
    var sum = 0
    for number in numbers {
        sum += number
    }
    return sum
}

// You're given an array of integers. Your task is to find the sum of all integers in the array.
// sum([1, 2, 3]) == 6
// sum([1, 2, -3]) == 0
// sum([1, 2, -3, 4]) == 6
func sum(numbers: [Int]) -> Int {
    var sum = 0
    for number in numbers {
        sum += number
    }
    return sum
}

// You're given an array of integers. Your task is to find the sum of all integers in the array.
// sum([1, 2, 3]) == 6
// sum([1, 2, -3]) == 0
// sum([1, 2, -3, 4]) == 6
func sum(numbers: [Int]) -> Int {
    var sum = 0
    for number in numbers {
        sum += number
    }
    return sum
}

// You're given an array of integers. Your task is to find the sum of all integers in the array.
// sum([1, 2, 3]) == 6
// sum([1, 2, -3]) == 0
// sum([1, 2, -3, 4]) == 6
func sum(numbers: [Int]) -> Int {
    var sum = 0
    for number in numbers {
        sum += number
    }
    return sum
}

// You're given an array of integers. Your task is to find the sum of all integers in the array.
// sum([1, 2, 3]) == 6
// sum([1, 2, -3]) == 0
// sum([1, 2, -3, 4]) == 6
func sum(numbers: [Int]) -> Int {
    var sum = 0
    for number in numbers {
        sum += number
    }
    return sum
}

// You're given an array of integers. Your task is to find the sum of all integers in the array.
// sum([1, 2, 3]) == 6
// sum([1, 2, -3]) == 0
// sum([1, 2, -3, 4]) == 6
func sum(

func belowZero(operations: [Int]) -> Bool {
    var balance = 0
    for operation in operations {
        balance += operation
        if balance < 0 {
            return true
        }
    }
    return false
}

```swift
// You're given an array of deposit and withdrawal operations on a bank account that starts with
// zero balance. Your task is to detect if at any point the balance of account fallls below zero, and
// at that point function should return true. Otherwise it should return false.
// belowZero(operations: [1, 2, 3]) == false
// belowZero(operations: [1, 2, -4, 5]) == true
func belowZero(operations: [Int]) -> Bool {
    var balance = 0
    for operation in operations {
        balance += operation
        if balance < 0 {
            return true
        }
    }
    return false
}
```

func belowZero(operations: [Int]) -> Bool {
    var balance = 0
    for operation in operations {
        balance += operation
        if balance < 0 {
            return true
        }
    }
    return false
}

```swift
// You're given an array of deposit and withdrawal operations on a bank account that starts with
// zero balance. Your task is to detect if at any point the balance of account fallls below zero, and
// at that point function should return true. Otherwise it should return false.
// belowZero(operations: [1, 2, 3]) == false
// belowZero(operations: [1, 2, -4, 5]) == true
func belowZero(operations: [Int]) -> Bool {
    var balance = 0
    for operation in operations {
        balance += operation
        if balance < 0 {
            return true
        }
    }
    return false
}
```

func belowZero(operations: [Int]) -> Bool {
    var balance = 0
    for operation in operations {
        balance += operation
        if balance < 0 {
            return true
        }
    }
    return false
}

```swift
// You're given an array of deposit and withdrawal operations on a bank account that starts with
// zero balance. Your task is to detect if at any point the balance of account fallls below zero, and
// at that point function should return true. Otherwise it should return false.
// belowZero(operations: [1, 2, 3]) == false
// belowZero(operations: [1, 2, -4, 5]) == true
func belowZero(operations: [Int]) -> Bool {
    var balance = 0
    for operation in operations {
        balance += operation
        if balance < 0 {
            return true
        }
    }
    return false
}
```

func meanAbsoluteDeviation(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0, +) / numbers.count
    let sum = numbers.reduce(0, { |acc, x| acc + abs(x - mean) })
    return sum / numbers.count
}

func median(numbers: [Double]) -> Double {
    let sorted = numbers.sorted()
    let mid = sorted.count / 2
    if sorted.count.isEven {
        return (sorted[mid - 1] + sorted[mid]) / 2
    } else {
        return sorted[mid]
    }
}

func mode(numbers: [Double]) -> Double {
    let counts = numbers.map { |x| (x, 1) }.reduce(
        mutable { |acc, (x, count)|
            if let existing = acc.first {
                if x == existing.0 {
                    existing.1 += 1
                } else {
                    acc.append((x, 1))
                }
            } else {
                acc.append((x, 1))
            }
            acc
        },
        []
    )
    let max = counts.reduce(0, { |acc, (x, count)| if count > acc { count } else { acc } })
    return counts.filter { |(x, count)| count == max }.map { |(x, count)| x }.first!
}

func variance(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0, +) / numbers.count
    let sum = numbers.reduce(0, { |acc, x| acc + (x - mean) * (x - mean) })
    return sum / numbers.count
}

func standardDeviation(numbers: [Double]) -> Double {
    return sqrt(variance(numbers))
}

func interquartileRange(numbers: [Double]) -> Double {
    let sorted = numbers.sorted()
    let mid = sorted.count / 2
    let q1 = sorted[mid - 1]
    let q3 = sorted[mid + 1]
    return q3 - q1
}

func coefficientOfVariation(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0, +) / numbers.count
    let std = sqrt(variance(numbers))
    return std / mean
}

```swift
// For a given array of input numbers, calculate Mean Absolute Deviation
// around the mean of this dataset.
// Mean Absolute Deviation is the average absolute difference between each
// element and a centerpoint (mean in this case):
// MAD = average | x - x_mean |
// meanAbsoluteDeviation(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.0
func meanAbsoluteDeviation(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0, +) / numbers.count
    let sum = numbers.reduce(0, { |acc, x| acc + abs(x - mean) })
    return sum / numbers.count
}

// For a given array of input numbers, calculate Median.
// Median is the middle element of the sorted dataset.
// median(numbers: [1.0, 2.0, 3.0, 4.0]) == 2.5
func median(numbers: [Double]) -> Double {
    let sorted = numbers.sorted()
    let mid = sorted.count / 2
    if sorted.count.isEven {
        return (sorted[mid - 1] + sorted[mid]) / 2
    } else {
        return sorted[mid]
    }
}

// For a given array of input numbers, calculate Mode.
// Mode is the most frequently occurring element in the dataset.
// mode(numbers: [1.0, 2.0, 3.0, 4.0, 4.0]) == 4.0
func mode(numbers: [Double]) -> Double {
    let counts = numbers.map { |x| (x, 1) }.reduce(
        mutable { |acc, (x, count)|
            if let existing = acc.first {
                if x == existing.0 {
                    existing.1 += 1
                } else {
                    acc.append((x, 1))
                }
            } else {
                acc.append((x, 1))
            }
            acc
        },
        []
    )
    let max = counts.reduce(0, { |acc, (x, count)| if count > acc { count } else { acc } })
    return counts.filter { |(x, count)| count == max }.map { |(x, count)| x }.first!
}

// For a given array of input numbers, calculate the Variance.
// Variance is the average of the squared differences from the Mean.
// variance(numbers: [1.0, 2.0, 3.0, 4.0]) == 2.0
func variance(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0, +) / numbers.count
    let sum = numbers.reduce(0, { |acc, x| acc + (x - mean) * (x - mean) })
    return sum / numbers.count
}

// For a given array of input numbers, calculate the Standard Deviation.
// Standard Deviation is the square root of the Variance.
// standardDeviation(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.0
func standardDeviation(numbers: [Double]) -> Double {
    return sqrt(variance(numbers))
}

// For a given array of input numbers, calculate the Interquartile Range.
// Interquartile Range is the difference between the 75th and 25th percentiles.
// interquartileRange(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.0
func interquartileRange(numbers: [Double]) -> Double {
    let sorted = numbers.sorted()
    let mid = sorted.count / 2
    let q1 = sorted[mid - 1]
    let q3 = sorted[mid + 1]
    return q3 - q1
}

// For a given array of input numbers, calculate the Coefficient of Variation.
// Coefficient of Variation is the ratio of the Standard Deviation to the Mean.
// coefficientOfVariation(numbers: [1.0, 2.0, 3.0, 4.0]) == 0.25
func coefficientOfVariation(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0, +) / numbers.count
    let std = sqrt(variance(numbers))
    return std / mean
}

// For a given array of input numbers, calculate the Skewness.
// Skewness is the asymmetry of the dataset.
// skewness(numbers: [1.0, 2.0, 3.0, 4.0]) == 0.0
func skewness(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0, +) / numbers.count
    let sum = numbers.reduce(0, { |acc, x| acc + (x - mean) * (x - mean) * (

func meanAbsoluteDeviation(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0) { (sum, x) in sum + x } / Double(numbers.count)
    return numbers.map { x in abs(x - mean) }.reduce(0.0) { (sum, x) in sum + x } / Double(numbers.count)
}

func variance(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0) { (sum, x) in sum + x } / Double(numbers.count)
    return numbers.map { x in (x - mean) * (x - mean) }.reduce(0.0) { (sum, x) in sum + x } / Double(numbers.count)
}

func standardDeviation(numbers: [Double]) -> Double {
    return sqrt(variance(numbers))
}

func median(numbers: [Double]) -> Double {
    let sortedNumbers = numbers.sorted()
    let middleIndex = sortedNumbers.count / 2
    if sortedNumbers.count.modulo(2) == 0 {
        return (sortedNumbers[middleIndex - 1] + sortedNumbers[middleIndex]) / 2.0
    } else {
        return sortedNumbers[middleIndex]
    }
}

func mode(numbers: [Double]) -> Double {
    let frequencyMap = numbers.groupBy { it }
    let maxFrequency = frequencyMap.map { (key, value) in value.count }.max()
    return frequencyMap.filter { (key, value) in value.count == maxFrequency }.keys.first!
}

func quantile(numbers: [Double], quantile: Double) -> Double {
    let sortedNumbers = numbers.sorted()
    let index = (sortedNumbers.count * quantile).floor()
    return sortedNumbers[index]
}

func interquartileRange(numbers: [Double]) -> Double {
    let sortedNumbers = numbers.sorted()
    let middleIndex = sortedNumbers.count / 2
    return quantile(sortedNumbers, 0.75) - quantile(sortedNumbers, 0.25)
}

```swift
// For a given array of input numbers, calculate Mean Absolute Deviation
// around the mean of this dataset.
// Mean Absolute Deviation is the average absolute difference between each
// element and a centerpoint (mean in this case):
// MAD = average | x - x_mean |
// meanAbsoluteDeviation(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.0
func meanAbsoluteDeviation(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0) { (sum, x) in sum + x } / Double(numbers.count)
    return numbers.map { x in abs(x - mean) }.reduce(0.0) { (sum, x) in sum + x } / Double(numbers.count)
}

// For a given array of input numbers, calculate the variance of this dataset.
// Variance is the average of squared differences from the mean:
// variance(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.25
func variance(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0) { (sum, x) in sum + x } / Double(numbers.count)
    return numbers.map { x in (x - mean) * (x - mean) }.reduce(0.0) { (sum, x) in sum + x } / Double(numbers.count)
}

// For a given array of input numbers, calculate the standard deviation of this dataset.
// Standard deviation is the square root of the variance:
// standardDeviation(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.118033988749895
func standardDeviation(numbers: [Double]) -> Double {
    return sqrt(variance(numbers))
}

// For a given array of input numbers, calculate the median of this dataset.
// Median is the middle value of the dataset.
// If the dataset has an even number of elements, the median is the average of the two middle elements.
// median(numbers: [1.0, 2.0, 3.0, 4.0]) == 2.5
func median(numbers: [Double]) -> Double {
    let sortedNumbers = numbers.sorted()
    let middleIndex = sortedNumbers.count / 2
    if sortedNumbers.count.modulo(2) == 0 {
        return (sortedNumbers[middleIndex - 1] + sortedNumbers[middleIndex]) / 2.0
    } else {
        return sortedNumbers[middleIndex]
    }
}

// For a given array of input numbers, calculate the mode of this dataset.
// Mode is the most frequently occurring value in the dataset.
// If there are multiple modes, return any one of them.
// mode(numbers: [1.0, 2.0, 2.0, 3.0, 4.0]) == 2.0
func mode(numbers: [Double]) -> Double {
    let frequencyMap = numbers.groupBy { it }
    let maxFrequency = frequencyMap.map { (key, value) in value.count }.max()
    return frequencyMap.filter { (key, value) in value.count == maxFrequency }.keys.first!
}

// For a given array of input numbers, calculate the quantile of this dataset.
// Quantile is the value below which a given percentage of observations in a dataset fall.
// For example, the 25th percentile (quantile) is the value below which 25% of the observations fall.
// quantile(numbers: [1.0, 2.0, 3.0, 4.0], quantile: 0.25) == 1.5
func quantile(numbers: [Double], quantile: Double) -> Double {
    let sortedNumbers = numbers.sorted()
    let index = (sortedNumbers.count * quantile).floor()
    return sortedNumbers[index]
}

// For a given array of input numbers, calculate the interquartile range of this dataset.
// Interquartile range is the difference between the 75th and 25th percentiles:
// interquartileRange(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.0
func interquartileRange(numbers: [Double]) -> Double {
    let sortedNumbers = numbers.sorted()
    let middleIndex = sortedNumbers.count / 2
    return quantile(sortedNumbers, 0.75) - quantile(sortedNumbers, 0.25)
}

// For a given array of input numbers, calculate the coefficient of variation of this dataset.
// Coefficient of variation is the ratio of the standard deviation to the mean:
// coefficientOfVariation(numbers: [1.0, 2.0, 3.0, 4.0]) == 

func meanAbsoluteDeviation(numbers: [Double]) -> Double {
  var sum = 0.0
  for _, number in numbers {
    sum += number
  }
  var mean = sum / Double(numbers.count)
  var sumOfAbsoluteDeviations = 0.0
  for _, number in numbers {
    var absoluteDeviation = abs(number - mean)
    sumOfAbsoluteDeviations += absoluteDeviation
  }
  return sumOfAbsoluteDeviations / Double(numbers.count)
}

func median(numbers: [Double]) -> Double {
  var sortedNumbers = numbers.sorted()
  var middleIndex = Int(sortedNumbers.count / 2)
  if sortedNumbers.count % 2 == 0 {
    return (sortedNumbers[middleIndex - 1] + sortedNumbers[middleIndex]) / 2.0
  } else {
    return sortedNumbers[middleIndex]
  }
}

func mode(numbers: [Double]) -> Double {
  var counts: [Double: Int] = [Double: Int]()
  for _, number in numbers {
    counts[number] = counts[number]! + 1
  }
  var maxCount = 0
  var mode: Double? = nil
  for key, value in counts {
    if value > maxCount {
      maxCount = value
      mode = key
    }
  }
  return mode!
}

func variance(numbers: [Double]) -> Double {
  var mean = mean(numbers)
  var sumOfSquaredDeviations = 0.0
  for _, number in numbers {
    var squaredDeviation = (number - mean) * (number - mean)
    sumOfSquaredDeviations += squaredDeviation
  }
  return sumOfSquaredDeviations / Double(numbers.count)
}

func standardDeviation(numbers: [Double]) -> Double {
  var variance = variance(numbers)
  return sqrt(variance)
}

func covariance(numbers: [Double], number: Double) -> Double {
  var mean = mean(numbers)
  var sumOfProductOfDifferences = 0.0
  for _, number in numbers {
    var productOfDifference = (number - mean) * (number - number)
    sumOfProductOfDifferences += productOfDifference
  }
  return sumOfProductOfDifferences / Double(numbers.count)
}

func correlation(numbers: [Double], number: Double) -> Double {
  var covariance = covariance(numbers, number)
  var standardDeviation = standardDeviation(numbers)
  return covariance / standardDeviation
}

```swift
// For a given array of input numbers, calculate Mean Absolute Deviation
// around the mean of this dataset.
// Mean Absolute Deviation is the average absolute difference between each
// element and a centerpoint (mean in this case):
// MAD = average | x - x_mean |
// meanAbsoluteDeviation(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.0
func meanAbsoluteDeviation(numbers: [Double]) -> Double {
  var sum = 0.0
  for _, number in numbers {
    sum += number
  }
  var mean = sum / Double(numbers.count)
  var sumOfAbsoluteDeviations = 0.0
  for _, number in numbers {
    var absoluteDeviation = abs(number - mean)
    sumOfAbsoluteDeviations += absoluteDeviation
  }
  return sumOfAbsoluteDeviations / Double(numbers.count)
}

// For a given array of input numbers, calculate Median of the dataset.
// Median is the middle value of the dataset when it is sorted in ascending
// order.
// median(numbers: [1.0, 2.0, 3.0, 4.0]) == 2.5
func median(numbers: [Double]) -> Double {
  var sortedNumbers = numbers.sorted()
  var middleIndex = Int(sortedNumbers.count / 2)
  if sortedNumbers.count % 2 == 0 {
    return (sortedNumbers[middleIndex - 1] + sortedNumbers[middleIndex]) / 2.0
  } else {
    return sortedNumbers[middleIndex]
  }
}

// For a given array of input numbers, calculate Mode of the dataset.
// Mode is the most frequently occurring value in the dataset.
// mode(numbers: [1.0, 2.0, 3.0, 4.0, 4.0]) == 4.0
func mode(numbers: [Double]) -> Double {
  var counts: [Double: Int] = [Double: Int]()
  for _, number in numbers {
    counts[number] = counts[number]! + 1
  }
  var maxCount = 0
  var mode: Double? = nil
  for key, value in counts {
    if value > maxCount {
      maxCount = value
      mode = key
    }
  }
  return mode!
}

// For a given array of input numbers, calculate the variance of the dataset.
// Variance is the average of the squared differences from the mean.
// variance(numbers: [1.0, 2.0, 3.0, 4.0]) == 2.0
func variance(numbers: [Double]) -> Double {
  var mean = mean(numbers)
  var sumOfSquaredDeviations = 0.0
  for _, number in numbers {
    var squaredDeviation = (number - mean) * (number - mean)
    sumOfSquaredDeviations += squaredDeviation
  }
  return sumOfSquaredDeviations / Double(numbers.count)
}

// For a given array of input numbers, calculate the standard deviation of the
// dataset.
// standardDeviation(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.0
func standardDeviation(numbers: [Double]) -> Double {
  var variance = variance(numbers)
  return sqrt(variance)
}

// For a given array of input numbers, calculate the covariance between the
// dataset and a given number.
// covariance(numbers: [1.0, 2.0, 3.0, 4.0], number: 2.0) == 1.0
func covariance(numbers: [Double], number: Double) -> Double {
  var mean = mean(numbers)
  var sumOfProductOfDifferences = 0.0
  for _, number in numbers {
    var productOfDifference = (number - mean) * (number - number)
    sumOfProductOfDifferences += productOfDifference
  }
  return sumOfProductOfDifferences / Double(numbers.count)
}

// For a given array of input numbers, calculate the correlation between the
// dataset and a given number.
// correlation(numbers: [1.0, 2.0, 3.0, 4.0], number: 2.0) == 1.0
func correlation(numbers: [Double], number: Double) -> Double {
  var covariance = covariance(numbers, number)
  var standardDeviation = standardDeviation(numbers)
  return covariance / standardDeviation
}

// For a given array of input numbers, calculate the linear regression of the
// dataset on a given number.
// linearRegression(numbers: [1.0, 2.0, 3.0, 4.0], number: 2.0) == 2.0
func linearRegression(numbers: [Double], number: Double) -> Double {
  var mean = mean

func meanAbsoluteDeviation(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0) { (acc, x) in acc + x } / Double(numbers.count)
    return numbers.reduce(0.0) { (acc, x) in acc + abs(x - mean) } / Double(numbers.count)
}

```swift
// For a given array of input numbers, calculate Mean Absolute Deviation
// around the mean of this dataset.
// Mean Absolute Deviation is the average absolute difference between each
// element and a centerpoint (mean in this case):
// MAD = average | x - x_mean |
// meanAbsoluteDeviation(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.0
func meanAbsoluteDeviation(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0) { (acc, x) in acc + x } / Double(numbers.count)
    return numbers.reduce(0.0) { (acc, x) in acc + abs(x - mean) } / Double(numbers.count)
}
<|file_separator|>```

func meanAbsoluteDeviation(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0) { (acc, x) in acc + x } / Double(numbers.count)
    let sum = numbers.reduce(0.0) { (acc, x) in acc + abs(x - mean) }
    return sum / Double(numbers.count)
}

func medianAbsoluteDeviation(numbers: [Double]) -> Double {
    let median = numbers.sorted().middleElement()
    let deviations = numbers.map { |x| abs(x - median) }
    return median(deviations)
}

func medianAbsoluteDeviation(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0) { (acc, x) in acc + x } / Double(numbers.count)
    let deviations = numbers.map { |x| abs(x - mean) }
    return median(deviations)
}

func variance(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0) { (acc, x) in acc + x } / Double(numbers.count)
    let squaredDeviations = numbers.map { |x| (x - mean) * (x - mean) }
    return squaredDeviations.reduce(0.0) { (acc, x) in acc + x } / Double(numbers.count)
}

func std(numbers: [Double]) -> Double {
    return sqrt(variance(numbers))
}

func covariance(numbers: [Double], other: [Double]) -> Double {
    let mean = numbers.reduce(0.0) { (acc, x) in acc + x } / Double(numbers.count)
    let otherMean = other.reduce(0.0) { (acc, x) in acc + x } / Double(other.count)
    let deviations = numbers.zip(other).map { (x, y) in (x - mean) * (y - otherMean) }
    return deviations.reduce(0.0) { (acc, x) in acc + x } / Double(numbers.count)
}

func correlation(numbers: [Double], other: [Double]) -> Double {
    return covariance(numbers, other) / (std(numbers) * std(other))
}

```swift
// For a given array of input numbers, calculate Mean Absolute Deviation
// around the mean of this dataset.
// Mean Absolute Deviation is the average absolute difference between each
// element and a centerpoint (mean in this case):
// MAD = average | x - x_mean |
// meanAbsoluteDeviation(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.0
func meanAbsoluteDeviation(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0) { (acc, x) in acc + x } / Double(numbers.count)
    let sum = numbers.reduce(0.0) { (acc, x) in acc + abs(x - mean) }
    return sum / Double(numbers.count)
}

// For a given array of input numbers, calculate Median Absolute Deviation
// around the median of this dataset.
// Median Absolute Deviation is the median of the absolute deviations from
// the median:
// MAD = median(|x - median(x)|)
// medianAbsoluteDeviation(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.0
func medianAbsoluteDeviation(numbers: [Double]) -> Double {
    let median = numbers.sorted().middleElement()
    let deviations = numbers.map { |x| abs(x - median) }
    return median(deviations)
}

// For a given array of input numbers, calculate Median Absolute Deviation
// around the mean of this dataset.
// Median Absolute Deviation is the median of the absolute deviations from
// the mean:
// MAD = median(|x - mean(x)|)
// medianAbsoluteDeviation(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.0
func medianAbsoluteDeviation(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0) { (acc, x) in acc + x } / Double(numbers.count)
    let deviations = numbers.map { |x| abs(x - mean) }
    return median(deviations)
}

// For a given array of input numbers, calculate the Variance of this dataset.
// Variance is the average of the squared deviations from the mean:
// variance(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.25
func variance(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0) { (acc, x) in acc + x } / Double(numbers.count)
    let squaredDeviations = numbers.map { |x| (x - mean) * (x - mean) }
    return squaredDeviations.reduce(0.0) { (acc, x) in acc + x } / Double(numbers.count)
}

// For a given array of input numbers, calculate the Standard Deviation of this
// dataset.
// Standard Deviation is the square root of the variance:
// std(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.118033988749895
func std(numbers: [Double]) -> Double {
    return sqrt(variance(numbers))
}

// For a given array of input numbers, calculate the Covariance of this dataset
// with respect to another dataset.
// Covariance is the average of the product of the deviations from each
// dataset:
// cov(numbers: [1.0, 2.0, 3.0, 4.0], other: [1.0, 2.0, 3.0, 4.0]) == 0.0
func covariance(numbers: [Double], other: [Double]) -> Double {
    let mean = numbers.reduce(0.0) { (acc, x) in acc + x } / Double(numbers.count)
    let otherMean = other.reduce(0.0) { (acc, x) in acc + x } / Double(other.count)
    let deviations = numbers.zip(other).map { (x, y) in (x - mean) * (y - otherMean) }
    return deviations.reduce(0.0) { (acc, x) in acc + x } / Double(numbers.count)
}

// For a given array of input numbers, calculate the Correlation of this dataset
// with respect to another dataset.
// Correlation is the covariance of this dataset with respect to another
// divided by the product of the standard deviations of each dataset:
// corr(numbers: [1.0, 2.0, 3.0, 4.0], other: [1.0, 2.0, 3.0, 4.0]) == 1.0
func correlation(numbers: [Double], other: [Double]) -> Double {
    return covariance(numbers, other) / (std(numbers) * std(other))
}

func meanAbsoluteDeviation(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0, +) / numbers.count
    return numbers.map { |x| abs(x - mean) }.reduce(0.0, +) / numbers.count
}

func median(numbers: [Double]) -> Double {
    let sorted = numbers.sorted()
    let middle = sorted.count / 2
    return if sorted.count.isEven {
        (sorted[middle - 1] + sorted[middle]) / 2
    } else {
        sorted[middle]
    }
}

func mode(numbers: [Double]) -> Double {
    let counts = numbers.map { |x| (x, 1) }.groupBy { it.0 }.mapValues { |_, v| v.count }
    let maxCount = counts.maxBy { |_, count| count }?.value
    return counts.filter { |_, count| count == maxCount }.keys.first!
}

func variance(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0, +) / numbers.count
    return numbers.map { |x| (x - mean) * (x - mean) }.reduce(0.0, +) / numbers.count
}

func standardDeviation(numbers: [Double]) -> Double {
    return sqrt(variance(numbers))
}

func skewness(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0, +) / numbers.count
    let variance = numbers.map { |x| (x - mean) * (x - mean) }.reduce(0.0, +) / numbers.count
    let stdDev = sqrt(variance)
    let thirdMoment = numbers.map { |x| (x - mean) * (x - mean) * (x - mean) }.reduce(0.0, +) / numbers.count
    return thirdMoment / (stdDev * stdDev * stdDev)
}

```swift
// For a given array of input numbers, calculate Mean Absolute Deviation
// around the mean of this dataset.
// Mean Absolute Deviation is the average absolute difference between each
// element and a centerpoint (mean in this case):
// MAD = average | x - x_mean |
// meanAbsoluteDeviation(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.0
func meanAbsoluteDeviation(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0, +) / numbers.count
    return numbers.map { |x| abs(x - mean) }.reduce(0.0, +) / numbers.count
}

// For a given array of input numbers, calculate the median of this dataset.
// The median is the middle value of the dataset when it is sorted in
// ascending order. If there are two middle values, then the median is the
// average of the two middle values.
// median(numbers: [1.0, 2.0, 3.0, 4.0]) == 2.5
func median(numbers: [Double]) -> Double {
    let sorted = numbers.sorted()
    let middle = sorted.count / 2
    return if sorted.count.isEven {
        (sorted[middle - 1] + sorted[middle]) / 2
    } else {
        sorted[middle]
    }
}

// For a given array of input numbers, calculate the mode of this dataset.
// The mode is the value that occurs most frequently.
// mode(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.0
func mode(numbers: [Double]) -> Double {
    let counts = numbers.map { |x| (x, 1) }.groupBy { it.0 }.mapValues { |_, v| v.count }
    let maxCount = counts.maxBy { |_, count| count }?.value
    return counts.filter { |_, count| count == maxCount }.keys.first!
}

// For a given array of input numbers, calculate the variance of this dataset.
// Variance is the average of the squared differences from the mean.
// variance(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.25
func variance(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0, +) / numbers.count
    return numbers.map { |x| (x - mean) * (x - mean) }.reduce(0.0, +) / numbers.count
}

// For a given array of input numbers, calculate the standard deviation of this
// dataset.
// standardDeviation(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.118033988749895
func standardDeviation(numbers: [Double]) -> Double {
    return sqrt(variance(numbers))
}

// For a given array of input numbers, calculate the skewness of this dataset.
// Skewness is a measure of the asymmetry of the dataset. A normal distribution
// has a skewness of 0. A distribution whose symmetric tails are on either
// side of the mean are said to be skewed.
// skewness(numbers: [1.0, 2.0, 3.0, 4.0]) == 0.0
func skewness(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0, +) / numbers.count
    let variance = numbers.map { |x| (x - mean) * (x - mean) }.reduce(0.0, +) / numbers.count
    let stdDev = sqrt(variance)
    let thirdMoment = numbers.map { |x| (x - mean) * (x - mean) * (x - mean) }.reduce(0.0, +) / numbers.count
    return thirdMoment / (stdDev * stdDev * stdDev)
}

// For a given array of input numbers, calculate the kurtosis of this dataset.
// Kurtosis is a measure of the peakedness of the dataset. A normal distribution
// has a kurtosis of 3. A distribution whose tails are on either side of the
// mean are said to be kurtosis-heavy.
// kurtosis(numbers: [1.0, 2.0, 3.0, 4.0]) == 0.0
func kurtosis(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0, +) / numbers.count
    let variance = numbers.map { |x| (x - mean) * (x - mean) }.reduce(0.0, +) / numbers.count
    let stdDev = sqrt(variance)
    let fourthMoment = numbers.map { |x| (x - mean) * (x - mean)

func meanAbsoluteDeviation(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0) { (acc, x) in acc + x } / Double(numbers.count)
    let sum = numbers.reduce(0.0) { (acc, x) in acc + (x - mean).abs() }
    return sum / Double(numbers.count)
}

func medianAbsoluteDeviation(numbers: [Double]) -> Double {
    let median = numbers.sorted().middleElement()
    let sum = numbers.reduce(0.0) { (acc, x) in acc + (x - median).abs() }
    return sum / Double(numbers.count)
}

func variance(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0) { (acc, x) in acc + x } / Double(numbers.count)
    let sum = numbers.reduce(0.0) { (acc, x) in acc + (x - mean).square() }
    return sum / Double(numbers.count)
}

func standardDeviation(numbers: [Double]) -> Double {
    return sqrt(variance(numbers))
}

func correlation(numbers1: [Double], numbers2: [Double]) -> Double {
    let mean1 = numbers1.reduce(0.0) { (acc, x) in acc + x } / Double(numbers1.count)
    let mean2 = numbers2.reduce(0.0) { (acc, x) in acc + x } / Double(numbers2.count)
    let sum = numbers1.reduce(0.0) { (acc, x, y) in acc + (x - mean1) * (y - mean2) }
    return sum / Double(numbers1.count)
}

```swift
// For a given array of input numbers, calculate Mean Absolute Deviation
// around the mean of this dataset.
// Mean Absolute Deviation is the average absolute difference between each
// element and a centerpoint (mean in this case):
// MAD = average | x - x_mean |
// meanAbsoluteDeviation(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.0
func meanAbsoluteDeviation(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0) { (acc, x) in acc + x } / Double(numbers.count)
    let sum = numbers.reduce(0.0) { (acc, x) in acc + (x - mean).abs() }
    return sum / Double(numbers.count)
}

// For a given array of input numbers, calculate Median Absolute Deviation
// around the median of this dataset.
// Median Absolute Deviation is the average absolute difference between each
// element and a centerpoint (median in this case):
// MAD = average | x - x_median |
// medianAbsoluteDeviation(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.0
func medianAbsoluteDeviation(numbers: [Double]) -> Double {
    let median = numbers.sorted().middleElement()
    let sum = numbers.reduce(0.0) { (acc, x) in acc + (x - median).abs() }
    return sum / Double(numbers.count)
}

// For a given array of input numbers, calculate Variance of this dataset.
// Variance is the average of the squared differences from the Mean:
// Variance = average(x - x_mean)^2
// variance(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.25
func variance(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0) { (acc, x) in acc + x } / Double(numbers.count)
    let sum = numbers.reduce(0.0) { (acc, x) in acc + (x - mean).square() }
    return sum / Double(numbers.count)
}

// For a given array of input numbers, calculate Standard Deviation of this
// dataset.
// Standard Deviation is the square root of Variance:
// Standard Deviation = sqrt(Variance)
// standardDeviation(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.118033988749895
func standardDeviation(numbers: [Double]) -> Double {
    return sqrt(variance(numbers))
}

// For a given array of input numbers, calculate the Correlation between this
// dataset and another dataset.
// Correlation is the average of the product of the differences of each
// element of the first dataset with the differences of each element of the
// second dataset:
// Correlation = average(x - x_mean)(y - y_mean)
// correlation(numbers: [1.0, 2.0, 3.0, 4.0], numbers: [1.0, 2.0, 3.0, 4.0]) == 1.0
func correlation(numbers1: [Double], numbers2: [Double]) -> Double {
    let mean1 = numbers1.reduce(0.0) { (acc, x) in acc + x } / Double(numbers1.count)
    let mean2 = numbers2.reduce(0.0) { (acc, x) in acc + x } / Double(numbers2.count)
    let sum = numbers1.reduce(0.0) { (acc, x, y) in acc + (x - mean1) * (y - mean2) }
    return sum / Double(numbers1.count)
}

// For a given array of input numbers, calculate the Covariance between this
// dataset and another dataset.
// Covariance is the average of the product of the differences of each
// element of the first dataset with the differences of each element of the
// second dataset:
// Covariance = average(x - x_mean)(y - y_mean)
// covariance(numbers: [1.0, 2.0, 3.0, 4.0], numbers: [1.0, 2.0, 3.0, 4.0]) == 1.0
func covariance(numbers1: [Double], numbers2: [Double]) -> Double {
    let mean1 = numbers1.reduce(0.0) { (acc, x) in acc + x } / Double(numbers1.count)
    let mean2 = numbers2.reduce(0.0) { (acc, x) in acc + x } / Double(numbers2.count)
    let sum = numbers1.reduce(0.0) { (acc, x, y) in acc + (x - mean1) * (y

func meanAbsoluteDeviation(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0) { (acc, x) in acc + x } / Double(numbers.count)
    return numbers.map { |x| abs(x - mean) }.reduce(0.0) { (acc, x) in acc + x } / Double(numbers.count)
}

func variance(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0) { (acc, x) in acc + x } / Double(numbers.count)
    return numbers.map { |x| (x - mean) * (x - mean) }.reduce(0.0) { (acc, x) in acc + x } / Double(numbers.count)
}

func standardDeviation(numbers: [Double]) -> Double {
    return sqrt(variance(numbers))
}

func median(numbers: [Double]) -> Double {
    let sorted = numbers.sorted()
    let mid = sorted.count / 2
    if sorted.count.modulo(2) == 0 {
        return (sorted[mid - 1] + sorted[mid]) / 2
    } else {
        return sorted[mid]
    }
}

func mode(numbers: [Double]) -> Double {
    let counts = numbers.groupBy { it }.map { (k, v) in (k, v.count()) }
    let maxCount = counts.maxBy { it.value }?.value
    return counts.filter { it.value == maxCount }.map { it.key }.first()
}

func range(numbers: [Double]) -> Double {
    return numbers.sorted()[numbers.count - 1] - numbers.sorted()[0]
}

func interquartileRange(numbers: [Double]) -> Double {
    let sorted = numbers.sorted()
    let mid = sorted.count / 2
    let q1 = sorted[mid - 1]
    let q3 = sorted[mid + 1]
    return q3 - q1
}

```swift
// For a given array of input numbers, calculate Mean Absolute Deviation
// around the mean of this dataset.
// Mean Absolute Deviation is the average absolute difference between each
// element and a centerpoint (mean in this case):
// MAD = average | x - x_mean |
// meanAbsoluteDeviation(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.0
func meanAbsoluteDeviation(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0) { (acc, x) in acc + x } / Double(numbers.count)
    return numbers.map { |x| abs(x - mean) }.reduce(0.0) { (acc, x) in acc + x } / Double(numbers.count)
}

// For a given array of input numbers, calculate Variance of the dataset.
// Variance is the average squared difference between each element and a
// centerpoint (mean in this case):
// Variance = average(x - x_mean)^2
// variance(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.25
func variance(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0) { (acc, x) in acc + x } / Double(numbers.count)
    return numbers.map { |x| (x - mean) * (x - mean) }.reduce(0.0) { (acc, x) in acc + x } / Double(numbers.count)
}

// For a given array of input numbers, calculate Standard Deviation of the dataset.
// Standard Deviation is the square root of Variance:
// Standard Deviation = sqrt(Variance)
// standardDeviation(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.118033988749895
func standardDeviation(numbers: [Double]) -> Double {
    return sqrt(variance(numbers))
}

// For a given array of input numbers, calculate the median of the dataset.
// The median is the middle value of the dataset when sorted in ascending order.
// If the dataset has an odd number of elements, the median is the middle element.
// If the dataset has an even number of elements, the median is the average of the
// two middle elements.
// median(numbers: [1.0, 2.0, 3.0, 4.0]) == 2.5
func median(numbers: [Double]) -> Double {
    let sorted = numbers.sorted()
    let mid = sorted.count / 2
    if sorted.count.modulo(2) == 0 {
        return (sorted[mid - 1] + sorted[mid]) / 2
    } else {
        return sorted[mid]
    }
}

// For a given array of input numbers, calculate the mode of the dataset.
// The mode is the most frequently occurring value in the dataset.
// mode(numbers: [1.0, 2.0, 3.0, 4.0, 4.0]) == 4.0
func mode(numbers: [Double]) -> Double {
    let counts = numbers.groupBy { it }.map { (k, v) in (k, v.count()) }
    let maxCount = counts.maxBy { it.value }?.value
    return counts.filter { it.value == maxCount }.map { it.key }.first()
}

// For a given array of input numbers, calculate the range of the dataset.
// The range is the difference between the largest and smallest values in the dataset.
// range(numbers: [1.0, 2.0, 3.0, 4.0]) == 3.0
func range(numbers: [Double]) -> Double {
    return numbers.sorted()[numbers.count - 1] - numbers.sorted()[0]
}

// For a given array of input numbers, calculate the interquartile range of the dataset.
// The interquartile range is the difference between the third quartile and the first quartile.
// interquartileRange(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.0
func interquartileRange(numbers: [Double]) -> Double {
    let sorted = numbers.sorted()
    let mid = sorted.count / 2
    let q1 = sorted[mid - 1]
    let q3 = sorted[mid + 1]
    return q3 - q1
}

// For a given array of input numbers, calculate the coefficient of variation of the dataset.
// The coefficient of variation is the ratio of the standard deviation to the mean.
// coefficientOfVariation(numbers: [1.0, 2.0, 3.0, 4.0]) == 0.5
func coefficientOfVariation(numbers: [Double]) -> Double {
    let mean = numbers

func meanAbsoluteDeviation(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0) { (acc, x) in acc + x } / numbers.count
    return numbers.reduce(0.0) { (acc, x) in acc + abs(x - mean) } / numbers.count
}

func variance(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0) { (acc, x) in acc + x } / numbers.count
    return numbers.reduce(0.0) { (acc, x) in acc + (x - mean) * (x - mean) } / numbers.count
}

func standardDeviation(numbers: [Double]) -> Double {
    let variance = variance(numbers)
    return sqrt(variance)
}

func median(numbers: [Double]) -> Double {
    let sorted = numbers.sorted()
    let middleIndex = sorted.count / 2
    return if sorted.count.modulo(2) == 0 {
        (sorted[middleIndex - 1] + sorted[middleIndex]) / 2
    } else {
        sorted[middleIndex]
    }
}

func mode(numbers: [Double]) -> Double {
    let counts = numbers.groupBy(Double.self) { it }
    let maxCount = counts.reduce(0) { (acc, x) in acc.count.max(x.count) }
    return counts.reduce(0) { (acc, x) in if x.count == maxCount { x.firstKey()! } else { acc } }
}

func interquartileRange(numbers: [Double]) -> Double {
    let sorted = numbers.sorted()
    let middleIndex = sorted.count / 2
    let lowerHalf = sorted[0..<middleIndex]
    let upperHalf = sorted[middleIndex..<sorted.count]
    return upperHalf.last - lowerHalf.first
}

func geometricMean(numbers: [Double]) -> Double {
    let product = numbers.reduce(1.0) { (acc, x) in acc * x }
    return pow(product, 1.0 / numbers.count)
}

```swift
// For a given array of input numbers, calculate Mean Absolute Deviation
// around the mean of this dataset.
// Mean Absolute Deviation is the average absolute difference between each
// element and a centerpoint (mean in this case):
// MAD = average | x - x_mean |
// meanAbsoluteDeviation(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.0
func meanAbsoluteDeviation(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0) { (acc, x) in acc + x } / numbers.count
    return numbers.reduce(0.0) { (acc, x) in acc + abs(x - mean) } / numbers.count
}

// For a given array of input numbers, calculate Variance of the dataset.
// Variance is the average of the squared differences from the mean:
// variance(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.25
func variance(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0) { (acc, x) in acc + x } / numbers.count
    return numbers.reduce(0.0) { (acc, x) in acc + (x - mean) * (x - mean) } / numbers.count
}

// For a given array of input numbers, calculate Standard Deviation of the dataset.
// Standard Deviation is the square root of the Variance:
// standardDeviation(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.118033988749895
func standardDeviation(numbers: [Double]) -> Double {
    let variance = variance(numbers)
    return sqrt(variance)
}

// For a given array of input numbers, calculate the Median of the dataset.
// Median is the middle number in an ordered dataset.
// median(numbers: [1.0, 2.0, 3.0, 4.0]) == 2.5
func median(numbers: [Double]) -> Double {
    let sorted = numbers.sorted()
    let middleIndex = sorted.count / 2
    return if sorted.count.modulo(2) == 0 {
        (sorted[middleIndex - 1] + sorted[middleIndex]) / 2
    } else {
        sorted[middleIndex]
    }
}

// For a given array of input numbers, calculate the Mode of the dataset.
// Mode is the most frequent number in an ordered dataset.
// mode(numbers: [1.0, 2.0, 3.0, 4.0, 4.0, 4.0]) == 4.0
func mode(numbers: [Double]) -> Double {
    let counts = numbers.groupBy(Double.self) { it }
    let maxCount = counts.reduce(0) { (acc, x) in acc.count.max(x.count) }
    return counts.reduce(0) { (acc, x) in if x.count == maxCount { x.firstKey()! } else { acc } }
}

// For a given array of input numbers, calculate the Interquartile Range of the dataset.
// Interquartile Range is the difference between the 75th and 25th percentiles:
// interquartileRange(numbers: [1.0, 2.0, 3.0, 4.0, 4.0, 4.0]) == 2.0
func interquartileRange(numbers: [Double]) -> Double {
    let sorted = numbers.sorted()
    let middleIndex = sorted.count / 2
    let lowerHalf = sorted[0..<middleIndex]
    let upperHalf = sorted[middleIndex..<sorted.count]
    return upperHalf.last - lowerHalf.first
}

// For a given array of input numbers, calculate the Geometric Mean of the dataset.
// Geometric Mean is the n-th root of the product of n numbers:
// geometricMean(numbers: [1.0, 2.0, 3.0, 4.0]) == 2.0
func geometricMean(numbers: [Double]) -> Double {
    let product = numbers.reduce(1.0) { (acc, x) in acc * x }
    return pow(product, 1.0 / numbers.count)
}

// For a given array of input numbers, calculate the Harmonic Mean of the dataset.
// Harmonic Mean is the reciprocal of the arithmetic mean of the reciprocals of the numbers:
// harmonicMean(numbers: [1.0, 2.0, 3.0, 4.0]) == 2.5
func harmonicMean(numbers: [Double]) -> Double {
    let reciprocals = numbers.map(1.0 / Double.self)
    return reciprocals.reduce(0.0) { (acc, x) in acc

func meanAbsoluteDeviation(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0) { (sum, x) in sum + x } / numbers.count
    return numbers.map { x in abs(x - mean) }.reduce(0.0) { (sum, x) in sum + x } / numbers.count
}

func variance(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0) { (sum, x) in sum + x } / numbers.count
    return numbers.map { x in (x - mean) * (x - mean) }.reduce(0.0) { (sum, x) in sum + x } / numbers.count
}

func standardDeviation(numbers: [Double]) -> Double {
    return sqrt(variance(numbers))
}

func median(numbers: [Double]) -> Double {
    let sorted = numbers.sorted()
    let middle = sorted.count / 2
    if sorted.count.modulo(2) == 0 {
        return (sorted[middle - 1] + sorted[middle]) / 2
    } else {
        return sorted[middle]
    }
}

func mode(numbers: [Double]) -> Double {
    let counts = numbers.groupBy { it }.map { (k, v) in (k, v.count) }
    let maxCount = counts.reduce(0) { (max, x) in max.max(x) }
    return counts.filter { (_, v) in v == maxCount }.map { (k, _) in k }.first.key
}

func interquartileRange(numbers: [Double]) -> Double {
    let sorted = numbers.sorted()
    let middle = sorted.count / 2
    let firstHalf = sorted.subarray(0, middle)
    let secondHalf = sorted.subarray(middle, sorted.count)
    return secondHalf.first - firstHalf.last
}

func geometricMean(numbers: [Double]) -> Double {
    let product = numbers.reduce(1.0) { (product, x) in product * x }
    return pow(product, 1.0 / numbers.count)
}

```swift
// For a given array of input numbers, calculate Mean Absolute Deviation
// around the mean of this dataset.
// Mean Absolute Deviation is the average absolute difference between each
// element and a centerpoint (mean in this case):
// MAD = average | x - x_mean |
// meanAbsoluteDeviation(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.0
func meanAbsoluteDeviation(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0) { (sum, x) in sum + x } / numbers.count
    return numbers.map { x in abs(x - mean) }.reduce(0.0) { (sum, x) in sum + x } / numbers.count
}

// For a given array of input numbers, calculate the Variance of these numbers.
// Variance is the average of the squared differences from the mean:
// variance(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.25
func variance(numbers: [Double]) -> Double {
    let mean = numbers.reduce(0.0) { (sum, x) in sum + x } / numbers.count
    return numbers.map { x in (x - mean) * (x - mean) }.reduce(0.0) { (sum, x) in sum + x } / numbers.count
}

// For a given array of input numbers, calculate the Standard Deviation of these numbers.
// Standard Deviation is the square root of the Variance:
// standardDeviation(numbers: [1.0, 2.0, 3.0, 4.0]) == 1.118033988749895
func standardDeviation(numbers: [Double]) -> Double {
    return sqrt(variance(numbers))
}

// For a given array of input numbers, calculate the Median of these numbers.
// Median is the middle number in an ordered list of numbers.
// If the list has an even number of elements, the median is the average of the two middle elements.
// median(numbers: [1.0, 2.0, 3.0, 4.0]) == 2.5
func median(numbers: [Double]) -> Double {
    let sorted = numbers.sorted()
    let middle = sorted.count / 2
    if sorted.count.modulo(2) == 0 {
        return (sorted[middle - 1] + sorted[middle]) / 2
    } else {
        return sorted[middle]
    }
}

// For a given array of input numbers, calculate the Mode of these numbers.
// Mode is the most frequently occurring number in a list of numbers.
// mode(numbers: [1.0, 2.0, 2.0, 3.0, 3.0, 3.0, 4.0]) == 3.0
func mode(numbers: [Double]) -> Double {
    let counts = numbers.groupBy { it }.map { (k, v) in (k, v.count) }
    let maxCount = counts.reduce(0) { (max, x) in max.max(x) }
    return counts.filter { (_, v) in v == maxCount }.map { (k, _) in k }.first.key
}

// For a given array of input numbers, calculate the Interquartile Range of these numbers.
// Interquartile Range is the difference between the first and third quartiles:
// interquartileRange(numbers: [1.0, 2.0, 3.0, 4.0]) == 2.0
func interquartileRange(numbers: [Double]) -> Double {
    let sorted = numbers.sorted()
    let middle = sorted.count / 2
    let firstHalf = sorted.subarray(0, middle)
    let secondHalf = sorted.subarray(middle, sorted.count)
    return secondHalf.first - firstHalf.last
}

// For a given array of input numbers, calculate the Geometric Mean of these numbers.
// Geometric Mean is the nth root of the product of the numbers:
// geometricMean(numbers: [1.0, 2.0, 3.0, 4.0]) == 2.0
func geometricMean(numbers: [Double]) -> Double {
    let product = numbers.reduce(1.0) { (product, x) in product * x }
    return pow(product, 1.0 / numbers.count)
}

// For a given array of input numbers, calculate the Harmonic Mean of these numbers.
// Harmonic Mean is the reciprocal of the average of the reciprocals of the numbers:
// harmonicMean(numbers: [1.0, 2.0, 3.0, 4.0]) == 2.5
func harmonicMean(numbers: [Double]) -> Double {
    let reciprocals = numbers.map { 1.0 / it }
    return

func intersperse(numbers: [Int], delimeter: Int) -> [Int] {
  let mut result = [] as [Int];
  for (i, number) in numbers.enumerated() {
    if i == 0 {
      result.append(&mut [number]);
    } else {
      result.append(&mut [delimeter, number]);
    }
  }
  return result;
}

func removeNumbers(numbers: [Int], toRemove: [Int]) -> [Int] {
  let mut result = [] as [Int];
  for number in numbers {
    if !toRemove.contains(&number) {
      result.append(&mut [number]);
    }
  }
  return result;
}

```swift
// Insert a number 'delimeter' between every two consecutive elements of input array `numbers'
// intersperse(numbers: [] as [Int], delimeter: 4) == [] as [Int]
// intersperse(numbers: [1, 2, 3], delimeter: 4) == [1, 4, 2, 4, 3]
func intersperse(numbers: [Int], delimeter: Int) -> [Int] {
  let mut result = [] as [Int];
  for (i, number) in numbers.enumerated() {
    if i == 0 {
      result.append(&mut [number]);
    } else {
      result.append(&mut [delimeter, number]);
    }
  }
  return result;
}

// Given a list of numbers, return a list of the numbers sorted in ascending order,
// except any three numbers in the list (in any order) should be left out.
// For example, given the input [4, 8, 1, 5, 3, 7, 2, 9] and the set {3, 1, 5},
// your function should return [4, 8, 2, 9, 7]
func removeNumbers(numbers: [Int], toRemove: [Int]) -> [Int] {
  let mut result = [] as [Int];
  for number in numbers {
    if !toRemove.contains(&number) {
      result.append(&mut [number]);
    }
  }
  return result;
}

// Given a list of numbers, return a list of the numbers sorted in ascending order,
// except any three numbers in the list (in any order) should be left out.
// For example, given the input [4, 8, 1, 5, 3, 7, 2, 9] and the set {3, 1, 5},
// your function should return [4, 8, 2, 9, 7]
func removeNumbers(numbers: [Int], toRemove: [Int]) -> [Int] {
  let mut result = [] as [Int];
  for number in numbers {
    if !toRemove.contains(&number) {
      result.append(&mut [number]);
    }
  }
  return result;
}

// Given a list of numbers, return a list of the numbers sorted in ascending order,
// except any three numbers in the list (in any order) should be left out.
// For example, given the input [4, 8, 1, 5, 3, 7, 2, 9] and the set {3, 1, 5},
// your function should return [4, 8, 2, 9, 7]
func removeNumbers(numbers: [Int], toRemove: [Int]) -> [Int] {
  let mut result = [] as [Int];
  for number in numbers {
    if !toRemove.contains(&number) {
      result.append(&mut [number]);
    }
  }
  return result;
}

// Given a list of numbers, return a list of the numbers sorted in ascending order,
// except any three numbers in the list (in any order) should be left out.
// For example, given the input [4, 8, 1, 5, 3, 7, 2, 9] and the set {3, 1, 5},
// your function should return [4, 8, 2, 9, 7]
func removeNumbers(numbers: [Int], toRemove: [Int]) -> [Int] {
  let mut result = [] as [Int];
  for number in numbers {
    if !toRemove.contains(&number) {
      result.append(&mut [number]);
    }
  }
  return result;
}

// Given a list of numbers, return a list of the numbers sorted in ascending order,
// except any three numbers in the list (in any order) should be left out.
// For example, given the input [4, 8, 1, 5, 3, 7, 2, 9] and the set {3, 1, 5},
// your function should return [4, 8, 2, 9, 7]
func removeNumbers(numbers: [Int], toRemove: [Int]) -> [Int] {
  let mut result = [] as [Int];
  for number in numbers {
    if !toRemove.contains(&number) {
      result.append(&mut [number]);
    }
  }
  return result;
}

// Given a list of numbers, return a list of the numbers sorted in ascending order,
// except any three numbers in the list (in any order) should be left out.
// For example, given the input [4, 8, 1, 5, 3, 7,

func intersperse(numbers: [Int], delimeter: Int) -> [Int] {
  var result = [Int]()
  for i in 0..<numbers.count {
    if i > 0 {
      result.append(delimeter)
    }
    result.append(numbers[i])
  }
  return result
}

func findSmallest(numbers: [Int]) -> Int {
  var smallest = numbers[0]
  for i in 1..<numbers.count {
    if numbers[i] < smallest {
      smallest = numbers[i]
    }
  }
  return smallest
}

func findLargest(numbers: [Int]) -> Int {
  var largest = numbers[0]
  for i in 1..<numbers.count {
    if numbers[i] > largest {
      largest = numbers[i]
    }
  }
  return largest
}

func findSmallestIndex(numbers: [Int]) -> Int {
  var smallest = numbers[0]
  var smallestIndex = 0
  for i in 1..<numbers.count {
    if numbers[i] < smallest {
      smallest = numbers[i]
      smallestIndex = i
    }
  }
  return smallestIndex
}

func findLargestIndex(numbers: [Int]) -> Int {
  var largest = numbers[0]
  var largestIndex = 0
  for i in 1..<numbers.count {
    if numbers[i] > largest {
      largest = numbers[i]
      largestIndex = i
    }
  }
  return largestIndex
}

```swift
// Insert a number 'delimeter' between every two consecutive elements of input array `numbers'
// intersperse(numbers: [] as [Int], delimeter: 4) == [] as [Int]
// intersperse(numbers: [1, 2, 3], delimeter: 4) == [1, 4, 2, 4, 3]
func intersperse(numbers: [Int], delimeter: Int) -> [Int] {
  var result = [Int]()
  for i in 0..<numbers.count {
    if i > 0 {
      result.append(delimeter)
    }
    result.append(numbers[i])
  }
  return result
}

// Find the smallest number in the array `numbers`
func findSmallest(numbers: [Int]) -> Int {
  var smallest = numbers[0]
  for i in 1..<numbers.count {
    if numbers[i] < smallest {
      smallest = numbers[i]
    }
  }
  return smallest
}

// Find the largest number in the array `numbers`
func findLargest(numbers: [Int]) -> Int {
  var largest = numbers[0]
  for i in 1..<numbers.count {
    if numbers[i] > largest {
      largest = numbers[i]
    }
  }
  return largest
}

// Find the smallest number in the array `numbers`
func findSmallestIndex(numbers: [Int]) -> Int {
  var smallest = numbers[0]
  var smallestIndex = 0
  for i in 1..<numbers.count {
    if numbers[i] < smallest {
      smallest = numbers[i]
      smallestIndex = i
    }
  }
  return smallestIndex
}

// Find the largest number in the array `numbers`
func findLargestIndex(numbers: [Int]) -> Int {
  var largest = numbers[0]
  var largestIndex = 0
  for i in 1..<numbers.count {
    if numbers[i] > largest {
      largest = numbers[i]
      largestIndex = i
    }
  }
  return largestIndex
}

// Find the smallest number in the array `numbers`
func findSmallest(numbers: [Int]) -> Int {
  var smallest = numbers[0]
  for i in 1..<numbers.count {
    if numbers[i] < smallest {
      smallest = numbers[i]
    }
  }
  return smallest
}

// Find the largest number in the array `numbers`
func findLargest(numbers: [Int]) -> Int {
  var largest = numbers[0]
  for i in 1..<numbers.count {
    if numbers[i] > largest {
      largest = numbers[i]
    }
  }
  return largest
}

// Find the smallest number in the array `numbers`
func findSmallestIndex(numbers: [Int]) -> Int {
  var smallest = numbers[0]
  var smallestIndex = 0
  for i in 1..<numbers.count {
    if numbers[i] < smallest {
      smallest = numbers[i]
      smallestIndex = i
    }
  }
  return smallestIndex
}

// Find the largest number in the array `numbers`
func findLargestIndex(numbers: [Int]) -> Int {
  var largest = numbers[0]
  var largestIndex = 0
  for i in 1..<numbers.count {
    if numbers[i] > largest {
      largest = numbers[i]
      largestIndex = i
    }
  }
  return largestIndex
}

// Find the smallest number in the array `numbers`
func findSmallest(numbers: [Int]) -> Int {
  var smallest = numbers[0]
  for i in 1..<numbers.count {
    if numbers[i] < smallest {
      smallest = numbers[i]
    }
  }
  return smallest
}

// Find the largest number in the array `numbers`
func findLargest(numbers: [Int]) -> Int {
  var largest = numbers[0]
  for i in 1..<numbers.count {
    if numbers[i] > largest {
      largest = numbers[i]
    }
  }
  return largest
}

// Find the smallest number in the array `numbers`
func findSmallestIndex(numbers: [Int]) -> Int {
  var smallest = numbers[0]
  var smallestIndex = 0
  for i in 1..<numbers.count {
    if numbers[i] < smallest {
      smallest = numbers[i]
      smallestIndex = i
    }
  }
  return smallestIndex
}

// Find the largest number in the array `numbers`
func findLargestIndex(numbers: [Int]) -> Int {
  var largest = numbers[0]
  var largestIndex = 0
  for i in 

func intersperse(numbers: [Int], delimeter: Int) -> [Int] {
  var result = [] as [Int]
  for i in 0..<numbers.count {
    if i > 0 {
      result.append(delimeter)
    }
    result.append(numbers[i])
  }
  return result
}

func sumPairs(numbers: [Int], sum: Int) -> [Int] {
  var result = [] as [Int]
  for i in 0..<numbers.count {
    for j in i + 1..<numbers.count {
      if numbers[i] + numbers[j] == sum {
        result.append(numbers[i])
        result.append(numbers[j])
        return result
      }
    }
  }
  return result
}

```swift
// Insert a number 'delimeter' between every two consecutive elements of input array `numbers'
// intersperse(numbers: [] as [Int], delimeter: 4) == [] as [Int]
// intersperse(numbers: [1, 2, 3], delimeter: 4) == [1, 4, 2, 4, 3]
func intersperse(numbers: [Int], delimeter: Int) -> [Int] {
  var result = [] as [Int]
  for i in 0..<numbers.count {
    if i > 0 {
      result.append(delimeter)
    }
    result.append(numbers[i])
  }
  return result
}

// Given a list of numbers, return a list of the numbers where the first number is the sum of the first two, the second is the sum of the second two, etc.
// sum_pairs([11, 1, 2, 3, 1, 7, 11], 10) == [11, 7]
// sum_pairs([4, 3, 2, 3, 4], 6) == [4, 2]
// sum_pairs([0, 0, -2, 3], 2) == [0, -2]
func sumPairs(numbers: [Int], sum: Int) -> [Int] {
  var result = [] as [Int]
  for i in 0..<numbers.count {
    for j in i + 1..<numbers.count {
      if numbers[i] + numbers[j] == sum {
        result.append(numbers[i])
        result.append(numbers[j])
        return result
      }
    }
  }
  return result
}
```

func intersperse(numbers: [Int], delimeter: Int) -> [Int] {
  var result = [] as [Int]
  for i in 0..<numbers.count {
    if i == numbers.count - 1 {
      result.append(numbers[i])
    } else {
      result.append(numbers[i])
      result.append(delimeter)
    }
  }
  return result
}

```swift
// Insert a number 'delimeter' between every two consecutive elements of input array `numbers'
// intersperse(numbers: [] as [Int], delimeter: 4) == [] as [Int]
// intersperse(numbers: [1, 2, 3], delimeter: 4) == [1, 4, 2, 4, 3]
func intersperse(numbers: [Int], delimeter: Int) -> [Int] {
  var result = [] as [Int]
  for i in 0..<numbers.count {
    if i == numbers.count - 1 {
      result.append(numbers[i])
    } else {
      result.append(numbers[i])
      result.append(delimeter)
    }
  }
  return result
}

// Insert a number 'delimeter' between every two consecutive elements of input array `numbers'
// intersperse(numbers: [] as [Int], delimeter: 4) == [] as [Int]
// intersperse(numbers: [1, 2, 3], delimeter: 4) == [1, 4, 2, 4, 3]
func intersperse(numbers: [Int], delimeter: Int) -> [Int] {
  var result = [] as [Int]
  for i in 0..<numbers.count {
    if i == numbers.count - 1 {
      result.append(numbers[i])
    } else {
      result.append(numbers[i])
      result.append(delimeter)
    }
  }
  return result
}

// Insert a number 'delimeter' between every two consecutive elements of input array `numbers'
// intersperse(numbers: [] as [Int], delimeter: 4) == [] as [Int]
// intersperse(numbers: [1, 2, 3], delimeter: 4) == [1, 4, 2, 4, 3]
func intersperse(numbers: [Int], delimeter: Int) -> [Int] {
  var result = [] as [Int]
  for i in 0..<numbers.count {
    if i == numbers.count - 1 {
      result.append(numbers[i])
    } else {
      result.append(numbers[i])
      result.append(delimeter)
    }
  }
  return result
}

// Insert a number 'delimeter' between every two consecutive elements of input array `numbers'
// intersperse(numbers: [] as [Int], delimeter: 4) == [] as [Int]
// intersperse(numbers: [1, 2, 3], delimeter: 4) == [1, 4, 2, 4, 3]
func intersperse(numbers: [Int], delimeter: Int) -> [Int] {
  var result = [] as [Int]
  for i in 0..<numbers.count {
    if i == numbers.count - 1 {
      result.append(numbers[i])
    } else {
      result.append(numbers[i])
      result.append(delimeter)
    }
  }
  return result
}

// Insert a number 'delimeter' between every two consecutive elements of input array `numbers'
// intersperse(numbers: [] as [Int], delimeter: 4) == [] as [Int]
// intersperse(numbers: [1, 2, 3], delimeter: 4) == [1, 4, 2, 4, 3]
func intersperse(numbers: [Int], delimeter: Int) -> [Int] {
  var result = [] as [Int]
  for i in 0..<numbers.count {
    if i == numbers.count - 1 {
      result.append(numbers[i])
    } else {
      result.append(numbers[i])
      result.append(delimeter)
    }
  }
  return result
}

// Insert a number 'delimeter' between every two consecutive elements of input array `numbers'
// intersperse(numbers: [] as [Int], delimeter: 4) == [] as [Int]
// intersperse(numbers: [1, 2, 3], delimeter: 4) == [1, 4, 2, 4, 3]
func intersperse(numbers: [Int], delimeter: Int) -> [Int] {
  var result = [] as [Int]
  for i in 0..<numbers.count {
    if i == numbers.count - 1 {
      result.append(numbers[i])
    } else {
      result.append(numbers[i])
      result.append(delimeter)
    }
  }
  return result
}

// Insert a number 'delimeter' between every two consecutive elements of input array `numbers'
// intersperse(numbers: [] as [Int], delimeter

func intersperse(numbers: [Int], delimeter: Int) -> [Int] {
    var result = [Int]()
    for i in 0 ..< numbers.count {
        if i == 0 {
            result.append(numbers[i])
            continue
        }
        result.append(delimeter)
        result.append(numbers[i])
    }
    return result
}

func double_array(numbers: [Int]) -> [Int] {
    return numbers.map { $0 * 2 }
}

func double_array2(numbers: [Int]) -> [Int] {
    return numbers.map { $0 * 2 }
}

func double_or_zero(numbers: [Int]) -> [Int] {
    if numbers.count == 0 {
        return []Int()
    }
    if numbers.count == 1 {
        return [numbers[0] * 2]
    }
    if numbers[0] > 100 {
        return []Int()
    }
    return [numbers[0] * 2] + numbers[1..]
}

func double_or_zero2(numbers: [Int]) -> [Int] {
    if numbers.count == 0 {
        return []Int()
    }
    if numbers.count == 1 {
        return [numbers[0] * 2]
    }
    if numbers[0] > 100 {
        return []Int()
    }
    return [numbers[0] * 2] + numbers[1..]
}

```swift
// Insert a number 'delimeter' between every two consecutive elements of input array `numbers'
// intersperse(numbers: [] as [Int], delimeter: 4) == [] as [Int]
// intersperse(numbers: [1, 2, 3], delimeter: 4) == [1, 4, 2, 4, 3]
func intersperse(numbers: [Int], delimeter: Int) -> [Int] {
    var result = [Int]()
    for i in 0 ..< numbers.count {
        if i == 0 {
            result.append(numbers[i])
            continue
        }
        result.append(delimeter)
        result.append(numbers[i])
    }
    return result
}

// Given an array of integers, return a new array with each value doubled.
// double_array([1, 2, 3]) == [2, 4, 6]
func double_array(numbers: [Int]) -> [Int] {
    return numbers.map { $0 * 2 }
}

// Given an array of integers, return a new array with twice the
// values of the input array.
// double_array([1, 2, 3]) == [2, 4, 6]
// double_array([4, 5, 6]) == [8, 10, 12]
func double_array2(numbers: [Int]) -> [Int] {
    return numbers.map { $0 * 2 }
}

// Given an array of integers, return a new array with the array
// values doubled.
// - if the first element of the input array is greater than 100,
//   then return the array without any values.
// - if the array is empty, return an empty array.
// - if the array has only one element, return the array unchanged.
// - if the array has more than one element, return a new array
//   with the first element doubled.
// example:
// double_or_zero([1, 2, 3]) == [2, 4, 6]
// double_or_zero([101, 2, 3]) == []
// double_or_zero([]) == []
// double_or_zero([1]) == [2]
func double_or_zero(numbers: [Int]) -> [Int] {
    if numbers.count == 0 {
        return []Int()
    }
    if numbers.count == 1 {
        return [numbers[0] * 2]
    }
    if numbers[0] > 100 {
        return []Int()
    }
    return [numbers[0] * 2] + numbers[1..]
}

// Given an array of integers, return a new array with the array
// values doubled.
// - if the first element of the input array is greater than 100,
//   then return the array without any values.
// - if the array is empty, return an empty array.
// - if the array has only one element, return the array unchanged.
// - if the array has more than one element, return a new array
//   with the first element doubled.
// example:
// double_or_zero([1, 2, 3]) == [2, 4, 6]
// double_or_zero([101, 2, 3]) == []
// double_or_zero([]) == []
// double_or_zero([1]) == [2]
func double_or_zero2(numbers: [Int]) -> [Int] {
    if numbers.count == 0 {
        return []Int()
    }
    if numbers.count == 1 {
        return [numbers[0] * 2]
    }
    if numbers[0] > 100 {
        return []Int()
    }
    return [numbers[0] * 2] + numbers[1..]
}

// Given an array of integers, return a new array with the array
// values doubled.
// - if the first element of the input array is greater than 100,
//   then return the array without any values.
// - if the array is empty, return an empty array.
// - if the array has only one element, return the array unchanged.
// - if the array has more than one element, return a new array
//   with the first element doubled.
// example:
// double_or_zero([1, 2, 3]) == [2, 4, 6]
// double_or_zero([101, 2, 3]) == []
// double_or_zero([]) == []
// double_or_zero([1]) == [2]
func double_or_zero3(numbers: [Int]) -> [Int] {
    if numbers.count == 0 {

func intersperse(numbers: [Int], delimeter: Int) -> [Int] {
  let mut result = [Int]()
  for (index, number) in numbers.enumerated() {
    if index != 0 {
      result.append(&mut [delimeter])
    }
    result.append(&mut [number])
  }
  return result
}

```swift
// Insert a number 'delimeter' between every two consecutive elements of input array `numbers'
// intersperse(numbers: [] as [Int], delimeter: 4) == [] as [Int]
// intersperse(numbers: [1, 2, 3], delimeter: 4) == [1, 4, 2, 4, 3]
func intersperse(numbers: [Int], delimeter: Int) -> [Int] {
  let mut result = [Int]()
  for (index, number) in numbers.enumerated() {
    if index != 0 {
      result.append(&mut [delimeter])
    }
    result.append(&mut [number])
  }
  return result
}

// Insert a number 'delimeter' between every two consecutive elements of input array `numbers'
// intersperse(numbers: [] as [Int], delimeter: 4) == [] as [Int]
// intersperse(numbers: [1, 2, 3], delimeter: 4) == [1, 4, 2, 4, 3]
func intersperse(numbers: [Int], delimeter: Int) -> [Int] {
  let mut result = [Int]()
  for (index, number) in numbers.enumerated() {
    if index != 0 {
      result.append(&mut [delimeter])
    }
    result.append(&mut [number])
  }
  return result
}

// Insert a number 'delimeter' between every two consecutive elements of input array `numbers'
// intersperse(numbers: [] as [Int], delimeter: 4) == [] as [Int]
// intersperse(numbers: [1, 2, 3], delimeter: 4) == [1, 4, 2, 4, 3]
func intersperse(numbers: [Int], delimeter: Int) -> [Int] {
  let mut result = [Int]()
  for (index, number) in numbers.enumerated() {
    if index != 0 {
      result.append(&mut [delimeter])
    }
    result.append(&mut [number])
  }
  return result
}

// Insert a number 'delimeter' between every two consecutive elements of input array `numbers'
// intersperse(numbers: [] as [Int], delimeter: 4) == [] as [Int]
// intersperse(numbers: [1, 2, 3], delimeter: 4) == [1, 4, 2, 4, 3]
func intersperse(numbers: [Int], delimeter: Int) -> [Int] {
  let mut result = [Int]()
  for (index, number) in numbers.enumerated() {
    if index != 0 {
      result.append(&mut [delimeter])
    }
    result.append(&mut [number])
  }
  return result
}

// Insert a number 'delimeter' between every two consecutive elements of input array `numbers'
// intersperse(numbers: [] as [Int], delimeter: 4) == [] as [Int]
// intersperse(numbers: [1, 2, 3], delimeter: 4) == [1, 4, 2, 4, 3]
func intersperse(numbers: [Int], delimeter: Int) -> [Int] {
  let mut result = [Int]()
  for (index, number) in numbers.enumerated() {
    if index != 0 {
      result.append(&mut [delimeter])
    }
    result.append(&mut [number])
  }
  return result
}

// Insert a number 'delimeter' between every two consecutive elements of input array `numbers'
// intersperse(numbers: [] as [Int], delimeter: 4) == [] as [Int]
// intersperse(numbers: [1, 2, 3], delimeter: 4) == [1, 4, 2, 4, 3]
func intersperse(numbers: [Int], delimeter: Int) -> [Int] {
  let mut result = [Int]()
  for (index, number) in numbers.enumerated() {
    if index != 0 {
      result.append(&mut [delimeter])
    }
    result.append(&mut [number])
  }
  return result
}

// Insert a number 'delimeter' between every two consecutive elements of input array `numbers'
// intersperse(numbers: [] as [Int], delimeter: 4) == [] as [Int]
// intersperse(numbers: [1, 2, 3], delimeter: 4) == [1, 4, 2, 4, 3]
func intersperse(numbers: [Int], delimeter: Int) -> [Int] {
  let mut result = [Int]()
  for (index, number) in numbers.enumerated

func intersperse(numbers: [Int], delimeter: Int) -> [Int] {
  let mut result = [] as [Int]
  for (i, number) in numbers.enumerated() {
    if i == 0 {
      result.append(number)
    } else {
      result.append(delimeter)
      result.append(number)
    }
  }
  return result
}

func productExceptSelf(numbers: [Int]) -> [Int] {
  let length = numbers.count
  let mut result = [] as [Int]
  let mut prefixProduct = 1
  let mut postfixProduct = 1
  let mut prefixArray = [0; length]
  let mut postfixArray = [0; length]

  // Compute prefix product array
  for i in 0..<length {
    prefixProduct *= numbers[i]
    prefixArray[i] = prefixProduct
  }

  // Compute postfix product array
  for i in (0..<length).reversed() {
    postfixProduct *= numbers[i]
    postfixArray[i] = postfixProduct
  }

  // Compute result array
  for i in 0..<length {
    if i == 0 {
      result.append(postfixArray[i + 1])
    } else if i == length - 1 {
      result.append(prefixArray[i - 1])
    } else {
      result.append(prefixArray[i - 1] * postfixArray[i + 1])
    }
  }

  return result
}

```swift
// Insert a number 'delimeter' between every two consecutive elements of input array `numbers'
// intersperse(numbers: [] as [Int], delimeter: 4) == [] as [Int]
// intersperse(numbers: [1, 2, 3], delimeter: 4) == [1, 4, 2, 4, 3]
func intersperse(numbers: [Int], delimeter: Int) -> [Int] {
  let mut result = [] as [Int]
  for (i, number) in numbers.enumerated() {
    if i == 0 {
      result.append(number)
    } else {
      result.append(delimeter)
      result.append(number)
    }
  }
  return result
}

// Given an array of integers, return a new array such that each element at index i of the new array is the product of all the numbers in the original array except the one at i.
// For example, if our input was [1, 2, 3, 4, 5], the expected output would be [120, 60, 40, 30, 24]. If our input was [3, 2, 1], the expected output would be [2, 3, 6].
// Follow-up: what if you can't use division?
func productExceptSelf(numbers: [Int]) -> [Int] {
  let length = numbers.count
  let mut result = [] as [Int]
  let mut prefixProduct = 1
  let mut postfixProduct = 1
  let mut prefixArray = [0; length]
  let mut postfixArray = [0; length]

  // Compute prefix product array
  for i in 0..<length {
    prefixProduct *= numbers[i]
    prefixArray[i] = prefixProduct
  }

  // Compute postfix product array
  for i in (0..<length).reversed() {
    postfixProduct *= numbers[i]
    postfixArray[i] = postfixProduct
  }

  // Compute result array
  for i in 0..<length {
    if i == 0 {
      result.append(postfixArray[i + 1])
    } else if i == length - 1 {
      result.append(prefixArray[i - 1])
    } else {
      result.append(prefixArray[i - 1] * postfixArray[i + 1])
    }
  }

  return result
}

// Given an array of integers, return a new array such that each element at index i of the new array is the product of all the numbers in the original array except the one at i.
// For example, if our input was [1, 2, 3, 4, 5], the expected output would be [120, 60, 40, 30, 24]. If our input was [3, 2, 1], the expected output would be [2, 3, 6].
// Follow-up: what if you can't use division?
func productExceptSelf(numbers: [Int]) -> [Int] {
  let length = numbers.count
  let mut result = [] as [Int]
  let mut prefixProduct = 1
  let mut postfixProduct = 1
  let mut prefixArray = [0; length]
  let mut postfixArray = [0; length]

  // Compute prefix product array
  for i in 0..<length {
    prefixProduct *= numbers[i]
    prefixArray[i] = prefixProduct
  }

  // Compute postfix product array
  for i in (0..<length).reversed() {
    postfixProduct *= numbers[i]
    postfixArray[i] = postfixProduct
  }

  // Compute result array
  for i in 0..<length {
    if i == 0 {
      result.append(postfixArray[i + 1])
    } else if i == length - 1 {
      result.append(prefixArray[i - 1])
    } else {
      result.append(prefixArray[i - 1] * postfixArray[i + 1])
    }
  }

  return result
}

// Given an array of integers, return a new array such that each element at index i of the new array is the product of all the numbers in the original array except the one at i.
// For example, if our input was [1, 2, 3, 4, 5], the expected output would be [120, 60, 40, 30, 24]. If our input was [3, 2, 1], the expected output would be [2, 3, 6].
// Follow-up: what if you can't use division?
func productExceptSelf(numbers: [Int]) -> [Int] {
  let length = numbers.count
  let mut

func intersperse(numbers: [Int], delimeter: Int) -> [Int] {
    var result = [Int]()
    for i in 0..<numbers.count {
        if i > 0 {
            result.append(delimeter)
        }
        result.append(numbers[i])
    }
    return result
}

func findIndex(haystack: [Int], needle: Int) -> Int {
    for i in 0..<haystack.count {
        if haystack[i] == needle {
            return i
        }
    }
    return -1
}

func findLastIndex(haystack: [Int], needle: Int) -> Int {
    for i in haystack.count - 1 downTo 0 {
        if haystack[i] == needle {
            return i
        }
    }
    return -1
}

func find<T>(haystack: [T], predicate: (T) -> Bool) -> T? {
    for _, element in haystack {
        if predicate(element) {
            return element
        }
    }
    return nil
}

func findLast<T>(haystack: [T], predicate: (T) -> Bool) -> T? {
    for i in haystack.count - 1 downTo 0 {
        if predicate(haystack[i]) {
            return haystack[i]
        }
    }
    return nil
}

func findIndex<T>(haystack: [T], predicate: (T) -> Bool) -> Int {
    for i in 0..<haystack.count {
        if predicate(haystack[i]) {
            return i
        }
    }
    return -1
}

func findLastIndex<T>(haystack: [T], predicate: (T) -> Bool) -> Int {
    for i in haystack.count - 1 downTo 0 {
        if predicate(haystack[i]) {
            return i
        }
    }
    return -1
}

```swift
// Insert a number 'delimeter' between every two consecutive elements of input array `numbers'
// intersperse(numbers: [] as [Int], delimeter: 4) == [] as [Int]
// intersperse(numbers: [1, 2, 3], delimeter: 4) == [1, 4, 2, 4, 3]
func intersperse(numbers: [Int], delimeter: Int) -> [Int] {
    var result = [Int]()
    for i in 0..<numbers.count {
        if i > 0 {
            result.append(delimeter)
        }
        result.append(numbers[i])
    }
    return result
}

// Find the index of the first occurrence of a given element 'needle' in the input array 'haystack'
// findIndex(haystack: [1, 2, 3, 4, 5], needle: 3) == 2
// findIndex(haystack: [1, 2, 3, 4, 5], needle: 6) == -1
func findIndex(haystack: [Int], needle: Int) -> Int {
    for i in 0..<haystack.count {
        if haystack[i] == needle {
            return i
        }
    }
    return -1
}

// Find the index of the last occurrence of a given element 'needle' in the input array 'haystack'
// findLastIndex(haystack: [1, 2, 3, 4, 5], needle: 3) == 2
// findLastIndex(haystack: [1, 2, 3, 4, 5], needle: 6) == -1
func findLastIndex(haystack: [Int], needle: Int) -> Int {
    for i in haystack.count - 1 downTo 0 {
        if haystack[i] == needle {
            return i
        }
    }
    return -1
}

// Find the first element in the input array 'haystack' that satisfies a given predicate 'predicate'
// find(haystack: [1, 2, 3, 4, 5], predicate: { &x in x > 3 }) == 4
// find(haystack: [1, 2, 3, 4, 5], predicate: { &x in x == 6 }) == nil
func find<T>(haystack: [T], predicate: (T) -> Bool) -> T? {
    for _, element in haystack {
        if predicate(element) {
            return element
        }
    }
    return nil
}

// Find the last element in the input array 'haystack' that satisfies a given predicate 'predicate'
// findLast(haystack: [1, 2, 3, 4, 5], predicate: { &x in x > 3 }) == 4
// findLast(haystack: [1, 2, 3, 4, 5], predicate: { &x in x == 6 }) == nil
func findLast<T>(haystack: [T], predicate: (T) -> Bool) -> T? {
    for i in haystack.count - 1 downTo 0 {
        if predicate(haystack[i]) {
            return haystack[i]
        }
    }
    return nil
}

// Find the index of the first element in the input array 'haystack' that satisfies a given predicate 'predicate'
// findIndex(haystack: [1, 2, 3, 4, 5], predicate: { &x in x > 3 }) == 3
// findIndex(haystack: [1, 2, 3, 4, 5], predicate: { &x in x == 6 }) == nil
func findIndex<T>(haystack: [T], predicate: (T) -> Bool) -> Int {
    for i in 0..<haystack.count {
        if predicate(haystack[i]) {
            return i
        }
    }
    return -1
}

// Find the index of the last element in the input array 'haystack' that satisfies a given predicate 'predicate'
// findLastIndex(haystack: [1, 2, 3, 4, 5], predicate: { &x in x > 3 }) == 3
// findLastIndex(haystack: [1, 2, 3, 4, 5], predicate: { &x in x == 6 }) == nil
func findLastIndex<T>(haystack: [T], predicate: (T) -> Bool) -> Int {
    for i in haystack.count - 1 downTo 0 {
        if predicate(haystack[i]) {
            return i
        }
    }
    return -1
}

// Find the first element in the input array 'haystack' that satisfies a given predicate 'predicate'
//

func intersperse(numbers: [Int], delimeter: Int) -> [Int] {
    var result = [Int]()
    for i in 0..<numbers.count {
        if i > 0 {
            result.append(delimeter)
        }
        result.append(numbers[i])
    }
    return result
}

func findPair(numbers: [Int], target: Int) -> (Int, Int)? {
    var seen = [Int: Int]()
    for i in 0..<numbers.count {
        var complement = target - numbers[i]
        if seen.contains(key: complement) {
            return (complement, numbers[i])
        }
        seen[numbers[i]] = i
    }
    return nil
}

```swift
// Insert a number 'delimeter' between every two consecutive elements of input array `numbers'
// intersperse(numbers: [] as [Int], delimeter: 4) == [] as [Int]
// intersperse(numbers: [1, 2, 3], delimeter: 4) == [1, 4, 2, 4, 3]
func intersperse(numbers: [Int], delimeter: Int) -> [Int] {
    var result = [Int]()
    for i in 0..<numbers.count {
        if i > 0 {
            result.append(delimeter)
        }
        result.append(numbers[i])
    }
    return result
}

// Find the first pair of elements in input array `numbers' that sum up to 'target'
// findPair(numbers: [1, 2, 3, 4], target: 5) == (1, 4)
// findPair(numbers: [1, 2, 3, 4], target: 6) == (2, 3)
// findPair(numbers: [1, 2, 3, 4], target: 7) == nil
func findPair(numbers: [Int], target: Int) -> (Int, Int)? {
    var seen = [Int: Int]()
    for i in 0..<numbers.count {
        var complement = target - numbers[i]
        if seen.contains(key: complement) {
            return (complement, numbers[i])
        }
        seen[numbers[i]] = i
    }
    return nil
}

// Find the first pair of elements in input array `numbers' that sum up to 'target'
// findPair(numbers: [1, 2, 3, 4], target: 5) == (1, 4)
// findPair(numbers: [1, 2, 3, 4], target: 6) == (2, 3)
// findPair(numbers: [1, 2, 3, 4], target: 7) == nil
func findPair(numbers: [Int], target: Int) -> (Int, Int)? {
    var seen = [Int: Int]()
    for i in 0..<numbers.count {
        var complement = target - numbers[i]
        if seen.contains(key: complement) {
            return (complement, numbers[i])
        }
        seen[numbers[i]] = i
    }
    return nil
}

// Find the first pair of elements in input array `numbers' that sum up to 'target'
// findPair(numbers: [1, 2, 3, 4], target: 5) == (1, 4)
// findPair(numbers: [1, 2, 3, 4], target: 6) == (2, 3)
// findPair(numbers: [1, 2, 3, 4], target: 7) == nil
func findPair(numbers: [Int], target: Int) -> (Int, Int)? {
    var seen = [Int: Int]()
    for i in 0..<numbers.count {
        var complement = target - numbers[i]
        if seen.contains(key: complement) {
            return (complement, numbers[i])
        }
        seen[numbers[i]] = i
    }
    return nil
}

// Find the first pair of elements in input array `numbers' that sum up to 'target'
// findPair(numbers: [1, 2, 3, 4], target: 5) == (1, 4)
// findPair(numbers: [1, 2, 3, 4], target: 6) == (2, 3)
// findPair(numbers: [1, 2, 3, 4], target: 7) == nil
func findPair(numbers: [Int], target: Int) -> (Int, Int)? {
    var seen = [Int: Int]()
    for i in 0..<numbers.count {
        var complement = target - numbers[i]
        if seen.contains(key: complement) {
            return (complement, numbers[i])
        }
        seen[numbers[i]] = i
    }
    return nil
}

// Find the first pair of elements in input array `numbers' that sum up to 'target'
// findPair(numbers: [1, 2, 3, 4], target: 5) == (1, 4)
// findPair(numbers: [1, 2, 3, 4], target: 6) == (2, 3)
// findPair(numbers: [1, 2, 3, 4], target: 7) == nil
func findPair(numbers: [Int], target: Int) -> (Int, Int)? {
    var seen = [Int

func intersperse(numbers: [Int], delimeter: Int) -> [Int] {
  var result = [Int]()
  for i in 0..<numbers.count {
    if i > 0 {
      result.append(delimeter)
    }
    result.append(numbers[i])
  }
  return result
}

func countMatches(text: String, pattern: String) -> Int {
  var count = 0
  var patternLength = pattern.length
  for i in 0..<text.length - patternLength + 1 {
    var subString = text.substring(startIndex: i, endIndex: i + patternLength)
    if subString == pattern {
      count += 1
    }
  }
  return count
}

func search(text: String, pattern: String) -> Int {
  var patternLength = pattern.length
  for i in 0..<text.length - patternLength + 1 {
    var subString = text.substring(startIndex: i, endIndex: i + patternLength)
    if subString == pattern {
      return i
    }
  }
  return -1
}

func searchLast(text: String, pattern: String) -> Int {
  var patternLength = pattern.length
  for i in 0..<text.length - patternLength + 1 {
    var subString = text.substring(startIndex: i, endIndex: i + patternLength)
    if subString == pattern {
      return i + patternLength - 1
    }
  }
  return -1
}

```swift
// Insert a number 'delimeter' between every two consecutive elements of input array `numbers'
// intersperse(numbers: [] as [Int], delimeter: 4) == [] as [Int]
// intersperse(numbers: [1, 2, 3], delimeter: 4) == [1, 4, 2, 4, 3]
func intersperse(numbers: [Int], delimeter: Int) -> [Int] {
  var result = [Int]()
  for i in 0..<numbers.count {
    if i > 0 {
      result.append(delimeter)
    }
    result.append(numbers[i])
  }
  return result
}

// Find the number of times a substring `pattern' appears in the string `text'
// countMatches(text: "abc", pattern: "bc") == 2
// countMatches(text: "abc", pattern: "b") == 1
// countMatches(text: "abc", pattern: "d") == 0
func countMatches(text: String, pattern: String) -> Int {
  var count = 0
  var patternLength = pattern.length
  for i in 0..<text.length - patternLength + 1 {
    var subString = text.substring(startIndex: i, endIndex: i + patternLength)
    if subString == pattern {
      count += 1
    }
  }
  return count
}

// Find the index of the first occurrence of a substring `pattern' in the string `text'
// or -1 if no such substring exists
// search(text: "sadbutsad", pattern: "sad") == 0
// search(text: "sadbutsad", pattern: "but") == 3
// search(text: "sadbutsad", pattern: "we") == -1
func search(text: String, pattern: String) -> Int {
  var patternLength = pattern.length
  for i in 0..<text.length - patternLength + 1 {
    var subString = text.substring(startIndex: i, endIndex: i + patternLength)
    if subString == pattern {
      return i
    }
  }
  return -1
}

// Find the index of the last occurrence of a substring `pattern' in the string `text'
// or -1 if no such substring exists
// search(text: "sadbutsad", pattern: "sad") == 9
// search(text: "sadbutsad", pattern: "but") == 6
// search(text: "sadbutsad", pattern: "we") == -1
func searchLast(text: String, pattern: String) -> Int {
  var patternLength = pattern.length
  for i in 0..<text.length - patternLength + 1 {
    var subString = text.substring(startIndex: i, endIndex: i + patternLength)
    if subString == pattern {
      return i + patternLength - 1
    }
  }
  return -1
}

// Find the index of the first occurrence of a substring `pattern' in the string `text'
// or -1 if no such substring exists
// search(text: "sadbutsad", pattern: "sad") == 0
// search(text: "sadbutsad", pattern: "but") == 3
// search(text: "sadbutsad", pattern: "we") == -1
func search(text: String, pattern: String) -> Int {
  var patternLength = pattern.length
  for i in 0..<text.length - patternLength + 1 {
    var subString = text.substring(startIndex: i, endIndex: i + patternLength)
    if subString == pattern {
      return i
    }
  }
  return -1
}

// Find the index of the last occurrence of a substring `pattern' in the string `text'
// or -1 if no such substring exists
// search(text: "sadbutsad", pattern: "sad") == 9
// search(text: "sadbutsad", pattern: "but") == 6
// search(text: "sadbutsad", pattern: "we") == -1
func searchLast(text: String, pattern: String) -> Int {
  var patternLength = pattern.length
  for i in 0..<text.length - patternLength + 1 {
    var subString = text.substring(startIndex: i, endIndex: i + patternLength)
    if subString == pattern {
      return i + patternLength - 1
    }
  }
  return -1
}

// Find the index of the first occurrence of a substring `pattern' in the string `text'
// or -1 if no such substring exists
// search(text: "sadbutsad", pattern: "sad") == 0
// search(text: "sadbutsad", pattern: "but") == 3
// search(text: "sad

func parseNestedParens(parenString: String) -> [Int] {
    let stack = ArrayDeque<Char>()
    var maxDepth = 0
    var currentDepth = 0
    var result = Array<Int>()
    for c in parenString {
        if c == '(' {
            stack.push(c)
            currentDepth += 1
            if currentDepth > maxDepth {
                maxDepth = currentDepth
            }
        } else if c == ')' {
            stack.pop()
            currentDepth -= 1
        }
    }
    result.append(maxDepth)
    return result
}

```swift
// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    let stack = ArrayDeque<Char>()
    var maxDepth = 0
    var currentDepth = 0
    var result = Array<Int>()
    for c in parenString {
        if c == '(' {
            stack.push(c)
            currentDepth += 1
            if currentDepth > maxDepth {
                maxDepth = currentDepth
            }
        } else if c == ')' {
            stack.pop()
            currentDepth -= 1
        }
    }
    result.append(maxDepth)
    return result
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    let stack = ArrayDeque<Char>()
    var maxDepth = 0
    var currentDepth = 0
    var result = Array<Int>()
    for c in parenString {
        if c == '(' {
            stack.push(c)
            currentDepth += 1
            if currentDepth > maxDepth {
                maxDepth = currentDepth
            }
        } else if c == ')' {
            stack.pop()
            currentDepth -= 1
        }
    }
    result.append(maxDepth)
    return result
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    let stack = ArrayDeque<Char>()
    var maxDepth = 0
    var currentDepth = 0
    var result = Array<Int>()
    for c in parenString {
        if c == '(' {
            stack.push(c)
            currentDepth += 1
            if currentDepth > maxDepth {
                maxDepth = currentDepth
            }
        } else if c == ')' {
            stack.pop()
            currentDepth -= 1
        }
    }
    result.append(maxDepth)
    return result
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    let stack = ArrayDeque<Char>()
    var maxDepth = 0
    var currentDepth = 0
    var result = Array<Int>()
    for c in parenString {
        if c == '(' {
            stack.push(c)
            currentDepth += 1
            if currentDepth > maxDepth {
                maxDepth = currentDepth
            }
        } else if c == ')' {
            stack.pop()
            currentDepth -= 1
        }
    }
    result.append(maxDepth)
    return result
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    let stack = ArrayDeque<Char>()
    var maxDepth = 0
    var currentDepth = 0
    var result = Array<Int>()
    for c in parenString {
        if c == '(' {
            stack.push(c)
            currentDepth += 1
            if currentDepth > maxDepth {
                maxDepth = currentDepth
            }
        } else

func parseNestedParens(parenString: String) -> [Int] {
    var result: [Int] = []
    var stack: [Int] = []
    var maxLevel: Int = 0
    for i in 0..<parenString.length {
        if parenString[i] == '(' {
            stack.append(i)
        } else if parenString[i] == ')' {
            var level: Int = 0
            var index: Int = stack.last()
            while index != -1 && parenString[index] == '(' {
                level += 1
                index = stack.last()
            }
            if level > maxLevel {
                maxLevel = level
            }
            stack.removeLast()
        }
    }
    for i in 0..<stack.count {
        var level: Int = 0
        var index: Int = stack[i]
        while index != -1 && parenString[index] == '(' {
            level += 1
            index = stack[i]
        }
        if level > maxLevel {
            maxLevel = level
        }
    }
    result.append(maxLevel)
    return result
}

```swift
// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    var result: [Int] = []
    var stack: [Int] = []
    var maxLevel: Int = 0
    for i in 0..<parenString.length {
        if parenString[i] == '(' {
            stack.append(i)
        } else if parenString[i] == ')' {
            var level: Int = 0
            var index: Int = stack.last()
            while index != -1 && parenString[index] == '(' {
                level += 1
                index = stack.last()
            }
            if level > maxLevel {
                maxLevel = level
            }
            stack.removeLast()
        }
    }
    for i in 0..<stack.count {
        var level: Int = 0
        var index: Int = stack[i]
        while index != -1 && parenString[index] == '(' {
            level += 1
            index = stack[i]
        }
        if level > maxLevel {
            maxLevel = level
        }
    }
    result.append(maxLevel)
    return result
}
```

func parseNestedParens(parenString: String) -> [Int] {
    let stack = ArrayDeque<Char>()
    let result = Array<Int>()
    for c in parenString {
        if c == '(' {
            stack.push(c)
        } else if c == ')' {
            if stack.isEmpty {
                result.append(0)
            } else {
                stack.pop()
            }
        }
    }
    for c in stack {
        result.append(0)
    }
    return result
}

```swift
// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    let stack = ArrayDeque<Char>()
    let result = Array<Int>()
    for c in parenString {
        if c == '(' {
            stack.push(c)
        } else if c == ')' {
            if stack.isEmpty {
                result.append(0)
            } else {
                stack.pop()
            }
        }
    }
    for c in stack {
        result.append(0)
    }
    return result
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    let stack = ArrayDeque<Char>()
    let result = Array<Int>()
    for c in parenString {
        if c == '(' {
            stack.push(c)
        } else if c == ')' {
            if stack.isEmpty {
                result.append(0)
            } else {
                stack.pop()
            }
        }
    }
    for c in stack {
        result.append(0)
    }
    return result
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    let stack = ArrayDeque<Char>()
    let result = Array<Int>()
    for c in parenString {
        if c == '(' {
            stack.push(c)
        } else if c == ')' {
            if stack.isEmpty {
                result.append(0)
            } else {
                stack.pop()
            }
        }
    }
    for c in stack {
        result.append(0)
    }
    return result
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    let stack = ArrayDeque<Char>()
    let result = Array<Int>()
    for c in parenString {
        if c == '(' {
            stack.push(c)
        } else if c == ')' {
            if stack.isEmpty {
                result.append(0)
            } else {
                stack.pop()
            }
        }
    }
    for c in stack {
        result.append(0)
    }
    return result
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    let stack = ArrayDeque<Char>()
    let result = Array<Int>()
    for c in parenString {
        if c == '(' {
            stack.push(c)
        } else if c == ')' {
            if stack.isEmpty {
                result.append(0)
            } else {
                stack.pop()
            }
        }
    }
    for c in stack {
        result.append(0)
    }
    return result
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum

func parseNestedParens(parenString: String) -> [Int] {
    let mut result = [0];
    var max = 0;
    var current = 0;
    for c in parenString {
        if c == '(' {
            current += 1;
        }
        else if c == ')' {
            current -= 1;
        }
        if current > max {
            max = current;
        }
        result.append(current);
    }
    return result;
}

```swift
// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    let mut result = [0];
    var max = 0;
    var current = 0;
    for c in parenString {
        if c == '(' {
            current += 1;
        }
        else if c == ')' {
            current -= 1;
        }
        if current > max {
            max = current;
        }
        result.append(current);
    }
    return result;
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    let mut result = [0];
    var max = 0;
    var current = 0;
    for c in parenString {
        if c == '(' {
            current += 1;
        }
        else if c == ')' {
            current -= 1;
        }
        if current > max {
            max = current;
        }
        result.append(current);
    }
    return result;
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    let mut result = [0];
    var max = 0;
    var current = 0;
    for c in parenString {
        if c == '(' {
            current += 1;
        }
        else if c == ')' {
            current -= 1;
        }
        if current > max {
            max = current;
        }
        result.append(current);
    }
    return result;
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    let mut result = [0];
    var max = 0;
    var current = 0;
    for c in parenString {
        if c == '(' {
            current += 1;
        }
        else if c == ')' {
            current -= 1;
        }
        if current > max {
            max = current;
        }
        result.append(current);
    }
    return result;
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    let mut result = [0];
    var max = 0;
    var current = 0;
    for c in parenString {
        if c == '(' {
            current += 1;
        }
        else if c == ')' {
            current -= 1;
        }
        if current > max {
            max = current;
        }
        result.append(current);
    }
    return result;
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1

func parseNestedParens(parenString: String) -> [Int] {
    let stack: [Int] = []
    var deepestLevel: Int = 0
    var currentLevel: Int = 0
    for c in parenString {
        if c == '(' {
            currentLevel += 1
        } else if c == ')' {
            currentLevel -= 1
        }
        if currentLevel > deepestLevel {
            deepestLevel = currentLevel
        }
        stack.append(currentLevel)
    }
    return stack
}

```swift
// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    let stack: [Int] = []
    var deepestLevel: Int = 0
    var currentLevel: Int = 0
    for c in parenString {
        if c == '(' {
            currentLevel += 1
        } else if c == ')' {
            currentLevel -= 1
        }
        if currentLevel > deepestLevel {
            deepestLevel = currentLevel
        }
        stack.append(currentLevel)
    }
    return stack
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    let stack: [Int] = []
    var deepestLevel: Int = 0
    var currentLevel: Int = 0
    for c in parenString {
        if c == '(' {
            currentLevel += 1
        } else if c == ')' {
            currentLevel -= 1
        }
        if currentLevel > deepestLevel {
            deepestLevel = currentLevel
        }
        stack.append(currentLevel)
    }
    return stack
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    let stack: [Int] = []
    var deepestLevel: Int = 0
    var currentLevel: Int = 0
    for c in parenString {
        if c == '(' {
            currentLevel += 1
        } else if c == ')' {
            currentLevel -= 1
        }
        if currentLevel > deepestLevel {
            deepestLevel = currentLevel
        }
        stack.append(currentLevel)
    }
    return stack
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    let stack: [Int] = []
    var deepestLevel: Int = 0
    var currentLevel: Int = 0
    for c in parenString {
        if c == '(' {
            currentLevel += 1
        } else if c == ')' {
            currentLevel -= 1
        }
        if currentLevel > deepestLevel {
            deepestLevel = currentLevel
        }
        stack.append(currentLevel)
    }
    return stack
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    let stack: [Int] = []
    var deepestLevel: Int = 0
    var currentLevel: Int = 0
    for c in parenString {
        if c == '(' {
            currentLevel += 1
        } else if c == ')' {
            currentLevel -= 1
        }
        if currentLevel > deepestLevel {
            deepestLevel = currentLevel
        }
        stack.append(currentLevel)
    }
    return stack
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while

func parseNestedParens(parenString: String) -> [Int] {
    var result: [Int] = []
    var stack: [Int] = []
    var maxDepth: Int = 0
    var currentDepth: Int = 0
    var i: Int = 0
    while i < parenString.length {
        if parenString[i] == '(' {
            stack.append(i)
            currentDepth += 1
        } else if parenString[i] == ')' {
            if currentDepth > maxDepth {
                maxDepth = currentDepth
            }
            stack.pop()
            currentDepth -= 1
        }
        i += 1
    }
    for i in stack {
        if currentDepth > maxDepth {
            maxDepth = currentDepth
        }
        currentDepth -= 1
    }
    return [maxDepth, maxDepth, maxDepth, maxDepth]
}

```swift
// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    var result: [Int] = []
    var stack: [Int] = []
    var maxDepth: Int = 0
    var currentDepth: Int = 0
    var i: Int = 0
    while i < parenString.length {
        if parenString[i] == '(' {
            stack.append(i)
            currentDepth += 1
        } else if parenString[i] == ')' {
            if currentDepth > maxDepth {
                maxDepth = currentDepth
            }
            stack.pop()
            currentDepth -= 1
        }
        i += 1
    }
    for i in stack {
        if currentDepth > maxDepth {
            maxDepth = currentDepth
        }
        currentDepth -= 1
    }
    return [maxDepth, maxDepth, maxDepth, maxDepth]
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    var result: [Int] = []
    var stack: [Int] = []
    var maxDepth: Int = 0
    var currentDepth: Int = 0
    var i: Int = 0
    while i < parenString.length {
        if parenString[i] == '(' {
            stack.append(i)
            currentDepth += 1
        } else if parenString[i] == ')' {
            if currentDepth > maxDepth {
                maxDepth = currentDepth
            }
            stack.pop()
            currentDepth -= 1
        }
        i += 1
    }
    for i in stack {
        if currentDepth > maxDepth {
            maxDepth = currentDepth
        }
        currentDepth -= 1
    }
    return [maxDepth, maxDepth, maxDepth, maxDepth]
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    var result: [Int] = []
    var stack: [Int] = []
    var maxDepth: Int = 0
    var currentDepth: Int = 0
    var i: Int = 0
    while i < parenString.length {
        if parenString[i] == '(' {
            stack.append(i)
            currentDepth += 1
        } else if parenString[i] == ')' {
            if currentDepth > maxDepth {
                maxDepth = currentDepth
            }
            stack.pop()
            currentDepth -= 1
        }
        i += 1
    }
    for i in stack {
        if currentDepth > maxDepth {
            maxDepth = currentDepth
        }
        currentDepth -= 1
    }
    return [maxDepth, maxDepth, maxDepth, maxDepth]
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    var result: [Int] = []
    var stack: [Int] = []
    var maxDepth: Int = 0
    var currentDepth: Int = 0
    var i: Int = 0
    while i < parenString.length {
        if parenString[i] == '(' {
            stack.append(i)
            currentDepth += 1
        } else if parenString[i] == ')' {
            if currentDepth > maxDepth {
                maxDepth = currentDepth

func parseNestedParens(parenString: String) -> [Int] {
    let stack = ArrayDeque<Char>()
    let result = Array<Int>()
    for c in parenString.characters {
        if c == '(' {
            stack.push(c)
        } else if c == ')' {
            if stack.isEmpty {
                result.append(0)
            } else {
                stack.pop()
                result.append(stack.count)
            }
        }
    }
    return result
}

func generateParentheses(n: Int) -> Int {
    let stack = ArrayDeque<Char>()
    let result = 0
    let generateParenthesesHelper(open: Int, close: Int) {
        if open == n && close == n {
            result += 1
        } else {
            if open < n {
                stack.push('(')
                generateParenthesesHelper(open + 1, close)
                stack.pop()
            }
            if close < open {
                stack.push(')')
                generateParenthesesHelper(open, close + 1)
                stack.pop()
            }
        }
    }
    generateParenthesesHelper(0, 0)
    return result
}

```swift
// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    let stack = ArrayDeque<Char>()
    let result = Array<Int>()
    for c in parenString.characters {
        if c == '(' {
            stack.push(c)
        } else if c == ')' {
            if stack.isEmpty {
                result.append(0)
            } else {
                stack.pop()
                result.append(stack.count)
            }
        }
    }
    return result
}

// Input to this function is a string representing a sequence of parentheses.
// Output is the number of valid parentheses sequences that can be generated.
// E.g. "((()))" is a valid sequence of parentheses.
// generateParentheses(n: 3) == 5
// Explanation:
// The 5 valid parentheses sequences are:
// "((()))", "(()())", "(())()", "()(())", "()()()"
func generateParentheses(n: Int) -> Int {
    let stack = ArrayDeque<Char>()
    let result = 0
    let generateParenthesesHelper(open: Int, close: Int) {
        if open == n && close == n {
            result += 1
        } else {
            if open < n {
                stack.push('(')
                generateParenthesesHelper(open + 1, close)
                stack.pop()
            }
            if close < open {
                stack.push(')')
                generateParenthesesHelper(open, close + 1)
                stack.pop()
            }
        }
    }
    generateParenthesesHelper(0, 0)
    return result
}

// Input to this function is a string representing a sequence of parentheses.
// Output is the number of valid parentheses sequences that can be generated.
// E.g. "((()))" is a valid sequence of parentheses.
// generateParentheses(n: 3) == 5
// Explanation:
// The 5 valid parentheses sequences are:
// "((()))", "(()())", "(())()", "()(())", "()()()"
func generateParentheses(n: Int) -> Int {
    let stack = ArrayDeque<Char>()
    let result = 0
    let generateParenthesesHelper(open: Int, close: Int) {
        if open == n && close == n {
            result += 1
        } else {
            if open < n {
                stack.push('(')
                generateParenthesesHelper(open + 1, close)
                stack.pop()
            }
            if close < open {
                stack.push(')')
                generateParenthesesHelper(open, close + 1)
                stack.pop()
            }
        }
    }
    generateParenthesesHelper(0, 0)
    return result
}

// Input to this function is a string representing a sequence of parentheses.
// Output is the number of valid parentheses sequences that can be generated.
// E.g. "((()))" is a valid sequence of parentheses.
// generateParentheses(n: 3) == 5
// Explanation:
// The 5 valid parentheses sequences are:
// "((()))", "(()())", "(())()", "()(())", "()()()"
func generateParentheses(n: Int) -> Int {
    let stack = ArrayDeque<Char>()
    let result = 0
    let generateParenthesesHelper(open: Int, close: Int) {
        if open == n && close == n {
            result += 1
        } else {
            if open < n {
                stack.push('(')
                generateParenthesesHelper(open + 1, close)
                stack.pop()
            }
            if close < open {
                stack.push(')')
                generateParenthesesHelper(open, close + 1)
                stack.pop()
            }
        }
    }
    generateParenthesesHelper(0, 0)
    return result
}

// Input to this function is a string representing a sequence of parentheses.
// Output is the number of valid parentheses sequences that can be generated.
// E.g. "((()))" is a valid sequence of parentheses.
// generateParentheses(n: 3) == 5
// Explanation:
// The 5 valid parentheses sequences are:
// "((()))", "(()())", "(())()", "()(())", "()()()"
func generateParentheses(n: Int) -> Int {
    let stack = ArrayDeque<Char>()
    let result = 0
    let generateParent

func parseNestedParens(parenString: String) -> [Int] {
    var result: [Int] = []
    var stack: [Char] = []
    var maxLevel: Int = 0
    var currentLevel: Int = 0
    for i in 0..<parenString.count {
        var char: Char = parenString[i]
        if char == '(' {
            stack.append(char)
            currentLevel += 1
            if currentLevel > maxLevel {
                maxLevel = currentLevel
            }
        } else if char == ')' {
            stack.pop()
            currentLevel -= 1
        }
        result.append(maxLevel)
    }
    return result
}

```swift
// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    var result: [Int] = []
    var stack: [Char] = []
    var maxLevel: Int = 0
    var currentLevel: Int = 0
    for i in 0..<parenString.count {
        var char: Char = parenString[i]
        if char == '(' {
            stack.append(char)
            currentLevel += 1
            if currentLevel > maxLevel {
                maxLevel = currentLevel
            }
        } else if char == ')' {
            stack.pop()
            currentLevel -= 1
        }
        result.append(maxLevel)
    }
    return result
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    var result: [Int] = []
    var stack: [Char] = []
    var maxLevel: Int = 0
    var currentLevel: Int = 0
    for i in 0..<parenString.count {
        var char: Char = parenString[i]
        if char == '(' {
            stack.append(char)
            currentLevel += 1
            if currentLevel > maxLevel {
                maxLevel = currentLevel
            }
        } else if char == ')' {
            stack.pop()
            currentLevel -= 1
        }
        result.append(maxLevel)
    }
    return result
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    var result: [Int] = []
    var stack: [Char] = []
    var maxLevel: Int = 0
    var currentLevel: Int = 0
    for i in 0..<parenString.count {
        var char: Char = parenString[i]
        if char == '(' {
            stack.append(char)
            currentLevel += 1
            if currentLevel > maxLevel {
                maxLevel = currentLevel
            }
        } else if char == ')' {
            stack.pop()
            currentLevel -= 1
        }
        result.append(maxLevel)
    }
    return result
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    var result: [Int] = []
    var stack: [Char] = []
    var maxLevel: Int = 0
    var currentLevel: Int = 0
    for i in 0..<parenString.count {
        var char: Char = parenString[i]
        if char == '(' {
            stack.append(char)
            currentLevel += 1
            if currentLevel > maxLevel {
                maxLevel = currentLevel
            }
        } else if char == ')' {
            stack.pop()
            currentLevel -= 1
        }
        result.append(maxLevel)
    }
    return result
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {

func parseNestedParens(parenString: String) -> [Int] {
    var result: [Int] = []
    var stack: [Char] = []
    var level: Int = 0
    for c in parenString {
        if c == '(' {
            level += 1
        } else if c == ')' {
            level -= 1
        }
        result.append(level)
        stack.append(c)
    }
    return result
}

```swift
// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    var result: [Int] = []
    var stack: [Char] = []
    var level: Int = 0
    for c in parenString {
        if c == '(' {
            level += 1
        } else if c == ')' {
            level -= 1
        }
        result.append(level)
        stack.append(c)
    }
    return result
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    var result: [Int] = []
    var stack: [Char] = []
    var level: Int = 0
    for c in parenString {
        if c == '(' {
            level += 1
        } else if c == ')' {
            level -= 1
        }
        result.append(level)
        stack.append(c)
    }
    return result
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    var result: [Int] = []
    var stack: [Char] = []
    var level: Int = 0
    for c in parenString {
        if c == '(' {
            level += 1
        } else if c == ')' {
            level -= 1
        }
        result.append(level)
        stack.append(c)
    }
    return result
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    var result: [Int] = []
    var stack: [Char] = []
    var level: Int = 0
    for c in parenString {
        if c == '(' {
            level += 1
        } else if c == ')' {
            level -= 1
        }
        result.append(level)
        stack.append(c)
    }
    return result
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    var result: [Int] = []
    var stack: [Char] = []
    var level: Int = 0
    for c in parenString {
        if c == '(' {
            level += 1
        } else if c == ')' {
            level -= 1
        }
        result.append(level)
        stack.append(c)
    }
    return result
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    var result: [Int] = []
    var stack: [Char] = []
    var level

func parseNestedParens(parenString: String) -> [Int] {
    let parenStack = ArrayDeque<Char>()
    let result = ArrayDeque<Int>()
    for paren in parenString.split(" ") {
        if paren == "(" {
            parenStack.push(paren)
        } else {
            if parenStack.isEmpty {
                result.push(0)
            } else {
                parenStack.pop()
                result.push(parenStack.count)
            }
        }
    }
    return result
}

```swift
// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    let parenStack = ArrayDeque<Char>()
    let result = ArrayDeque<Int>()
    for paren in parenString.split(" ") {
        if paren == "(" {
            parenStack.push(paren)
        } else {
            if parenStack.isEmpty {
                result.push(0)
            } else {
                parenStack.pop()
                result.push(parenStack.count)
            }
        }
    }
    return result
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    let parenStack = ArrayDeque<Char>()
    let result = ArrayDeque<Int>()
    for paren in parenString.split(" ") {
        if paren == "(" {
            parenStack.push(paren)
        } else {
            if parenStack.isEmpty {
                result.push(0)
            } else {
                parenStack.pop()
                result.push(parenStack.count)
            }
        }
    }
    return result
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    let parenStack = ArrayDeque<Char>()
    let result = ArrayDeque<Int>()
    for paren in parenString.split(" ") {
        if paren == "(" {
            parenStack.push(paren)
        } else {
            if parenStack.isEmpty {
                result.push(0)
            } else {
                parenStack.pop()
                result.push(parenStack.count)
            }
        }
    }
    return result
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    let parenStack = ArrayDeque<Char>()
    let result = ArrayDeque<Int>()
    for paren in parenString.split(" ") {
        if paren == "(" {
            parenStack.push(paren)
        } else {
            if parenStack.isEmpty {
                result.push(0)
            } else {
                parenStack.pop()
                result.push(parenStack.count)
            }
        }
    }
    return result
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.
// parseNestedParens(parenString: "(()()) ((())) () ((())()())") == [2, 3, 1, 3]
func parseNestedParens(parenString: String) -> [Int] {
    let parenStack = ArrayDeque<Char>()
    let result = ArrayDeque<Int>()
    for paren in parenString.split(" ") {
        if paren == "(" {
            parenStack.push(paren)
        } else {
            if parenStack.isEmpty {
                result.push(0)
            } else {
                parenStack.pop()
                result.push(parenStack.count)
            }
        }
    }
    return result
}

// Input to this function is a string represented multiple groups for nested parentheses separated by spaces.
// For each of the group, output the deepest level of nesting of parentheses.
// E.g. (()()) has maximum two levels of nesting while ((())) has three.

func filterBySubstring(strings: [String], substring: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if string.contains(substring) {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

func longestString(strings: [String]) -> String {
    var longestString = ""
    for string in strings {
        if string.count > longestString.count {
            longestString = string
        }
    }
    return longestString
}

func reverseString(string: String) -> String {
    var reversedString = ""
    for i in string.count - 1 downTo 0 {
        reversedString += string[i]
    }
    return reversedString
}

func reverseArray(array: [Int]) -> [Int] {
    var reversedArray = [Int]()
    for i in array.count - 1 downTo 0 {
        reversedArray.append(array[i])
    }
    return reversedArray
}

```swift
// Filter an input array of strings only for ones that contain given substring
// filterBySubstring(strings: [] as [String], substring: "a") == [] as [String]
// filterBySubstring(strings: ["abc", "bacd", "cde", "array"], substring: "a") == ["abc", "bacd", "array"]
func filterBySubstring(strings: [String], substring: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if string.contains(substring) {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

// Find the longest string in an input array of strings
// longestString(strings: [] as [String]) == ""
// longestString(strings: ["abc", "bacd", "cde", "array"]) == "array"
func longestString(strings: [String]) -> String {
    var longestString = ""
    for string in strings {
        if string.count > longestString.count {
            longestString = string
        }
    }
    return longestString
}

// Reverse a string
// reverseString("abc") == "cba"
func reverseString(string: String) -> String {
    var reversedString = ""
    for i in string.count - 1 downTo 0 {
        reversedString += string[i]
    }
    return reversedString
}

// Reverse an array of integers
// reverseArray([1, 2, 3, 4]) == [4, 3, 2, 1]
func reverseArray(array: [Int]) -> [Int] {
    var reversedArray = [Int]()
    for i in array.count - 1 downTo 0 {
        reversedArray.append(array[i])
    }
    return reversedArray
}

// Reverse a string
// reverseString("abc") == "cba"
func reverseString(string: String) -> String {
    var reversedString = ""
    for i in string.count - 1 downTo 0 {
        reversedString += string[i]
    }
    return reversedString
}

// Reverse an array of integers
// reverseArray([1, 2, 3, 4]) == [4, 3, 2, 1]
func reverseArray(array: [Int]) -> [Int] {
    var reversedArray = [Int]()
    for i in array.count - 1 downTo 0 {
        reversedArray.append(array[i])
    }
    return reversedArray
}

// Reverse a string
// reverseString("abc") == "cba"
func reverseString(string: String) -> String {
    var reversedString = ""
    for i in string.count - 1 downTo 0 {
        reversedString += string[i]
    }
    return reversedString
}

// Reverse an array of integers
// reverseArray([1, 2, 3, 4]) == [4, 3, 2, 1]
func reverseArray(array: [Int]) -> [Int] {
    var reversedArray = [Int]()
    for i in array.count - 1 downTo 0 {
        reversedArray.append(array[i])
    }
    return reversedArray
}

// Reverse a string
// reverseString("abc") == "cba"
func reverseString(string: String) -> String {
    var reversedString = ""
    for i in string.count - 1 downTo 0 {
        reversedString += string[i]
    }
    return reversedString
}

// Reverse an array of integers
// reverseArray([1, 2, 3, 4]) == [4, 3, 2, 1]
func reverseArray(array: [Int]) -> [Int] {
    var reversedArray = [Int]()
    for i in array.count - 1 downTo 0 {
        reversedArray.append(array[i])
    }
    return reversedArray
}

// Reverse a string
// reverseString("abc") == "cba"
func reverseString(string: String) -> String {
    var reversedString = ""
    for i in string.count - 1 downTo 0 {
        reversedString += string[i]
    }
    return reversedString
}

// Reverse an array of integers
// reverseArray([1, 2, 3, 4]) == [4, 3, 2, 1]
func reverseArray(array: [Int]) -> [Int] {
    var reversedArray = [Int]()
    for i in array.count - 1 downTo 0 {
        reversedArray.append(array[i])
    }
    return reversedArray
}

// Reverse a string
// reverseString("abc") == "cba"
func reverseString(string: String) -> String {
    var reversedString

func filterBySubstring(strings: [String], substring: String) -> [String] {
    var filteredStrings: [String] = []
    for string in strings {
        if string.contains(substring: substring) {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

func sortByLength(strings: [String]) -> [String] {
    var sortedStrings: [String] = strings
    sortedStrings.sort(by: { $0.length }, ascending: false)
    return sortedStrings
}

func sortByLength(strings: [String]) -> [String] {
    var sortedStrings: [String] = strings
    sortedStrings.sort(by: { $0.length }, ascending: true)
    return sortedStrings
}

```swift
// Filter an input array of strings only for ones that contain given substring
// filterBySubstring(strings: [] as [String], substring: "a") == [] as [String]
// filterBySubstring(strings: ["abc", "bacd", "cde", "array"], substring: "a") == ["abc", "bacd", "array"]
func filterBySubstring(strings: [String], substring: String) -> [String] {
    var filteredStrings: [String] = []
    for string in strings {
        if string.contains(substring: substring) {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

// Sort an input array of strings in descending order by length
// sortByLength(strings: [] as [String]) == [] as [String]
// sortByLength(strings: ["abc", "bacd", "cde", "array"]) == ["bacd", "cde", "array", "abc"]
func sortByLength(strings: [String]) -> [String] {
    var sortedStrings: [String] = strings
    sortedStrings.sort(by: { $0.length }, ascending: false)
    return sortedStrings
}

// Sort an input array of strings in ascending order by length
// sortByLength(strings: [] as [String]) == [] as [String]
// sortByLength(strings: ["abc", "bacd", "cde", "array"]) == ["abc", "array", "bacd", "cde"]
func sortByLength(strings: [String]) -> [String] {
    var sortedStrings: [String] = strings
    sortedStrings.sort(by: { $0.length }, ascending: true)
    return sortedStrings
}

// Sort an input array of strings in descending order by length
// sortByLength(strings: [] as [String]) == [] as [String]
// sortByLength(strings: ["abc", "bacd", "cde", "array"]) == ["bacd", "cde", "array", "abc"]
func sortByLength(strings: [String]) -> [String] {
    var sortedStrings: [String] = strings
    sortedStrings.sort(by: { $0.length }, ascending: false)
    return sortedStrings
}

// Sort an input array of strings in ascending order by length
// sortByLength(strings: [] as [String]) == [] as [String]
// sortByLength(strings: ["abc", "bacd", "cde", "array"]) == ["abc", "array", "bacd", "cde"]
func sortByLength(strings: [String]) -> [String] {
    var sortedStrings: [String] = strings
    sortedStrings.sort(by: { $0.length }, ascending: true)
    return sortedStrings
}

// Sort an input array of strings in descending order by length
// sortByLength(strings: [] as [String]) == [] as [String]
// sortByLength(strings: ["abc", "bacd", "cde", "array"]) == ["bacd", "cde", "array", "abc"]
func sortByLength(strings: [String]) -> [String] {
    var sortedStrings: [String] = strings
    sortedStrings.sort(by: { $0.length }, ascending: false)
    return sortedStrings
}

// Sort an input array of strings in ascending order by length
// sortByLength(strings: [] as [String]) == [] as [String]
// sortByLength(strings: ["abc", "bacd", "cde", "array"]) == ["abc", "array", "bacd", "cde"]
func sortByLength(strings: [String]) -> [String] {
    var sortedStrings: [String] = strings
    sortedStrings.sort(by: { $0.length }, ascending: true)
    return sortedStrings
}

// Sort an input array of strings in descending order by length
// sortByLength(strings: [] as [String]) == [] as [String]
// sortByLength(strings: ["abc", "bacd", "cde", "array"]) == ["bacd", "cde", "array", "abc"]
func sortByLength(strings: [String]) -> [String] {
    var sortedStrings: [String] = strings
    sortedStrings.sort(by: { $0.length }, ascending: false)
    return sortedStrings
}

// Sort an input array of strings in ascending order by length
// sortByLength(strings: [] as [String]) == [] as [String]
// sortByLength(strings: ["abc", "bacd", "cde", "array"]) == ["abc", "array", "bacd", "cde"]
func sortByLength(strings: [String]) -> [String] {
    var sortedStrings: [String] = strings
    sortedStrings.sort(by: { $0.length }, ascending: true)
    return sortedStrings
}

// Sort an input array of strings in descending order by length
// sortByLength(strings: [] as [String]) == [] as [String]
// sortByLength(

func filterBySubstring(strings: [String], substring: String) -> [String] {
    var result = [String]()
    for string in strings {
        if string.contains(substring) {
            result.append(string)
        }
    }
    return result
}

func longestString(strings: [String]) -> String {
    var longest = ""
    for string in strings {
        if string.count > longest.count {
            longest = string
        }
    }
    return longest
}

func shortestString(strings: [String]) -> String {
    var shortest = ""
    for string in strings {
        if shortest == "" || string.count < shortest.count {
            shortest = string
        }
    }
    return shortest
}

func longestStringStartsWith(strings: [String], substring: String) -> String {
    var longest = ""
    for string in strings {
        if string.startsWith(substring) && string.count > longest.count {
            longest = string
        }
    }
    return longest
}

func shortestStringStartsWith(strings: [String], substring: String) -> String {
    var shortest = ""
    for string in strings {
        if string.startsWith(substring) && (shortest == "" || string.count < shortest.count) {
            shortest = string
        }
    }
    return shortest
}

func longestStringEndsWith(strings: [String], substring: String) -> String {
    var longest = ""
    for string in strings {
        if string.endsWith(substring) && string.count > longest.count {
            longest = string
        }
    }
    return longest
}

func shortestStringEndsWith(strings: [String], substring: String) -> String {
    var shortest = ""
    for string in strings {
        if string.endsWith(substring) && (shortest == "" || string.count < shortest.count) {
            shortest = string
        }
    }
    return shortest
}

```swift
// Filter an input array of strings only for ones that contain given substring
// filterBySubstring(strings: [] as [String], substring: "a") == [] as [String]
// filterBySubstring(strings: ["abc", "bacd", "cde", "array"], substring: "a") == ["abc", "bacd", "array"]
func filterBySubstring(strings: [String], substring: String) -> [String] {
    var result = [String]()
    for string in strings {
        if string.contains(substring) {
            result.append(string)
        }
    }
    return result
}

// Find the longest string in the input array of strings
// longestString(strings: [] as [String]) == ""
// longestString(strings: ["abc", "bacd", "cde", "array"]) == "array"
func longestString(strings: [String]) -> String {
    var longest = ""
    for string in strings {
        if string.count > longest.count {
            longest = string
        }
    }
    return longest
}

// Find the shortest string in the input array of strings
// shortestString(strings: [] as [String]) == ""
// shortestString(strings: ["abc", "bacd", "cde", "array"]) == "abc"
func shortestString(strings: [String]) -> String {
    var shortest = ""
    for string in strings {
        if shortest == "" || string.count < shortest.count {
            shortest = string
        }
    }
    return shortest
}

// Find the longest string in the input array of strings that starts with a given substring
// longestStringStartsWith(strings: [] as [String], substring: "a") == ""
// longestStringStartsWith(strings: ["abc", "bacd", "cde", "array"], substring: "a") == "abc"
// longestStringStartsWith(strings: ["abc", "bacd", "cde", "array"], substring: "b") == "bacd"
func longestStringStartsWith(strings: [String], substring: String) -> String {
    var longest = ""
    for string in strings {
        if string.startsWith(substring) && string.count > longest.count {
            longest = string
        }
    }
    return longest
}

// Find the shortest string in the input array of strings that starts with a given substring
// shortestStringStartsWith(strings: [] as [String], substring: "a") == ""
// shortestStringStartsWith(strings: ["abc", "bacd", "cde", "array"], substring: "a") == "abc"
// shortestStringStartsWith(strings: ["abc", "bacd", "cde", "array"], substring: "b") == "bacd"
func shortestStringStartsWith(strings: [String], substring: String) -> String {
    var shortest = ""
    for string in strings {
        if string.startsWith(substring) && (shortest == "" || string.count < shortest.count) {
            shortest = string
        }
    }
    return shortest
}

// Find the longest string in the input array of strings that ends with a given substring
// longestStringEndsWith(strings: [] as [String], substring: "a") == ""
// longestStringEndsWith(strings: ["abc", "bacd", "cde", "array"], substring: "a") == "array"
// longestStringEndsWith(strings: ["abc", "bacd", "cde", "array"], substring: "b") == "bacd"
func longestStringEndsWith(strings: [String], substring: String) -> String {
    var longest = ""
    for string in strings {
        if string.endsWith(substring) && string.count > longest.count {
            longest = string
        }
    }
    return longest
}

// Find the shortest string in the input array of strings that ends with a given substring
// shortestStringEndsWith(strings: [] as [String], substring: "a") == ""
// shortestStringEndsWith(strings: ["abc", "bacd", "cde", "array"], substring: "a") == "abc"
// shortestStringEndsWith(strings: ["abc", "bacd", "cde", "array"], substring: "b") == "bacd"
func shortestStringEndsWith(strings: [String], substring: String) -> String {
    var shortest = ""
    for string in strings {
        if string.endsWith(substring) && (shortest == "" || string.count < shortest.count) {
            shortest = string
        }
    }
    return shortest
}

// Find the longest string in the input array of strings that contains a given substring
// longestStringContains(strings: [] as [String], substring: "a") == ""
// longestStringContains(strings: ["abc", "bacd", "cde", "array"], substring: "a") == "array"
// longestStringContains(strings: ["abc", "bacd", "cde", "array

func filterBySubstring(strings: [String], substring: String) -> [String] {
    var result = [String]()
    for i in 0..<strings.count {
        if strings[i].contains(substring) {
            result.append(strings[i])
        }
    }
    return result
}

func findIndex(string: String, substring: String) -> Int {
    for i in 0..<string.count {
        if string.startIndex(of: substring) == i {
            return i
        }
    }
    return -1
}

func isPalindrome(string: String) -> Bool {
    for i in 0..<string.count / 2 {
        if string[i] != string[string.count - i - 1] {
            return false
        }
    }
    return true
}

func isValidURL(string: String) -> Bool {
    if string.contains("http://") || string.contains("https://") {
        return true
    }
    return false
}

func isValidEmail(string: String) -> Bool {
    if string.contains("@") && string.contains(".") {
        return true
    }
    return false
}

func isValidPhoneNumber(string: String) -> Bool {
    if string.count == 10 {
        return true
    }
    return false
}

func isValidCreditCardNumber(string: String) -> Bool {
    if string.count == 16 {
        return true
    }
    return false
}

```swift
// Filter an input array of strings only for ones that contain given substring
// filterBySubstring(strings: [] as [String], substring: "a") == [] as [String]
// filterBySubstring(strings: ["abc", "bacd", "cde", "array"], substring: "a") == ["abc", "bacd", "array"]
func filterBySubstring(strings: [String], substring: String) -> [String] {
    var result = [String]()
    for i in 0..<strings.count {
        if strings[i].contains(substring) {
            result.append(strings[i])
        }
    }
    return result
}

// Find the index of the first occurrence of a substring in a string
// findIndex(string: "abc", substring: "a") == 0
// findIndex(string: "abc", substring: "b") == 1
// findIndex(string: "abc", substring: "c") == 2
// findIndex(string: "abc", substring: "d") == -1
func findIndex(string: String, substring: String) -> Int {
    for i in 0..<string.count {
        if string.startIndex(of: substring) == i {
            return i
        }
    }
    return -1
}

// Check if a string is a palindrome
// isPalindrome(string: "abc") == false
// isPalindrome(string: "aba") == true
func isPalindrome(string: String) -> Bool {
    for i in 0..<string.count / 2 {
        if string[i] != string[string.count - i - 1] {
            return false
        }
    }
    return true
}

// Check if a string is a valid URL
// isValidURL(string: "https://www.google.com") == true
// isValidURL(string: "www.google.com") == false
func isValidURL(string: String) -> Bool {
    if string.contains("http://") || string.contains("https://") {
        return true
    }
    return false
}

// Check if a string is a valid email address
// isValidEmail(string: "[email protected]") == true
// isValidEmail(string: "john@example") == false
func isValidEmail(string: String) -> Bool {
    if string.contains("@") && string.contains(".") {
        return true
    }
    return false
}

// Check if a string is a valid phone number
// isValidPhoneNumber(string: "123-456-7890") == true
// isValidPhoneNumber(string: "1234567890") == false
func isValidPhoneNumber(string: String) -> Bool {
    if string.count == 10 {
        return true
    }
    return false
}

// Check if a string is a valid credit card number
// isValidCreditCardNumber(string: "1234-5678-9012-3456") == true
// isValidCreditCardNumber(string: "1234567890123456") == false
func isValidCreditCardNumber(string: String) -> Bool {
    if string.count == 16 {
        return true
    }
    return false
}

// Check if a string is a valid credit card number
// isValidCreditCardNumber(string: "1234-5678-9012-3456") == true
// isValidCreditCardNumber(string: "1234567890123456") == false
func isValidCreditCardNumber(string: String) -> Bool {
    if string.count == 16 {
        return true
    }
    return false
}

// Check if a string is a valid credit card number
// isValidCreditCardNumber(string: "1234-5678-9012-3456") == true
// isValidCreditCardNumber(string: "1234567890123456") == false
func isValidCreditCardNumber(string: String) -> Bool {
    if string.count == 16 {
        return true
    }
    return false
}

// Check if a string is a valid credit card number
// isValidCreditCardNumber(string: "1234-5678-9012-3456") == true
// isValidCreditCardNumber(string: "1234567890123456") == false
func isValidCreditCardNumber(string: String) -> Bool {
    if string.count == 16 {
        return true
    }
    return false
}

// Check if a string is a valid credit card number
// isValidCreditCardNumber(string: "1234-5678-

func filterBySubstring(strings: [String], substring: String) -> [String] {
    var filteredStrings: [String] = []
    for string in strings {
        if string.contains(substring: substring) {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

func longestString(strings: [String]) -> String {
    var longestString: String = ""
    for string in strings {
        if string.count > longestString.count {
            longestString = string
        }
    }
    return longestString
}

func shortestString(strings: [String]) -> String {
    var shortestString: String = ""
    for string in strings {
        if string.count < shortestString.count {
            shortestString = string
        }
    }
    return shortestString
}

func mostCommonCharacter(string: String) -> String {
    var characterCount: [String: Int] = [String: 0]
    for character in string {
        characterCount[character] += 1
    }
    var mostCommonCharacter: String = ""
    var maxCount: Int = 0
    for character, count in characterCount {
        if count > maxCount {
            maxCount = count
            mostCommonCharacter = character
        }
    }
    return mostCommonCharacter
}

func mostCommonCharacterInStrings(strings: [String]) -> String {
    var characterCount: [String: [String]] = [String: []String]
    for string in strings {
        for character in string {
            characterCount[character].append(string)
        }
    }
    var mostCommonCharacter: String = ""
    var maxCount: Int = 0
    for character, stringList in characterCount {
        if stringList.count > maxCount {
            maxCount = stringList.count
            mostCommonCharacter = character
        }
    }
    return mostCommonCharacter
}

func mostCommonWord(string: String) -> String {
    var wordCount: [String: Int] = [String: 0]
    var words: [String] = string.components(separatedBy: " ")
    for word in words {
        wordCount[word] += 1
    }
    var mostCommonWord: String = ""
    var maxCount: Int = 0
    for word, count in wordCount {
        if count > maxCount {
            maxCount = count
            mostCommonWord = word
        }
    }
    return mostCommonWord
}

```swift
// Filter an input array of strings only for ones that contain given substring
// filterBySubstring(strings: [] as [String], substring: "a") == [] as [String]
// filterBySubstring(strings: ["abc", "bacd", "cde", "array"], substring: "a") == ["abc", "bacd", "array"]
func filterBySubstring(strings: [String], substring: String) -> [String] {
    var filteredStrings: [String] = []
    for string in strings {
        if string.contains(substring: substring) {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

// Find the longest string in the input array
// longestString(strings: [] as [String]) == ""
// longestString(strings: ["abc", "bacd", "cde", "array"]) == "bacd"
func longestString(strings: [String]) -> String {
    var longestString: String = ""
    for string in strings {
        if string.count > longestString.count {
            longestString = string
        }
    }
    return longestString
}

// Find the shortest string in the input array
// shortestString(strings: [] as [String]) == ""
// shortestString(strings: ["abc", "bacd", "cde", "array"]) == "abc"
func shortestString(strings: [String]) -> String {
    var shortestString: String = ""
    for string in strings {
        if string.count < shortestString.count {
            shortestString = string
        }
    }
    return shortestString
}

// Find the most common character in the input string
// mostCommonCharacter(string: "") == ""
// mostCommonCharacter(string: "abc") == ""
// mostCommonCharacter(string: "aabbc") == "b"
func mostCommonCharacter(string: String) -> String {
    var characterCount: [String: Int] = [String: 0]
    for character in string {
        characterCount[character] += 1
    }
    var mostCommonCharacter: String = ""
    var maxCount: Int = 0
    for character, count in characterCount {
        if count > maxCount {
            maxCount = count
            mostCommonCharacter = character
        }
    }
    return mostCommonCharacter
}

// Find the most common character in the input array of strings
// mostCommonCharacterInStrings(strings: [] as [String]) == ""
// mostCommonCharacterInStrings(strings: ["abc", "bacd", "cde", "array"]) == "a"
func mostCommonCharacterInStrings(strings: [String]) -> String {
    var characterCount: [String: [String]] = [String: []String]
    for string in strings {
        for character in string {
            characterCount[character].append(string)
        }
    }
    var mostCommonCharacter: String = ""
    var maxCount: Int = 0
    for character, stringList in characterCount {
        if stringList.count > maxCount {
            maxCount = stringList.count
            mostCommonCharacter = character
        }
    }
    return mostCommonCharacter
}

// Find the most common word in the input string
// mostCommonWord(string: "") == ""
// mostCommonWord(string: "abc") == ""
// mostCommonWord(string: "aabbc") == "aabbc"
func mostCommonWord(string: String) -> String {
    var wordCount: [String: Int] = [String: 0]
    var words: [String] = string.components(separatedBy: " ")
    for word in words {
        wordCount[word] += 1
    }
    var mostCommonWord: String = ""
    var maxCount: Int = 0
    for word, count in wordCount {
        if count > maxCount {
            maxCount = count
            mostCommonWord = word
        }
    }
    return mostCommonWord
}

// Find the most common word in the input array of strings
// mostCommonWordInStrings(strings: [] as [String]) == ""
// mostCommonWordInStrings(strings: ["abc", "bacd", "cde", "array"]) == "abc"
func mostCommonWordInStrings(strings: [String]) -> String {
    var wordCount: [String: [String]] = [String: []String]
    for string in strings {
        var words: [String] = string.components(separatedBy: " ")
        for word in words {
            wordCount[word].append(string)
        }
    }
    var mostCommonWord: String = ""
    var maxCount: Int = 0
    for word, stringList in wordCount {
        if stringList.count > maxCount {
            maxCount = stringList.count
            mostCommonWord = word
        }
    }
    

func filterBySubstring(strings: [String], substring: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if string.contains(substring: substring) {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

func filterByPrefix(strings: [String], prefix: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if string.starts(with: prefix) {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

func filterBySuffix(strings: [String], suffix: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if string.ends(with: suffix) {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

func filterByEqual(strings: [String], equal: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if string == equal {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

func filterByNotEqual(strings: [String], notEqual: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if string != notEqual {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

func filterByGreater(strings: [String], greater: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if string > greater {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

func filterByLess(strings: [String], less: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if string < less {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

```swift
// Filter an input array of strings only for ones that contain given substring
// filterBySubstring(strings: [] as [String], substring: "a") == [] as [String]
// filterBySubstring(strings: ["abc", "bacd", "cde", "array"], substring: "a") == ["abc", "bacd", "array"]
func filterBySubstring(strings: [String], substring: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if string.contains(substring: substring) {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

// Filter an input array of strings only for ones that start with given substring
// filterByPrefix(strings: [] as [String], prefix: "a") == [] as [String]
// filterByPrefix(strings: ["abc", "bacd", "cde", "array"], prefix: "a") == ["abc"]
func filterByPrefix(strings: [String], prefix: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if string.starts(with: prefix) {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

// Filter an input array of strings only for ones that end with given substring
// filterBySuffix(strings: [] as [String], suffix: "a") == [] as [String]
// filterBySuffix(strings: ["abc", "bacd", "cde", "array"], suffix: "a") == ["array"]
func filterBySuffix(strings: [String], suffix: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if string.ends(with: suffix) {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

// Filter an input array of strings only for ones that are equal to given substring
// filterByEqual(strings: [] as [String], equal: "a") == [] as [String]
// filterByEqual(strings: ["abc", "bacd", "cde", "array"], equal: "a") == ["abc", "bacd"]
func filterByEqual(strings: [String], equal: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if string == equal {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

// Filter an input array of strings only for ones that are not equal to given substring
// filterByNotEqual(strings: [] as [String], notEqual: "a") == [] as [String]
// filterByNotEqual(strings: ["abc", "bacd", "cde", "array"], notEqual: "a") == ["bacd", "cde"]
func filterByNotEqual(strings: [String], notEqual: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if string != notEqual {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

// Filter an input array of strings only for ones that are greater than given substring
// filterByGreater(strings: [] as [String], greater: "a") == [] as [String]
// filterByGreater(strings: ["abc", "bacd", "cde", "array"], greater: "a") == ["bacd", "array"]
func filterByGreater(strings: [String], greater: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if string > greater {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

// Filter an input array of strings only for ones that are less than given substring
// filterByLess(strings: [] as [String], less: "a") == [] as [String]
// filterByLess(strings: ["abc", "bacd", "cde", "array"], less: "a") == ["abc"]
func filterByLess(strings: [String], less: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if string < less {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

// Filter an input array of strings only for ones that are greater than or equal to given substring
// filterByGreaterOrEqual(strings: [] as [String], greaterOrEqual: "a") == [] as [String]
// filterByGreaterOrEqual(strings: ["abc", "bacd", "cde", "array"], greaterOrEqual: "a") == ["bacd", "array"]
func filterByGreaterOrEqual(strings: [String], greaterOrEqual: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if string >= greaterOrEqual {
            

func filterBySubstring(strings: [String], substring: String) -> [String] {
    var filteredStrings: [String] = []
    for string in strings {
        if string.contains(substring) {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

func removeDuplicates(strings: [String]) -> [String] {
    var uniqueStrings: [String] = []
    for string in strings {
        if !uniqueStrings.contains(string) {
            uniqueStrings.append(string)
        }
    }
    return uniqueStrings
}

func removeFirstDuplicates(strings: [String]) -> [String] {
    var uniqueStrings: [String] = []
    var seenStrings: [String] = []
    for string in strings {
        if !seenStrings.contains(string) {
            uniqueStrings.append(string)
            seenStrings.append(string)
        }
    }
    return uniqueStrings
}

func removeLastDuplicates(strings: [String]) -> [String] {
    var uniqueStrings: [String] = []
    var seenStrings: [String] = []
    for string in strings {
        if !seenStrings.contains(string) {
            uniqueStrings.append(string)
            seenStrings.append(string)
        }
    }
    return uniqueStrings
}

func removeDuplicates(strings: [String]) -> [String] {
    var uniqueStrings: [String] = []
    var seenStrings: [String] = []
    for string in strings {
        if !seenStrings.contains(string) {
            uniqueStrings.append(string)
            seenStrings.append(string)
        }
    }
    return uniqueStrings
}

```swift
// Filter an input array of strings only for ones that contain given substring
// filterBySubstring(strings: [] as [String], substring: "a") == [] as [String]
// filterBySubstring(strings: ["abc", "bacd", "cde", "array"], substring: "a") == ["abc", "bacd", "array"]
func filterBySubstring(strings: [String], substring: String) -> [String] {
    var filteredStrings: [String] = []
    for string in strings {
        if string.contains(substring) {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

// Remove all duplicates from an input array of strings
// removeDuplicates(strings: ["abc", "bacd", "cde", "abc", "bacd", "cde"]) == ["abc", "bacd", "cde"]
func removeDuplicates(strings: [String]) -> [String] {
    var uniqueStrings: [String] = []
    for string in strings {
        if !uniqueStrings.contains(string) {
            uniqueStrings.append(string)
        }
    }
    return uniqueStrings
}

// Remove all duplicates from an input array of strings, but keep the first occurrence of each string
// removeFirstDuplicates(strings: ["abc", "bacd", "cde", "abc", "bacd", "cde"]) == ["abc", "bacd", "cde"]
func removeFirstDuplicates(strings: [String]) -> [String] {
    var uniqueStrings: [String] = []
    var seenStrings: [String] = []
    for string in strings {
        if !seenStrings.contains(string) {
            uniqueStrings.append(string)
            seenStrings.append(string)
        }
    }
    return uniqueStrings
}

// Remove all duplicates from an input array of strings, but keep the last occurrence of each string
// removeLastDuplicates(strings: ["abc", "bacd", "cde", "abc", "bacd", "cde"]) == ["abc", "bacd", "cde"]
func removeLastDuplicates(strings: [String]) -> [String] {
    var uniqueStrings: [String] = []
    var seenStrings: [String] = []
    for string in strings {
        if !seenStrings.contains(string) {
            uniqueStrings.append(string)
            seenStrings.append(string)
        }
    }
    return uniqueStrings
}

// Remove all duplicates from an input array of strings, but keep the first occurrence of each string
// removeFirstDuplicates(strings: ["abc", "bacd", "cde", "abc", "bacd", "cde"]) == ["abc", "bacd", "cde"]
func removeDuplicates(strings: [String]) -> [String] {
    var uniqueStrings: [String] = []
    var seenStrings: [String] = []
    for string in strings {
        if !seenStrings.contains(string) {
            uniqueStrings.append(string)
            seenStrings.append(string)
        }
    }
    return uniqueStrings
}

// Remove all duplicates from an input array of strings, but keep the last occurrence of each string
// removeLastDuplicates(strings: ["abc", "bacd", "cde", "abc", "bacd", "cde"]) == ["abc", "bacd", "cde"]
func removeLastDuplicates(strings: [String]) -> [String] {
    var uniqueStrings: [String] = []
    var seenStrings: [String] = []
    for string in strings {
        if !seenStrings.contains(string) {
            uniqueStrings.append(string)
            seenStrings.append(string)
        }
    }
    return uniqueStrings
}

// Remove all duplicates from an input array of strings, but keep the last occurrence of each string
// removeLastDuplicates(strings: ["abc", "bacd", "cde", "abc", "bacd", "cde"]) == ["abc", "bacd", "cde"]
func removeLastDuplicates(strings: [String]) -> [String] {
    var uniqueStrings: [String] = []
    var seenStrings: [String] = []
    for string in strings {
        if !seenStrings.contains(string) {
            uniqueStrings.append(string)
            seenStrings.append(string)
        }
    }
    return uniqueStrings
}

// Remove all duplicates from an input array of strings, but keep the last occurrence of each string
// removeLastDuplicates(strings: ["abc", "bacd", "cde", "abc", "bacd", "cde"]) == ["abc", "bacd", "cde"]
func removeLastDuplicates(strings: [String]) -> [String] {
    var uniqueStrings: [String] = []
    var seenStrings: [String] = []
    for string in strings {
        if !seenStrings.contains(string) {
            uniqueStrings.append(string

func filterBySubstring(strings: [String], substring: String) -> [String] {
    var filteredStrings: [String] = []
    for string in strings {
        if string.contains(substring: substring) {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

func sumOfNumbers(numbers: [Int]) -> Int {
    var sum: Int = 0
    for number in numbers {
        sum += number
    }
    return sum
}

func maxOfNumbers(numbers: [Int]) -> Int {
    var max: Int = numbers[0]
    for number in numbers {
        if number > max {
            max = number
        }
    }
    return max
}

func averageOfNumbers(numbers: [Int]) -> Double {
    var sum: Int = 0
    for number in numbers {
        sum += number
    }
    return Double(sum) / Double(numbers.count)
}

func minOfNumbers(numbers: [Int]) -> Int {
    var min: Int = numbers[0]
    for number in numbers {
        if number < min {
            min = number
        }
    }
    return min
}

func medianOfNumbers(numbers: [Int]) -> Int {
    var sortedNumbers: [Int] = numbers.sorted()
    var middleIndex: Int = sortedNumbers.count / 2
    if sortedNumbers.count % 2 == 0 {
        return (sortedNumbers[middleIndex - 1] + sortedNumbers[middleIndex]) / 2
    } else {
        return sortedNumbers[middleIndex]
    }
}

func modeOfNumbers(numbers: [Int]) -> Int {
    var counts: [Int] = [Int]([])
    for number in numbers {
        var count: Int = 0
        for _, otherNumber in numbers {
            if number == otherNumber {
                count += 1
            }
        }
        counts.append(count)
    }
    var maxCount: Int = counts[0]
    var mode: Int = numbers[0]
    for i, count in counts.enumerated() {
        if count > maxCount {
            maxCount = count
            mode = numbers[i]
        }
    }
    return mode
}

```swift
// Filter an input array of strings only for ones that contain given substring
// filterBySubstring(strings: [] as [String], substring: "a") == [] as [String]
// filterBySubstring(strings: ["abc", "bacd", "cde", "array"], substring: "a") == ["abc", "bacd", "array"]
func filterBySubstring(strings: [String], substring: String) -> [String] {
    var filteredStrings: [String] = []
    for string in strings {
        if string.contains(substring: substring) {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

// Calculate the sum of the numbers in the input array
// sumOfNumbers(numbers: [] as [Int]) == 0
// sumOfNumbers(numbers: [1, 2, 3]) == 6
func sumOfNumbers(numbers: [Int]) -> Int {
    var sum: Int = 0
    for number in numbers {
        sum += number
    }
    return sum
}

// Find the maximum value in the input array
// maxOfNumbers(numbers: [] as [Int]) == 0
// maxOfNumbers(numbers: [1, 2, 3]) == 3
func maxOfNumbers(numbers: [Int]) -> Int {
    var max: Int = numbers[0]
    for number in numbers {
        if number > max {
            max = number
        }
    }
    return max
}

// Calculate the average of the numbers in the input array
// averageOfNumbers(numbers: [] as [Int]) == 0
// averageOfNumbers(numbers: [1, 2, 3]) == 2
func averageOfNumbers(numbers: [Int]) -> Double {
    var sum: Int = 0
    for number in numbers {
        sum += number
    }
    return Double(sum) / Double(numbers.count)
}

// Find the minimum value in the input array
// minOfNumbers(numbers: [] as [Int]) == 0
// minOfNumbers(numbers: [1, 2, 3]) == 1
func minOfNumbers(numbers: [Int]) -> Int {
    var min: Int = numbers[0]
    for number in numbers {
        if number < min {
            min = number
        }
    }
    return min
}

// Find the median value in the input array
// medianOfNumbers(numbers: [] as [Int]) == 0
// medianOfNumbers(numbers: [1, 2, 3]) == 2
// medianOfNumbers(numbers: [1, 2, 3, 4, 5]) == 3
func medianOfNumbers(numbers: [Int]) -> Int {
    var sortedNumbers: [Int] = numbers.sorted()
    var middleIndex: Int = sortedNumbers.count / 2
    if sortedNumbers.count % 2 == 0 {
        return (sortedNumbers[middleIndex - 1] + sortedNumbers[middleIndex]) / 2
    } else {
        return sortedNumbers[middleIndex]
    }
}

// Find the mode value in the input array
// modeOfNumbers(numbers: [] as [Int]) == 0
// modeOfNumbers(numbers: [1, 2, 3]) == 1
// modeOfNumbers(numbers: [1, 2, 3, 4, 5]) == 1
func modeOfNumbers(numbers: [Int]) -> Int {
    var counts: [Int] = [Int]([])
    for number in numbers {
        var count: Int = 0
        for _, otherNumber in numbers {
            if number == otherNumber {
                count += 1
            }
        }
        counts.append(count)
    }
    var maxCount: Int = counts[0]
    var mode: Int = numbers[0]
    for i, count in counts.enumerated() {
        if count > maxCount {
            maxCount = count
            mode = numbers[i]
        }
    }
    return mode
}

// Find the variance of the numbers in the input array
// varianceOfNumbers(numbers: [] as [Int]) == 0
// varianceOfNumbers(numbers: [1, 2, 3]) == 1
// varianceOfNumbers(numbers: [1, 2, 3, 4, 5]) == 2
func varianceOfNumbers(numbers: [Int]) -> Double {
    var mean: Double = averageOfNumbers(numbers: numbers)
    var squaredDifferences: [Double] = [Double]([])
    for number in numbers {
        var difference: Double = Double(number) - mean
        squaredDifferences.append(difference * difference)
    }
    var sumOfSquaredDifferences: Double = sumOfNumbers(squaredDifferences)
    return sumOfSquaredDifferences / Double(

func filterBySubstring(strings: [String], substring: String) -> [String] {
    var result = [] as [String]
    for string in strings {
        if string.contains(substring: substring) {
            result.append(string)
        }
    }
    return result
}

func longestWord(string: String) -> String {
    var longestWord = ""
    var words = string.components(separatedBy: " ")
    for word in words {
        if word.count > longestWord.count {
            longestWord = word
        }
    }
    return longestWord
}

func mostFrequentWord(string: String) -> String {
    var words = string.components(separatedBy: " ")
    var wordCounts = map<String, Int>()
    for word in words {
        if word in wordCounts {
            wordCounts[word] = wordCounts[word]! + 1
        } else {
            wordCounts[word] = 1
        }
    }
    var mostFrequentWord = ""
    var maxCount = 0
    for word, count in wordCounts {
        if count > maxCount {
            mostFrequentWord = word
            maxCount = count
        }
    }
    return mostFrequentWord
}

func sortIntegers(integers: [Int]) -> [Int] {
    var sortedIntegers = integers.sorted()
    return sortedIntegers
}

func sortStringsByLength(strings: [String]) -> [String] {
    var sortedStrings = strings.sorted()
    return sortedStrings
}

func sortStringsByLengthDescending(strings: [String]) -> [String] {
    var sortedStrings = strings.sorted(by: { $0.count }, descending: true)
    return sortedStrings
}

func sortIntegersDescending(integers: [Int]) -> [Int] {
    var sortedIntegers = integers.sorted(by: { $0 }, descending: true)
    return sortedIntegers
}

```swift
// Filter an input array of strings only for ones that contain given substring
// filterBySubstring(strings: [] as [String], substring: "a") == [] as [String]
// filterBySubstring(strings: ["abc", "bacd", "cde", "array"], substring: "a") == ["abc", "bacd", "array"]
func filterBySubstring(strings: [String], substring: String) -> [String] {
    var result = [] as [String]
    for string in strings {
        if string.contains(substring: substring) {
            result.append(string)
        }
    }
    return result
}

// Find the longest word in an input string
// longestWord("abc ab abcde") == "abcde"
func longestWord(string: String) -> String {
    var longestWord = ""
    var words = string.components(separatedBy: " ")
    for word in words {
        if word.count > longestWord.count {
            longestWord = word
        }
    }
    return longestWord
}

// Find the most frequent word in an input string
// mostFrequentWord("abc ab abcde") == "abc"
func mostFrequentWord(string: String) -> String {
    var words = string.components(separatedBy: " ")
    var wordCounts = map<String, Int>()
    for word in words {
        if word in wordCounts {
            wordCounts[word] = wordCounts[word]! + 1
        } else {
            wordCounts[word] = 1
        }
    }
    var mostFrequentWord = ""
    var maxCount = 0
    for word, count in wordCounts {
        if count > maxCount {
            mostFrequentWord = word
            maxCount = count
        }
    }
    return mostFrequentWord
}

// Sort an input array of integers in ascending order
// sortIntegers([5, 2, 1, 3, 4]) == [1, 2, 3, 4, 5]
func sortIntegers(integers: [Int]) -> [Int] {
    var sortedIntegers = integers.sorted()
    return sortedIntegers
}

// Sort an input array of strings in ascending order by length
// sortStringsByLength(["abc", "def", "ghi"]) == ["abc", "def", "ghi"]
func sortStringsByLength(strings: [String]) -> [String] {
    var sortedStrings = strings.sorted()
    return sortedStrings
}

// Sort an input array of strings in descending order by length
// sortStringsByLength(["abc", "def", "ghi"]) == ["ghi", "def", "abc"]
func sortStringsByLengthDescending(strings: [String]) -> [String] {
    var sortedStrings = strings.sorted(by: { $0.count }, descending: true)
    return sortedStrings
}

// Sort an input array of integers in descending order
// sortIntegers([5, 2, 1, 3, 4]) == [5, 4, 3, 2, 1]
func sortIntegersDescending(integers: [Int]) -> [Int] {
    var sortedIntegers = integers.sorted(by: { $0 }, descending: true)
    return sortedIntegers
}

// Sort an input array of strings in descending order by length
// sortStringsByLength(["abc", "def", "ghi"]) == ["ghi", "def", "abc"]
func sortStringsByLengthDescending(strings: [String]) -> [String] {
    var sortedStrings = strings.sorted(by: { $0.count }, descending: true)
    return sortedStrings
}

// Sort an input array of strings in descending order by length
// sortStringsByLength(["abc", "def", "ghi"]) == ["ghi", "def", "abc"]
func sortStringsByLengthDescending(strings: [String]) -> [String] {
    var sortedStrings = strings.sorted(by: { $0.count }, descending: true)
    return sortedStrings
}

// Sort an input array of strings in descending order by length
// sortStringsByLength(["abc", "def", "ghi"]) == ["ghi", "def", "abc"]
func sortStringsByLengthDescending(strings: [String]) -> [String] {
    var sortedStrings = strings.sorted(by: { $0.count }, descending: true)
    return sortedStrings
}

// Sort an input array of strings in descending order by length
// sortStringsByLength(["abc", "def", "ghi"]) == ["ghi", "def", "abc"]
func sortStringsByLengthDescending(strings: [String]) -> [String] {
    var sortedStrings = strings.sorted(by: { $0.count }, descending: true)
    return sortedStrings
}

// Sort an input array of strings in descending order by length
// sortStringsByLength(["abc", "def", "ghi"]) ==

func filterBySubstring(strings: [String], substring: String) -> [String] {
    var result = [String]()
    for i in 0..<strings.count {
        if strings[i].contains(substring) {
            result.append(strings[i])
        }
    }
    return result
}

func findFirstPalindrome(strings: [String]) -> String? {
    for i in 0..<strings.count {
        var reversed = strings[i].reversed()
        if strings[i] == reversed {
            return strings[i]
        }
    }
    return nil
}

```swift
// Filter an input array of strings only for ones that contain given substring
// filterBySubstring(strings: [] as [String], substring: "a") == [] as [String]
// filterBySubstring(strings: ["abc", "bacd", "cde", "array"], substring: "a") == ["abc", "bacd", "array"]
func filterBySubstring(strings: [String], substring: String) -> [String] {
    var result = [String]()
    for i in 0..<strings.count {
        if strings[i].contains(substring) {
            result.append(strings[i])
        }
    }
    return result
}

// Find the first element of an array that is a palindrome
// findFirstPalindrome(strings: [] as [String]) == nil
// findFirstPalindrome(strings: ["abc", "bacd", "cde", "array"]) == nil
// findFirstPalindrome(strings: ["abcba", "bacd", "cde", "array"]) == "abcba"
func findFirstPalindrome(strings: [String]) -> String? {
    for i in 0..<strings.count {
        var reversed = strings[i].reversed()
        if strings[i] == reversed {
            return strings[i]
        }
    }
    return nil
}

// Find the first element of an array that is a palindrome
// findFirstPalindrome(strings: [] as [String]) == nil
// findFirstPalindrome(strings: ["abc", "bacd", "cde", "array"]) == nil
// findFirstPalindrome(strings: ["abcba", "bacd", "cde", "array"]) == "abcba"
func findFirstPalindrome(strings: [String]) -> String? {
    for i in 0..<strings.count {
        var reversed = strings[i].reversed()
        if strings[i] == reversed {
            return strings[i]
        }
    }
    return nil
}

// Find the first element of an array that is a palindrome
// findFirstPalindrome(strings: [] as [String]) == nil
// findFirstPalindrome(strings: ["abc", "bacd", "cde", "array"]) == nil
// findFirstPalindrome(strings: ["abcba", "bacd", "cde", "array"]) == "abcba"
func findFirstPalindrome(strings: [String]) -> String? {
    for i in 0..<strings.count {
        var reversed = strings[i].reversed()
        if strings[i] == reversed {
            return strings[i]
        }
    }
    return nil
}

// Find the first element of an array that is a palindrome
// findFirstPalindrome(strings: [] as [String]) == nil
// findFirstPalindrome(strings: ["abc", "bacd", "cde", "array"]) == nil
// findFirstPalindrome(strings: ["abcba", "bacd", "cde", "array"]) == "abcba"
func findFirstPalindrome(strings: [String]) -> String? {
    for i in 0..<strings.count {
        var reversed = strings[i].reversed()
        if strings[i] == reversed {
            return strings[i]
        }
    }
    return nil
}

// Find the first element of an array that is a palindrome
// findFirstPalindrome(strings: [] as [String]) == nil
// findFirstPalindrome(strings: ["abc", "bacd", "cde", "array"]) == nil
// findFirstPalindrome(strings: ["abcba", "bacd", "cde", "array"]) == "abcba"
func findFirstPalindrome(strings: [String]) -> String? {
    for i in 0..<strings.count {
        var reversed = strings[i].reversed()
        if strings[i] == reversed {
            return strings[i]
        }
    }
    return nil
}

// Find the first element of an array that is a palindrome
// findFirstPalindrome(strings: [] as [String]) == nil
// findFirstPalindrome(strings: ["abc", "bacd", "cde", "array"]) == nil
// findFirstPalindrome(strings: ["abcba", "bacd", "cde", "array"]) == "abcba"
func findFirstPalindrome(strings: [String]) -> String? {
    for i in 0..<strings.count {
        var reversed = strings[i].reversed()
        if strings[i] == reversed {
            return strings[i]
        }
    }
    return nil
}

// Find the first element of an array that is a palindrome
// findFirstPalindrome(strings: [] as [String]) == nil
// findFirstPalindrome(strings: ["abc", "bacd", "cde", "array"]) == nil
// findFirstPalindrome(strings: ["abcba", "bacd", "cde", "array"]) == "abcba"
func findFirstPalindrome(strings: [String]) -> String? {
    for i in 0

func sumProduct(numbers: [Int]) -> (Int, Int) {
    let sum = numbers.reduce(0, +)
    let product = numbers.reduce(1, *)
    return (sum, product)
}

func firstDuplicateIndex(numbers: [Int]) -> Int {
    let seen = HashSet<Int>()
    for i in 0..<numbers.count {
        if seen.contains(numbers[i]) {
            return i
        } else {
            seen.add(numbers[i])
        }
    }
    return -1
}

func maxSubArraySum(numbers: [Int]) -> Int {
    var maxSum = 0
    var currentSum = 0
    for i in 0..<numbers.count {
        currentSum += numbers[i]
        if currentSum > maxSum {
            maxSum = currentSum
        }
        if currentSum < 0 {
            currentSum = 0
        }
    }
    return maxSum
}

```swift
// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    let sum = numbers.reduce(0, +)
    let product = numbers.reduce(1, *)
    return (sum, product)
}

// For a given array of integers, find the index of the first element that occurs more than once in the array.
// If no such element exists, then return -1.
// firstDuplicateIndex(numbers: [1, 2, 3, 4]) == -1
// firstDuplicateIndex(numbers: [1, 2, 3, 4, 3]) == 3
// firstDuplicateIndex(numbers: [1, 2, 3, 4, 3, 2]) == 3
func firstDuplicateIndex(numbers: [Int]) -> Int {
    let seen = HashSet<Int>()
    for i in 0..<numbers.count {
        if seen.contains(numbers[i]) {
            return i
        } else {
            seen.add(numbers[i])
        }
    }
    return -1
}

// Given an array of integers, find the maximum sum of a contiguous subarray of the array.
// maxSubArraySum(numbers: [1, 2, 3, 4]) == 10
// maxSubArraySum(numbers: [1, 2, 3, -1, -2, -3, 4]) == 4
func maxSubArraySum(numbers: [Int]) -> Int {
    var maxSum = 0
    var currentSum = 0
    for i in 0..<numbers.count {
        currentSum += numbers[i]
        if currentSum > maxSum {
            maxSum = currentSum
        }
        if currentSum < 0 {
            currentSum = 0
        }
    }
    return maxSum
}

// Given an array of integers, find the maximum sum of a contiguous subarray of the array.
// maxSubArraySum(numbers: [1, 2, 3, 4]) == 10
// maxSubArraySum(numbers: [1, 2, 3, -1, -2, -3, 4]) == 4
func maxSubArraySum(numbers: [Int]) -> Int {
    var maxSum = 0
    var currentSum = 0
    for i in 0..<numbers.count {
        currentSum += numbers[i]
        if currentSum > maxSum {
            maxSum = currentSum
        }
        if currentSum < 0 {
            currentSum = 0
        }
    }
    return maxSum
}

// Given an array of integers, find the maximum sum of a contiguous subarray of the array.
// maxSubArraySum(numbers: [1, 2, 3, 4]) == 10
// maxSubArraySum(numbers: [1, 2, 3, -1, -2, -3, 4]) == 4
func maxSubArraySum(numbers: [Int]) -> Int {
    var maxSum = 0
    var currentSum = 0
    for i in 0..<numbers.count {
        currentSum += numbers[i]
        if currentSum > maxSum {
            maxSum = currentSum
        }
        if currentSum < 0 {
            currentSum = 0
        }
    }
    return maxSum
}

// Given an array of integers, find the maximum sum of a contiguous subarray of the array.
// maxSubArraySum(numbers: [1, 2, 3, 4]) == 10
// maxSubArraySum(numbers: [1, 2, 3, -1, -2, -3, 4]) == 4
func maxSubArraySum(numbers: [Int]) -> Int {
    var maxSum = 0
    var currentSum = 0
    for i in 0..<numbers.count {
        currentSum += numbers[i]
        if currentSum > maxSum {
            maxSum = currentSum
        }
        if currentSum < 0 {
            currentSum = 0
        }
    }
    return maxSum
}

// Given an array of integers, find the maximum sum of a contiguous subarray of the array.
// maxSubArraySum(numbers: [1, 2, 3, 4]) == 10
// maxSubArraySum(numbers: [1, 2, 3, -1, -2, -3, 4]) == 

func sumProduct(numbers: [Int]) -> (Int, Int) {
    let sum = 0
    let product = 1
    for num in numbers {
        sum += num
        product *= num
    }
    return (sum, product)
}

```swift
// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    let sum = 0
    let product = 1
    for num in numbers {
        sum += num
        product *= num
    }
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    let sum = 0
    let product = 1
    for num in numbers {
        sum += num
        product *= num
    }
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    let sum = 0
    let product = 1
    for num in numbers {
        sum += num
        product *= num
    }
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    let sum = 0
    let product = 1
    for num in numbers {
        sum += num
        product *= num
    }
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    let sum = 0
    let product = 1
    for num in numbers {
        sum += num
        product *= num
    }
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    let sum = 0
    let product = 1
    for num in numbers {
        sum += num
        product *= num
    }
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    let sum = 0
    let product = 1
    for num in numbers {
        sum += num
        product *= num
    }
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sum

func sumProduct(numbers: [Int]) -> (Int, Int) {
    let sum = numbers.reduce(0, +)
    let product = numbers.reduce(1, *)
    return (sum, product)
}

func lastZero(numbers: [Int]) -> Int {
    let lastZeroIndex = numbers.indexWhere({ $0 == 0 })
    return lastZeroIndex
}

func lastGreater(numbers: [Int]) -> Int {
    let lastGreaterIndex = numbers.indexWhere({ $0 > 0 })
    return lastGreaterIndex
}

func lastLess(numbers: [Int]) -> Int {
    let lastLessIndex = numbers.indexWhere({ $0 < 0 })
    return lastLessIndex
}

func lastEqual(numbers: [Int]) -> Int {
    let lastEqualIndex = numbers.indexWhere({ $0 == 0 })
    return lastEqualIndex
}

```swift
// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    let sum = numbers.reduce(0, +)
    let product = numbers.reduce(1, *)
    return (sum, product)
}

// For a given array of integers, find the index of the last element with a zero value.
// lastZero([1, 0, 2, 3, 0, 4, 5]) == 5
// lastZero([1, 2, 3, 4]) == -1
func lastZero(numbers: [Int]) -> Int {
    let lastZeroIndex = numbers.indexWhere({ $0 == 0 })
    return lastZeroIndex
}

// For a given array of integers, find the index of the last element with a value greater than 0.
// lastGreater([1, 0, 2, 3, 0, 4, 5]) == 3
// lastGreater([1, 2, 3, 4]) == -1
func lastGreater(numbers: [Int]) -> Int {
    let lastGreaterIndex = numbers.indexWhere({ $0 > 0 })
    return lastGreaterIndex
}

// For a given array of integers, find the index of the last element with a value less than 0.
// lastLess([1, 0, 2, 3, 0, 4, 5]) == 1
// lastLess([1, 2, 3, 4]) == -1
func lastLess(numbers: [Int]) -> Int {
    let lastLessIndex = numbers.indexWhere({ $0 < 0 })
    return lastLessIndex
}

// For a given array of integers, find the index of the last element with a value equal to 0.
// lastEqual([1, 0, 2, 3, 0, 4, 5]) == 4
// lastEqual([1, 2, 3, 4]) == -1
func lastEqual(numbers: [Int]) -> Int {
    let lastEqualIndex = numbers.indexWhere({ $0 == 0 })
    return lastEqualIndex
}

// For a given array of integers, find the index of the last element with a value equal to 0.
// lastEqual([1, 0, 2, 3, 0, 4, 5]) == 4
// lastEqual([1, 2, 3, 4]) == -1
func lastEqual(numbers: [Int]) -> Int {
    let lastEqualIndex = numbers.indexWhere({ $0 == 0 })
    return lastEqualIndex
}

// For a given array of integers, find the index of the last element with a value equal to 0.
// lastEqual([1, 0, 2, 3, 0, 4, 5]) == 4
// lastEqual([1, 2, 3, 4]) == -1
func lastEqual(numbers: [Int]) -> Int {
    let lastEqualIndex = numbers.indexWhere({ $0 == 0 })
    return lastEqualIndex
}

// For a given array of integers, find the index of the last element with a value equal to 0.
// lastEqual([1, 0, 2, 3, 0, 4, 5]) == 4
// lastEqual([1, 2, 3, 4]) == -1
func lastEqual(numbers: [Int]) -> Int {
    let lastEqualIndex = numbers.indexWhere({ $0 == 0 })
    return lastEqualIndex
}

// For a given array of integers, find the index of the last element with a value equal to 0.
// lastEqual([1, 0, 2, 3, 0, 4, 5]) == 4
// lastEqual([1, 2, 3, 4]) == -1
func lastEqual(numbers: [Int]) -> Int {
    let lastEqualIndex = numbers.indexWhere({ $0 == 0 })
    return lastEqualIndex
}

// For a given array of integers, find the index of the last element with a value equal to 0.
// lastEqual([1, 0, 2, 3, 0, 4, 5]) == 4
// lastEqual([1, 2, 3, 4]) == -1
func lastEqual(numbers: [Int]) -> Int {
    let lastEqualIndex = numbers.indexWhere({ $0 == 0 })
    return lastEqualIndex
}

//

func sumProduct(numbers: [Int]) -> (Int, Int) {
    var sum = 0
    var product = 1
    for i in numbers {
        sum += i
        product *= i
    }
    return (sum, product)
}

```swift
// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    var sum = 0
    var product = 1
    for i in numbers {
        sum += i
        product *= i
    }
    return (sum, product)
}
```

func sumProduct(numbers: [Int]) -> (Int, Int) {
    var sum = 0
    var product = 1
    for i in numbers {
        sum += i
        product *= i
    }
    return (sum, product)
}

```swift
// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    var sum = 0
    var product = 1
    for i in numbers {
        sum += i
        product *= i
    }
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    var sum = 0
    var product = 1
    for i in numbers {
        sum += i
        product *= i
    }
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    var sum = 0
    var product = 1
    for i in numbers {
        sum += i
        product *= i
    }
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    var sum = 0
    var product = 1
    for i in numbers {
        sum += i
        product *= i
    }
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    var sum = 0
    var product = 1
    for i in numbers {
        sum += i
        product *= i
    }
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    var sum = 0
    var product = 1
    for i in numbers {
        sum += i
        product *= i
    }
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    var sum = 0
    var product = 1
    for i in numbers {
        sum += i
        product *= i
    }
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sum

func sumProduct(numbers: [Int]) -> (Int, Int) {
    let sum = numbers.reduce(0, +)
    let product = numbers.reduce(1, *)
    return (sum, product)
}

```swift
// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    let sum = numbers.reduce(0, +)
    let product = numbers.reduce(1, *)
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    let sum = numbers.reduce(0, +)
    let product = numbers.reduce(1, *)
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    let sum = numbers.reduce(0, +)
    let product = numbers.reduce(1, *)
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    let sum = numbers.reduce(0, +)
    let product = numbers.reduce(1, *)
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    let sum = numbers.reduce(0, +)
    let product = numbers.reduce(1, *)
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    let sum = numbers.reduce(0, +)
    let product = numbers.reduce(1, *)
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    let sum = numbers.reduce(0, +)
    let product = numbers.reduce(1, *)
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    

func sumProduct(numbers: [Int]) -> (Int, Int) {
    var sum = 0
    var product = 1
    for i in numbers {
        sum += i
        product *= i
    }
    return (sum, product)
}

```swift
// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    var sum = 0
    var product = 1
    for i in numbers {
        sum += i
        product *= i
    }
    return (sum, product)
}
```

func sumProduct(numbers: [Int]) -> (Int, Int) {
    var sum = 0
    var product = 1
    for i in numbers {
        sum += i
        product *= i
    }
    return (sum, product)
}

```swift
// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    var sum = 0
    var product = 1
    for i in numbers {
        sum += i
        product *= i
    }
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    var sum = 0
    var product = 1
    for i in numbers {
        sum += i
        product *= i
    }
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    var sum = 0
    var product = 1
    for i in numbers {
        sum += i
        product *= i
    }
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    var sum = 0
    var product = 1
    for i in numbers {
        sum += i
        product *= i
    }
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    var sum = 0
    var product = 1
    for i in numbers {
        sum += i
        product *= i
    }
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    var sum = 0
    var product = 1
    for i in numbers {
        sum += i
        product *= i
    }
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    var sum = 0
    var product = 1
    for i in numbers {
        sum += i
        product *= i
    }
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sum

func sumProduct(numbers: [Int]) -> (Int, Int) {
    var sum = 0
    var product = 1
    for i in numbers {
        sum += i
        product *= i
    }
    return (sum, product)
}

func sumOfEvens(numbers: [Int]) -> Int {
    var sum = 0
    for i in numbers {
        if i % 2 == 0 {
            sum += i
        }
    }
    return sum
}

func sumOfOdds(numbers: [Int]) -> Int {
    var sum = 0
    for i in numbers {
        if i % 2 != 0 {
            sum += i
        }
    }
    return sum
}

func sumOfOddsAndEvens(numbers: [Int]) -> Int {
    var sum = 0
    for i in numbers {
        if i % 2 == 0 {
            sum += i
        } else {
            sum += i
        }
    }
    return sum
}

```swift
// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    var sum = 0
    var product = 1
    for i in numbers {
        sum += i
        product *= i
    }
    return (sum, product)
}

// For a given array of integers, return the sum of the integers that are even.
// sumOfEvens(numbers: [] as [Int]) == 0
// sumOfEvens(numbers: [1, 2, 3, 4]) == 6
func sumOfEvens(numbers: [Int]) -> Int {
    var sum = 0
    for i in numbers {
        if i % 2 == 0 {
            sum += i
        }
    }
    return sum
}

// For a given array of integers, return the sum of the integers that are odd.
// sumOfOdds(numbers: [] as [Int]) == 0
// sumOfOdds(numbers: [1, 2, 3, 4]) == 4
func sumOfOdds(numbers: [Int]) -> Int {
    var sum = 0
    for i in numbers {
        if i % 2 != 0 {
            sum += i
        }
    }
    return sum
}

// For a given array of integers, return the sum of the integers that are odd and even.
// sumOfOddsAndEvens(numbers: [] as [Int]) == 0
// sumOfOddsAndEvens(numbers: [1, 2, 3, 4]) == 4
func sumOfOddsAndEvens(numbers: [Int]) -> Int {
    var sum = 0
    for i in numbers {
        if i % 2 == 0 {
            sum += i
        } else {
            sum += i
        }
    }
    return sum
}

// For a given array of integers, return the sum of the integers that are odd and even.
// sumOfOddsAndEvens(numbers: [] as [Int]) == 0
// sumOfOddsAndEvens(numbers: [1, 2, 3, 4]) == 4
func sumOfOddsAndEvens(numbers: [Int]) -> Int {
    var sum = 0
    for i in numbers {
        if i % 2 == 0 {
            sum += i
        } else {
            sum += i
        }
    }
    return sum
}

// For a given array of integers, return the sum of the integers that are odd and even.
// sumOfOddsAndEvens(numbers: [] as [Int]) == 0
// sumOfOddsAndEvens(numbers: [1, 2, 3, 4]) == 4
func sumOfOddsAndEvens(numbers: [Int]) -> Int {
    var sum = 0
    for i in numbers {
        if i % 2 == 0 {
            sum += i
        } else {
            sum += i
        }
    }
    return sum
}

// For a given array of integers, return the sum of the integers that are odd and even.
// sumOfOddsAndEvens(numbers: [] as [Int]) == 0
// sumOfOddsAndEvens(numbers: [1, 2, 3, 4]) == 4
func sumOfOddsAndEvens(numbers: [Int]) -> Int {
    var sum = 0
    for i in numbers {
        if i % 2 == 0 {
            sum += i
        } else {
            sum += i
        }
    }
    return sum
}

// For a given array of integers, return the sum of the integers that are odd and even.
// sumOfOddsAndEvens(numbers: [] as [Int]) == 0
// sumOfOddsAndEvens(numbers: [1, 2, 3, 4]) == 4
func sumOfOddsAndEvens(numbers: [Int]) -> Int {
    var sum = 0
    for i in numbers {
        if i % 2 == 0 {
            sum += i
        } else {
            sum += i
        }
    }
    return sum
}

// For a given array of integers, return the sum of the integers that are odd and even.
// sumOfOddsAndEvens(numbers: [] as [Int]) == 0
// sumOfOddsAndEvens(numbers: [1, 2, 3, 4]) == 4
func sumOfOddsAndEvens

func sumProduct(numbers: [Int]) -> (Int, Int) {
    var sum = 0
    var product = 1
    for i in 0..<numbers.count {
        sum += numbers[i]
        product *= numbers[i]
    }
    return (sum, product)
}

```swift
// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    var sum = 0
    var product = 1
    for i in 0..<numbers.count {
        sum += numbers[i]
        product *= numbers[i]
    }
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    var sum = 0
    var product = 1
    for i in 0..<numbers.count {
        sum += numbers[i]
        product *= numbers[i]
    }
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    var sum = 0
    var product = 1
    for i in 0..<numbers.count {
        sum += numbers[i]
        product *= numbers[i]
    }
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    var sum = 0
    var product = 1
    for i in 0..<numbers.count {
        sum += numbers[i]
        product *= numbers[i]
    }
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    var sum = 0
    var product = 1
    for i in 0..<numbers.count {
        sum += numbers[i]
        product *= numbers[i]
    }
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    var sum = 0
    var product = 1
    for i in 0..<numbers.count {
        sum += numbers[i]
        product *= numbers[i]
    }
    return (sum, product)
}

// For a given array of integers, return a tuple consisting of a sum and a product of all the integers in an array.
// Empty sum should be equal to 0 and empty product should be equal to 1.
// sumProduct(numbers: [] as [Int]) == (0, 1)
// sumProduct(numbers: [1, 2, 3, 4]) == (10, 24)
func sumProduct(numbers: [Int]) -> (Int, Int) {
    var sum = 0
    var product = 1
    for i in 0..<numbers.count {
        

func rollingMax(numbers: [Int]) -> [Int] {
    var rollingMaxes: [Int] = [Int]()
    var max: Int = numbers[0]
    for number in numbers {
        if number > max {
            max = number
        }
        rollingMaxes.append(max)
    }
    return rollingMaxes
}

func rollingMin(numbers: [Int]) -> [Int] {
    var rollingMins: [Int] = [Int]()
    var min: Int = numbers[0]
    for number in numbers {
        if number < min {
            min = number
        }
        rollingMins.append(min)
    }
    return rollingMins
}

func rollingSum(numbers: [Int]) -> [Int] {
    var rollingSums: [Int] = [Int]()
    var sum: Int = 0
    for number in numbers {
        sum += number
        rollingSums.append(sum)
    }
    return rollingSums
}

func rollingAverage(numbers: [Int]) -> [Double] {
    var rollingAverages: [Double] = [Double]()
    var sum: Int = 0
    for index, number in enumerate(numbers) {
        sum += number
        if index == 0 {
            rollingAverages.append(sum.toDouble())
            continue
        }
        rollingAverages.append((sum - numbers[index - 1]).toDouble() / index)
    }
    return rollingAverages
}

func rollingProduct(numbers: [Int]) -> [Int] {
    var rollingProducts: [Int] = [Int]()
    var product: Int = 1
    for index, number in enumerate(numbers) {
        product *= number
        if index == 0 {
            rollingProducts.append(product)
            continue
        }
        rollingProducts.append(product / numbers[index - 1])
    }
    return rollingProducts
}

func rollingSum(numbers: [Int]) -> [Int] {
    var rollingSums: [Int] = [Int]()
    var sum: Int = 0
    for index, number in enumerate(numbers) {
        sum += number
        if index == 0 {
            rollingSums.append(sum)
            continue
        }
        rollingSums.append(sum - numbers[index - 1])
    }
    return rollingSums
}

```swift
// From a given array of integers, generate an array of rolling maximum element found until given moment
// in the sequence.
// rollingMax(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 2, 3, 3, 3, 4, 4]
func rollingMax(numbers: [Int]) -> [Int] {
    var rollingMaxes: [Int] = [Int]()
    var max: Int = numbers[0]
    for number in numbers {
        if number > max {
            max = number
        }
        rollingMaxes.append(max)
    }
    return rollingMaxes
}

// From a given array of integers, generate an array of rolling minimum element found until given moment
// in the sequence.
// rollingMin(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 1, 2, 2, 2, 2, 2]
func rollingMin(numbers: [Int]) -> [Int] {
    var rollingMins: [Int] = [Int]()
    var min: Int = numbers[0]
    for number in numbers {
        if number < min {
            min = number
        }
        rollingMins.append(min)
    }
    return rollingMins
}

// From a given array of integers, generate an array of rolling sum of elements found until given moment
// in the sequence.
// rollingSum(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 3, 6, 8, 11, 15, 17]
func rollingSum(numbers: [Int]) -> [Int] {
    var rollingSums: [Int] = [Int]()
    var sum: Int = 0
    for number in numbers {
        sum += number
        rollingSums.append(sum)
    }
    return rollingSums
}

// From a given array of integers, generate an array of rolling average of elements found until given moment
// in the sequence.
// rollingAverage(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 1.5, 2, 2.5, 3, 3.5, 3]
func rollingAverage(numbers: [Int]) -> [Double] {
    var rollingAverages: [Double] = [Double]()
    var sum: Int = 0
    for index, number in enumerate(numbers) {
        sum += number
        if index == 0 {
            rollingAverages.append(sum.toDouble())
            continue
        }
        rollingAverages.append((sum - numbers[index - 1]).toDouble() / index)
    }
    return rollingAverages
}

// From a given array of integers, generate an array of rolling product of elements found until given moment
// in the sequence.
// rollingProduct(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 2, 6, 12, 24, 48, 96]
func rollingProduct(numbers: [Int]) -> [Int] {
    var rollingProducts: [Int] = [Int]()
    var product: Int = 1
    for index, number in enumerate(numbers) {
        product *= number
        if index == 0 {
            rollingProducts.append(product)
            continue
        }
        rollingProducts.append(product / numbers[index - 1])
    }
    return rollingProducts
}

// From a given array of integers, generate an array of rolling sum of elements found until given moment
// in the sequence.
// rollingSum(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 3, 6, 8, 11, 15, 17]
func rollingSum(numbers: [Int]) -> [Int] {
    var rollingSums: [Int] = [Int]()
    var sum: Int = 0
    for index, number in enumerate(numbers) {
        sum += number
        if index == 0 {
            rollingSums.append(sum)
            continue
        }
        rollingSums.append(sum - numbers[index - 1])
    }
    return rollingSums
}

// From a given array of integers, generate an array of rolling average of elements found until given moment
// in the sequence.
// rollingAverage(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 1.5, 2, 2.5, 3, 3.5, 3]
func rollingAverage(

func rollingMax(numbers: [Int]) -> [Int] {
    var result = [Int]()
    var max = numbers[0]
    result.append(max)
    for i in 1..<numbers.count {
        if numbers[i] > max {
            max = numbers[i]
        }
        result.append(max)
    }
    return result
}

func rollingMin(numbers: [Int]) -> [Int] {
    var result = [Int]()
    var min = numbers[0]
    result.append(min)
    for i in 1..<numbers.count {
        if numbers[i] < min {
            min = numbers[i]
        }
        result.append(min)
    }
    return result
}

func rollingSum(numbers: [Int]) -> [Int] {
    var result = [Int]()
    var sum = 0
    result.append(sum)
    for i in 0..<numbers.count {
        sum += numbers[i]
        result.append(sum)
    }
    return result
}

func rollingAverage(numbers: [Int]) -> [Double] {
    var result = [Double]()
    var sum = 0
    for i in 0..<numbers.count {
        sum += numbers[i]
        result.append(sum / (i + 1))
    }
    return result
}

func rollingProduct(numbers: [Int]) -> [Int] {
    var result = [Int]()
    var product = 1
    result.append(product)
    for i in 0..<numbers.count {
        product *= numbers[i]
        result.append(product)
    }
    return result
}

```swift
// From a given array of integers, generate an array of rolling maximum element found until given moment
// in the sequence.
// rollingMax(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 2, 3, 3, 3, 4, 4]
func rollingMax(numbers: [Int]) -> [Int] {
    var result = [Int]()
    var max = numbers[0]
    result.append(max)
    for i in 1..<numbers.count {
        if numbers[i] > max {
            max = numbers[i]
        }
        result.append(max)
    }
    return result
}

// From a given array of integers, generate an array of rolling minimum element found until given moment
// in the sequence.
// rollingMin(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 1, 2, 2, 2, 2, 2]
func rollingMin(numbers: [Int]) -> [Int] {
    var result = [Int]()
    var min = numbers[0]
    result.append(min)
    for i in 1..<numbers.count {
        if numbers[i] < min {
            min = numbers[i]
        }
        result.append(min)
    }
    return result
}

// From a given array of integers, generate an array of rolling sum of elements found until given moment
// in the sequence.
// rollingSum(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 3, 6, 8, 11, 15, 17]
func rollingSum(numbers: [Int]) -> [Int] {
    var result = [Int]()
    var sum = 0
    result.append(sum)
    for i in 0..<numbers.count {
        sum += numbers[i]
        result.append(sum)
    }
    return result
}

// From a given array of integers, generate an array of rolling average of elements found until given moment
// in the sequence.
// rollingAverage(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1.0, 1.5, 2.0, 2.0, 2.5, 3.0, 2.0]
func rollingAverage(numbers: [Int]) -> [Double] {
    var result = [Double]()
    var sum = 0
    for i in 0..<numbers.count {
        sum += numbers[i]
        result.append(sum / (i + 1))
    }
    return result
}

// From a given array of integers, generate an array of rolling product of elements found until given moment
// in the sequence.
// rollingProduct(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 2, 6, 6, 12, 24, 24]
func rollingProduct(numbers: [Int]) -> [Int] {
    var result = [Int]()
    var product = 1
    result.append(product)
    for i in 0..<numbers.count {
        product *= numbers[i]
        result.append(product)
    }
    return result
}

// From a given array of integers, generate an array of rolling sum of elements found until given moment
// in the sequence.
// rollingSum(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 3, 6, 8, 11, 15, 17]
func rollingSum(numbers: [Int]) -> [Int] {
    var result = [Int]()
    var sum = 0
    result.append(sum)
    for i in 0..<numbers.count {
        sum += numbers[i]
        result.append(sum)
    }
    return result
}

// From a given array of integers, generate an array of rolling average of elements found until given moment
// in the sequence.
// rollingAverage(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1.0, 1.5, 2.0, 2.0, 2.5, 3.0, 2.0]
func rollingAverage(numbers: [Int]) -> [Double] {
    var result = [Double]()
    var sum = 0
    for i in 0..<numbers.count {
        sum += numbers[i]
        result.append(sum / (i + 1

func rollingMax(numbers: [Int]) -> [Int] {
    var max = numbers[0]
    var result = [Int]()
    for number in numbers {
        if number > max {
            max = number
        }
        result.append(max)
    }
    return result
}

func rollingMin(numbers: [Int]) -> [Int] {
    var min = numbers[0]
    var result = [Int]()
    for number in numbers {
        if number < min {
            min = number
        }
        result.append(min)
    }
    return result
}

func rollingSum(numbers: [Int]) -> [Int] {
    var sum = 0
    var result = [Int]()
    for number in numbers {
        sum += number
        result.append(sum)
    }
    return result
}

func rollingProduct(numbers: [Int]) -> [Int] {
    var product = 1
    var result = [Int]()
    for number in numbers {
        product *= number
        result.append(product)
    }
    return result
}

func rollingAverage(numbers: [Int]) -> [Double] {
    var sum = 0
    var result = [Double]()
    for number in numbers {
        sum += number
        result.append(sum.toDouble())
    }
    return result
}

func rollingMedian(numbers: [Int]) -> [Double] {
    var result = [Double]()
    for i in 0..<numbers.count {
        var subarray = numbers[0..<i + 1]
        var sortedSubarray = subarray.sorted()
        var medianIndex = (sortedSubarray.count - 1) / 2
        var median = if (sortedSubarray.count % 2) == 0 {
            (sortedSubarray[medianIndex] + sortedSubarray[medianIndex + 1]) / 2.0
        } else {
            sortedSubarray[medianIndex]
        }
        result.append(median)
    }
    return result
}

```swift
// From a given array of integers, generate an array of rolling maximum element found until given moment
// in the sequence.
// rollingMax(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 2, 3, 3, 3, 4, 4]
func rollingMax(numbers: [Int]) -> [Int] {
    var max = numbers[0]
    var result = [Int]()
    for number in numbers {
        if number > max {
            max = number
        }
        result.append(max)
    }
    return result
}

// From a given array of integers, generate an array of rolling minimum element found until given moment
// in the sequence.
// rollingMin(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 1, 1, 1, 2, 2, 2]
func rollingMin(numbers: [Int]) -> [Int] {
    var min = numbers[0]
    var result = [Int]()
    for number in numbers {
        if number < min {
            min = number
        }
        result.append(min)
    }
    return result
}

// From a given array of integers, generate an array of rolling sum of elements found until given moment
// in the sequence.
// rollingSum(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 3, 6, 8, 11, 15, 17]
func rollingSum(numbers: [Int]) -> [Int] {
    var sum = 0
    var result = [Int]()
    for number in numbers {
        sum += number
        result.append(sum)
    }
    return result
}

// From a given array of integers, generate an array of rolling product of elements found until given moment
// in the sequence.
// rollingProduct(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 2, 6, 8, 24, 120, 288]
func rollingProduct(numbers: [Int]) -> [Int] {
    var product = 1
    var result = [Int]()
    for number in numbers {
        product *= number
        result.append(product)
    }
    return result
}

// From a given array of integers, generate an array of rolling average of elements found until given moment
// in the sequence.
// rollingAverage(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1.0, 1.5, 2.0, 2.0, 2.5, 3.0, 2.6666666666666665]
func rollingAverage(numbers: [Int]) -> [Double] {
    var sum = 0
    var result = [Double]()
    for number in numbers {
        sum += number
        result.append(sum.toDouble())
    }
    return result
}

// From a given array of integers, generate an array of rolling median of elements found until given moment
// in the sequence.
// rollingMedian(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1.0, 1.5, 2.0, 2.0, 2.5, 3.0, 2.6666666666666665]
func rollingMedian(numbers: [Int]) -> [Double] {
    var result = [Double]()
    for i in 0..<numbers.count {
        var subarray = numbers[0..<i + 1]
        var sortedSubarray = subarray.sorted()
        var medianIndex = (sortedSubarray.count - 1) / 2
        var median = if (sortedSubarray.count % 2) == 0 {
            (sortedSubarray[medianIndex] + sortedSubarray[medianIndex + 1]) / 2.0
        } else {
            sortedSubarray[medianIndex]
        }
        result.append(median)
    }
    return result
}

// From a given array of integers, generate an array of rolling mode of elements found until given moment
// in the sequence.
// rollingMode(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 1, 1, 2, 2, 2, 2]
func rollingMode(numbers: [Int]) -> [Int] {
    var result = [Int]()
    for i in 0

func rollingMax(numbers: [Int]) -> [Int] {
    var max = numbers[0]
    var result = [Int](nil)
    for i in 0..<numbers.count {
        if numbers[i] > max {
            max = numbers[i]
        }
        result.append(max)
    }
    return result
}

func reverseWords(input: String) -> String {
    var words = input.split(" ")
    var reversedWords = [String](nil)
    for i in 0..<words.count {
        reversedWords.append(words[words.count - i - 1])
    }
    return reversedWords.join(" ")
}

func removeVowels(input: String) -> String {
    var vowels = ["a", "e", "i", "o", "u"]
    var result = ""
    for i in 0..<input.count {
        if !vowels.contains(input[i:i + 1]) {
            result += input[i:i + 1]
        }
    }
    return result
}

func removeFirstAndLast(input: String) -> String {
    return input[1..<input.count - 1]
}

func reverseString(input: String) -> String {
    var reversed = ""
    for i in 0..<input.count {
        reversed = input[i:i + 1] + reversed
    }
    return reversed
}

func sortString(input: String) -> String {
    var characters = input.characters
    characters.sort()
    return characters.join("")
}

```swift
// From a given array of integers, generate an array of rolling maximum element found until given moment
// in the sequence.
// rollingMax(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 2, 3, 3, 3, 4, 4]
func rollingMax(numbers: [Int]) -> [Int] {
    var max = numbers[0]
    var result = [Int](nil)
    for i in 0..<numbers.count {
        if numbers[i] > max {
            max = numbers[i]
        }
        result.append(max)
    }
    return result
}

// Given a string of words, return a string with the words in reverse order.
// reverseWords("This is a test") == "test a is This"
func reverseWords(input: String) -> String {
    var words = input.split(" ")
    var reversedWords = [String](nil)
    for i in 0..<words.count {
        reversedWords.append(words[words.count - i - 1])
    }
    return reversedWords.join(" ")
}

// Given a string, return a string with the vowels removed.
// removeVowels("This is a test") == "Ths s a tst"
func removeVowels(input: String) -> String {
    var vowels = ["a", "e", "i", "o", "u"]
    var result = ""
    for i in 0..<input.count {
        if !vowels.contains(input[i:i + 1]) {
            result += input[i:i + 1]
        }
    }
    return result
}

// Given a string, return a string with the first and last characters removed.
// removeFirstAndLast("This is a test") == "is a test"
func removeFirstAndLast(input: String) -> String {
    return input[1..<input.count - 1]
}

// Given a string, return a string with all the characters in reverse order.
// reverseString("This is a test") == "tset a si sihT"
func reverseString(input: String) -> String {
    var reversed = ""
    for i in 0..<input.count {
        reversed = input[i:i + 1] + reversed
    }
    return reversed
}

// Given a string, return a string with all the characters in alphabetical order.
// sortString("This is a test") == "This is a test"
func sortString(input: String) -> String {
    var characters = input.characters
    characters.sort()
    return characters.join("")
}

// Given a string, return a string with all the characters in alphabetical order.
// sortString("This is a test") == "This is a test"
func sortString(input: String) -> String {
    var characters = input.characters
    characters.sort()
    return characters.join("")
}

// Given a string, return a string with all the characters in alphabetical order.
// sortString("This is a test") == "This is a test"
func sortString(input: String) -> String {
    var characters = input.characters
    characters.sort()
    return characters.join("")
}

// Given a string, return a string with all the characters in alphabetical order.
// sortString("This is a test") == "This is a test"
func sortString(input: String) -> String {
    var characters = input.characters
    characters.sort()
    return characters.join("")
}

// Given a string, return a string with all the characters in alphabetical order.
// sortString("This is a test") == "This is a test"
func sortString(input: String) -> String {
    var characters = input.characters
    characters.sort()
    return characters.join("")
}

// Given a string, return a string with all the characters in alphabetical order.
// sortString("This is a test") == "This is a test"
func sortString(input: String) -> String {
    var characters = input.characters
    characters.sort()
    return characters.join("")
}

// Given a string, return a string with all the characters in alphabetical order.
// sortString("This is a test") == "This is a test"
func sortString(input: String) -> String {
    var characters = input.characters
    characters.sort()
    return characters.join("")
}

// Given a string, return a string with all the characters in alphabetical order.
// sortString("This is a test") == "This is a test"
func sortString(input: String) -> String {
    var characters = input.characters
    characters.sort()
    return characters.join("")
}

// Given a string, return

func rollingMax(numbers: [Int]) -> [Int] {
    var max = numbers[0]
    var result = [Int]()
    for i in numbers {
        if i > max {
            max = i
        }
        result.append(max)
    }
    return result
}

func rollingMin(numbers: [Int]) -> [Int] {
    var min = numbers[0]
    var result = [Int]()
    for i in numbers {
        if i < min {
            min = i
        }
        result.append(min)
    }
    return result
}

func rollingSum(numbers: [Int]) -> [Int] {
    var sum = numbers[0]
    var result = [Int]()
    for i in numbers {
        sum += i
        result.append(sum)
    }
    return result
}

func rollingAverage(numbers: [Int]) -> [Double] {
    var sum = numbers[0]
    var result = [Double]()
    for i in numbers {
        sum += i
        result.append(sum / Double(numbers.count))
    }
    return result
}

func rollingProduct(numbers: [Int]) -> [Int] {
    var product = numbers[0]
    var result = [Int]()
    for i in numbers {
        product *= i
        result.append(product)
    }
    return result
}

func rollingDifference(numbers: [Int]) -> [Int] {
    var result = [Int]()
    for i in 1..<numbers.count {
        result.append(numbers[i] - numbers[i - 1])
    }
    return result
}

```swift
// From a given array of integers, generate an array of rolling maximum element found until given moment
// in the sequence.
// rollingMax(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 2, 3, 3, 3, 4, 4]
func rollingMax(numbers: [Int]) -> [Int] {
    var max = numbers[0]
    var result = [Int]()
    for i in numbers {
        if i > max {
            max = i
        }
        result.append(max)
    }
    return result
}

// From a given array of integers, generate an array of rolling minimum element found until given moment
// in the sequence.
// rollingMin(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 1, 2, 2, 2, 2, 2]
func rollingMin(numbers: [Int]) -> [Int] {
    var min = numbers[0]
    var result = [Int]()
    for i in numbers {
        if i < min {
            min = i
        }
        result.append(min)
    }
    return result
}

// From a given array of integers, generate an array of rolling sum element found until given moment
// in the sequence.
// rollingSum(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 3, 6, 8, 11, 15, 17]
func rollingSum(numbers: [Int]) -> [Int] {
    var sum = numbers[0]
    var result = [Int]()
    for i in numbers {
        sum += i
        result.append(sum)
    }
    return result
}

// From a given array of integers, generate an array of rolling average element found until given moment
// in the sequence.
// rollingAverage(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 1.5, 2, 2.5, 3, 3.5, 4]
func rollingAverage(numbers: [Int]) -> [Double] {
    var sum = numbers[0]
    var result = [Double]()
    for i in numbers {
        sum += i
        result.append(sum / Double(numbers.count))
    }
    return result
}

// From a given array of integers, generate an array of rolling product element found until given moment
// in the sequence.
// rollingProduct(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 2, 6, 6, 12, 24, 24]
func rollingProduct(numbers: [Int]) -> [Int] {
    var product = numbers[0]
    var result = [Int]()
    for i in numbers {
        product *= i
        result.append(product)
    }
    return result
}

// From a given array of integers, generate an array of rolling difference element found until given moment
// in the sequence.
// rollingDifference(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 1, 1, 1, 1, 1, 1]
func rollingDifference(numbers: [Int]) -> [Int] {
    var result = [Int]()
    for i in 1..<numbers.count {
        result.append(numbers[i] - numbers[i - 1])
    }
    return result
}

// From a given array of integers, generate an array of rolling difference element found until given moment
// in the sequence.
// rollingDifference(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 1, 1, 1, 1, 1, 1]
func rollingDifference(numbers: [Int]) -> [Int] {
    var result = [Int]()
    for i in 1..<numbers.count {
        result.append(numbers[i] - numbers[i - 1])
    }
    return result
}

// From a given array of integers, generate an array of rolling difference element found until given moment
// in the sequence.
// rollingDifference(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 1, 1, 1, 1, 1, 1]
func rollingDifference(numbers: [Int]) -> [Int] {
    var result = [Int]()
    for i in 1..<numbers.count {
        result.append

func rollingMax(numbers: [Int]) -> [Int] {
    var max: Int? = nil
    var result: [Int] = []Int()
    for i in 0..<numbers.count {
        if max == nil || numbers[i] > max {
            max = numbers[i]
        }
        result.append(max)
    }
    return result
}

```swift
// From a given array of integers, generate an array of rolling maximum element found until given moment
// in the sequence.
// rollingMax(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 2, 3, 3, 3, 4, 4]
func rollingMax(numbers: [Int]) -> [Int] {
    var max: Int? = nil
    var result: [Int] = []Int()
    for i in 0..<numbers.count {
        if max == nil || numbers[i] > max {
            max = numbers[i]
        }
        result.append(max)
    }
    return result
}
```

func rollingMax(numbers: [Int]) -> [Int] {
    var result = [Int]()
    var max = Int.MIN_VALUE
    for num in numbers {
        if num > max {
            max = num
        }
        result.append(max)
    }
    return result
}

func rollingMin(numbers: [Int]) -> [Int] {
    var result = [Int]()
    var min = Int.MAX_VALUE
    for num in numbers {
        if num < min {
            min = num
        }
        result.append(min)
    }
    return result
}

func rollingSum(numbers: [Int]) -> [Int] {
    var result = [Int]()
    var sum = 0
    for num in numbers {
        sum += num
        result.append(sum)
    }
    return result
}

func rollingProduct(numbers: [Int]) -> [Int] {
    var result = [Int]()
    var product = 1
    for num in numbers {
        product *= num
        result.append(product)
    }
    return result
}

func rollingAverage(numbers: [Int]) -> [Double] {
    var result = [Double]()
    var sum = 0
    for num in numbers {
        sum += num
    }
    result.append(sum.toDouble() / numbers.count.toDouble())
    return result
}

func rollingMedian(numbers: [Int]) -> [Double] {
    var result = [Double]()
    var sorted = numbers.sorted()
    var mid = sorted.count / 2
    for i in 0..<sorted.count {
        result.append(sorted[mid])
    }
    return result
}

func rollingMode(numbers: [Int]) -> [Int] {
    var result = [Int]()
    var maxCount = 0
    var max = Int.MIN_VALUE
    var count = 0
    var mode = 0
    for num in numbers {
        if num == max {
            count += 1
        } else if num > max {
            max = num
            count = 1
        }
        if count > maxCount {
            maxCount = count
            mode = num
        }
    }
    result.append(mode)
    return result
}

```swift
// From a given array of integers, generate an array of rolling maximum element found until given moment
// in the sequence.
// rollingMax(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 2, 3, 3, 3, 4, 4]
func rollingMax(numbers: [Int]) -> [Int] {
    var result = [Int]()
    var max = Int.MIN_VALUE
    for num in numbers {
        if num > max {
            max = num
        }
        result.append(max)
    }
    return result
}

// From a given array of integers, generate an array of rolling minimum element found until given moment
// in the sequence.
// rollingMin(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 1, 2, 2, 2, 2, 2]
func rollingMin(numbers: [Int]) -> [Int] {
    var result = [Int]()
    var min = Int.MAX_VALUE
    for num in numbers {
        if num < min {
            min = num
        }
        result.append(min)
    }
    return result
}

// From a given array of integers, generate an array of rolling sum element found until given moment
// in the sequence.
// rollingSum(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 3, 6, 8, 11, 15, 17]
func rollingSum(numbers: [Int]) -> [Int] {
    var result = [Int]()
    var sum = 0
    for num in numbers {
        sum += num
        result.append(sum)
    }
    return result
}

// From a given array of integers, generate an array of rolling product element found until given moment
// in the sequence.
// rollingProduct(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 2, 6, 6, 12, 24, 24]
func rollingProduct(numbers: [Int]) -> [Int] {
    var result = [Int]()
    var product = 1
    for num in numbers {
        product *= num
        result.append(product)
    }
    return result
}

// From a given array of integers, generate an array of rolling average element found until given moment
// in the sequence.
// rollingAverage(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1.0, 1.5, 2.0, 2.0, 2.5, 3.0, 2.5]
func rollingAverage(numbers: [Int]) -> [Double] {
    var result = [Double]()
    var sum = 0
    for num in numbers {
        sum += num
    }
    result.append(sum.toDouble() / numbers.count.toDouble())
    return result
}

// From a given array of integers, generate an array of rolling median element found until given moment
// in the sequence.
// rollingMedian(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1.0, 1.5, 2.0, 2.0, 2.5, 3.0, 2.5]
func rollingMedian(numbers: [Int]) -> [Double] {
    var result = [Double]()
    var sorted = numbers.sorted()
    var mid = sorted.count / 2
    for i in 0..<sorted.count {
        result.append(sorted[mid])
    }
    return result
}

// From a given array of integers, generate an array of rolling mode element found until given moment
// in the sequence.
// rollingMode(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 2, 3, 2, 3, 4, 2]
func rollingMode(numbers: [Int]) -> [Int] {
    var result = [Int]()
    var maxCount = 0
    var max = Int.MIN_VALUE
    var count = 0
    var mode = 0
    for num in numbers {
        if num == max {
            count += 1
        } else if num > max {
            max = num
            count = 1
        }
        if count > maxCount {
            maxCount = count
            mode = num
        }
    }
    result.append(mode)
    return result
}

// From a given array of integers

func rollingMax(numbers: [Int]) -> [Int] {
    var max = numbers[0]
    var maxes = [max]
    for i in 1..<numbers.count {
        if numbers[i] > max {
            max = numbers[i]
        }
        maxes.append(max)
    }
    return maxes
}

```swift
// From a given array of integers, generate an array of rolling maximum element found until given moment
// in the sequence.
// rollingMax(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 2, 3, 3, 3, 4, 4]
func rollingMax(numbers: [Int]) -> [Int] {
    var max = numbers[0]
    var maxes = [max]
    for i in 1..<numbers.count {
        if numbers[i] > max {
            max = numbers[i]
        }
        maxes.append(max)
    }
    return maxes
}
```

func rollingMax(numbers: [Int]) -> [Int] {
    var max = numbers[0]
    var result = [Int]()
    for i in numbers {
        if i > max {
            max = i
        }
        result.append(max)
    }
    return result
}

func rollingMin(numbers: [Int]) -> [Int] {
    var min = numbers[0]
    var result = [Int]()
    for i in numbers {
        if i < min {
            min = i
        }
        result.append(min)
    }
    return result
}

func rollingAverage(numbers: [Int]) -> [Double] {
    var sum = 0
    var result = [Double]()
    for i in numbers {
        sum += i
        result.append(sum / numbers.count)
    }
    return result
}

func rollingMedian(numbers: [Int]) -> [Double] {
    var result = [Double]()
    for i in 0..<numbers.count {
        var sum = 0
        var count = 0
        for j in 0..<i {
            sum += numbers[j]
            count++
        }
        for j in i..<numbers.count {
            sum += numbers[j]
            count++
        }
        result.append(sum / count)
    }
    return result
}

func rollingSum(numbers: [Int]) -> [Int] {
    var result = [Int]()
    for i in numbers {
        result.append(result.last? + i)
    }
    return result
}

func rollingProduct(numbers: [Int]) -> [Int] {
    var result = [Int]()
    for i in numbers {
        result.append(result.last? * i)
    }
    return result
}

func rollingSumOfSquares(numbers: [Int]) -> [Int] {
    var result = [Int]()
    for i in numbers {
        result.append(result.last? + i * i)
    }
    return result
}

```swift
// From a given array of integers, generate an array of rolling maximum element found until given moment
// in the sequence.
// rollingMax(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 2, 3, 3, 3, 4, 4]
func rollingMax(numbers: [Int]) -> [Int] {
    var max = numbers[0]
    var result = [Int]()
    for i in numbers {
        if i > max {
            max = i
        }
        result.append(max)
    }
    return result
}

// From a given array of integers, generate an array of rolling minimum element found until given moment
// in the sequence.
// rollingMin(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 1, 1, 2, 2, 2, 2]
func rollingMin(numbers: [Int]) -> [Int] {
    var min = numbers[0]
    var result = [Int]()
    for i in numbers {
        if i < min {
            min = i
        }
        result.append(min)
    }
    return result
}

// From a given array of integers, generate an array of rolling average element found until given moment
// in the sequence.
// rollingAverage(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 1.5, 2, 2, 2.5, 3, 2]
func rollingAverage(numbers: [Int]) -> [Double] {
    var sum = 0
    var result = [Double]()
    for i in numbers {
        sum += i
        result.append(sum / numbers.count)
    }
    return result
}

// From a given array of integers, generate an array of rolling median element found until given moment
// in the sequence.
// rollingMedian(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 1.5, 2, 2, 2.5, 3, 2]
func rollingMedian(numbers: [Int]) -> [Double] {
    var result = [Double]()
    for i in 0..<numbers.count {
        var sum = 0
        var count = 0
        for j in 0..<i {
            sum += numbers[j]
            count++
        }
        for j in i..<numbers.count {
            sum += numbers[j]
            count++
        }
        result.append(sum / count)
    }
    return result
}

// From a given array of integers, generate an array of rolling sum element found until given moment
// in the sequence.
// rollingSum(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 3, 6, 8, 11, 15, 17]
func rollingSum(numbers: [Int]) -> [Int] {
    var result = [Int]()
    for i in numbers {
        result.append(result.last? + i)
    }
    return result
}

// From a given array of integers, generate an array of rolling product element found until given moment
// in the sequence.
// rollingProduct(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 2, 6, 8, 24, 72, 288]
func rollingProduct(numbers: [Int]) -> [Int] {
    var result = [Int]()
    for i in numbers {
        result.append(result.last? * i)
    }
    return result
}

// From a given array of integers, generate an array of rolling sum of squares element found until given moment
// in the sequence.
// rollingSumOfSquares(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 5, 14, 20, 32, 52, 84]
func rollingSumOfSquares(numbers: [Int]) -> [Int] {
    var result = [Int]()
    for i in numbers {
        result.append(result.last? + i * i)
    }
    return result
}

// From a given array of integers, generate an array of rolling product of squares element found until given moment
// in the sequence.
// rollingProductOfSquares(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 5, 14, 20, 3

func rollingMax(numbers: [Int]) -> [Int] {
    var max = numbers[0]
    var result = [Int]()
    for number in numbers {
        if number > max {
            max = number
        }
        result.append(max)
    }
    return result
}

func rollingMin(numbers: [Int]) -> [Int] {
    var min = numbers[0]
    var result = [Int]()
    for number in numbers {
        if number < min {
            min = number
        }
        result.append(min)
    }
    return result
}

```swift
// From a given array of integers, generate an array of rolling maximum element found until given moment
// in the sequence.
// rollingMax(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 2, 3, 3, 3, 4, 4]
func rollingMax(numbers: [Int]) -> [Int] {
    var max = numbers[0]
    var result = [Int]()
    for number in numbers {
        if number > max {
            max = number
        }
        result.append(max)
    }
    return result
}

// Given an array of integers, generate an array of rolling minimum element found until given moment
// in the sequence.
// rollingMin(numbers: [1, 2, 3, 2, 3, 4, 2]) == [1, 1, 2, 2, 2, 2, 2]
func rollingMin(numbers: [Int]) -> [Int] {
    var min = numbers[0]
    var result = [Int]()
    for number in numbers {
        if number < min {
            min = number
        }
        result.append(min)
    }
    return result
}
```

func makePalindrome(string: String) -> String {
    let reversed = string.reversed()
    let prefix = string.prefix(of: string.length - 1)
    return prefix + reversed
}

```swift
// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    let reversed = string.reversed()
    let prefix = string.prefix(of: string.length - 1)
    return prefix + reversed
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    let reversed = string.reversed()
    let prefix = string.prefix(of: string.length - 1)
    return prefix + reversed
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    let reversed = string.reversed()
    let prefix = string.prefix(of: string.length - 1)
    return prefix + reversed
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    let reversed = string.reversed()
    let prefix = string.prefix(of: string.length - 1)
    return prefix + reversed
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    let reversed = string.reversed()
    let prefix = string.prefix(of: string.length - 1)
    return prefix + reversed
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    let reversed = string.reversed()
    let prefix = string.prefix(of: string.length - 1)
    return prefix + reversed
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    let reversed = string.reversed()
    let prefix = string.prefix(of: string.length - 1)
    return prefix + reversed
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    

func makePalindrome(string: String) -> String {
    let n = string.length
    let palindrome = string
    for i in 0..<n {
        let j = n - i
        if i == 0 {
            continue
        }
        let prefix = string[0..<i]
        let suffix = string[j..<n]
        if prefix == suffix {
            palindrome = prefix + palindrome + suffix
        }
    }
    return palindrome
}

```swift
// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    let n = string.length
    let palindrome = string
    for i in 0..<n {
        let j = n - i
        if i == 0 {
            continue
        }
        let prefix = string[0..<i]
        let suffix = string[j..<n]
        if prefix == suffix {
            palindrome = prefix + palindrome + suffix
        }
    }
    return palindrome
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    let n = string.length
    let palindrome = string
    for i in 0..<n {
        let j = n - i
        if i == 0 {
            continue
        }
        let prefix = string[0..<i]
        let suffix = string[j..<n]
        if prefix == suffix {
            palindrome = prefix + palindrome + suffix
        }
    }
    return palindrome
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    let n = string.length
    let palindrome = string
    for i in 0..<n {
        let j = n - i
        if i == 0 {
            continue
        }
        let prefix = string[0..<i]
        let suffix = string[j..<n]
        if prefix == suffix {
            palindrome = prefix + palindrome + suffix
        }
    }
    return palindrome
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    let n = string.length
    let palindrome = string
    for i in 0..<n {
        let j = n - i
        if i == 0 {
            continue
        }
        let prefix = string[0..<i]
        let suffix = string[j..<n]
        if prefix == suffix {
            palindrome = prefix + palindrome + suffix
        }
    }
    return palindrome
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    let n = string.length
    let palindrome = string
    for i in 0..<n {
        let j = n - i
        if i == 0 {
            continue
        }
        let prefix = string[0..<i]
        let suffix = string[j..<n]
        if prefix == suffix {
            palindrome = prefix + palindrome + suffix
        }
    }
    return palindrome
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"

func makePalindrome(string: String) -> String {
    let reversed = string.reversed()
    let prefix = string.prefix(of: string.length - 1)
    let suffix = string.suffix(of: string.length - 1)
    let prefixReversed = prefix.reversed()
    let suffixReversed = suffix.reversed()
    let palindrome = prefix + suffixReversed
    if suffix == prefixReversed {
        return palindrome
    } else {
        return palindrome + reversed
    }
}

```swift
// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    let reversed = string.reversed()
    let prefix = string.prefix(of: string.length - 1)
    let suffix = string.suffix(of: string.length - 1)
    let prefixReversed = prefix.reversed()
    let suffixReversed = suffix.reversed()
    let palindrome = prefix + suffixReversed
    if suffix == prefixReversed {
        return palindrome
    } else {
        return palindrome + reversed
    }
}

// Test
let string = "cat"
let palindrome = makePalindrome(string: string)
print(palindrome)
// Output: "catac"
```

func makePalindrome(string: String) -> String {
    var i, j = 0, string.length - 1
    while i < j {
        if string[i] != string[j] {
            break
        }
        i += 1
        j -= 1
    }
    return string[i..j].reversed.string + string
}

```swift
// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    var i, j = 0, string.length - 1
    while i < j {
        if string[i] != string[j] {
            break
        }
        i += 1
        j -= 1
    }
    return string[i..j].reversed.string + string
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    var i, j = 0, string.length - 1
    while i < j {
        if string[i] != string[j] {
            break
        }
        i += 1
        j -= 1
    }
    return string[i..j].reversed.string + string
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    var i, j = 0, string.length - 1
    while i < j {
        if string[i] != string[j] {
            break
        }
        i += 1
        j -= 1
    }
    return string[i..j].reversed.string + string
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    var i, j = 0, string.length - 1
    while i < j {
        if string[i] != string[j] {
            break
        }
        i += 1
        j -= 1
    }
    return string[i..j].reversed.string + string
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    var i, j = 0, string.length - 1
    while i < j {
        if string[i] != string[j] {
            break
        }
        i += 1
        j -= 1
    }
    return string[i..j].reversed.string + string
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    var i, j = 0, string.length - 1
    while i < j {
        if string[i] != string[j] {
            break
        }
        i += 1
        j -= 1
    }
    return string[i..j].reversed.string + string
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that

func makePalindrome(string: String) -> String {
    var palindrome = string
    var i = 0
    var j = string.length - 1
    while i < j {
        var temp = palindrome[i]
        palindrome[i] = palindrome[j]
        palindrome[j] = temp
        i += 1
        j -= 1
    }
    return palindrome
}

```swift
// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    var palindrome = string
    var i = 0
    var j = string.length - 1
    while i < j {
        var temp = palindrome[i]
        palindrome[i] = palindrome[j]
        palindrome[j] = temp
        i += 1
        j -= 1
    }
    return palindrome
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    var palindrome = string
    var i = 0
    var j = string.length - 1
    while i < j {
        var temp = palindrome[i]
        palindrome[i] = palindrome[j]
        palindrome[j] = temp
        i += 1
        j -= 1
    }
    return palindrome
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    var palindrome = string
    var i = 0
    var j = string.length - 1
    while i < j {
        var temp = palindrome[i]
        palindrome[i] = palindrome[j]
        palindrome[j] = temp
        i += 1
        j -= 1
    }
    return palindrome
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    var palindrome = string
    var i = 0
    var j = string.length - 1
    while i < j {
        var temp = palindrome[i]
        palindrome[i] = palindrome[j]
        palindrome[j] = temp
        i += 1
        j -= 1
    }
    return palindrome
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    var palindrome = string
    var i = 0
    var j = string.length - 1
    while i < j {
        var temp = palindrome[i]
        palindrome[i] = palindrome[j]
        palindrome[j] = temp
        i += 1
        j -= 1
    }
    return palindrome
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    var palindrome = string
    var i = 0
    var j = string.length - 1
    while i < j {
        var temp = palindrome[i]
        palindrome[i] = palindrome[j]
        palindrome[j] = temp
        i += 1
        j -=

func makePalindrome(string: String) -> String {
    let reversed = string.reversed()
    let prefix = string.prefix(count: string.prefixLength(from: reversed))
    return prefix + reversed
}

```swift
// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    let reversed = string.reversed()
    let prefix = string.prefix(count: string.prefixLength(from: reversed))
    return prefix + reversed
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    let reversed = string.reversed()
    let prefix = string.prefix(count: string.prefixLength(from: reversed))
    return prefix + reversed
}
```

func makePalindrome(string: String) -> String {
    var reversedString = string.reversed()
    var prefix = string.prefix(string.length - reversedString.length)
    return prefix + reversedString
}

```swift
// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    var reversedString = string.reversed()
    var prefix = string.prefix(string.length - reversedString.length)
    return prefix + reversedString
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    var reversedString = string.reversed()
    var prefix = string.prefix(string.length - reversedString.length)
    return prefix + reversedString
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    var reversedString = string.reversed()
    var prefix = string.prefix(string.length - reversedString.length)
    return prefix + reversedString
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    var reversedString = string.reversed()
    var prefix = string.prefix(string.length - reversedString.length)
    return prefix + reversedString
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    var reversedString = string.reversed()
    var prefix = string.prefix(string.length - reversedString.length)
    return prefix + reversedString
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    var reversedString = string.reversed()
    var prefix = string.prefix(string.length - reversedString.length)
    return prefix + reversedString
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    var reversedString = string.reversed()
    var prefix = string.prefix(string.length - reversedString.length)
    return prefix + reversedString
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"

func makePalindrome(string: String) -> String {
    var longestPalindromePrefix = ""
    var longestPalindrome = ""
    var longestPalindromeSuffix = ""
    var longestPalindromePrefixLength = 0
    for i in 0..<string.length {
        var prefix = string[..<i]
        var suffix = string[i..<string.length]
        if prefix == suffix.reversed {
            if longestPalindromePrefixLength < prefix.length {
                longestPalindromePrefix = prefix
                longestPalindromePrefixLength = prefix.length
            }
        }
    }
    if longestPalindromePrefix.isEmpty {
        return string
    }
    longestPalindromeSuffix = longestPalindromePrefix.reversed
    return longestPalindromePrefix + longestPalindromeSuffix
}

```swift
// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    var longestPalindromePrefix = ""
    var longestPalindrome = ""
    var longestPalindromeSuffix = ""
    var longestPalindromePrefixLength = 0
    for i in 0..<string.length {
        var prefix = string[..<i]
        var suffix = string[i..<string.length]
        if prefix == suffix.reversed {
            if longestPalindromePrefixLength < prefix.length {
                longestPalindromePrefix = prefix
                longestPalindromePrefixLength = prefix.length
            }
        }
    }
    if longestPalindromePrefix.isEmpty {
        return string
    }
    longestPalindromeSuffix = longestPalindromePrefix.reversed
    return longestPalindromePrefix + longestPalindromeSuffix
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    var longestPalindromePrefix = ""
    var longestPalindrome = ""
    var longestPalindromeSuffix = ""
    var longestPalindromePrefixLength = 0
    for i in 0..<string.length {
        var prefix = string[..<i]
        var suffix = string[i..<string.length]
        if prefix == suffix.reversed {
            if longestPalindromePrefixLength < prefix.length {
                longestPalindromePrefix = prefix
                longestPalindromePrefixLength = prefix.length
            }
        }
    }
    if longestPalindromePrefix.isEmpty {
        return string
    }
    longestPalindromeSuffix = longestPalindromePrefix.reversed
    return longestPalindromePrefix + longestPalindromeSuffix
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    var longestPalindromePrefix = ""
    var longestPalindrome = ""
    var longestPalindromeSuffix = ""
    var longestPalindromePrefixLength = 0
    for i in 0..<string.length {
        var prefix = string[..<i]
        var suffix = string[i..<string.length]
        if prefix == suffix.reversed {
            if longestPalindromePrefixLength < prefix.length {
                longestPalindromePrefix = prefix
                longestPalindromePrefixLength = prefix.length
            }
        }
    }
    if longestPalindromePrefix.isEmpty {
        return string
    }
    longestPalindromeSuffix = longestPalindromePrefix.reversed
    return longestPalindromePrefix + longestPalindromeSuffix
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    var longestPalindromePrefix = ""
    var longestPalindrome = ""
    var longestPalindromeSuffix = ""
    var longestPalindromePrefixLength = 0
    for i in 0..<string.length {
        var prefix = string[..<i]
        var suffix = string[i..<string.length]
        if prefix == suffix.reversed {
            if longestPalindromePrefixLength < prefix.length {
                longestPalindromePrefix = prefix
                longestPalindromePrefixLength = prefix.length
            }
        }
    }
    if longestPalindromePrefix.isEmpty {
        return string
    }
    longestPalindromeSuffix = longestPalind<|file_separator|>

func makePalindrome(string: String) -> String {
    let n = string.length
    let isPalindrome = {
        let s = String(string: string)
        let reversed = s.reversed()
        s == reversed
    }
    let longestPalindrome = {
        let s = String(string: string)
        for i in 0..<n {
            for j in i..<n {
                if isPalindrome(s[i..<j+1]) {
                    return s[i..<j+1]
                }
            }
        }
        ""
    }
    let prefix = String(string: string)
    prefix.reversed().append(longestPalindrome).append(prefix)
}

```swift
// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    let n = string.length
    let isPalindrome = {
        let s = String(string: string)
        let reversed = s.reversed()
        s == reversed
    }
    let longestPalindrome = {
        let s = String(string: string)
        for i in 0..<n {
            for j in i..<n {
                if isPalindrome(s[i..<j+1]) {
                    return s[i..<j+1]
                }
            }
        }
        ""
    }
    let prefix = String(string: string)
    prefix.reversed().append(longestPalindrome).append(prefix)
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    let n = string.length
    let isPalindrome = {
        let s = String(string: string)
        let reversed = s.reversed()
        s == reversed
    }
    let longestPalindrome = {
        let s = String(string: string)
        for i in 0..<n {
            for j in i..<n {
                if isPalindrome(s[i..<j+1]) {
                    return s[i..<j+1]
                }
            }
        }
        ""
    }
    let prefix = String(string: string)
    prefix.reversed().append(longestPalindrome).append(prefix)
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    let n = string.length
    let isPalindrome = {
        let s = String(string: string)
        let reversed = s.reversed()
        s == reversed
    }
    let longestPalindrome = {
        let s = String(string: string)
        for i in 0..<n {
            for j in i..<n {
                if isPalindrome(s[i..<j+1]) {
                    return s[i..<j+1]
                }
            }
        }
        ""
    }
    let prefix = String(string: string)
    prefix.reversed().append(longestPalindrome).append(prefix)
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    let n = string.length
    let isPalindrome = {
        let s = String(string: string)
        let reversed = s.reversed()
        s == reversed
    }
    let longestPalindrome = {
        let s = String(string: string)
        for i in 0..<n {
            for j in i..<n {
                if isPalindrome(s[i..<j+1]) {
                    return s[i..<j+1]
                }
            }
        }
        ""
    }
    let prefix = String(string: string)
    prefix.reversed().append(longestPalindrome).append(prefix)
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") ==

func makePalindrome(string: String) -> String {
    let n = string.length
    let i = 0
    let j = n - 1
    while i < j {
        if string[i] != string[j] {
            break
        }
        i += 1
        j -= 1
    }
    let prefix = string[..i - 1]
    let suffix = string[i..]
    let reversed = suffix.reversed
    return prefix + reversed
}

```swift
// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    let n = string.length
    let i = 0
    let j = n - 1
    while i < j {
        if string[i] != string[j] {
            break
        }
        i += 1
        j -= 1
    }
    let prefix = string[..i - 1]
    let suffix = string[i..]
    let reversed = suffix.reversed
    return prefix + reversed
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    let n = string.length
    let i = 0
    let j = n - 1
    while i < j {
        if string[i] != string[j] {
            break
        }
        i += 1
        j -= 1
    }
    let prefix = string[..i - 1]
    let suffix = string[i..]
    let reversed = suffix.reversed
    return prefix + reversed
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    let n = string.length
    let i = 0
    let j = n - 1
    while i < j {
        if string[i] != string[j] {
            break
        }
        i += 1
        j -= 1
    }
    let prefix = string[..i - 1]
    let suffix = string[i..]
    let reversed = suffix.reversed
    return prefix + reversed
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    let n = string.length
    let i = 0
    let j = n - 1
    while i < j {
        if string[i] != string[j] {
            break
        }
        i += 1
        j -= 1
    }
    let prefix = string[..i - 1]
    let suffix = string[i..]
    let reversed = suffix.reversed
    return prefix + reversed
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string: "") == ""
// makePalindrome(string: "cat") == "catac"
// makePalindrome(string: "cata") == "catac"
func makePalindrome(string: String) -> String {
    let n = string.length
    let i = 0
    let j = n - 1
    while i < j {
        if string[i] != string[j] {
            break
        }
        i += 1
        j -= 1
    }
    let prefix = string[..i - 1]
    let suffix = string[i..]
    let reversed = suffix.reversed
    return prefix + reversed
}

// Find the shortest palindrome that begins with a supplied string.
// Algorithm idea is simple:
// - Find the longest postfix of supplied string that is a palindrome.
// - Append to the end of the string reverse of a string prefix that comes before the palindromic suffix.
// makePalindrome(string

func stringXor(a: String, b: String) -> String {
    let a = a.map(String.characterAtIndex)
    let b = b.map(String.characterAtIndex)
    var result = ""
    for i in 0..<a.count {
        result += (a[i] ^ b[i]).toString()
    }
    return result
}

func stringAnd(a: String) -> String {
    let a = a.map(String.characterAtIndex)
    var result = ""
    for i in 0..<a.count {
        result += (a[i] & a[i]).toString()
    }
    return result
}

func stringOr(a: String) -> String {
    let a = a.map(String.characterAtIndex)
    var result = ""
    for i in 0..<a.count {
        result += (a[i] | a[i]).toString()
    }
    return result
}

func stringNot(a: String) -> String {
    let a = a.map(String.characterAtIndex)
    var result = ""
    for i in 0..<a.count {
        result += (a[i] ^ 1).toString()
    }
    return result
}

```swift
// Input are two strings a and b consisting only of 1s and 0s.
// Perform binary XOR on these inputs and return result also as a string.
// stringXor(a: "010", b: "110") == "100"
func stringXor(a: String, b: String) -> String {
    let a = a.map(String.characterAtIndex)
    let b = b.map(String.characterAtIndex)
    var result = ""
    for i in 0..<a.count {
        result += (a[i] ^ b[i]).toString()
    }
    return result
}

// Input is a string consisting of 1s and 0s.
// Perform binary AND on this input and return result also as a string.
// stringAnd(a: "110") == "110"
func stringAnd(a: String) -> String {
    let a = a.map(String.characterAtIndex)
    var result = ""
    for i in 0..<a.count {
        result += (a[i] & a[i]).toString()
    }
    return result
}

// Input is a string consisting of 1s and 0s.
// Perform binary OR on this input and return result also as a string.
// stringOr(a: "110") == "111"
func stringOr(a: String) -> String {
    let a = a.map(String.characterAtIndex)
    var result = ""
    for i in 0..<a.count {
        result += (a[i] | a[i]).toString()
    }
    return result
}

// Input is a string consisting of 1s and 0s.
// Perform binary NOT on this input and return result also as a string.
// stringNot(a: "110") == "001"
func stringNot(a: String) -> String {
    let a = a.map(String.characterAtIndex)
    var result = ""
    for i in 0..<a.count {
        result += (a[i] ^ 1).toString()
    }
    return result
}

// Input is a string consisting of 1s and 0s.
// Perform binary XOR on this input and return result also as a string.
// stringXor(a: "010", b: "110") == "100"
func stringXor(a: String, b: String) -> String {
    let a = a.map(String.characterAtIndex)
    let b = b.map(String.characterAtIndex)
    var result = ""
    for i in 0..<a.count {
        result += (a[i] ^ b[i]).toString()
    }
    return result
}

// Input is a string consisting of 1s and 0s.
// Perform binary AND on this input and return result also as a string.
// stringAnd(a: "110") == "110"
func stringAnd(a: String) -> String {
    let a = a.map(String.characterAtIndex)
    var result = ""
    for i in 0..<a.count {
        result += (a[i] & a[i]).toString()
    }
    return result
}

// Input is a string consisting of 1s and 0s.
// Perform binary OR on this input and return result also as a string.
// stringOr(a: "110") == "111"
func stringOr(a: String) -> String {
    let a = a.map(String.characterAtIndex)
    var result = ""
    for i in 0..<a.count {
        result += (a[i] | a[i]).toString()
    }
    return result
}

// Input is a string consisting of 1s and 0s.
// Perform binary NOT on this input and return result also as a string.
// stringNot(a: "110") == "001"
func stringNot(a: String) -> String {
    let a = a.map(String.characterAtIndex)
    var result = ""
    for i in 0..<a.count {
        result += (a[i] ^ 1).toString()
    }
    return result
}

// Input is a string consisting of 1s and 0s.
// Perform binary XOR on this input and return result also as a string.
// stringXor(a: "010", b: "110") == "100"
func stringXor(a: String, b: String) -> String {
    let a = a.map(String.characterAtIndex)
    let b = b.map(String

func stringXor(a: String, b: String) -> String {
    var result = ""
    for i in 0..<max(a.length, b.length) {
        result += (a[i] ^ b[i]).toString()
    }
    return result
}

```swift
// Input are two strings a and b consisting only of 1s and 0s.
// Perform binary XOR on these inputs and return result also as a string.
// stringXor(a: "010", b: "110") == "100"
func stringXor(a: String, b: String) -> String {
    var result = ""
    for i in 0..<max(a.length, b.length) {
        result += (a[i] ^ b[i]).toString()
    }
    return result
}

// Test cases
print(stringXor(a: "010", b: "110")) // Output: "100"
print(stringXor(a: "101", b: "101")) // Output: "000"
print(stringXor(a: "111", b: "000")) // Output: "111"
print(stringXor(a: "000", b: "000")) // Output: "000"
print(stringXor(a: "1111", b: "1111")) // Output: "0000"
print(stringXor(a: "1111", b: "11111")) // Output: "000000"
```

func stringXor(a: String, b: String) -> String {
    let result = "";
    for i in 0..<max(a.length, b.length) {
        result += (a.characterAtIndex(i) ^ b.characterAtIndex(i)).stringValue;
    }
    return result;
}

func stringXor(a: String) -> String {
    let result = "";
    for i in 0..<a.length {
        result += (a.characterAtIndex(i) ^ '0').stringValue;
    }
    return result;
}

func stringXor(a: String) -> String {
    let result = "";
    for i in 0..<a.length {
        result += (a.characterAtIndex(i) ^ '1').stringValue;
    }
    return result;
}

```swift
// Input are two strings a and b consisting only of 1s and 0s.
// Perform binary XOR on these inputs and return result also as a string.
// stringXor(a: "010", b: "110") == "100"
func stringXor(a: String, b: String) -> String {
    let result = "";
    for i in 0..<max(a.length, b.length) {
        result += (a.characterAtIndex(i) ^ b.characterAtIndex(i)).stringValue;
    }
    return result;
}

// Input is a string consisting of 1s and 0s.
// Perform binary XOR on the input string and return result also as a string.
// stringXor(a: "010") == "101"
func stringXor(a: String) -> String {
    let result = "";
    for i in 0..<a.length {
        result += (a.characterAtIndex(i) ^ '0').stringValue;
    }
    return result;
}

// Input is a string consisting of 1s and 0s.
// Perform binary XOR on the input string and return result also as a string.
// stringXor(a: "110") == "001"
func stringXor(a: String) -> String {
    let result = "";
    for i in 0..<a.length {
        result += (a.characterAtIndex(i) ^ '1').stringValue;
    }
    return result;
}

// Input is a string consisting of 1s and 0s.
// Perform binary XOR on the input string and return result also as a string.
// stringXor(a: "111") == "000"
func stringXor(a: String) -> String {
    let result = "";
    for i in 0..<a.length {
        result += (a.characterAtIndex(i) ^ '0').stringValue;
    }
    return result;
}

// Input is a string consisting of 1s and 0s.
// Perform binary XOR on the input string and return result also as a string.
// stringXor(a: "000") == "111"
func stringXor(a: String) -> String {
    let result = "";
    for i in 0..<a.length {
        result += (a.characterAtIndex(i) ^ '1').stringValue;
    }
    return result;
}

// Input is a string consisting of 1s and 0s.
// Perform binary XOR on the input string and return result also as a string.
// stringXor(a: "001") == "110"
func stringXor(a: String) -> String {
    let result = "";
    for i in 0..<a.length {
        result += (a.characterAtIndex(i) ^ '0').stringValue;
    }
    return result;
}

// Input is a string consisting of 1s and 0s.
// Perform binary XOR on the input string and return result also as a string.
// stringXor(a: "011") == "100"
func stringXor(a: String) -> String {
    let result = "";
    for i in 0..<a.length {
        result += (a.characterAtIndex(i) ^ '1').stringValue;
    }
    return result;
}

// Input is a string consisting of 1s and 0s.
// Perform binary XOR on the input string and return result also as a string.
// stringXor(a: "101") == "010"
func stringXor(a: String) -> String {
    let result = "";
    for i in 0..<a.length {
        result += (a.characterAtIndex(i) ^ '0').stringValue;
    }
    return result;
}

// Input is a string consisting of 1s and 0s.
// Perform binary XOR on the input string and return result also as a string.
// stringXor(a: "100") == "011"
func stringXor(a: String) -> String {
    let result = "";
    for i in 0..<a.length {
        result += (a.characterAtIndex(i) ^ '1').stringValue;
    }
    return result;
}

// Input is a string consisting of 1s and 0s.
// Perform binary XOR on the input string and return result also as a string.
// stringXor(a: "010") == "101"
func stringXor(a: String) -> String {
    let result = "";
    for i in 0..<a.length {
        result += (a.characterAtIndex(i) ^ '

func stringXor(a: String, b: String) -> String {
    let result = "";
    for i in 0..<max(a.length, b.length) {
        let digitA = if i < a.length { a[i] } else { '0' };
        let digitB = if i < b.length { b[i] } else { '0' };
        result += (digitA ^ digitB).toString();
    }
    return result;
}

```swift
// Input are two strings a and b consisting only of 1s and 0s.
// Perform binary XOR on these inputs and return result also as a string.
// stringXor(a: "010", b: "110") == "100"
func stringXor(a: String, b: String) -> String {
    let result = "";
    for i in 0..<max(a.length, b.length) {
        let digitA = if i < a.length { a[i] } else { '0' };
        let digitB = if i < b.length { b[i] } else { '0' };
        result += (digitA ^ digitB).toString();
    }
    return result;
}

// Test the function
let a = "010";
let b = "110";
let result = stringXor(a, b);
print(result); // Output: "100"
```

func stringXor(a: String, b: String) -> String {
    var result = ""
    for i in 0..<max(a.count, b.count) {
        result += (a.characterAtIndex(i) ^ b.characterAtIndex(i)).stringValue
    }
    return result
}

func stringAnd(a: String) -> String {
    var result = ""
    for i in 0..<a.count {
        result += (a.characterAtIndex(i) & a.characterAtIndex(i)).stringValue
    }
    return result
}

func stringOr(a: String) -> String {
    var result = ""
    for i in 0..<a.count {
        result += (a.characterAtIndex(i) | a.characterAtIndex(i)).stringValue
    }
    return result
}

func stringNot(a: String) -> String {
    var result = ""
    for i in 0..<a.count {
        result += (a.characterAtIndex(i) ^ 1).stringValue
    }
    return result
}

```swift
// Input are two strings a and b consisting only of 1s and 0s.
// Perform binary XOR on these inputs and return result also as a string.
// stringXor(a: "010", b: "110") == "100"
func stringXor(a: String, b: String) -> String {
    var result = ""
    for i in 0..<max(a.count, b.count) {
        result += (a.characterAtIndex(i) ^ b.characterAtIndex(i)).stringValue
    }
    return result
}

// Input is a string consisting of 1s and 0s.
// Perform binary AND on this input and return result also as a string.
// stringAnd(a: "010") == "010"
func stringAnd(a: String) -> String {
    var result = ""
    for i in 0..<a.count {
        result += (a.characterAtIndex(i) & a.characterAtIndex(i)).stringValue
    }
    return result
}

// Input is a string consisting of 1s and 0s.
// Perform binary OR on this input and return result also as a string.
// stringOr(a: "010") == "110"
func stringOr(a: String) -> String {
    var result = ""
    for i in 0..<a.count {
        result += (a.characterAtIndex(i) | a.characterAtIndex(i)).stringValue
    }
    return result
}

// Input is a string consisting of 1s and 0s.
// Perform binary NOT on this input and return result also as a string.
// stringNot(a: "010") == "101"
func stringNot(a: String) -> String {
    var result = ""
    for i in 0..<a.count {
        result += (a.characterAtIndex(i) ^ 1).stringValue
    }
    return result
}

// Input is a string consisting of 1s and 0s.
// Perform binary XOR on this input and return result also as a string.
// stringXor(a: "010", b: "110") == "100"
func stringXor(a: String, b: String) -> String {
    var result = ""
    for i in 0..<max(a.count, b.count) {
        result += (a.characterAtIndex(i) ^ b.characterAtIndex(i)).stringValue
    }
    return result
}

// Input is a string consisting of 1s and 0s.
// Perform binary AND on this input and return result also as a string.
// stringAnd(a: "010") == "010"
func stringAnd(a: String) -> String {
    var result = ""
    for i in 0..<a.count {
        result += (a.characterAtIndex(i) & a.characterAtIndex(i)).stringValue
    }
    return result
}

// Input is a string consisting of 1s and 0s.
// Perform binary OR on this input and return result also as a string.
// stringOr(a: "010") == "110"
func stringOr(a: String) -> String {
    var result = ""
    for i in 0..<a.count {
        result += (a.characterAtIndex(i) | a.characterAtIndex(i)).stringValue
    }
    return result
}

// Input is a string consisting of 1s and 0s.
// Perform binary NOT on this input and return result also as a string.
// stringNot(a: "010") == "101"
func stringNot(a: String) -> String {
    var result = ""
    for i in 0..<a.count {
        result += (a.characterAtIndex(i) ^ 1).stringValue
    }
    return result
}

// Input is a string consisting of 1s and 0s.
// Perform binary XOR on this input and return result also as a string.
// stringXor(a: "010", b: "110") == "100"
func stringXor(a: String, b: String) -> String {
    var result = ""
    for i in 0..<max(a.count, b.count) {
        result += (a.characterAtIndex(i) ^ b.characterAtIndex(i)).stringValue
    }
    return result
}

// Input is a string consisting of 1s and 0s.
// Perform binary AND on this input and return result also as a string.
// stringAnd(a: "010") == "010"
func stringAnd(a: String) -> String

func stringXor(a: String, b: String) -> String {
    var result = "";
    for i in 0..<max(a.count, b.count) {
        result += (a.characterAtIndex(i) ^ b.characterAtIndex(i)).stringValue;
    }
    return result;
}

func arrayXor(a: [Int]) -> [Int] {
    var result = [Int](nil);
    for i in 0..<a.count {
        result.append(a[i] ^ a[i + 1]);
    }
    return result;
}

func stringXor(a: String) -> String {
    var result = "";
    for i in 0..<a.count {
        result += (a.characterAtIndex(i) ^ a.characterAtIndex(i + 1)).stringValue;
    }
    return result;
}

```swift
// Input are two strings a and b consisting only of 1s and 0s.
// Perform binary XOR on these inputs and return result also as a string.
// stringXor(a: "010", b: "110") == "100"
func stringXor(a: String, b: String) -> String {
    var result = "";
    for i in 0..<max(a.count, b.count) {
        result += (a.characterAtIndex(i) ^ b.characterAtIndex(i)).stringValue;
    }
    return result;
}

// Input is an array of integers.
// Perform binary XOR on all elements of the array and return result also as an array.
// arrayXor([1, 2, 3]) == [4, 0, 7]
func arrayXor(a: [Int]) -> [Int] {
    var result = [Int](nil);
    for i in 0..<a.count {
        result.append(a[i] ^ a[i + 1]);
    }
    return result;
}

// Input is a string consisting of 1s and 0s.
// Perform binary XOR on all elements of the string and return result also as a string.
// stringXor("010") == "110"
func stringXor(a: String) -> String {
    var result = "";
    for i in 0..<a.count {
        result += (a.characterAtIndex(i) ^ a.characterAtIndex(i + 1)).stringValue;
    }
    return result;
}

// Input is a string consisting of 1s and 0s.
// Perform binary XOR on all elements of the string and return result also as a string.
// stringXor("010") == "110"
func stringXor(a: String) -> String {
    var result = "";
    for i in 0..<a.count {
        result += (a.characterAtIndex(i) ^ a.characterAtIndex(i + 1)).stringValue;
    }
    return result;
}

// Input is an array of integers.
// Perform binary XOR on all elements of the array and return result also as an array.
// arrayXor([1, 2, 3]) == [4, 0, 7]
func arrayXor(a: [Int]) -> [Int] {
    var result = [Int](nil);
    for i in 0..<a.count {
        result.append(a[i] ^ a[i + 1]);
    }
    return result;
}

// Input is an array of integers.
// Perform binary XOR on all elements of the array and return result also as an array.
// arrayXor([1, 2, 3]) == [4, 0, 7]
func arrayXor(a: [Int]) -> [Int] {
    var result = [Int](nil);
    for i in 0..<a.count {
        result.append(a[i] ^ a[i + 1]);
    }
    return result;
}

// Input is an array of integers.
// Perform binary XOR on all elements of the array and return result also as an array.
// arrayXor([1, 2, 3]) == [4, 0, 7]
func arrayXor(a: [Int]) -> [Int] {
    var result = [Int](nil);
    for i in 0..<a.count {
        result.append(a[i] ^ a[i + 1]);
    }
    return result;
}

// Input is an array of integers.
// Perform binary XOR on all elements of the array and return result also as an array.
// arrayXor([1, 2, 3]) == [4, 0, 7]
func arrayXor(a: [Int]) -> [Int] {
    var result = [Int](nil);
    for i in 0..<a.count {
        result.append(a[i] ^ a[i + 1]);
    }
    return result;
}

// Input is an array of integers.
// Perform binary XOR on all elements of the array and return result also as an array.
// arrayXor([1, 2, 3]) == [4, 0, 7]
func arrayXor(a: [Int]) -> [Int] {
    var result = [Int](nil);
    for i in 0..<a.count {
        result.append(a[i] ^ a[i + 1]);
    }
    return result;
}

// Input is an array of integers.
// Perform binary XOR on all elements of the array and return result also as an array.
// arrayXor([1, 2, 3])

func stringXor(a: String, b: String) -> String {
    var result = ""
    for i in 0..<max(a.length, b.length) {
        var aChar = if i < a.length { a[i] } else { '0' }
        var bChar = if i < b.length { b[i] } else { '0' }
        result += String(aChar ^ bChar)
    }
    return result
}

```swift
// Input are two strings a and b consisting only of 1s and 0s.
// Perform binary XOR on these inputs and return result also as a string.
// stringXor(a: "010", b: "110") == "100"
func stringXor(a: String, b: String) -> String {
    var result = ""
    for i in 0..<max(a.length, b.length) {
        var aChar = if i < a.length { a[i] } else { '0' }
        var bChar = if i < b.length { b[i] } else { '0' }
        result += String(aChar ^ bChar)
    }
    return result
}

// Test cases
print(stringXor(a: "010", b: "110")) // Output: "100"
print(stringXor(a: "101", b: "011")) // Output: "110"
print(stringXor(a: "10010", b: "10101")) // Output: "00111"
print(stringXor(a: "11100", b: "00011")) // Output: "11111"
```

func stringXor(a: String, b: String) -> String {
    var result = ""
    for i in 0..<max(a.length, b.length) {
        if i < a.length && i < b.length {
            result += (a[i] ^ b[i]).toString()
        } else if i < a.length {
            result += a[i].toString()
        } else {
            result += b[i].toString()
        }
    }
    return result
}

```swift
// Input are two strings a and b consisting only of 1s and 0s.
// Perform binary XOR on these inputs and return result also as a string.
// stringXor(a: "010", b: "110") == "100"
func stringXor(a: String, b: String) -> String {
    var result = ""
    for i in 0..<max(a.length, b.length) {
        if i < a.length && i < b.length {
            result += (a[i] ^ b[i]).toString()
        } else if i < a.length {
            result += a[i].toString()
        } else {
            result += b[i].toString()
        }
    }
    return result
}
```

func stringXor(a: String, b: String) -> String {
    var result = "";
    for i in 0..<max(a.length, b.length) {
        result += (a[i] ^ b[i]).toString();
    }
    return result;
}

func arrayXor(arr: [Int]) -> String {
    var result = "";
    for i in 0..<arr.count {
        result += (arr[i] ^ arr[i + 1]).toString();
    }
    return result;
}

```swift
// Input are two strings a and b consisting only of 1s and 0s.
// Perform binary XOR on these inputs and return result also as a string.
// stringXor(a: "010", b: "110") == "100"
func stringXor(a: String, b: String) -> String {
    var result = "";
    for i in 0..<max(a.length, b.length) {
        result += (a[i] ^ b[i]).toString();
    }
    return result;
}

// Input is an array of integers.
// Perform binary XOR on all the elements of the array and return the result as a string.
// arrayXor([1, 2, 3, 4]) == "11"
func arrayXor(arr: [Int]) -> String {
    var result = "";
    for i in 0..<arr.count {
        result += (arr[i] ^ arr[i + 1]).toString();
    }
    return result;
}

// Input is an array of integers.
// Perform binary XOR on all the elements of the array and return the result as a string.
// arrayXor([1, 2, 3, 4]) == "11"
func arrayXor(arr: [Int]) -> String {
    var result = "";
    for i in 0..<arr.count {
        result += (arr[i] ^ arr[i + 1]).toString();
    }
    return result;
}

// Input is an array of integers.
// Perform binary XOR on all the elements of the array and return the result as a string.
// arrayXor([1, 2, 3, 4]) == "11"
func arrayXor(arr: [Int]) -> String {
    var result = "";
    for i in 0..<arr.count {
        result += (arr[i] ^ arr[i + 1]).toString();
    }
    return result;
}

// Input is an array of integers.
// Perform binary XOR on all the elements of the array and return the result as a string.
// arrayXor([1, 2, 3, 4]) == "11"
func arrayXor(arr: [Int]) -> String {
    var result = "";
    for i in 0..<arr.count {
        result += (arr[i] ^ arr[i + 1]).toString();
    }
    return result;
}

// Input is an array of integers.
// Perform binary XOR on all the elements of the array and return the result as a string.
// arrayXor([1, 2, 3, 4]) == "11"
func arrayXor(arr: [Int]) -> String {
    var result = "";
    for i in 0..<arr.count {
        result += (arr[i] ^ arr[i + 1]).toString();
    }
    return result;
}

// Input is an array of integers.
// Perform binary XOR on all the elements of the array and return the result as a string.
// arrayXor([1, 2, 3, 4]) == "11"
func arrayXor(arr: [Int]) -> String {
    var result = "";
    for i in 0..<arr.count {
        result += (arr[i] ^ arr[i + 1]).toString();
    }
    return result;
}

// Input is an array of integers.
// Perform binary XOR on all the elements of the array and return the result as a string.
// arrayXor([1, 2, 3, 4]) == "11"
func arrayXor(arr: [Int]) -> String {
    var result = "";
    for i in 0..<arr.count {
        result += (arr[i] ^ arr[i + 1]).toString();
    }
    return result;
}

// Input is an array of integers.
// Perform binary XOR on all the elements of the array and return the result as a string.
// arrayXor([1, 2, 3, 4]) == "11"
func arrayXor(arr: [Int]) -> String {
    var result = "";
    for i in 0..<arr.count {
        result += (arr[i] ^ arr[i + 1]).toString();
    }
    return result;
}

// Input is an array of integers.
// Perform binary XOR on all the elements of the array and return the result as a string.
// arrayXor([1, 2, 3, 4]) == "11"
func arrayXor(arr: [Int]) -> String {
    var result = "";
    for i in 0..<arr.count {
        result += (arr[i] ^ arr[

func stringXor(a: String, b: String) -> String {
    var result = "";
    for i in 0..<max(a.length, b.length) {
        if a.length > i {
            result += a[i];
        }
        if b.length > i {
            result += b[i];
        }
    }
    return result;
}

func stringAnd(a: String) -> String {
    var result = "";
    for i in 0..<a.length {
        if a[i] == '1' {
            result += a[i];
        }
    }
    return result;
}

func stringOr(a: String) -> String {
    var result = "";
    for i in 0..<a.length {
        if a[i] == '1' {
            result += a[i];
        }
    }
    return result;
}

func stringNot(a: String) -> String {
    var result = "";
    for i in 0..<a.length {
        if a[i] == '1' {
            result += '0';
        } else {
            result += '1';
        }
    }
    return result;
}

```swift
// Input are two strings a and b consisting only of 1s and 0s.
// Perform binary XOR on these inputs and return result also as a string.
// stringXor(a: "010", b: "110") == "100"
func stringXor(a: String, b: String) -> String {
    var result = "";
    for i in 0..<max(a.length, b.length) {
        if a.length > i {
            result += a[i];
        }
        if b.length > i {
            result += b[i];
        }
    }
    return result;
}

// Input is a string consisting of 1s and 0s.
// Perform binary AND on this input and return result also as a string.
// stringAnd(a: "010") == "010"
func stringAnd(a: String) -> String {
    var result = "";
    for i in 0..<a.length {
        if a[i] == '1' {
            result += a[i];
        }
    }
    return result;
}

// Input is a string consisting of 1s and 0s.
// Perform binary OR on this input and return result also as a string.
// stringOr(a: "010") == "011"
func stringOr(a: String) -> String {
    var result = "";
    for i in 0..<a.length {
        if a[i] == '1' {
            result += a[i];
        }
    }
    return result;
}

// Input is a string consisting of 1s and 0s.
// Perform binary NOT on this input and return result also as a string.
// stringNot(a: "010") == "101"
func stringNot(a: String) -> String {
    var result = "";
    for i in 0..<a.length {
        if a[i] == '1' {
            result += '0';
        } else {
            result += '1';
        }
    }
    return result;
}

// Input is a string consisting of 1s and 0s.
// Perform binary XOR on this input and return result also as a string.
// stringXor(a: "010", b: "110") == "100"
func stringXor(a: String, b: String) -> String {
    var result = "";
    for i in 0..<max(a.length, b.length) {
        if a.length > i {
            result += a[i];
        }
        if b.length > i {
            result += b[i];
        }
    }
    return result;
}

// Input is a string consisting of 1s and 0s.
// Perform binary AND on this input and return result also as a string.
// stringAnd(a: "010") == "010"
func stringAnd(a: String) -> String {
    var result = "";
    for i in 0..<a.length {
        if a[i] == '1' {
            result += a[i];
        }
    }
    return result;
}

// Input is a string consisting of 1s and 0s.
// Perform binary OR on this input and return result also as a string.
// stringOr(a: "010") == "011"
func stringOr(a: String) -> String {
    var result = "";
    for i in 0..<a.length {
        if a[i] == '1' {
            result += a[i];
        }
    }
    return result;
}

// Input is a string consisting of 1s and 0s.
// Perform binary NOT on this input and return result also as a string.
// stringNot(a: "010") == "101"
func stringNot(a: String) -> String {
    var result = "";
    for i in 0..<a.length {
        if a[i] == '1' {
            result += '0';
        } else {
            result += '1';
        }
    }
    return result;
}

// Input is a string consisting of 1s and 0s.
// Perform binary XOR on this input and return result also as a string.
// stringXor(a: "010", b: "110") == "100"
func stringXor(a: String, b: String) -> String {
    var result = "";
    for i in 0..<max(a.length, b.length) {
        if

func longest(strings: [String]) -> String? {
    var longestString: String? = nil
    var longestStringLength: Int = 0
    for _, string in strings {
        if string.length > longestStringLength {
            longestString = string
            longestStringLength = string.length
        }
    }
    return longestString
}

func longer_strings(strings: [String], n: Int) -> [String] {
    var longerStrings: [String] = []
    for _, string in strings {
        if string.length > n {
            longerStrings.append(string)
        }
    }
    return longerStrings
}

func shorter_strings(strings: [String], n: Int) -> [String] {
    var shorterStrings: [String] = []
    for _, string in strings {
        if string.length < n {
            shorterStrings.append(string)
        }
    }
    return shorterStrings
}

func starts_with_a(strings: [String]) -> [String] {
    var startsWithA: [String] = []
    for _, string in strings {
        if string.subscript(0) == "a" {
            startsWithA.append(string)
        }
    }
    return startsWithA
}

func ends_with_a(strings: [String]) -> [String] {
    var endsWithA: [String] = []
    for _, string in strings {
        if string.subscript(string.length - 1) == "a" {
            endsWithA.append(string)
        }
    }
    return endsWithA
}

func contains_a(strings: [String]) -> [String] {
    var containsA: [String] = []
    for _, string in strings {
        if string.contains("a") {
            containsA.append(string)
        }
    }
    return containsA
}

```swift
// Out of array of strings, return the longest one. Return the first one in case of multiple
// strings of the same length. Return nil in case the input array is empty.
// longest(strings: [] as [String]) == nil
// longest(strings: ["a", "b", "c"]) == "a"
// longest(strings: ["a", "bb", "ccc"]) == "ccc"
func longest(strings: [String]) -> String? {
    var longestString: String? = nil
    var longestStringLength: Int = 0
    for _, string in strings {
        if string.length > longestStringLength {
            longestString = string
            longestStringLength = string.length
        }
    }
    return longestString
}

// Given an array of strings, return a new array that contains only strings longer than n.
// longer_strings(strings: ["a", "b", "c"], n: 1) == ["b", "c"]
// longer_strings(strings: ["a", "b", "c"], n: 2) == ["a", "b", "c"]
// longer_strings(strings: ["a", "b", "c"], n: 3) == []
func longer_strings(strings: [String], n: Int) -> [String] {
    var longerStrings: [String] = []
    for _, string in strings {
        if string.length > n {
            longerStrings.append(string)
        }
    }
    return longerStrings
}

// Given an array of strings, return a new array that contains only strings shorter than n.
// shorter_strings(strings: ["a", "b", "c"], n: 1) == ["a"]
// shorter_strings(strings: ["a", "b", "c"], n: 2) == ["b"]
// shorter_strings(strings: ["a", "b", "c"], n: 3) == ["a", "b", "c"]
func shorter_strings(strings: [String], n: Int) -> [String] {
    var shorterStrings: [String] = []
    for _, string in strings {
        if string.length < n {
            shorterStrings.append(string)
        }
    }
    return shorterStrings
}

// Given an array of strings, return a new array that contains only strings that start with
// the letter a.
// starts_with_a(strings: ["a", "b", "c"]) == ["a"]
// starts_with_a(strings: ["a", "b", "c"]) == ["a"]
// starts_with_a(strings: ["a", "b", "c"]) == ["a"]
func starts_with_a(strings: [String]) -> [String] {
    var startsWithA: [String] = []
    for _, string in strings {
        if string.subscript(0) == "a" {
            startsWithA.append(string)
        }
    }
    return startsWithA
}

// Given an array of strings, return a new array that contains only strings that end with the
// letter a.
// ends_with_a(strings: ["a", "b", "c"]) == []
// ends_with_a(strings: ["a", "b", "c"]) == []
// ends_with_a(strings: ["a", "b", "c"]) == []
func ends_with_a(strings: [String]) -> [String] {
    var endsWithA: [String] = []
    for _, string in strings {
        if string.subscript(string.length - 1) == "a" {
            endsWithA.append(string)
        }
    }
    return endsWithA
}

// Given an array of strings, return a new array that contains only strings that contain the
// letter a.
// contains_a(strings: ["a", "b", "c"]) == ["a", "b", "c"]
// contains_a(strings: ["a", "b", "c"]) == ["a", "b", "c"]
// contains_a(strings: ["a", "b", "c"]) == ["a", "b", "c"]
func contains_a(strings: [String]) -> [String] {
    var containsA: [String] = []
    for _, string in strings {
        if string.contains("a") {
            containsA.append(string)
        }
    }
    return containsA
}

// Given an array of strings, return a new array that contains only strings that do not contain
// the letter a.
// does_not_contain_a(strings: ["a", "b", "c"]) == []
// does_not_contain_a(strings: ["a", "b", "c"]) == []
// does_not_contain_a(strings: ["a", "b", "c"]) == []
func does

func longest(strings: [String]) -> String? {
    var longestString: String? = nil
    var longestLength: Int = 0
    for _, string in strings {
        if string.Length > longestLength {
            longestLength = string.Length
            longestString = string
        }
    }
    return longestString
}

```swift
// Out of array of strings, return the longest one. Return the first one in case of multiple
// strings of the same length. Return nil in case the input array is empty.
// longest(strings: [] as [String]) == nil
// longest(strings: ["a", "b", "c"]) == "a"
// longest(strings: ["a", "bb", "ccc"]) == "ccc"
func longest(strings: [String]) -> String? {
    var longestString: String? = nil
    var longestLength: Int = 0
    for _, string in strings {
        if string.Length > longestLength {
            longestLength = string.Length
            longestString = string
        }
    }
    return longestString
}

// Out of array of strings, return the longest one. Return the first one in case of multiple
// strings of the same length. Return nil in case the input array is empty.
// longest(strings: [] as [String]) == nil
// longest(strings: ["a", "b", "c"]) == "a"
// longest(strings: ["a", "bb", "ccc"]) == "ccc"
func longest(strings: [String]) -> String? {
    var longestString: String? = nil
    var longestLength: Int = 0
    for _, string in strings {
        if string.Length > longestLength {
            longestLength = string.Length
            longestString = string
        }
    }
    return longestString
}

// Out of array of strings, return the longest one. Return the first one in case of multiple
// strings of the same length. Return nil in case the input array is empty.
// longest(strings: [] as [String]) == nil
// longest(strings: ["a", "b", "c"]) == "a"
// longest(strings: ["a", "bb", "ccc"]) == "ccc"
func longest(strings: [String]) -> String? {
    var longestString: String? = nil
    var longestLength: Int = 0
    for _, string in strings {
        if string.Length > longestLength {
            longestLength = string.Length
            longestString = string
        }
    }
    return longestString
}

// Out of array of strings, return the longest one. Return the first one in case of multiple
// strings of the same length. Return nil in case the input array is empty.
// longest(strings: [] as [String]) == nil
// longest(strings: ["a", "b", "c"]) == "a"
// longest(strings: ["a", "bb", "ccc"]) == "ccc"
func longest(strings: [String]) -> String? {
    var longestString: String? = nil
    var longestLength: Int = 0
    for _, string in strings {
        if string.Length > longestLength {
            longestLength = string.Length
            longestString = string
        }
    }
    return longestString
}

// Out of array of strings, return the longest one. Return the first one in case of multiple
// strings of the same length. Return nil in case the input array is empty.
// longest(strings: [] as [String]) == nil
// longest(strings: ["a", "b", "c"]) == "a"
// longest(strings: ["a", "bb", "ccc"]) == "ccc"
func longest(strings: [String]) -> String? {
    var longestString: String? = nil
    var longestLength: Int = 0
    for _, string in strings {
        if string.Length > longestLength {
            longestLength = string.Length
            longestString = string
        }
    }
    return longestString
}

// Out of array of strings, return the longest one. Return the first one in case of multiple
// strings of the same length. Return nil in case the input array is empty.
// longest(strings: [] as [String]) == nil
// longest(strings: ["a", "b", "c"]) == "a"
// longest(strings: ["a", "bb", "ccc"]) == "ccc"
func longest(strings: [String]) -> String? {
    var longestString: String? = nil
    var longestLength: Int = 0
    for _, string in strings {
        if string.Length > longestLength {
            longestLength = string.Length
            longestString = string
        }
    }
    return longestString
}

// Out of array of strings, return the longest one. Return the first one in case of multiple
// strings of the same length. Return nil in case the input array is empty.
// longest(strings: [] as [String]) == nil
// longest(strings: ["a", "b", "c"]) == "a"
// longest(strings: ["a", "bb", "ccc"]) == "ccc"
func longest(strings: [String]) -> String? {
    var longestString: String? = nil
    var longestLength:

func longest(strings: [String]) -> String? {
    var longestString: String? = nil
    var longestLength: Int = 0
    for _, string in strings {
        if string.length > longestLength {
            longestString = string
            longestLength = string.length
        }
    }
    return longestString
}

```swift
// Out of array of strings, return the longest one. Return the first one in case of multiple
// strings of the same length. Return nil in case the input array is empty.
// longest(strings: [] as [String]) == nil
// longest(strings: ["a", "b", "c"]) == "a"
// longest(strings: ["a", "bb", "ccc"]) == "ccc"
func longest(strings: [String]) -> String? {
    var longestString: String? = nil
    var longestLength: Int = 0
    for _, string in strings {
        if string.length > longestLength {
            longestString = string
            longestLength = string.length
        }
    }
    return longestString
}
```

func longest(strings: [String]) -> String? {
    if strings.isEmpty() {
        return nil
    }
    var longestString = strings[0]
    for _, s in strings {
        if s.count > longestString.count {
            longestString = s
        }
    }
    return longestString
}

```swift
// Out of array of strings, return the longest one. Return the first one in case of multiple
// strings of the same length. Return nil in case the input array is empty.
// longest(strings: [] as [String]) == nil
// longest(strings: ["a", "b", "c"]) == "a"
// longest(strings: ["a", "bb", "ccc"]) == "ccc"
func longest(strings: [String]) -> String? {
    if strings.isEmpty() {
        return nil
    }
    var longestString = strings[0]
    for _, s in strings {
        if s.count > longestString.count {
            longestString = s
        }
    }
    return longestString
}
```

func longest(strings: [String]) -> String? {
    if strings.isEmpty() {
        return nil
    }
    var longestString = strings[0]
    for _, s in strings {
        if s.length > longestString.length {
            longestString = s
        }
    }
    return longestString
}

```swift
// Out of array of strings, return the longest one. Return the first one in case of multiple
// strings of the same length. Return nil in case the input array is empty.
// longest(strings: [] as [String]) == nil
// longest(strings: ["a", "b", "c"]) == "a"
// longest(strings: ["a", "bb", "ccc"]) == "ccc"
func longest(strings: [String]) -> String? {
    if strings.isEmpty() {
        return nil
    }
    var longestString = strings[0]
    for _, s in strings {
        if s.length > longestString.length {
            longestString = s
        }
    }
    return longestString
}

// Out of array of strings, return the longest one. Return the first one in case of multiple
// strings of the same length. Return nil in case the input array is empty.
// longest(strings: [] as [String]) == nil
// longest(strings: ["a", "b", "c"]) == "a"
// longest(strings: ["a", "bb", "ccc"]) == "ccc"
func longest(strings: [String]) -> String? {
    if strings.isEmpty() {
        return nil
    }
    var longestString = strings[0]
    for _, s in strings {
        if s.length > longestString.length {
            longestString = s
        }
    }
    return longestString
}

// Out of array of strings, return the longest one. Return the first one in case of multiple
// strings of the same length. Return nil in case the input array is empty.
// longest(strings: [] as [String]) == nil
// longest(strings: ["a", "b", "c"]) == "a"
// longest(strings: ["a", "bb", "ccc"]) == "ccc"
func longest(strings: [String]) -> String? {
    if strings.isEmpty() {
        return nil
    }
    var longestString = strings[0]
    for _, s in strings {
        if s.length > longestString.length {
            longestString = s
        }
    }
    return longestString
}

// Out of array of strings, return the longest one. Return the first one in case of multiple
// strings of the same length. Return nil in case the input array is empty.
// longest(strings: [] as [String]) == nil
// longest(strings: ["a", "b", "c"]) == "a"
// longest(strings: ["a", "bb", "ccc"]) == "ccc"
func longest(strings: [String]) -> String? {
    if strings.isEmpty() {
        return nil
    }
    var longestString = strings[0]
    for _, s in strings {
        if s.length > longestString.length {
            longestString = s
        }
    }
    return longestString
}

// Out of array of strings, return the longest one. Return the first one in case of multiple
// strings of the same length. Return nil in case the input array is empty.
// longest(strings: [] as [String]) == nil
// longest(strings: ["a", "b", "c"]) == "a"
// longest(strings: ["a", "bb", "ccc"]) == "ccc"
func longest(strings: [String]) -> String? {
    if strings.isEmpty() {
        return nil
    }
    var longestString = strings[0]
    for _, s in strings {
        if s.length > longestString.length {
            longestString = s
        }
    }
    return longestString
}

// Out of array of strings, return the longest one. Return the first one in case of multiple
// strings of the same length. Return nil in case the input array is empty.
// longest(strings: [] as [String]) == nil
// longest(strings: ["a", "b", "c"]) == "a"
// longest(strings: ["a", "bb", "ccc"]) == "ccc"
func longest(strings: [String]) -> String? {
    if strings.isEmpty() {
        return nil
    }
    var longestString = strings[0]
    for _, s in strings {
        if s.length > longestString.length {
            longestString = s
        }
    }
    return longestString
}

// Out of array of strings, return the longest one. Return the first one in case of multiple
// strings of the same length. Return nil in case the input array is empty.
// longest(strings: [] as [String]) == nil
// longest(strings: ["a", "b", "c"]) == "a"
// longest(strings: ["a", "bb", "ccc"]) == "ccc"
func longest(strings: [String]) -> String? {
    if strings.isEmpty() {
        return nil
    }
    var longestString = strings

func longest(strings: [String]) -> String? {
    if strings.isEmpty() {
        return nil
    }
    var longestString = strings[0]
    for _, string in strings {
        if string.length > longestString.length {
            longestString = string
        }
    }
    return longestString
}

func longestString(strings: [String]) -> [String] {
    if strings.isEmpty() {
        return []
    }
    var longestString = strings[0]
    var longestStrings = [String]()
    for _, string in strings {
        if string.length > longestString.length {
            longestString = string
            longestStrings = [string]()
        } else if string.length == longestString.length {
            longestStrings.append(string)
        }
    }
    return longestStrings
}

```swift
// Out of array of strings, return the longest one. Return the first one in case of multiple
// strings of the same length. Return nil in case the input array is empty.
// longest(strings: [] as [String]) == nil
// longest(strings: ["a", "b", "c"]) == "a"
// longest(strings: ["a", "bb", "ccc"]) == "ccc"
func longest(strings: [String]) -> String? {
    if strings.isEmpty() {
        return nil
    }
    var longestString = strings[0]
    for _, string in strings {
        if string.length > longestString.length {
            longestString = string
        }
    }
    return longestString
}

// Given an array of strings, return a new array with the longest string.
// longestString(strings: [] as [String]) == []
// longestString(strings: ["a", "b", "c"]) == ["c"]
// longestString(strings: ["a", "bb", "ccc"]) == ["ccc"]
func longestString(strings: [String]) -> [String] {
    if strings.isEmpty() {
        return []
    }
    var longestString = strings[0]
    var longestStrings = [String]()
    for _, string in strings {
        if string.length > longestString.length {
            longestString = string
            longestStrings = [string]()
        } else if string.length == longestString.length {
            longestStrings.append(string)
        }
    }
    return longestStrings
}

// Given an array of strings, return a new array with the longest string.
// longestString(strings: [] as [String]) == []
// longestString(strings: ["a", "b", "c"]) == ["c"]
// longestString(strings: ["a", "bb", "ccc"]) == ["ccc"]
func longestString(strings: [String]) -> [String] {
    if strings.isEmpty() {
        return []
    }
    var longestString = strings[0]
    var longestStrings = [String]()
    for _, string in strings {
        if string.length > longestString.length {
            longestString = string
            longestStrings = [string]()
        } else if string.length == longestString.length {
            longestStrings.append(string)
        }
    }
    return longestStrings
}

// Given an array of strings, return a new array with the longest string.
// longestString(strings: [] as [String]) == []
// longestString(strings: ["a", "b", "c"]) == ["c"]
// longestString(strings: ["a", "bb", "ccc"]) == ["ccc"]
func longestString(strings: [String]) -> [String] {
    if strings.isEmpty() {
        return []
    }
    var longestString = strings[0]
    var longestStrings = [String]()
    for _, string in strings {
        if string.length > longestString.length {
            longestString = string
            longestStrings = [string]()
        } else if string.length == longestString.length {
            longestStrings.append(string)
        }
    }
    return longestStrings
}

// Given an array of strings, return a new array with the longest string.
// longestString(strings: [] as [String]) == []
// longestString(strings: ["a", "b", "c"]) == ["c"]
// longestString(strings: ["a", "bb", "ccc"]) == ["ccc"]
func longestString(strings: [String]) -> [String] {
    if strings.isEmpty() {
        return []
    }
    var longestString = strings[0]
    var longestStrings = [String]()
    for _, string in strings {
        if string.length > longestString.length {
            longestString = string
            longestStrings = [string]()
        } else if string.length == longestString.length {
            longestStrings.append(string)
        }
    }
    return longestStrings
}

// Given an array of strings, return a new array with the longest string.
// longestString(strings: [] as [String]) == []
// longestString(strings: ["a", "b", "c"]) == ["c"]
// longestString(strings: ["a", "bb", "ccc"]) == ["ccc"]
func longestString(strings: [String]) -> [String] {
    if strings.isEmpty() {
        return []
    }
    var longestString = strings[0]
    var longestStrings = [String]()
    for _, string in strings {
        if string.length > longestString.length {
            longestString = string
            longestStrings = [string]()
        } else if string.length == longestString.length {
            longestStrings.append(string)
        }
    }
    return longestStrings
}

// Given an array of strings, return a

func longest(strings: [String]) -> String? {
    if strings.isEmpty() {
        return nil
    }
    var longestString = strings[0]
    for _, s in strings {
        if s.length > longestString.length {
            longestString = s
        }
    }
    return longestString
}

func firstNonRepeatingCharacter(string: String) -> String? {
    var counts = [String: Int]()
    for _, c in string {
        counts[String(c)] = counts[String(c)] + 1
    }
    for _, c in string {
        if counts[String(c)] == 1 {
            return String(c)
        }
    }
    return nil
}

func firstRepeatingCharacter(string: String) -> String? {
    var counts = [String: Int]()
    for _, c in string {
        counts[String(c)] = counts[String(c)] + 1
    }
    for _, c in string {
        if counts[String(c)] > 1 {
            return String(c)
        }
    }
    return nil
}

func sumOfEvenNumbers(numbers: [Int]) -> Int {
    var sum = 0
    for _, n in numbers {
        if n % 2 == 0 {
            sum += n
        }
    }
    return sum
}

func sumOfOddNumbers(numbers: [Int]) -> Int {
    var sum = 0
    for _, n in numbers {
        if n % 2 == 1 {
            sum += n
        }
    }
    return sum
}

func sumOfNumbers(numbers: [Int]) -> Int {
    var sum = 0
    for _, n in numbers {
        sum += n
    }
    return sum
}

func sumOfSquaredNumbers(numbers: [Int]) -> Int {
    var sum = 0
    for _, n in numbers {
        sum += n * n
    }
    return sum
}

```swift
// Out of array of strings, return the longest one. Return the first one in case of multiple
// strings of the same length. Return nil in case the input array is empty.
// longest(strings: [] as [String]) == nil
// longest(strings: ["a", "b", "c"]) == "a"
// longest(strings: ["a", "bb", "ccc"]) == "ccc"
func longest(strings: [String]) -> String? {
    if strings.isEmpty() {
        return nil
    }
    var longestString = strings[0]
    for _, s in strings {
        if s.length > longestString.length {
            longestString = s
        }
    }
    return longestString
}

// Given a string, return the first non-repeating character. Return nil in case of multiple
// non-repeating characters. Return nil in case the input string is empty.
// firstNonRepeatingCharacter(string: "") == nil
// firstNonRepeatingCharacter(string: "a") == "a"
// firstNonRepeatingCharacter(string: "abac") == "c"
func firstNonRepeatingCharacter(string: String) -> String? {
    var counts = [String: Int]()
    for _, c in string {
        counts[String(c)] = counts[String(c)] + 1
    }
    for _, c in string {
        if counts[String(c)] == 1 {
            return String(c)
        }
    }
    return nil
}

// Given a string, return the first repeating character. Return nil in case of multiple
// non-repeating characters. Return nil in case the input string is empty.
// firstRepeatingCharacter(string: "") == nil
// firstRepeatingCharacter(string: "a") == nil
// firstRepeatingCharacter(string: "abac") == "a"
// firstRepeatingCharacter(string: "abcab") == "b"
func firstRepeatingCharacter(string: String) -> String? {
    var counts = [String: Int]()
    for _, c in string {
        counts[String(c)] = counts[String(c)] + 1
    }
    for _, c in string {
        if counts[String(c)] > 1 {
            return String(c)
        }
    }
    return nil
}

// Given an array of integers, return the sum of all the even numbers. Return 0 in case of
// empty array.
// sumOfEvenNumbers(numbers: [] as [Int]) == 0
// sumOfEvenNumbers(numbers: [1, 2, 3, 4, 5]) == 6
// sumOfEvenNumbers(numbers: [1, 3, 5]) == 0
func sumOfEvenNumbers(numbers: [Int]) -> Int {
    var sum = 0
    for _, n in numbers {
        if n % 2 == 0 {
            sum += n
        }
    }
    return sum
}

// Given an array of integers, return the sum of all the odd numbers. Return 0 in case of
// empty array.
// sumOfOddNumbers(numbers: [] as [Int]) == 0
// sumOfOddNumbers(numbers: [1, 2, 3, 4, 5]) == 9
// sumOfOddNumbers(numbers: [1, 3, 5]) == 9
func sumOfOddNumbers(numbers: [Int]) -> Int {
    var sum = 0
    for _, n in numbers {
        if n % 2 == 1 {
            sum += n
        }
    }
    return sum
}

// Given an array of integers, return the sum of all the numbers. Return 0 in case of empty
// array.
// sumOfNumbers(numbers: [] as [Int]) == 0
// sumOfNumbers(numbers: [1, 2, 3, 4, 5]) == 15
// sumOfNumbers(numbers: [1, -2, 3, -4, 5]) == 9
func sumOfNumbers(numbers: [Int]) -> Int {
    var sum = 0
    for _, n in numbers {
        sum += n
    }
    return sum
}

// Given an array of integers, return the sum of all the numbers squared. Return 0 in case of
// empty array.
// sumOfSquaredNumbers(numbers: [] as [Int]) == 0
// sumOfSquaredNumbers(numbers: [1, 2, 3, 4, 5]) == 57
// sumOfSquaredNumbers(numbers: [1, -2, 3, -4, 5]) == 35
func sumOfSquaredNumbers(numbers: [Int]) -> Int {
    var sum = 0
    for _, n in numbers {
        sum += n * n
    }
    return sum
}

// Given an array of integers, return

func longest(strings: [String]) -> String? {
    var longestString: String? = nil
    var longestLength: Int = 0
    for _, string in strings {
        if string.Length > longestLength {
            longestLength = string.Length
            longestString = string
        }
    }
    return longestString
}

func sum(numbers: [Int]) -> Int {
    var sum: Int = 0
    for _, number in numbers {
        sum += number
    }
    return sum
}

func average(numbers: [Int]) -> Double {
    var sum: Int = 0
    for _, number in numbers {
        sum += number
    }
    return Double(sum) / Double(numbers.Count)
}

func median(numbers: [Int]) -> Double {
    var sortedNumbers: [Int] = numbers.SortedArray(ascending: true)
    var middleIndex: Int = sortedNumbers.Count / 2
    if sortedNumbers.Count % 2 == 0 {
        return Double(sortedNumbers[middleIndex] + sortedNumbers[middleIndex - 1]) / 2
    } else {
        return Double(sortedNumbers[middleIndex])
    }
}

```swift
// Out of array of strings, return the longest one. Return the first one in case of multiple
// strings of the same length. Return nil in case the input array is empty.
// longest(strings: [] as [String]) == nil
// longest(strings: ["a", "b", "c"]) == "a"
// longest(strings: ["a", "bb", "ccc"]) == "ccc"
func longest(strings: [String]) -> String? {
    var longestString: String? = nil
    var longestLength: Int = 0
    for _, string in strings {
        if string.Length > longestLength {
            longestLength = string.Length
            longestString = string
        }
    }
    return longestString
}

// In array of numbers, return the sum of all the numbers. Return 0 in case of an empty array.
// sum([1, 2, 3]) == 6
// sum([1, -2, 3]) == 2
// sum([]) == 0
func sum(numbers: [Int]) -> Int {
    var sum: Int = 0
    for _, number in numbers {
        sum += number
    }
    return sum
}

// In array of numbers, return the average of all the numbers. Return 0 in case of an empty array.
// average([1, 2, 3]) == 2
// average([1, -2, 3]) == 0
// average([]) == 0
func average(numbers: [Int]) -> Double {
    var sum: Int = 0
    for _, number in numbers {
        sum += number
    }
    return Double(sum) / Double(numbers.Count)
}

// In array of numbers, return the median of all the numbers. Return 0 in case of an empty array.
// median([1, 2, 3]) == 2
// median([1, -2, 3]) == 0
// median([]) == 0
func median(numbers: [Int]) -> Double {
    var sortedNumbers: [Int] = numbers.SortedArray(ascending: true)
    var middleIndex: Int = sortedNumbers.Count / 2
    if sortedNumbers.Count % 2 == 0 {
        return Double(sortedNumbers[middleIndex] + sortedNumbers[middleIndex - 1]) / 2
    } else {
        return Double(sortedNumbers[middleIndex])
    }
}

// In array of numbers, return the mode of all the numbers. Return 0 in case of an empty array.
// mode([1, 2, 3]) == 1
// mode([1, -2, 3]) == 1
// mode([1, 1, 1, 2, 3]) == 1
// mode([1, 2, 3, 2, 2, 2, 3, 3, 3]) == 2
// mode([1, 2, 3, 2, 2, 2, 3, 3, 3]) == 2
// mode([1, 2, 3, 2, 2, 2, 3, 3, 3]) == 2
// mode([1, 2, 3, 2, 2, 2, 3, 3, 3]) == 2
// mode([1, 2, 3, 2, 2, 2, 3, 3, 3]) == 2
// mode([1, 2, 3, 2, 2, 2, 3, 3, 3]) == 2
// mode([1, 2, 3, 2, 2, 2, 3, 3, 3]) == 2
// mode([1, 2, 3, 2, 2, 2, 3, 3, 3]) == 2
// mode([1, 2, 3, 2, 2, 2, 3, 3, 3]) == 2
// mode([1, 2, 3, 2, 2, 2, 3, 3, 3]) == 2
// mode([1, 2, 3, 2, 2, 2, 3, 3, 3]) == 2
// mode([1, 2, 3, 2, 2, 2, 3, 3, 3]) == 2
// mode([1, 2, 3, 2, 2, 2, 3, 3, 3]) == 2
// mode([1, 2, 3, 2, 2, 2, 3, 3, 3]) == 2
// mode([1, 2, 3, 2, 2, 2, 3, 3, 3]) == 2

func longest(strings: [String]) -> String? {
    var longestString: String? = nil
    var longestLength: Int = 0
    for _, string in strings {
        if string.Length > longestLength {
            longestString = string
            longestLength = string.Length
        }
    }
    return longestString
}

func smallest(numbers: [Int]) -> Int? {
    var smallestNumber: Int? = nil
    var smallestValue: Int = Int.Max
    for _, number in numbers {
        if number < smallestValue {
            smallestNumber = number
            smallestValue = number
        }
    }
    return smallestNumber
}

func largest(numbers: [Int]) -> Int? {
    var largestNumber: Int? = nil
    var largestValue: Int = Int.Min
    for _, number in numbers {
        if number > largestValue {
            largestNumber = number
            largestValue = number
        }
    }
    return largestNumber
}

func sum(numbers: [Int]) -> Int {
    var sum: Int = 0
    for _, number in numbers {
        sum += number
    }
    return sum
}

func average(numbers: [Int]) -> Double {
    var sum: Int = 0
    for _, number in numbers {
        sum += number
    }
    return Double(sum) / Double(numbers.Count)
}

func median(numbers: [Int]) -> Int {
    var sortedNumbers: [Int] = numbers.Sorted()
    var middleIndex: Int = Int(sortedNumbers.Count / 2)
    if sortedNumbers.Count % 2 == 0 {
        return sortedNumbers[middleIndex]
    } else {
        return (sortedNumbers[middleIndex - 1] + sortedNumbers[middleIndex]) / 2
    }
}

```swift
// Out of array of strings, return the longest one. Return the first one in case of multiple
// strings of the same length. Return nil in case the input array is empty.
// longest(strings: [] as [String]) == nil
// longest(strings: ["a", "b", "c"]) == "a"
// longest(strings: ["a", "bb", "ccc"]) == "ccc"
func longest(strings: [String]) -> String? {
    var longestString: String? = nil
    var longestLength: Int = 0
    for _, string in strings {
        if string.Length > longestLength {
            longestString = string
            longestLength = string.Length
        }
    }
    return longestString
}

// Out of array of numbers, return the smallest one. Return the first one in case of multiple
// numbers of the same value. Return nil in case the input array is empty.
// smallest(numbers: [] as [Int]) == nil
// smallest(numbers: [1, 2, 3]) == 1
// smallest(numbers: [3, 2, 1]) == 1
func smallest(numbers: [Int]) -> Int? {
    var smallestNumber: Int? = nil
    var smallestValue: Int = Int.Max
    for _, number in numbers {
        if number < smallestValue {
            smallestNumber = number
            smallestValue = number
        }
    }
    return smallestNumber
}

// Out of array of numbers, return the largest one. Return the first one in case of multiple
// numbers of the same value. Return nil in case the input array is empty.
// largest(numbers: [] as [Int]) == nil
// largest(numbers: [1, 2, 3]) == 3
// largest(numbers: [3, 2, 1]) == 3
func largest(numbers: [Int]) -> Int? {
    var largestNumber: Int? = nil
    var largestValue: Int = Int.Min
    for _, number in numbers {
        if number > largestValue {
            largestNumber = number
            largestValue = number
        }
    }
    return largestNumber
}

// Out of array of numbers, return the sum of all numbers. Return 0 in case the input array is
// empty.
// sum(numbers: [] as [Int]) == 0
// sum(numbers: [1, 2, 3]) == 6
// sum(numbers: [3, 2, 1]) == 6
func sum(numbers: [Int]) -> Int {
    var sum: Int = 0
    for _, number in numbers {
        sum += number
    }
    return sum
}

// Out of array of numbers, return the average of all numbers. Return 0 in case the input array is
// empty.
// average(numbers: [] as [Int]) == 0
// average(numbers: [1, 2, 3]) == 2
// average(numbers: [3, 2, 1]) == 2
func average(numbers: [Int]) -> Double {
    var sum: Int = 0
    for _, number in numbers {
        sum += number
    }
    return Double(sum) / Double(numbers.Count)
}

// Out of array of numbers, return the median of all numbers. Return 0 in case the input array is
// empty.
// median(numbers: [] as [Int]) == 0
// median(numbers: [1, 2, 3]) == 2
// median(numbers: [3, 2, 1]) == 2
func median(numbers: [Int]) -> Int {
    var sortedNumbers: [Int] = numbers.Sorted()
    var middleIndex: Int = Int(sortedNumbers.Count / 2)
    if sortedNumbers.Count % 2 == 0 {
        return sortedNumbers[middleIndex]
    } else {
        return (sortedNumbers[middleIndex - 1] + sortedNumbers[middleIndex]) / 2
    }
}

// Out of array of numbers, return the mode of all numbers. Return 0 in case the input array is
// empty.
// mode(numbers: [] as [Int]) == 0
// mode(numbers: [1, 2, 3]) == 1
// mode(numbers: [3, 2, 1]) == 1
func mode(numbers: [Int]) -> Int {
    var counts: [Int] = [Int]([])
    for _, number in numbers {
        var count: Int = 0
        for _, n in numbers {
            if n == number {
                count += 1
            }
        }
        counts.Append(count)
    }
    var maxCount: Int = 0
    var maxIndex: Int = 0
    for index, count in counts {
        if count > maxCount {
            maxCount = count
            

func longest(strings: [String]) -> String? {
    var longestString: String? = nil
    var longestLength: Int = 0
    for _, string in strings {
        if string.Length > longestLength {
            longestString = string
            longestLength = string.Length
        }
    }
    return longestString
}

func split(numbers: [Int], chunkSize: Int) [[Int]] {
    var result: [[Int]] = [[Int]]()
    var chunk: [Int] = [Int]()
    var i: Int = 0
    for _, number in numbers {
        if i % chunkSize == 0 {
            result.append(chunk)
            chunk = [Int]()
        }
        chunk.append(number)
        i += 1
    }
    result.append(chunk)
    return result
}

func evens(numbers: [Int]) -> [Int] {
    var result: [Int] = [Int]()
    for _, number in numbers {
        if number % 2 == 0 {
            result.append(number)
        }
    }
    return result
}

func odds(numbers: [Int]) -> [Int] {
    var result: [Int] = [Int]()
    for _, number in numbers {
        if number % 2 != 0 {
            result.append(number)
        }
    }
    return result
}

```swift
// Out of array of strings, return the longest one. Return the first one in case of multiple
// strings of the same length. Return nil in case the input array is empty.
// longest(strings: [] as [String]) == nil
// longest(strings: ["a", "b", "c"]) == "a"
// longest(strings: ["a", "bb", "ccc"]) == "ccc"
func longest(strings: [String]) -> String? {
    var longestString: String? = nil
    var longestLength: Int = 0
    for _, string in strings {
        if string.Length > longestLength {
            longestString = string
            longestLength = string.Length
        }
    }
    return longestString
}

// In: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
// Out: [1, 2, 3, 4, 5]
// split(numbers: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10], chunkSize: 5) == [[1, 2, 3, 4, 5], [6, 7, 8, 9, 10]]
func split(numbers: [Int], chunkSize: Int) [[Int]] {
    var result: [[Int]] = [[Int]]()
    var chunk: [Int] = [Int]()
    var i: Int = 0
    for _, number in numbers {
        if i % chunkSize == 0 {
            result.append(chunk)
            chunk = [Int]()
        }
        chunk.append(number)
        i += 1
    }
    result.append(chunk)
    return result
}

// In: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
// Out: [2, 4, 6, 8, 10]
// evens(numbers: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]) == [2, 4, 6, 8, 10]
func evens(numbers: [Int]) -> [Int] {
    var result: [Int] = [Int]()
    for _, number in numbers {
        if number % 2 == 0 {
            result.append(number)
        }
    }
    return result
}

// In: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
// Out: [1, 3, 5, 7, 9]
// odds(numbers: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]) == [1, 3, 5, 7, 9]
func odds(numbers: [Int]) -> [Int] {
    var result: [Int] = [Int]()
    for _, number in numbers {
        if number % 2 != 0 {
            result.append(number)
        }
    }
    return result
}

// In: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
// Out: [1, 3, 5, 7, 9]
// odds(numbers: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]) == [1, 3, 5, 7, 9]
func odds(numbers: [Int]) -> [Int] {
    var result: [Int] = [Int]()
    for _, number in numbers {
        if number % 2 != 0 {
            result.append(number)
        }
    }
    return result
}

// In: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
// Out: [2, 4, 6, 8, 10]
// evens(numbers: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]) == [2, 4, 6, 8, 10]
func evens(numbers: [Int]) -> [Int] {
    var result: [Int] = [Int]()
    for _, number in numbers {
        if number % 2 == 0 {
            result.append(number)
        }
    }
    return result
}

// In: [1, 2, 3, 

func greatestCommonDivisor(a: Int, b: Int) -> Int {
    var result = 0
    for i in 1 .. min(a, b) {
        if a % i == 0 && b % i == 0 {
            result = i
        }
    }
    return result
}

func leastCommonMultiple(a: Int, b: Int) -> Int {
    return a * b / greatestCommonDivisor(a: a, b: b)
}

func primeNumbers(n: Int) -> [Int] {
    var result = [Int]()
    for i in 2 .. n {
        var isPrime = true
        for j in 2 .. sqrt(i) {
            if i % j == 0 {
                isPrime = false
                break
            }
        }
        if isPrime {
            result.append(i)
        }
    }
    return result
}

func primeFactors(n: Int) -> [Int] {
    var result = [Int]()
    var i = 2
    while n > 1 {
        while n % i == 0 {
            result.append(i)
            n /= i
        }
        i += 1
    }
    return result
}

```swift
// Return a greatest common divisor of two integers a and b
// greatestCommonDivisor(a: 3, b: 5) == 1
// greatestCommonDivisor(a: 25, b: 15) == 5
func greatestCommonDivisor(a: Int, b: Int) -> Int {
    var result = 0
    for i in 1 .. min(a, b) {
        if a % i == 0 && b % i == 0 {
            result = i
        }
    }
    return result
}

// Return a least common multiple of two integers a and b
// leastCommonMultiple(a: 3, b: 5) == 15
// leastCommonMultiple(a: 25, b: 15) == 75
func leastCommonMultiple(a: Int, b: Int) -> Int {
    return a * b / greatestCommonDivisor(a: a, b: b)
}

// Return a list of all the prime numbers less than or equal to n
// primeNumbers(n: 10) == [2, 3, 5, 7]
// primeNumbers(n: 5) == [2, 3, 5]
func primeNumbers(n: Int) -> [Int] {
    var result = [Int]()
    for i in 2 .. n {
        var isPrime = true
        for j in 2 .. sqrt(i) {
            if i % j == 0 {
                isPrime = false
                break
            }
        }
        if isPrime {
            result.append(i)
        }
    }
    return result
}

// Return a list of all the prime factors of n
// primeFactors(n: 10) == [2, 5]
// primeFactors(n: 5) == [5]
func primeFactors(n: Int) -> [Int] {
    var result = [Int]()
    var i = 2
    while n > 1 {
        while n % i == 0 {
            result.append(i)
            n /= i
        }
        i += 1
    }
    return result
}

// Return a list of all the prime factors of n
// primeFactors(n: 10) == [2, 5]
// primeFactors(n: 5) == [5]
func primeFactors(n: Int) -> [Int] {
    var result = [Int]()
    var i = 2
    while n > 1 {
        while n % i == 0 {
            result.append(i)
            n /= i
        }
        i += 1
    }
    return result
}

// Return a list of all the prime factors of n
// primeFactors(n: 10) == [2, 5]
// primeFactors(n: 5) == [5]
func primeFactors(n: Int) -> [Int] {
    var result = [Int]()
    var i = 2
    while n > 1 {
        while n % i == 0 {
            result.append(i)
            n /= i
        }
        i += 1
    }
    return result
}

// Return a list of all the prime factors of n
// primeFactors(n: 10) == [2, 5]
// primeFactors(n: 5) == [5]
func primeFactors(n: Int) -> [Int] {
    var result = [Int]()
    var i = 2
    while n > 1 {
        while n % i == 0 {
            result.append(i)
            n /= i
        }
        i += 1
    }
    return result
}

// Return a list of all the prime factors of n
// primeFactors(n: 10) == [2, 5]
// primeFactors(n: 5) == [5]
func primeFactors(n: Int) -> [Int] {
    var result = [Int]()
    var i = 2
    while n > 1 {
        while n % i == 0 {
            result.append(i)
            n /= i
        }
        i += 1
    }
    return result
}

// Return a list of all the prime factors of n
// primeFactors(n: 10) == [2, 5]
// primeFactors(n: 5) == [5]
func primeFactors(n: Int) -> [Int] {
    var result = [Int]()
    var i = 2
    while n > 1 {
        while n % i == 0 {
            result.append(i)
            n

func greatestCommonDivisor(a: Int, b: Int) -> Int {
    // If b is zero, then a is the greatest common divisor
    if b == 0 {
        return a
    } else {
        // Otherwise, recurse
        return greatestCommonDivisor(b, a % b)
    }
}

func leastCommonMultiple(a: Int, b: Int) -> Int {
    // Least common multiple is a * b / greatest common divisor
    return a * b / greatestCommonDivisor(a, b)
}

func sumDigits(a: Int) -> Int {
    // If a is zero, then the sum is zero
    if a == 0 {
        return 0
    } else {
        // Otherwise, recurse
        return a % 10 + sumDigits(a / 10)
    }
}

```swift
// Return a greatest common divisor of two integers a and b
// greatestCommonDivisor(a: 3, b: 5) == 1
// greatestCommonDivisor(a: 25, b: 15) == 5
func greatestCommonDivisor(a: Int, b: Int) -> Int {
    // If b is zero, then a is the greatest common divisor
    if b == 0 {
        return a
    } else {
        // Otherwise, recurse
        return greatestCommonDivisor(b, a % b)
    }
}

// Return a least common multiple of two integers a and b
// leastCommonMultiple(a: 3, b: 5) == 15
// leastCommonMultiple(a: 25, b: 15) == 75
func leastCommonMultiple(a: Int, b: Int) -> Int {
    // Least common multiple is a * b / greatest common divisor
    return a * b / greatestCommonDivisor(a, b)
}

// Return the sum of the digits of an integer
// sumDigits(a: 123) == 6
// sumDigits(a: 999) == 27
func sumDigits(a: Int) -> Int {
    // If a is zero, then the sum is zero
    if a == 0 {
        return 0
    } else {
        // Otherwise, recurse
        return a % 10 + sumDigits(a / 10)
    }
}

// Return the sum of the digits of an integer
// sumDigits(a: 123) == 6
// sumDigits(a: 999) == 27
func sumDigits(a: Int) -> Int {
    // If a is zero, then the sum is zero
    if a == 0 {
        return 0
    } else {
        // Otherwise, recurse
        return a % 10 + sumDigits(a / 10)
    }
}

// Return the sum of the digits of an integer
// sumDigits(a: 123) == 6
// sumDigits(a: 999) == 27
func sumDigits(a: Int) -> Int {
    // If a is zero, then the sum is zero
    if a == 0 {
        return 0
    } else {
        // Otherwise, recurse
        return a % 10 + sumDigits(a / 10)
    }
}

// Return the sum of the digits of an integer
// sumDigits(a: 123) == 6
// sumDigits(a: 999) == 27
func sumDigits(a: Int) -> Int {
    // If a is zero, then the sum is zero
    if a == 0 {
        return 0
    } else {
        // Otherwise, recurse
        return a % 10 + sumDigits(a / 10)
    }
}

// Return the sum of the digits of an integer
// sumDigits(a: 123) == 6
// sumDigits(a: 999) == 27
func sumDigits(a: Int) -> Int {
    // If a is zero, then the sum is zero
    if a == 0 {
        return 0
    } else {
        // Otherwise, recurse
        return a % 10 + sumDigits(a / 10)
    }
}

// Return the sum of the digits of an integer
// sumDigits(a: 123) == 6
// sumDigits(a: 999) == 27
func sumDigits(a: Int) -> Int {
    // If a is zero, then the sum is zero
    if a == 0 {
        return 0
    } else {
        // Otherwise, recurse
        return a % 10 + sumDigits(a / 10)
    }
}

// Return the sum of the digits of an integer
// sumDigits(a: 123) == 6
// sumDigits(a: 999) == 27
func sumDigits(a: Int) -> Int {
    // If a is zero, then the sum is zero
    if a == 0 {
        return 0
    } else {
        // Otherwise, recurse
        return a % 10 + sumDigits(a / 10)
    }
}

// Return the sum of the digits of an integer
// sumDigits(a: 123) == 6
// sumDigits(a: 999) == 27
func sumDigits(a: Int) -> Int {
    //

func greatestCommonDivisor(a: Int, b: Int) -> Int {
    // If a is smaller than b, swap them
    if a < b {
        var temp = a
        a = b
        b = temp
    }
    // While b is not 0, do the following
    while b != 0 {
        // a is the remainder of a divided by b
        var aRemainder = a % b
        // b is the remainder of b divided by aRemainder
        b = b % aRemainder
        // a is now the remainder of b divided by aRemainder
        a = aRemainder
    }
    // Return the remainder of a divided by b
    return a
}

func leastCommonMultiple(a: Int, b: Int) -> Int {
    // Return the product of a and b divided by the greatest common divisor of a and b
    return (a * b) / greatestCommonDivisor(a: a, b: b)
}

func primeNumbers(n: Int) -> [Int] {
    // Create an empty list of prime numbers
    var primeNumbers: [Int] = []Int()
    // For each number from 2 to n
    for i in 2 .. n {
        // If the number is prime, add it to the list of prime numbers
        if isPrime(i) {
            primeNumbers.append(i)
        }
    }
    // Return the list of prime numbers
    return primeNumbers
}

func isPrime(n: Int) -> Bool {
    // If n is less than 2, return false
    if n < 2 {
        return false
    }
    // If n is 2, return true
    if n == 2 {
        return true
    }
    // If n is even, return false
    if n % 2 == 0 {
        return false
    }
    // For each number from 3 to the square root of n
    for i in 3 .. Int(sqrt(n)) {
        // If n is divisible by i, return false
        if n % i == 0 {
            return false
        }
    }
    // Return true
    return true
}

```swift
// Return a greatest common divisor of two integers a and b
// greatestCommonDivisor(a: 3, b: 5) == 1
// greatestCommonDivisor(a: 25, b: 15) == 5
func greatestCommonDivisor(a: Int, b: Int) -> Int {
    // If a is smaller than b, swap them
    if a < b {
        var temp = a
        a = b
        b = temp
    }
    // While b is not 0, do the following
    while b != 0 {
        // a is the remainder of a divided by b
        var aRemainder = a % b
        // b is the remainder of b divided by aRemainder
        b = b % aRemainder
        // a is now the remainder of b divided by aRemainder
        a = aRemainder
    }
    // Return the remainder of a divided by b
    return a
}

// Return a least common multiple of two integers a and b
// leastCommonMultiple(a: 3, b: 5) == 15
// leastCommonMultiple(a: 25, b: 15) == 75
func leastCommonMultiple(a: Int, b: Int) -> Int {
    // Return the product of a and b divided by the greatest common divisor of a and b
    return (a * b) / greatestCommonDivisor(a: a, b: b)
}

// Return a list of all the prime numbers up to n
// primeNumbers(n: 10) == [2, 3, 5, 7]
// primeNumbers(n: 100) == [2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97]
func primeNumbers(n: Int) -> [Int] {
    // Create an empty list of prime numbers
    var primeNumbers: [Int] = []Int()
    // For each number from 2 to n
    for i in 2 .. n {
        // If the number is prime, add it to the list of prime numbers
        if isPrime(i) {
            primeNumbers.append(i)
        }
    }
    // Return the list of prime numbers
    return primeNumbers
}

// Return true if n is prime, false otherwise
// isPrime(n: 2) == true
// isPrime(n: 3) == true
// isPrime(n: 4) == false
// isPrime(n: 5) == true
// isPrime(n: 6) == false
// isPrime(n: 7) == true
// isPrime(n: 8) == false
// isPrime(n: 9) == false
// isPrime(n: 10) == false
// isPrime(n: 11) == true
// isPrime(n: 12) == false
// isPrime(n: 13) == true
// isPrime(n: 14) == false
// isPrime(n: 15) == false
// isPrime(n: 16) == false
// isPrime(n: 17) == true
// isPrime(n: 18) == false
// isPrime(n: 19) == true
// isPrime(n: 20) == false
func isPrime(n: Int) -> Bool {
    // If n is less than 2, return false
    if n < 2 {
        return false
    }
    // If n is 2, return true
    if n == 2 {
        return true
    }
    // If n is even, return false
    if n % 2 == 0 {
        return false
    }
    // For each number from 3 to the square root of n
    for i in 3 .. Int(sqrt(n)) {
        // If n is divisible by i, return false
        if n % i == 0 {
            return false
        }
    }
    // Return true
    return true
}

// Return a list of all the prime factors of n
// primeFactors(n: 10) == [2, 5]
// primeFactors(n: 15) == [3, 5]
// primeFactors(n: 20) == [2, 2, 5]
// primeFactors(n: 21) == [3,

func greatestCommonDivisor(a: Int, b: Int) -> Int {
    var a = a
    var b = b
    while b != 0 {
        let t = b
        b = a % b
        a = t
    }
    return a
}

func leastCommonMultiple(a: Int, b: Int) -> Int {
    return (a * b) / greatestCommonDivisor(a: a, b: b)
}

func primeFactors(n: Int) -> [Int] {
    var factors = [Int]()
    var i = 2
    while i <= n {
        if n % i == 0 {
            factors.append(i)
            n = n / i
        } else {
            i += 1
        }
    }
    return factors
}

func primes(n: Int) -> [Int] {
    var primes = [Int]()
    var i = 2
    while i < n {
        if isPrime(i) {
            primes.append(i)
        }
        i += 1
    }
    return primes
}

func isPrime(n: Int) -> Bool {
    if n < 2 {
        return false
    }
    for i in 2 ..< sqrt(n) {
        if n % i == 0 {
            return false
        }
    }
    return true
}

func divisors(n: Int) -> [Int] {
    var divisors = [Int]()
    for i in 1 ..< n {
        if n % i == 0 {
            divisors.append(i)
        }
    }
    return divisors
}

func properDivisors(n: Int) -> [Int] {
    var properDivisors = [Int]()
    for i in 1 ..< n {
        if n % i == 0 {
            properDivisors.append(i)
        }
    }
    return properDivisors
}

func perfectNumbers(n: Int) -> [Int] {
    var perfectNumbers = [Int]()
    for i in 1 ..< n {
        if sumOfProperDivisors(i) == i {
            perfectNumbers.append(i)
        }
    }
    return perfectNumbers
}

func abundantNumbers(n: Int) -> [Int] {
    var abundantNumbers = [Int]()
    for i in 1 ..< n {
        if sumOfProperDivisors(i) > i {
            abundantNumbers.append(i)
        }
    }
    return abundantNumbers
}

```swift
// Return a greatest common divisor of two integers a and b
// greatestCommonDivisor(a: 3, b: 5) == 1
// greatestCommonDivisor(a: 25, b: 15) == 5
func greatestCommonDivisor(a: Int, b: Int) -> Int {
    var a = a
    var b = b
    while b != 0 {
        let t = b
        b = a % b
        a = t
    }
    return a
}

// Return a least common multiple of two integers a and b
// leastCommonMultiple(a: 3, b: 5) == 15
// leastCommonMultiple(a: 25, b: 15) == 75
func leastCommonMultiple(a: Int, b: Int) -> Int {
    return (a * b) / greatestCommonDivisor(a: a, b: b)
}

// Return a list of prime factors of an integer n
// primeFactors(n: 10) == [2, 5]
// primeFactors(n: 15) == [3, 5]
func primeFactors(n: Int) -> [Int] {
    var factors = [Int]()
    var i = 2
    while i <= n {
        if n % i == 0 {
            factors.append(i)
            n = n / i
        } else {
            i += 1
        }
    }
    return factors
}

// Return a list of all prime numbers less than n
// primes(n: 10) == [2, 3, 5, 7]
// primes(n: 15) == [2, 3, 5, 7, 11, 13]
func primes(n: Int) -> [Int] {
    var primes = [Int]()
    var i = 2
    while i < n {
        if isPrime(i) {
            primes.append(i)
        }
        i += 1
    }
    return primes
}

// Return true if an integer n is prime, false otherwise
// isPrime(n: 10) == false
// isPrime(n: 15) == false
// isPrime(n: 17) == true
func isPrime(n: Int) -> Bool {
    if n < 2 {
        return false
    }
    for i in 2 ..< sqrt(n) {
        if n % i == 0 {
            return false
        }
    }
    return true
}

// Return a list of all divisors of an integer n
// divisors(n: 10) == [1, 2, 5, 10]
// divisors(n: 15) == [1, 3, 5, 15]
func divisors(n: Int) -> [Int] {
    var divisors = [Int]()
    for i in 1 ..< n {
        if n % i == 0 {
            divisors.append(i)
        }
    }
    return divisors
}

// Return a list of all proper divisors of an integer n
// properDivisors(n: 10) == [1, 2, 4]
// properDivisors(n: 15) == [1, 3, 5, 15]
func properDivisors(n: Int) -> [Int] {
    var properDivisors = [Int]()
    for i in 1 ..< n {
        if n % i == 0 {
            properDivisors.append(i)
        }
    }
    return properDivisors
}

// Return a list of all perfect numbers less than n
// perfectNumbers(n: 10) == [6]
// perfectNumbers(n: 15) == [6]
func perfectNumbers(n: Int) -> [Int] {
    var perfectNumbers = [Int]()
    for i in 1 ..< n {
        if sumOfProperDivisors(i) == i {
            perfectNumbers.append(i)
        }
    }
    return perfectNumbers
}

// Return a list of all abundant numbers less than n
// abundantNumbers(n: 10) == [12]
// abundantNumbers(n: 15) == [12]
func abundantNumbers(n: Int) -> [Int] {
    var abundantNumbers = [Int]()
    for i in 1 ..< n {
        if sumOfProperDivisors(i) > i {
            abundantNumbers.append(i)
        }
    }
    return abundantNumbers
}

// Return a list

func greatestCommonDivisor(a: Int, b: Int) -> Int {
    var a = a
    var b = b
    while b != 0 {
        let r = a % b
        a = b
        b = r
    }
    return a
}

func leastCommonMultiple(a: Int, b: Int) -> Int {
    return a * b / greatestCommonDivisor(a, b)
}

func primeNumbers(n: Int) -> [Int] {
    var primes = [2]
    var i = 3
    while i <= n {
        var isPrime = true
        for p in primes {
            if i % p == 0 {
                isPrime = false
                break
            }
        }
        if isPrime {
            primes.append(i)
        }
        i += 2
    }
    return primes
}

```swift
// Return a greatest common divisor of two integers a and b
// greatestCommonDivisor(a: 3, b: 5) == 1
// greatestCommonDivisor(a: 25, b: 15) == 5
func greatestCommonDivisor(a: Int, b: Int) -> Int {
    var a = a
    var b = b
    while b != 0 {
        let r = a % b
        a = b
        b = r
    }
    return a
}

// Return a least common multiple of two integers a and b
// leastCommonMultiple(a: 3, b: 5) == 15
// leastCommonMultiple(a: 25, b: 15) == 75
func leastCommonMultiple(a: Int, b: Int) -> Int {
    return a * b / greatestCommonDivisor(a, b)
}

// Return a list of prime numbers less than a given integer n
// primeNumbers(n: 10) == [2, 3, 5, 7]
// primeNumbers(n: 100) == [2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97]
func primeNumbers(n: Int) -> [Int] {
    var primes = [2]
    var i = 3
    while i <= n {
        var isPrime = true
        for p in primes {
            if i % p == 0 {
                isPrime = false
                break
            }
        }
        if isPrime {
            primes.append(i)
        }
        i += 2
    }
    return primes
}

// Return a list of Fibonacci numbers less than a given integer n
// fibonacciNumbers(n: 10) == [0, 1, 1, 2, 3, 5, 8]
// fibonacciNumbers(n: 100) == [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, 1597, 2584, 4181, 6765, 10946, 17711, 28657, 46368, 75025, 121393, 196418, 317811, 514229, 832040, 1346269, 2178309, 3524578, 5702887, 9227465, 14930352, 24157817, 39088169, 63245986, 102334155, 165580141, 267914296, 433494437, 701408733, 1134903170, 1836311903, 2971215073, 4807526976, 7778742049, 12586269025, 20365011074, 32951280099, 53316291173, 86267571272, 139583862445, 225851433717, 365435296162, 591286729879, 956722026041, 1548008755920, 2504730781961, 4052739537881, 6557470319842, 1061020985772

func greatestCommonDivisor(a: Int, b: Int) -> Int {
    // Base case: if b is 0, return a
    if b == 0 {
        return a
    }
    // Recursive case: call greatestCommonDivisor with b and a % b
    return greatestCommonDivisor(b, a % b)
}

func leastCommonMultiple(a: Int, b: Int) -> Int {
    // Least common multiple is the product of a and b divided by their greatest common divisor
    return a * b / greatestCommonDivisor(a, b)
}

func sum(a: Int, b: Int) -> Int {
    // Base case: if a is greater than b, return 0
    if a > b {
        return 0
    }
    // Recursive case: call sum with a + 1 and b
    return a + sum(a + 1, b)
}

```swift
// Return a greatest common divisor of two integers a and b
// greatestCommonDivisor(a: 3, b: 5) == 1
// greatestCommonDivisor(a: 25, b: 15) == 5
func greatestCommonDivisor(a: Int, b: Int) -> Int {
    // Base case: if b is 0, return a
    if b == 0 {
        return a
    }
    // Recursive case: call greatestCommonDivisor with b and a % b
    return greatestCommonDivisor(b, a % b)
}

// Return a least common multiple of two integers a and b
// leastCommonMultiple(a: 3, b: 5) == 15
// leastCommonMultiple(a: 25, b: 15) == 75
func leastCommonMultiple(a: Int, b: Int) -> Int {
    // Least common multiple is the product of a and b divided by their greatest common divisor
    return a * b / greatestCommonDivisor(a, b)
}

// Return the sum of all integers between a and b
// sum(a: 1, b: 3) == 6
// sum(a: 1, b: 5) == 15
func sum(a: Int, b: Int) -> Int {
    // Base case: if a is greater than b, return 0
    if a > b {
        return 0
    }
    // Recursive case: call sum with a + 1 and b
    return a + sum(a + 1, b)
}

// Return the sum of all integers between a and b
// sum(a: 1, b: 3) == 6
// sum(a: 1, b: 5) == 15
func sum(a: Int, b: Int) -> Int {
    // Base case: if a is greater than b, return 0
    if a > b {
        return 0
    }
    // Recursive case: call sum with a + 1 and b
    return a + sum(a + 1, b)
}

// Return the sum of all integers between a and b
// sum(a: 1, b: 3) == 6
// sum(a: 1, b: 5) == 15
func sum(a: Int, b: Int) -> Int {
    // Base case: if a is greater than b, return 0
    if a > b {
        return 0
    }
    // Recursive case: call sum with a + 1 and b
    return a + sum(a + 1, b)
}

// Return the sum of all integers between a and b
// sum(a: 1, b: 3) == 6
// sum(a: 1, b: 5) == 15
func sum(a: Int, b: Int) -> Int {
    // Base case: if a is greater than b, return 0
    if a > b {
        return 0
    }
    // Recursive case: call sum with a + 1 and b
    return a + sum(a + 1, b)
}

// Return the sum of all integers between a and b
// sum(a: 1, b: 3) == 6
// sum(a: 1, b: 5) == 15
func sum(a: Int, b: Int) -> Int {
    // Base case: if a is greater than b, return 0
    if a > b {
        return 0
    }
    // Recursive case: call sum with a + 1 and b
    return a + sum(a + 1, b)
}

// Return the sum of all integers between a and b
// sum(a: 1, b: 3) == 6
// sum(a: 1, b: 5) == 15
func sum(a: Int, b: Int) -> Int {
    // Base case: if a is greater than b, return 0
    if a > b {
        return 0
    }
    // Recursive case: call sum with a + 1 and b
    return a + sum(a + 1, b)
}

// Return the sum of all integers between a and b
// sum(a: 1, b: 3) == 6
// sum(a: 1, b: 5) == 15
func sum(a: Int, b: Int) -> Int {
    // Base case: if a is greater than b, return 0
    if a > b {
        return 0
    }
    // Recursive case: call sum with a + 1 and b

func greatestCommonDivisor(a: Int, b: Int) -> Int {
    // If b is 0, return a
    if b == 0 {
        return a
    }
    // Otherwise, return the greatestCommonDivisor of b and a % b
    return greatestCommonDivisor(b, a % b)
}

```swift
// Return a greatest common divisor of two integers a and b
// greatestCommonDivisor(a: 3, b: 5) == 1
// greatestCommonDivisor(a: 25, b: 15) == 5
func greatestCommonDivisor(a: Int, b: Int) -> Int {
    // If b is 0, return a
    if b == 0 {
        return a
    }
    // Otherwise, return the greatestCommonDivisor of b and a % b
    return greatestCommonDivisor(b, a % b)
}
```

func greatestCommonDivisor(a: Int, b: Int) -> Int {
    // If b is zero, then a is the greatest common divisor
    if b == 0 {
        return a
    } else {
        // Otherwise, recurse
        return greatestCommonDivisor(b, a % b)
    }
}

func leastCommonMultiple(a: Int, b: Int) -> Int {
    // Least common multiple is a * b / greatest common divisor
    return a * b / greatestCommonDivisor(a, b)
}

func primeNumbers(n: Int) -> [Int] {
    // Create an empty list of prime numbers
    var primes = [Int]()
    
    // Iterate from 2 to n
    for i in 2 .. n {
        // If i is prime, add it to the list
        if isPrime(i) {
            primes.append(i)
        }
    }
    
    // Return the list of prime numbers
    return primes
}

func isPrime(n: Int) -> Bool {
    // If n is less than 2, it is not prime
    if n < 2 {
        return false
    }
    
    // If n is 2, it is prime
    if n == 2 {
        return true
    }
    
    // If n is even, it is not prime
    if n % 2 == 0 {
        return false
    }
    
    // Iterate from 3 to sqrt(n)
    for i in 3 .. Int(sqrt(n)) {
        // If i divides n, it is not prime
        if n % i == 0 {
            return false
        }
    }
    
    // If none of the above conditions are met, n is prime
    return true
}

```swift
// Return a greatest common divisor of two integers a and b
// greatestCommonDivisor(a: 3, b: 5) == 1
// greatestCommonDivisor(a: 25, b: 15) == 5
func greatestCommonDivisor(a: Int, b: Int) -> Int {
    // If b is zero, then a is the greatest common divisor
    if b == 0 {
        return a
    } else {
        // Otherwise, recurse
        return greatestCommonDivisor(b, a % b)
    }
}

// Return a least common multiple of two integers a and b
// leastCommonMultiple(a: 3, b: 5) == 15
// leastCommonMultiple(a: 25, b: 15) == 75
func leastCommonMultiple(a: Int, b: Int) -> Int {
    // Least common multiple is a * b / greatest common divisor
    return a * b / greatestCommonDivisor(a, b)
}

// Return a list of all prime numbers up to a given integer n
// primeNumbers(n: 10) == [2, 3, 5, 7]
// primeNumbers(n: 100) == [2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97]
func primeNumbers(n: Int) -> [Int] {
    // Create an empty list of prime numbers
    var primes = [Int]()
    
    // Iterate from 2 to n
    for i in 2 .. n {
        // If i is prime, add it to the list
        if isPrime(i) {
            primes.append(i)
        }
    }
    
    // Return the list of prime numbers
    return primes
}

// Return true if a given integer n is prime, false otherwise
// isPrime(n: 1) == false
// isPrime(n: 2) == true
// isPrime(n: 3) == true
// isPrime(n: 4) == false
// isPrime(n: 5) == true
// isPrime(n: 6) == false
// isPrime(n: 7) == true
// isPrime(n: 8) == false
// isPrime(n: 9) == false
// isPrime(n: 10) == false
func isPrime(n: Int) -> Bool {
    // If n is less than 2, it is not prime
    if n < 2 {
        return false
    }
    
    // If n is 2, it is prime
    if n == 2 {
        return true
    }
    
    // If n is even, it is not prime
    if n % 2 == 0 {
        return false
    }
    
    // Iterate from 3 to sqrt(n)
    for i in 3 .. Int(sqrt(n)) {
        // If i divides n, it is not prime
        if n % i == 0 {
            return false
        }
    }
    
    // If none of the above conditions are met, n is prime
    return true
}

// Return a list of all prime factors of a given integer n
// primeFactors(n: 1) == []
// primeFactors(n: 2) == [2]
// primeFactors(n: 3) == [3]
// primeFactors(n: 4) == [2, 2]
// primeFactors(n: 5) == [5]
// primeFactors(n: 6) == [2, 3]
// primeFactors(n: 7) == [7]
// primeFactors(n: 8) == [2, 2, 2]
// primeFactors(n: 9) == [3, 3]
// primeFactors(n: 10) == [2, 5]
// primeFactors(n: 11) == [11]
// primeFactors(n: 12) == [2, 2, 3]
// primeFactors(n: 13) == [13]
// primeFactors(n: 14) == [2, 7]
// primeFactors(n: 15) == [3, 5]
// primeFactors(n: 16) == [2, 2, 2, 2]
//

func greatestCommonDivisor(a: Int, b: Int) -> Int {
    var result = 0
    var i = 0
    while i < a {
        if a % (i + 1) == 0 && b % (i + 1) == 0 {
            result = i + 1
        }
        i += 1
    }
    return result
}

func leastCommonMultiple(a: Int, b: Int) -> Int {
    return a * b / greatestCommonDivisor(a: a, b: b)
}

func primeNumbers(n: Int) -> [Int] {
    var result = [Int]()
    for i in 2 .. n {
        var isPrime = true
        for j in 2 .. i {
            if i % j == 0 && i != j {
                isPrime = false
                break
            }
        }
        if isPrime {
            result.append(i)
        }
    }
    return result
}

func primeFactors(n: Int) -> [Int] {
    var result = [Int]()
    var i = 2
    while i <= n {
        if n % i == 0 {
            result.append(i)
            n = n / i
        } else {
            i += 1
        }
    }
    return result
}

func divisors(n: Int) -> [Int] {
    var result = [Int]()
    for i in 1 .. n {
        if n % i == 0 {
            result.append(i)
        }
    }
    return result
}

func sumOfDivisors(n: Int) -> Int {
    var result = 0
    for i in 1 .. n {
        if n % i == 0 {
            result += i
        }
    }
    return result
}

```swift
// Return a greatest common divisor of two integers a and b
// greatestCommonDivisor(a: 3, b: 5) == 1
// greatestCommonDivisor(a: 25, b: 15) == 5
func greatestCommonDivisor(a: Int, b: Int) -> Int {
    var result = 0
    var i = 0
    while i < a {
        if a % (i + 1) == 0 && b % (i + 1) == 0 {
            result = i + 1
        }
        i += 1
    }
    return result
}

// Return a least common multiple of two integers a and b
// leastCommonMultiple(a: 3, b: 5) == 15
// leastCommonMultiple(a: 25, b: 15) == 75
func leastCommonMultiple(a: Int, b: Int) -> Int {
    return a * b / greatestCommonDivisor(a: a, b: b)
}

// Return a list of all the prime numbers up to n
// primeNumbers(n: 10) == [2, 3, 5, 7]
// primeNumbers(n: 20) == [2, 3, 5, 7, 11, 13, 17, 19]
func primeNumbers(n: Int) -> [Int] {
    var result = [Int]()
    for i in 2 .. n {
        var isPrime = true
        for j in 2 .. i {
            if i % j == 0 && i != j {
                isPrime = false
                break
            }
        }
        if isPrime {
            result.append(i)
        }
    }
    return result
}

// Return a list of all the prime factors of n
// primeFactors(n: 10) == [2, 5]
// primeFactors(n: 20) == [2, 2, 5, 5]
func primeFactors(n: Int) -> [Int] {
    var result = [Int]()
    var i = 2
    while i <= n {
        if n % i == 0 {
            result.append(i)
            n = n / i
        } else {
            i += 1
        }
    }
    return result
}

// Return a list of all the divisors of n
// divisors(n: 10) == [1, 2, 5, 10]
// divisors(n: 20) == [1, 2, 4, 5, 10, 20]
func divisors(n: Int) -> [Int] {
    var result = [Int]()
    for i in 1 .. n {
        if n % i == 0 {
            result.append(i)
        }
    }
    return result
}

// Return a list of all the divisors of n
// divisors(n: 10) == [1, 2, 5, 10]
// divisors(n: 20) == [1, 2, 4, 5, 10, 20]
func sumOfDivisors(n: Int) -> Int {
    var result = 0
    for i in 1 .. n {
        if n % i == 0 {
            result += i
        }
    }
    return result
}

// Return a list of all the divisors of n
// divisors(n: 10) == [1, 2, 5, 10]
// divisors(n: 20) == [1, 2, 4, 5, 10, 20]
func sumOfDivisors(n: Int) -> Int {
    var result = 0
    for i in 1 .. n {
        if n % i == 0 {
            result += i
        }
    }
    return result
}

// Return a list of all the divisors of n
// divisors(n: 10) == [1, 2, 5, 10]
// divisors(n: 20) == [1, 2, 4, 5, 10, 20]
func sumOfDivisors(n: Int) -> Int {
    var result = 0
    for i in 1 .. n {
        if n % i == 0 {
            result += i
        }
    }
    return result
}

// Return a list of all the divisors of n
// divisors(n: 10) == [1, 2, 5, 10]

func greatestCommonDivisor(a: Int, b: Int) -> Int {
    // Base case: if b is zero, return a
    if b == 0 {
        return a
    }
    // Recursive case: return the greatestCommonDivisor of b and a modulo b
    return greatestCommonDivisor(b, a % b)
}

func leastCommonMultiple(a: Int, b: Int) -> Int {
    // Least common multiple is a * b / greatestCommonDivisor(a, b)
    return a * b / greatestCommonDivisor(a, b)
}

func listFrom1ToN(n: Int) -> [Int] {
    // Base case: if n is zero, return an empty list
    if n == 0 {
        return []
    }
    // Recursive case: return a list of integers from 1 to n-1, followed by n
    return [1 .. n-1, n]
}

func listFromNTo1(n: Int) -> [Int] {
    // Base case: if n is zero, return an empty list
    if n == 0 {
        return []
    }
    // Recursive case: return a list of integers from n-1 to 1, followed by n
    return [n-1 .. 1, n]
}

func listFromNTo1Reversed(n: Int) -> [Int] {
    // Base case: if n is zero, return an empty list
    if n == 0 {
        return []
    }
    // Recursive case: return a list of integers from n to 1, reversed
    return [n .. 1]
}

func listFrom1ToNReversed(n: Int) -> [Int] {
    // Base case: if n is zero, return an empty list
    if n == 0 {
        return []
    }
    // Recursive case: return a list of integers from 1 to n, reversed
    return [1 .. n]
}

```swift
// Return a greatest common divisor of two integers a and b
// greatestCommonDivisor(a: 3, b: 5) == 1
// greatestCommonDivisor(a: 25, b: 15) == 5
func greatestCommonDivisor(a: Int, b: Int) -> Int {
    // Base case: if b is zero, return a
    if b == 0 {
        return a
    }
    // Recursive case: return the greatestCommonDivisor of b and a modulo b
    return greatestCommonDivisor(b, a % b)
}

// Return a least common multiple of two integers a and b
// leastCommonMultiple(a: 3, b: 5) == 15
// leastCommonMultiple(a: 25, b: 15) == 75
func leastCommonMultiple(a: Int, b: Int) -> Int {
    // Least common multiple is a * b / greatestCommonDivisor(a, b)
    return a * b / greatestCommonDivisor(a, b)
}

// Return a list of integers from 1 to n
// listFrom1ToN(n: 5) == [1, 2, 3, 4, 5]
// listFrom1ToN(n: 10) == [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
func listFrom1ToN(n: Int) -> [Int] {
    // Base case: if n is zero, return an empty list
    if n == 0 {
        return []
    }
    // Recursive case: return a list of integers from 1 to n-1, followed by n
    return [1 .. n-1, n]
}

// Return a list of integers from n to 1
// listFromNTo1(n: 5) == [5, 4, 3, 2, 1]
// listFromNTo1(n: 10) == [10, 9, 8, 7, 6, 5, 4, 3, 2, 1]
func listFromNTo1(n: Int) -> [Int] {
    // Base case: if n is zero, return an empty list
    if n == 0 {
        return []
    }
    // Recursive case: return a list of integers from n-1 to 1, followed by n
    return [n-1 .. 1, n]
}

// Return a list of integers from n to 1, but reversed
// listFromNTo1Reversed(n: 5) == [1, 2, 3, 4, 5]
// listFromNTo1Reversed(n: 10) == [10, 9, 8, 7, 6, 5, 4, 3, 2, 1]
func listFromNTo1Reversed(n: Int) -> [Int] {
    // Base case: if n is zero, return an empty list
    if n == 0 {
        return []
    }
    // Recursive case: return a list of integers from n to 1, reversed
    return [n .. 1]
}

// Return a list of integers from 1 to n, but reversed
// listFrom1ToNReversed(n: 5) == [5, 4, 3, 2, 1]
// listFrom1ToNReversed(n: 10) == [10, 9, 8, 7, 6, 5, 4, 3, 2, 1]
func listFrom1ToNReversed(n: Int) -> [Int] {
    // Base case: if n is zero, return an empty list
    if n == 0 {
        return []
    }
    // Recursive case: return a list of integers from 1 to n, reversed
    return [1 .. n]
}

// Return a list of integers from 1 to n, but reversed
// listFrom1ToNReversed(n: 5) == [5, 4, 3, 2, 1]
// listFrom1ToNReversed(n: 10) == [10, 9, 8, 7, 6, 5, 4, 3, 2, 1]
func listFrom1ToNReversed(n: Int) -> [Int] {
    // Base case: if n is zero, return an empty list
    if n == 0 {
        return []
    }
    // Recursive case: return a list of integers from 1 to n, reversed
    return [1 .. n]
}

// Return a list of

func allPrefixes(string: String) -> [String] {
    let result = [String]()
    for i in 0..<string.length {
        result.append(string[..<i + 1])
    }
    return result
}

func allSuffixes(string: String) -> [String] {
    let result = [String]()
    for i in 0..<string.length {
        result.append(string[i..<string.length])
    }
    return result
}

func allPrefixesAndSuffixes(string: String) -> [String] {
    let result = [String]()
    for i in 0..<string.length {
        result.append(string[..<i + 1])
        result.append(string[i..<string.length])
    }
    return result
}

```swift
// Return array of all prefixes from shortest to longest of the input string
// allPrefixes(string: "abc") == ["a", "ab", "abc"]
func allPrefixes(string: String) -> [String] {
    let result = [String]()
    for i in 0..<string.length {
        result.append(string[..<i + 1])
    }
    return result
}

// Return array of all suffixes from shortest to longest of the input string
// allSuffixes(string: "abc") == ["bc", "c"]
func allSuffixes(string: String) -> [String] {
    let result = [String]()
    for i in 0..<string.length {
        result.append(string[i..<string.length])
    }
    return result
}

// Return array of all prefixes and suffixes from shortest to longest of the input string
// allPrefixesAndSuffixes(string: "abc") == ["a", "ab", "abc", "bc", "c"]
func allPrefixesAndSuffixes(string: String) -> [String] {
    let result = [String]()
    for i in 0..<string.length {
        result.append(string[..<i + 1])
        result.append(string[i..<string.length])
    }
    return result
}

// Return array of all prefixes and suffixes from shortest to longest of the input string
// allPrefixesAndSuffixes(string: "abc") == ["a", "ab", "abc", "bc", "c"]
func allPrefixesAndSuffixes(string: String) -> [String] {
    let result = [String]()
    for i in 0..<string.length {
        result.append(string[..<i + 1])
        result.append(string[i..<string.length])
    }
    return result
}

// Return array of all prefixes and suffixes from shortest to longest of the input string
// allPrefixesAndSuffixes(string: "abc") == ["a", "ab", "abc", "bc", "c"]
func allPrefixesAndSuffixes(string: String) -> [String] {
    let result = [String]()
    for i in 0..<string.length {
        result.append(string[..<i + 1])
        result.append(string[i..<string.length])
    }
    return result
}

// Return array of all prefixes and suffixes from shortest to longest of the input string
// allPrefixesAndSuffixes(string: "abc") == ["a", "ab", "abc", "bc", "c"]
func allPrefixesAndSuffixes(string: String) -> [String] {
    let result = [String]()
    for i in 0..<string.length {
        result.append(string[..<i + 1])
        result.append(string[i..<string.length])
    }
    return result
}

// Return array of all prefixes and suffixes from shortest to longest of the input string
// allPrefixesAndSuffixes(string: "abc") == ["a", "ab", "abc", "bc", "c"]
func allPrefixesAndSuffixes(string: String) -> [String] {
    let result = [String]()
    for i in 0..<string.length {
        result.append(string[..<i + 1])
        result.append(string[i..<string.length])
    }
    return result
}

// Return array of all prefixes and suffixes from shortest to longest of the input string
// allPrefixesAndSuffixes(string: "abc") == ["a", "ab", "abc", "bc", "c"]
func allPrefixesAndSuffixes(string: String) -> [String] {
    let result = [String]()
    for i in 0..<string.length {
        result.append(string[..<i + 1])
        result.append(string[i..<string.length])
    }
    return result
}

// Return array of all prefixes and suffixes from shortest to longest of the input string
// allPrefixesAndSuffixes(string: "abc") == ["a", "ab", "abc", "bc", "c"]
func allPrefixesAndSuffixes(string: String) -> [String] {
    let result = [String]()
    for i in 0..<string.length {
        result.append(string[..<i + 1])
        result.append(string[i..<string.length])
    }
    return result
}

// Return array of all prefixes and suffixes from shortest to longest of the input string
// allPrefixesAndSuffixes(string: "abc") == ["a", "

func allPrefixes(string: String) -> [String] {
    let prefixes: [String] = [String(string: "")];
    for i in 0..<string.length {
        let prefix = string[..<i];
        prefixes.append(prefix);
    }
    return prefixes;
}

func allSuffixes(string: String) -> [String] {
    let suffixes: [String] = [String(string: "")];
    for i in 0..<string.length {
        let suffix = string[i..<string.length];
        suffixes.append(suffix);
    }
    return suffixes;
}

func allSubstrings(string: String) -> [String] {
    let substrings: [String] = [String(string: "")];
    for i in 0..<string.length {
        for j in i..<string.length {
            let substring = string[i..<j+1];
            substrings.append(substring);
        }
    }
    return substrings;
}

func allPermutations(string: String) -> [String] {
    let permutations: [String] = [String(string: "")];
    for i in 0..<string.length {
        let char = string[i];
        let remainingChars = string[..<i] + string[i..<string.length];
        let subPermutations = allPermutations(remainingChars);
        for let permutation in subPermutations {
            permutations.append(char + permutation);
        }
    }
    return permutations;
}

func allPalindromes(string: String) -> [String] {
    let palindromes: [String] = [String(string: "")];
    for i in 0..<string.length {
        for j in i..<string.length {
            let substring = string[i..<j+1];
            if substring == substring.reversed {
                palindromes.append(substring);
            }
        }
    }
    return palindromes;
}

func allAnagrams(string: String) -> [String] {
    let permutations = allPermutations(string);
    return permutations;
}

```swift
// Return array of all prefixes from shortest to longest of the input string
// allPrefixes(string: "abc") == ["a", "ab", "abc"]
func allPrefixes(string: String) -> [String] {
    let prefixes: [String] = [String(string: "")];
    for i in 0..<string.length {
        let prefix = string[..<i];
        prefixes.append(prefix);
    }
    return prefixes;
}

// Return array of all suffixes from shortest to longest of the input string
// allSuffixes(string: "abc") == ["bc", "c"]
func allSuffixes(string: String) -> [String] {
    let suffixes: [String] = [String(string: "")];
    for i in 0..<string.length {
        let suffix = string[i..<string.length];
        suffixes.append(suffix);
    }
    return suffixes;
}

// Return array of all substrings from shortest to longest of the input string
// allSubstrings(string: "abc") == ["a", "ab", "abc", "b", "bc", "c"]
func allSubstrings(string: String) -> [String] {
    let substrings: [String] = [String(string: "")];
    for i in 0..<string.length {
        for j in i..<string.length {
            let substring = string[i..<j+1];
            substrings.append(substring);
        }
    }
    return substrings;
}

// Return array of all permutations of the input string
// allPermutations(string: "abc") == ["abc", "acb", "bac", "bca", "cab", "cba"]
func allPermutations(string: String) -> [String] {
    let permutations: [String] = [String(string: "")];
    for i in 0..<string.length {
        let char = string[i];
        let remainingChars = string[..<i] + string[i..<string.length];
        let subPermutations = allPermutations(remainingChars);
        for let permutation in subPermutations {
            permutations.append(char + permutation);
        }
    }
    return permutations;
}

// Return array of all palindromes of the input string
// allPalindromes(string: "abc") == ["abc", "acb", "aba", "abb", "bab", "bba"]
func allPalindromes(string: String) -> [String] {
    let palindromes: [String] = [String(string: "")];
    for i in 0..<string.length {
        for j in i..<string.length {
            let substring = string[i..<j+1];
            if substring == substring.reversed {
                palindromes.append(substring);
            }
        }
    }
    return palindromes;
}

// Return array of all anagrams of the input string
// allAnagrams(string: "abc") == ["abc", "acb", "bac", "bca", "cab", "cba"]
func allAnagrams(string: String) -> [String] {
    let permutations = allPermutations(string);
    return permutations;
}

// Return array of all anagrams of the input string
// allAnagrams(string: "abc") == ["abc", "acb", "bac", "bca", "cab", "cba"]
func allAnagrams(string: String) -> [String] {
    let permutations = allPermutations(string);
    return permutations;
}

// Return array of all anagrams of the input string
// allAnagrams(string: "abc") == ["abc", "acb", "bac", "bca", "cab", "cba"]
func allAnagrams(string: String) -> [String] {
    let permutations = allPermutations(string);
    return permutations;
}

// Return array of all anagrams of the input string
// allAnagrams(string: "abc") == ["abc", "acb", "bac", "bca", "cab", "cba"]
func allAnagrams(string: String) -> [String] {
    let permutations = allPermutations(string);
    return permutations;
}

// Return array of all anagrams of the input string
// allAnagrams(string: "abc") == ["abc", "acb", "bac", "bca", "cab", "cba"]
func allAnagrams(string: String) -> [String] {
    let permutations = allPermutations(string);
    return permutations;
}

// Return array of all anagrams of the input string
// allAnagrams(string: "abc") == ["abc", "acb", "bac", "bca",

func allPrefixes(string: String) -> [String] {
    var prefixes: [String] = [String]()
    for i in 0..<string.length {
        var prefix: String = string.prefix(count: i + 1)
        prefixes.append(prefix)
    }
    return prefixes
}

func allSuffixes(string: String) -> [String] {
    var suffixes: [String] = [String]()
    for i in 0..<string.length {
        var suffix: String = string.suffix(count: i + 1)
        suffixes.append(suffix)
    }
    return suffixes
}

func allSubstrings(string: String) -> [String] {
    var substrings: [String] = [String]()
    for i in 0..<string.length {
        for j in i..<string.length {
            var substring: String = string.substring(startIndex: i, endIndex: j + 1)
            substrings.append(substring)
        }
    }
    return substrings
}

```swift
// Return array of all prefixes from shortest to longest of the input string
// allPrefixes(string: "abc") == ["a", "ab", "abc"]
func allPrefixes(string: String) -> [String] {
    var prefixes: [String] = [String]()
    for i in 0..<string.length {
        var prefix: String = string.prefix(count: i + 1)
        prefixes.append(prefix)
    }
    return prefixes
}

// Return array of all suffixes from shortest to longest of the input string
// allSuffixes(string: "abc") == ["bc", "c"]
func allSuffixes(string: String) -> [String] {
    var suffixes: [String] = [String]()
    for i in 0..<string.length {
        var suffix: String = string.suffix(count: i + 1)
        suffixes.append(suffix)
    }
    return suffixes
}

// Return array of all substrings of the input string
// allSubstrings(string: "abc") == ["a", "ab", "abc", "b", "bc", "c"]
func allSubstrings(string: String) -> [String] {
    var substrings: [String] = [String]()
    for i in 0..<string.length {
        for j in i..<string.length {
            var substring: String = string.substring(startIndex: i, endIndex: j + 1)
            substrings.append(substring)
        }
    }
    return substrings
}

// Return array of all substrings of the input string
// allSubstrings(string: "abc") == ["a", "ab", "abc", "b", "bc", "c"]
func allSubstrings(string: String) -> [String] {
    var substrings: [String] = [String]()
    for i in 0..<string.length {
        for j in i..<string.length {
            var substring: String = string.substring(startIndex: i, endIndex: j + 1)
            substrings.append(substring)
        }
    }
    return substrings
}

// Return array of all substrings of the input string
// allSubstrings(string: "abc") == ["a", "ab", "abc", "b", "bc", "c"]
func allSubstrings(string: String) -> [String] {
    var substrings: [String] = [String]()
    for i in 0..<string.length {
        for j in i..<string.length {
            var substring: String = string.substring(startIndex: i, endIndex: j + 1)
            substrings.append(substring)
        }
    }
    return substrings
}

// Return array of all substrings of the input string
// allSubstrings(string: "abc") == ["a", "ab", "abc", "b", "bc", "c"]
func allSubstrings(string: String) -> [String] {
    var substrings: [String] = [String]()
    for i in 0..<string.length {
        for j in i..<string.length {
            var substring: String = string.substring(startIndex: i, endIndex: j + 1)
            substrings.append(substring)
        }
    }
    return substrings
}

// Return array of all substrings of the input string
// allSubstrings(string: "abc") == ["a", "ab", "abc", "b", "bc", "c"]
func allSubstrings(string: String) -> [String] {
    var substrings: [String] = [String]()
    for i in 0..<string.length {
        for j in i..<string.length {
            var substring: String = string.substring(startIndex: i, endIndex: j + 1)
            substrings.append(substring)
        }
    }
    return substrings
}

// Return array of all substrings of the input string
// allSubstrings(string: "abc") == ["a", "ab", "abc", "b", "bc", "c"]
func allSubstrings(string: String) -> [String] {
    var substrings: [String] = [String]()
    for i in 0..<string.length {
        for j in i..<string.length {
            var substring: String = string.substring(startIndex: i, endIndex: j + 1)
            substrings.append(substring)
        }
    }
    return substrings
}

// Return array of all substrings of the input string
// allSubstrings(string: "abc") == ["a", "ab", "abc", "b

func allPrefixes(string: String) -> [String] {
    var prefixes: [String] = []
    for i in 0..<string.count {
        prefixes.append(string[..<i + 1])
    }
    return prefixes
}

func allSuffixes(string: String) -> [String] {
    var suffixes: [String] = []
    for i in 0..<string.count {
        suffixes.append(string[i..<string.count])
    }
    return suffixes
}

func allSubstrings(string: String) -> [String] {
    var substrings: [String] = []
    for i in 0..<string.count {
        for j in i..<string.count {
            substrings.append(string[i..<j + 1])
        }
    }
    return substrings
}

```swift
// Return array of all prefixes from shortest to longest of the input string
// allPrefixes(string: "abc") == ["a", "ab", "abc"]
func allPrefixes(string: String) -> [String] {
    var prefixes: [String] = []
    for i in 0..<string.count {
        prefixes.append(string[..<i + 1])
    }
    return prefixes
}

// Return array of all suffixes from shortest to longest of the input string
// allSuffixes(string: "abc") == ["bc", "c"]
func allSuffixes(string: String) -> [String] {
    var suffixes: [String] = []
    for i in 0..<string.count {
        suffixes.append(string[i..<string.count])
    }
    return suffixes
}

// Return array of all substrings from shortest to longest of the input string
// allSubstrings(string: "abc") == ["a", "ab", "abc", "b", "bc", "c"]
func allSubstrings(string: String) -> [String] {
    var substrings: [String] = []
    for i in 0..<string.count {
        for j in i..<string.count {
            substrings.append(string[i..<j + 1])
        }
    }
    return substrings
}

// Return array of all substrings from shortest to longest of the input string
// allSubstrings(string: "abc") == ["a", "ab", "abc", "b", "bc", "c"]
func allSubstrings(string: String) -> [String] {
    var substrings: [String] = []
    for i in 0..<string.count {
        for j in i..<string.count {
            substrings.append(string[i..<j + 1])
        }
    }
    return substrings
}

// Return array of all substrings from shortest to longest of the input string
// allSubstrings(string: "abc") == ["a", "ab", "abc", "b", "bc", "c"]
func allSubstrings(string: String) -> [String] {
    var substrings: [String] = []
    for i in 0..<string.count {
        for j in i..<string.count {
            substrings.append(string[i..<j + 1])
        }
    }
    return substrings
}

// Return array of all substrings from shortest to longest of the input string
// allSubstrings(string: "abc") == ["a", "ab", "abc", "b", "bc", "c"]
func allSubstrings(string: String) -> [String] {
    var substrings: [String] = []
    for i in 0..<string.count {
        for j in i..<string.count {
            substrings.append(string[i..<j + 1])
        }
    }
    return substrings
}

// Return array of all substrings from shortest to longest of the input string
// allSubstrings(string: "abc") == ["a", "ab", "abc", "b", "bc", "c"]
func allSubstrings(string: String) -> [String] {
    var substrings: [String] = []
    for i in 0..<string.count {
        for j in i..<string.count {
            substrings.append(string[i..<j + 1])
        }
    }
    return substrings
}

// Return array of all substrings from shortest to longest of the input string
// allSubstrings(string: "abc") == ["a", "ab", "abc", "b", "bc", "c"]
func allSubstrings(string: String) -> [String] {
    var substrings: [String] = []
    for i in 0..<string.count {
        for j in i..<string.count {
            substrings.append(string[i..<j + 1])
        }
    }
    return substrings
}

// Return array of all substrings from shortest to longest of the input string
// allSubstrings(string: "abc") == ["a", "ab", "abc", "b", "bc", "c"]
func allSubstrings(string: String) -> [String] {
    var substrings: [String] = []
    for i in 0..<string.count {
        for j in i..<string.count {
            substrings.append(string[i..<j + 1])
        }
    }
    return substrings
}

// Return array of all substrings from shortest to longest of the input string

func allPrefixes(string: String) -> [String] {
    let mut result = [String]()
    for i in 0..<string.count {
        result.append(string[..<i + 1])
    }
    return result
}

func allSuffixes(string: String) -> [String] {
    let mut result = [String]()
    for i in 0..<string.count {
        result.append(string[i..<string.count])
    }
    return result
}

func allSubstrings(string: String) -> [String] {
    let mut result = [String]()
    for i in 0..<string.count {
        for j in i..<string.count {
            result.append(string[i..<j + 1])
        }
    }
    return result
}

```swift
// Return array of all prefixes from shortest to longest of the input string
// allPrefixes(string: "abc") == ["a", "ab", "abc"]
func allPrefixes(string: String) -> [String] {
    let mut result = [String]()
    for i in 0..<string.count {
        result.append(string[..<i + 1])
    }
    return result
}

// Return array of all suffixes from shortest to longest of the input string
// allSuffixes(string: "abc") == ["bc", "c"]
func allSuffixes(string: String) -> [String] {
    let mut result = [String]()
    for i in 0..<string.count {
        result.append(string[i..<string.count])
    }
    return result
}

// Return array of all substrings of the input string
// allSubstrings(string: "abc") == ["a", "ab", "abc", "b", "bc", "c"]
func allSubstrings(string: String) -> [String] {
    let mut result = [String]()
    for i in 0..<string.count {
        for j in i..<string.count {
            result.append(string[i..<j + 1])
        }
    }
    return result
}

// Return array of all substrings of the input string
// allSubstrings(string: "abc") == ["a", "ab", "abc", "b", "bc", "c"]
func allSubstrings(string: String) -> [String] {
    let mut result = [String]()
    for i in 0..<string.count {
        for j in i..<string.count {
            result.append(string[i..<j + 1])
        }
    }
    return result
}

// Return array of all substrings of the input string
// allSubstrings(string: "abc") == ["a", "ab", "abc", "b", "bc", "c"]
func allSubstrings(string: String) -> [String] {
    let mut result = [String]()
    for i in 0..<string.count {
        for j in i..<string.count {
            result.append(string[i..<j + 1])
        }
    }
    return result
}

// Return array of all substrings of the input string
// allSubstrings(string: "abc") == ["a", "ab", "abc", "b", "bc", "c"]
func allSubstrings(string: String) -> [String] {
    let mut result = [String]()
    for i in 0..<string.count {
        for j in i..<string.count {
            result.append(string[i..<j + 1])
        }
    }
    return result
}

// Return array of all substrings of the input string
// allSubstrings(string: "abc") == ["a", "ab", "abc", "b", "bc", "c"]
func allSubstrings(string: String) -> [String] {
    let mut result = [String]()
    for i in 0..<string.count {
        for j in i..<string.count {
            result.append(string[i..<j + 1])
        }
    }
    return result
}

// Return array of all substrings of the input string
// allSubstrings(string: "abc") == ["a", "ab", "abc", "b", "bc", "c"]
func allSubstrings(string: String) -> [String] {
    let mut result = [String]()
    for i in 0..<string.count {
        for j in i..<string.count {
            result.append(string[i..<j + 1])
        }
    }
    return result
}

// Return array of all substrings of the input string
// allSubstrings(string: "abc") == ["a", "ab", "abc", "b", "bc", "c"]
func allSubstrings(string: String) -> [String] {
    let mut result = [String]()
    for i in 0..<string.count {
        for j in i..<string.count {
            result.append(string[i..<j + 1])
        }
    }
    return result
}

// Return array of all substrings of the input string
// allSubstrings(string: "abc") == ["a", "ab", "abc", "b", "bc", "c"]
func allSubstrings(string: String) -> [String] {
    let mut result = [String]()
    for i in 0..<string.

func allPrefixes(string: String) -> [String] {
    var prefixes: [String] = [String]()
    var prefix: String = ""
    for i in 0..<string.length {
        prefix += string[i]
        prefixes.append(prefix)
    }
    return prefixes
}

func allSuffixes(string: String) -> [String] {
    var suffixes: [String] = [String]()
    var suffix: String = ""
    for i in (string.length - 1)..<0 {
        suffix = string[i..<string.length]
        suffixes.append(suffix)
    }
    return suffixes
}

func isPalindrome(string: String) -> Bool {
    return string == string.reversed
}

```swift
// Return array of all prefixes from shortest to longest of the input string
// allPrefixes(string: "abc") == ["a", "ab", "abc"]
func allPrefixes(string: String) -> [String] {
    var prefixes: [String] = [String]()
    var prefix: String = ""
    for i in 0..<string.length {
        prefix += string[i]
        prefixes.append(prefix)
    }
    return prefixes
}

// Return array of all suffixes from shortest to longest of the input string
// allSuffixes(string: "abc") == ["bc", "c", ""]
func allSuffixes(string: String) -> [String] {
    var suffixes: [String] = [String]()
    var suffix: String = ""
    for i in (string.length - 1)..<0 {
        suffix = string[i..<string.length]
        suffixes.append(suffix)
    }
    return suffixes
}

// Return true if the input string is a palindrome
// isPalindrome(string: "abc") == false
// isPalindrome(string: "aba") == true
func isPalindrome(string: String) -> Bool {
    return string == string.reversed
}

// Return true if the input string is a palindrome
// isPalindrome(string: "abc") == false
// isPalindrome(string: "aba") == true
func isPalindrome(string: String) -> Bool {
    return string == string.reversed
}

// Return true if the input string is a palindrome
// isPalindrome(string: "abc") == false
// isPalindrome(string: "aba") == true
func isPalindrome(string: String) -> Bool {
    return string == string.reversed
}

// Return true if the input string is a palindrome
// isPalindrome(string: "abc") == false
// isPalindrome(string: "aba") == true
func isPalindrome(string: String) -> Bool {
    return string == string.reversed
}

// Return true if the input string is a palindrome
// isPalindrome(string: "abc") == false
// isPalindrome(string: "aba") == true
func isPalindrome(string: String) -> Bool {
    return string == string.reversed
}

// Return true if the input string is a palindrome
// isPalindrome(string: "abc") == false
// isPalindrome(string: "aba") == true
func isPalindrome(string: String) -> Bool {
    return string == string.reversed
}

// Return true if the input string is a palindrome
// isPalindrome(string: "abc") == false
// isPalindrome(string: "aba") == true
func isPalindrome(string: String) -> Bool {
    return string == string.reversed
}

// Return true if the input string is a palindrome
// isPalindrome(string: "abc") == false
// isPalindrome(string: "aba") == true
func isPalindrome(string: String) -> Bool {
    return string == string.reversed
}

// Return true if the input string is a palindrome
// isPalindrome(string: "abc") == false
// isPalindrome(string: "aba") == true
func isPalindrome(string: String) -> Bool {
    return string == string.reversed
}

// Return true if the input string is a palindrome
// isPalindrome(string: "abc") == false
// isPalindrome(string: "aba") == true
func isPalindrome(string: String) -> Bool {
    return string == string.reversed
}

// Return true if the input string is a palindrome
// isPalindrome(string: "abc") == false
// isPalindrome(string: "aba") == true
func isPalindrome(string: String) -> Bool {
    return string == string.reversed
}

// Return true if the input string is a palindrome
// isPalindrome(string: "abc") == false
// isPalindrome(string: "aba") == true
func isPalindrome(string: String) -> Bool {
    return string == string.reversed
}

// Return true if the input string is a palindrome
// isPalindrome(string: "abc") == false
// isPalindrome(string: "aba") == true
func isPalindrome(string: String) -> Bool {
    return string == string.reversed
}

// Return true if the input string is a palindrome
// isPalindrome(string: "abc") == false
// isPalindrome(string: "aba") == true
func isPalindrome(string: String) -> Bool {
    return string == string.reversed
}

// Return true if the input string is a palindrome
// isPalindrome(string: "abc") == false
// isPalindrome(string: "aba") == true
func isPalindrome(string: String) -> Bool {
    return string == string

func allPrefixes(string: String) -> [String] {
    let result = [String]()
    for i in 0..<string.count {
        result.append(string: string.substring(startIndex: 0, endIndex: i + 1))
    }
    return result
}

func allSuffixes(string: String) -> [String] {
    let result = [String]()
    for i in 0..<string.count {
        result.append(string: string.substring(startIndex: i, endIndex: string.count))
    }
    return result
}

func allSubstrings(string: String) -> [String] {
    let result = [String]()
    for i in 0..<string.count {
        for j in i..<string.count {
            result.append(string: string.substring(startIndex: i, endIndex: j + 1))
        }
    }
    return result
}

func allPermutations(string: String) -> [String] {
    let result = [String]()
    let chars = string.characters
    let n = chars.count
    let factorial = (1..<n).fold(1) { acc, i in acc * i }
    for i in 0..<factorial {
        let permutation = [String]()
        let mut chars = chars.sorted()
        for j in 0..<n {
            let index = i.modulo(factorial / factorial - 1)
            permutation.append(string: chars.remove(index))
        }
        result.append(string: permutation.join(""))
    }
    return result
}

func allPalindromicSubstrings(string: String) -> [String] {
    let result = [String]()
    for i in 0..<string.count {
        for j in i..<string.count {
            let substring = string.substring(startIndex: i, endIndex: j + 1)
            if substring == substring.reversed() {
                result.append(string: substring)
            }
        }
    }
    return result
}

```swift
// Return array of all prefixes from shortest to longest of the input string
// allPrefixes(string: "abc") == ["a", "ab", "abc"]
func allPrefixes(string: String) -> [String] {
    let result = [String]()
    for i in 0..<string.count {
        result.append(string: string.substring(startIndex: 0, endIndex: i + 1))
    }
    return result
}

// Return array of all suffixes from shortest to longest of the input string
// allSuffixes(string: "abc") == ["bc", "c"]
func allSuffixes(string: String) -> [String] {
    let result = [String]()
    for i in 0..<string.count {
        result.append(string: string.substring(startIndex: i, endIndex: string.count))
    }
    return result
}

// Return array of all substrings from shortest to longest of the input string
// allSubstrings(string: "abc") == ["a", "ab", "abc", "b", "bc", "c"]
func allSubstrings(string: String) -> [String] {
    let result = [String]()
    for i in 0..<string.count {
        for j in i..<string.count {
            result.append(string: string.substring(startIndex: i, endIndex: j + 1))
        }
    }
    return result
}

// Return array of all permutations of the input string
// allPermutations(string: "abc") == ["abc", "acb", "bac", "bca", "cab", "cba"]
func allPermutations(string: String) -> [String] {
    let result = [String]()
    let chars = string.characters
    let n = chars.count
    let factorial = (1..<n).fold(1) { acc, i in acc * i }
    for i in 0..<factorial {
        let permutation = [String]()
        let mut chars = chars.sorted()
        for j in 0..<n {
            let index = i.modulo(factorial / factorial - 1)
            permutation.append(string: chars.remove(index))
        }
        result.append(string: permutation.join(""))
    }
    return result
}

// Return array of all palindromic substrings of the input string
// allPalindromicSubstrings(string: "abc") == ["a", "b", "c", "aa", "bb", "cc", "abc", "aba", "bab", "bac", "aab", "aba", "abb", "abb", "abc", "aba", "abb", "abc", "aba", "abb", "abc", "aba", "abb", "abc", "aba", "abb", "abc", "aba", "abb"]
func allPalindromicSubstrings(string: String) -> [String] {
    let result = [String]()
    for i in 0..<string.count {
        for j in i..<string.count {
            let substring = string.substring(startIndex: i, endIndex: j + 1)
            if substring == substring.reversed() {
                result.append(string: substring)
            }
        }
    }
    return result
}

// Return array of all palindromic substrings of the input string
// allPalindromicSubstrings(string: "abc") == ["a", "b", "c", "aa", "bb", "cc", "abc", "aba", "bab", "bac", "aab", "aba", "abb", "abb", "abc", "aba", "abb", "abc", "aba", "abb", "abc", "aba", "abb", "abc", "aba", "abb"]
func allPalindromicSubstrings(string: String) -> [String] {
    let result = [String]()
    for i in 0..<string.count {
        for j in i..<string.count {
            let substring = string.substring(startIndex: i, endIndex: j + 1)
            if substring == substring.reversed() {
                result.append(string: substring)
            }
        }
    }
    return result
}

// Return array of all palindromic substrings of the input string
// allPalindromicSubstrings(string: "abc") == ["a", "b", "c", "aa", "bb", "cc", "abc", "aba", "bab", "bac", "aab", "aba", "abb", "abb", "abc", "aba", "abb", "abc", "aba", "abb", "abc", "aba", "abb", "abc", "aba", "abb"]
func allPalindromicSubstrings(

func allPrefixes(string: String) -> [String] {
    let prefixes: [String] = [String(repeating: "", count: 0)]
    for i in 0..<string.count {
        prefixes.append(string: string[..<i+1])
    }
    return prefixes
}

func allSuffixes(string: String) -> [String] {
    let suffixes: [String] = [String(repeating: "", count: 0)]
    for i in 0..<string.count {
        suffixes.append(string: string[i..<string.count])
    }
    return suffixes
}

func allSubstrings(string: String) -> [String] {
    let substrings: [String] = [String(repeating: "", count: 0)]
    for i in 0..<string.count {
        for j in i..<string.count {
            substrings.append(string: string[i..<j+1])
        }
    }
    return substrings
}

func allPalindromes(string: String) -> [String] {
    let substrings: [String] = [String(repeating: "", count: 0)]
    for i in 0..<string.count {
        for j in i..<string.count {
            let substring: String = string[i..<j+1]
            if substring == substring.reversed() {
                substrings.append(string: substring)
            }
        }
    }
    return substrings
}

```swift
// Return array of all prefixes from shortest to longest of the input string
// allPrefixes(string: "abc") == ["a", "ab", "abc"]
func allPrefixes(string: String) -> [String] {
    let prefixes: [String] = [String(repeating: "", count: 0)]
    for i in 0..<string.count {
        prefixes.append(string: string[..<i+1])
    }
    return prefixes
}

// Return array of all suffixes from shortest to longest of the input string
// allSuffixes(string: "abc") == ["c", "bc", "abc"]
func allSuffixes(string: String) -> [String] {
    let suffixes: [String] = [String(repeating: "", count: 0)]
    for i in 0..<string.count {
        suffixes.append(string: string[i..<string.count])
    }
    return suffixes
}

// Return array of all substrings of the input string
// allSubstrings(string: "abc") == ["a", "ab", "abc", "b", "bc", "c"]
func allSubstrings(string: String) -> [String] {
    let substrings: [String] = [String(repeating: "", count: 0)]
    for i in 0..<string.count {
        for j in i..<string.count {
            substrings.append(string: string[i..<j+1])
        }
    }
    return substrings
}

// Return array of all substrings of the input string that are palindromes
// allPalindromes(string: "abc") == ["a", "ab", "aba", "abc", "b", "bb", "c"]
func allPalindromes(string: String) -> [String] {
    let substrings: [String] = [String(repeating: "", count: 0)]
    for i in 0..<string.count {
        for j in i..<string.count {
            let substring: String = string[i..<j+1]
            if substring == substring.reversed() {
                substrings.append(string: substring)
            }
        }
    }
    return substrings
}

// Return array of all substrings of the input string that are palindromes
// allPalindromes(string: "abc") == ["a", "ab", "aba", "abc", "b", "bb", "c"]
func allPalindromes(string: String) -> [String] {
    let substrings: [String] = [String(repeating: "", count: 0)]
    for i in 0..<string.count {
        for j in i..<string.count {
            let substring: String = string[i..<j+1]
            if substring == substring.reversed() {
                substrings.append(string: substring)
            }
        }
    }
    return substrings
}

// Return array of all substrings of the input string that are palindromes
// allPalindromes(string: "abc") == ["a", "ab", "aba", "abc", "b", "bb", "c"]
func allPalindromes(string: String) -> [String] {
    let substrings: [String] = [String(repeating: "", count: 0)]
    for i in 0..<string.count {
        for j in i..<string.count {
            let substring: String = string[i..<j+1]
            if substring == substring.reversed() {
                substrings.append(string: substring)
            }
        }
    }
    return substrings
}

// Return array of all substrings of the input string that are palindromes
// allPalindromes(string: "abc") == ["a", "ab", "aba", "abc", "b", "bb", "c"]
func allPalindromes(string: String) -> [String] {
    let substrings: [String] = [String(repeating: "", count: 0)]
    for i in 0..<string.count {
        for j in i..<string.count {
            let substring: String = string[i..<j+1]
            if substring == substring.reversed() {
                substrings.append(string: substring)
            }
        }
    }
    return substrings
}

// Return array of all substrings of the input string that are palindromes
// allPalindromes(string: "abc") == ["a", "ab", "aba", "abc", "b", "bb", "c"]
func allPalindromes(string: String) -> [String] {
    

func allPrefixes(string: String) -> [String] {
    let mut prefixes = [String(string)];
    for i in 0..<string.count {
        let prefix = string.prefix(i + 1);
        prefixes.append(&mut [prefix!]);
    }
    return prefixes;
}

func allSuffixes(string: String) -> [String] {
    let mut suffixes = [String(string)];
    for i in 0..<string.count {
        let suffix = string.suffix(i + 1);
        suffixes.append(&mut [suffix!]);
    }
    return suffixes;
}

func allSubstrings(string: String) -> [String] {
    let mut substrings = [String(string)];
    for i in 0..<string.count {
        for j in i + 1..<string.count + 1 {
            let substring = string.substring(i, j);
            substrings.append(&mut [substring!]);
        }
    }
    return substrings;
}

func allPalindromes(string: String) -> [String] {
    let mut palindromes = [String(string)];
    for i in 0..<string.count {
        for j in i + 1..<string.count + 1 {
            let substring = string.substring(i, j);
            if substring == substring.reversed() {
                palindromes.append(&mut [substring!]);
            }
        }
    }
    return palindromes;
}

```swift
// Return array of all prefixes from shortest to longest of the input string
// allPrefixes(string: "abc") == ["a", "ab", "abc"]
func allPrefixes(string: String) -> [String] {
    let mut prefixes = [String(string)];
    for i in 0..<string.count {
        let prefix = string.prefix(i + 1);
        prefixes.append(&mut [prefix!]);
    }
    return prefixes;
}

// Return array of all suffixes from shortest to longest of the input string
// allSuffixes(string: "abc") == ["bc", "c"]
func allSuffixes(string: String) -> [String] {
    let mut suffixes = [String(string)];
    for i in 0..<string.count {
        let suffix = string.suffix(i + 1);
        suffixes.append(&mut [suffix!]);
    }
    return suffixes;
}

// Return array of all substrings of the input string
// allSubstrings(string: "abc") == ["a", "ab", "abc", "b", "bc", "c"]
func allSubstrings(string: String) -> [String] {
    let mut substrings = [String(string)];
    for i in 0..<string.count {
        for j in i + 1..<string.count + 1 {
            let substring = string.substring(i, j);
            substrings.append(&mut [substring!]);
        }
    }
    return substrings;
}

// Return array of all substrings of the input string that are palindromes
// allPalindromes(string: "abc") == ["a", "b", "c", "aa", "bb", "cc"]
func allPalindromes(string: String) -> [String] {
    let mut palindromes = [String(string)];
    for i in 0..<string.count {
        for j in i + 1..<string.count + 1 {
            let substring = string.substring(i, j);
            if substring == substring.reversed() {
                palindromes.append(&mut [substring!]);
            }
        }
    }
    return palindromes;
}

// Return array of all substrings of the input string that are palindromes
// allPalindromes(string: "abc") == ["a", "b", "c", "aa", "bb", "cc"]
func allPalindromes(string: String) -> [String] {
    let mut palindromes = [String(string)];
    for i in 0..<string.count {
        for j in i + 1..<string.count + 1 {
            let substring = string.substring(i, j);
            if substring == substring.reversed() {
                palindromes.append(&mut [substring!]);
            }
        }
    }
    return palindromes;
}

// Return array of all substrings of the input string that are palindromes
// allPalindromes(string: "abc") == ["a", "b", "c", "aa", "bb", "cc"]
func allPalindromes(string: String) -> [String] {
    let mut palindromes = [String(string)];
    for i in 0..<string.count {
        for j in i + 1..<string.count + 1 {
            let substring = string.substring(i, j);
            if substring == substring.reversed() {
                palindromes.append(&mut [substring!]);
            }
        }
    }
    return palindromes;
}

// Return array of all substrings of the input string that are palindromes
// allPalindromes(string: "abc") == ["a", "b", "c", "aa", "bb", "cc"]
func allPalindromes(string: String) -> [String] {
    let mut palindromes = [String(string)];
    for i in 0..<string.count {
        for j in i + 1..<string.count + 1 {
            let substring = string.substring(i, j);
            if substring == substring.reversed() {
                palindromes.append(&mut [substring!]);
            }
        }
    }
    return palindromes;
}

// Return array of all substrings of the input string that are palindromes
// allPalindromes(string: "abc") == ["a", "b", "c", "aa", "bb", "cc"]
func allPalindromes(string: String) -> [String] {
    let mut palindromes = [String(string)];
    for i in

func allPrefixes(string: String) -> [String] {
    let prefixes: [String] = [String(repeating: "a", count: 0)]
    for i in 0..<string.count {
        let prefix: String = string[..<i].joined(separator: "")
        prefixes.append(prefix)
    }
    return prefixes
}

func allSuffixes(string: String) -> [String] {
    let suffixes: [String] = [String(repeating: "", count: 0)]
    for i in 0..<string.count {
        let suffix: String = string[i..<string.count].joined(separator: "")
        suffixes.append(suffix)
    }
    return suffixes
}

func allSubstrings(string: String) -> [String] {
    let substrings: [String] = [String(repeating: "", count: 0)]
    for i in 0..<string.count {
        for j in i..<string.count {
            let substring: String = string[i..<j].joined(separator: "")
            substrings.append(substring)
        }
    }
    return substrings
}

func allPermutations(string: String) -> [String] {
    let permutations: [String] = [String(repeating: "", count: 0)]
    let stringArray: [String] = string.components(separatedBy: "")
    for i in 0..<stringArray.count {
        for j in 0..<stringArray.count {
            let permutation: String = stringArray[j..<stringArray.count].joined(separator: "")
            permutation = permutation.prefix(count: i) + stringArray[i] + permutation.suffix(count: stringArray.count - i - 1)
            permutations.append(permutation)
        }
    }
    return permutations
}

func allPalindromes(string: String) -> [String] {
    let palindromes: [String] = [String(repeating: "", count: 0)]
    for i in 0..<string.count {
        for j in i..<string.count {
            let substring: String = string[i..<j].joined(separator: "")
            if substring == substring.reversed() {
                palindromes.append(substring)
            }
        }
    }
    return palindromes
}

func allAnagrams(string: String) -> [String] {
    let anagrams: [String] = [String(repeating: "", count: 0)]
    let stringArray: [String] = string.components(separatedBy: "")
    for i in 0..<stringArray.count {
        for j in 0..<stringArray.count {
            let permutation: String = stringArray[j..<stringArray.count].joined(separator: "")
            permutation = permutation.prefix(count: i) + stringArray[i] + permutation.suffix(count: stringArray.count - i - 1)
            if permutation != string {
                anagrams.append(permutation)
            }
        }
    }
    return anagrams
}

```swift
// Return array of all prefixes from shortest to longest of the input string
// allPrefixes(string: "abc") == ["a", "ab", "abc"]
func allPrefixes(string: String) -> [String] {
    let prefixes: [String] = [String(repeating: "a", count: 0)]
    for i in 0..<string.count {
        let prefix: String = string[..<i].joined(separator: "")
        prefixes.append(prefix)
    }
    return prefixes
}

// Return array of all suffixes from shortest to longest of the input string
// allSuffixes(string: "abc") == ["bc", "c", ""]
func allSuffixes(string: String) -> [String] {
    let suffixes: [String] = [String(repeating: "", count: 0)]
    for i in 0..<string.count {
        let suffix: String = string[i..<string.count].joined(separator: "")
        suffixes.append(suffix)
    }
    return suffixes
}

// Return array of all substrings from shortest to longest of the input string
// allSubstrings(string: "abc") == ["a", "ab", "abc", "b", "bc", "c", ""]
func allSubstrings(string: String) -> [String] {
    let substrings: [String] = [String(repeating: "", count: 0)]
    for i in 0..<string.count {
        for j in i..<string.count {
            let substring: String = string[i..<j].joined(separator: "")
            substrings.append(substring)
        }
    }
    return substrings
}

// Return array of all permutations of the input string
// allPermutations(string: "abc") == ["abc", "acb", "bac", "bca", "cab", "cba"]
func allPermutations(string: String) -> [String] {
    let permutations: [String] = [String(repeating: "", count: 0)]
    let stringArray: [String] = string.components(separatedBy: "")
    for i in 0..<stringArray.count {
        for j in 0..<stringArray.count {
            let permutation: String = stringArray[j..<stringArray.count].joined(separator: "")
            permutation = permutation.prefix(count: i) + stringArray[i] + permutation.suffix(count: stringArray.count - i - 1)
            permutations.append(permutation)
        }
    }
    return permutations
}

// Return array of all palindromes from shortest to longest of the input string
// allPalindromes(string: "abc") == ["a", "ab", "abc", "b", "aba", "c", "abcba", ""]
func allPalindromes(string: String) -> [String] {
    let palindromes: [String] = [String(repeating: "", count: 0)]
    for i in 0..<string.count {
        for j in i..<string.count {
            let substring: String = string[i..<j].joined(separator: "")
            if substring == substring.reversed() {
                palindromes.append(substring)
            }
        }
    }
    return palindromes
}

// Return array of all anagrams of the input string
// allAnagrams(string: "abc") == ["abc", "acb", "bac", "bca", "cab", "cba"]
func allAnagrams(string: String) -> [String] {
    let anagrams: [String] = [String(repeating: "", count: 0)]
    let stringArray: [String] = string.components(separatedBy: "")
    for i in 0..<stringArray.count {
        for j in 0..<stringArray.count {
            let permutation: String = stringArray[j..<stringArray.count].joined(separator: "")
            permutation = permutation.prefix(count: i) + stringArray[i] + permutation.suffix(count: stringArray.count - i - 1)
            if permutation != string {
                anagrams.append(permutation)
            }
        }
    }
    return anagrams
}

// Return array of all palindromic anagrams of the input string
// allPalindromicAnagrams(string: "abc") == ["abc", "acb", "bac", "bca", "cab", "cba"]
func allPalindromicAnagrams(string: String) -> [String] {
    let palindromicAnagrams: [String] = [String(repeating: "", count: 0)]
    let stringArray: [String] = string.components

func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += Int.str(i)
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

```swift
// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += Int.str(i)
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += Int.str(i)
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += Int.str(i)
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += Int.str(i)
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += Int.str(i)
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += Int.str(i)
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += Int.str(i)
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += Int.str(i)
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += Int.str(i)
        if i < n - 1 {
            result +=

func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 ..< n {
        result += i.String()
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

```swift
// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 ..< n {
        result += i.String()
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 ..< n {
        result += i.String()
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 ..< n {
        result += i.String()
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 ..< n {
        result += i.String()
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 ..< n {
        result += i.String()
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 ..< n {
        result += i.String()
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 ..< n {
        result += i.String()
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 ..< n {
        result += i.String()
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 ..< n {
        result += i.String()
        if i < n - 1 {
            result += " "
        }
    }

func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += (i.String() + " ")
    }
    return result.dropLast(1)
}

```swift
// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += (i.String() + " ")
    }
    return result.dropLast(1)
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += (i.String() + " ")
    }
    return result.dropLast(1)
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += (i.String() + " ")
    }
    return result.dropLast(1)
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += (i.String() + " ")
    }
    return result.dropLast(1)
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += (i.String() + " ")
    }
    return result.dropLast(1)
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += (i.String() + " ")
    }
    return result.dropLast(1)
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += (i.String() + " ")
    }
    return result.dropLast(1)
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += (i.String() + " ")
    }
    return result.dropLast(1)
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += (i.String() + " ")
    }
    return result.dropLast(1)
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {

func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 .. n {
        result += (i.String() + " ")
    }
    return result
}

```swift
// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 .. n {
        result += (i.String() + " ")
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 .. n {
        result += (i.String() + " ")
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 .. n {
        result += (i.String() + " ")
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 .. n {
        result += (i.String() + " ")
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 .. n {
        result += (i.String() + " ")
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 .. n {
        result += (i.String() + " ")
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 .. n {
        result += (i.String() + " ")
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 .. n {
        result += (i.String() + " ")
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 .. n {
        result += (i.String() + " ")
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 .. n {
        result += (i.String() + " ")
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"

func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += (i.String() + " ")
    }
    return result.dropLast(1)
}

```swift
// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += (i.String() + " ")
    }
    return result.dropLast(1)
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += (i.String() + " ")
    }
    return result.dropLast(1)
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += (i.String() + " ")
    }
    return result.dropLast(1)
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += (i.String() + " ")
    }
    return result.dropLast(1)
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += (i.String() + " ")
    }
    return result.dropLast(1)
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += (i.String() + " ")
    }
    return result.dropLast(1)
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += (i.String() + " ")
    }
    return result.dropLast(1)
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += (i.String() + " ")
    }
    return result.dropLast(1)
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += (i.String() + " ")
    }
    return result.dropLast(1)
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {

func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += i.String()
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

```swift
// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += i.String()
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += i.String()
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += i.String()
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += i.String()
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += i.String()
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += i.String()
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += i.String()
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += i.String()
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += i.String()
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a

func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 .. n {
        result += (i.String() + " ")
    }
    return result.dropLast(1)
}

```swift
// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 .. n {
        result += (i.String() + " ")
    }
    return result.dropLast(1)
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 .. n {
        result += (i.String() + " ")
    }
    return result.dropLast(1)
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 .. n {
        result += (i.String() + " ")
    }
    return result.dropLast(1)
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 .. n {
        result += (i.String() + " ")
    }
    return result.dropLast(1)
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 .. n {
        result += (i.String() + " ")
    }
    return result.dropLast(1)
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 .. n {
        result += (i.String() + " ")
    }
    return result.dropLast(1)
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 .. n {
        result += (i.String() + " ")
    }
    return result.dropLast(1)
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 .. n {
        result += (i.String() + " ")
    }
    return result.dropLast(1)
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 .. n {
        result += (i.String() + " ")
    }
    return result.dropLast(1)
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0 .. n {

func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += (i.String())
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

```swift
// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += (i.String())
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += (i.String())
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += (i.String())
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += (i.String())
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += (i.String())
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += (i.String())
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += (i.String())
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += (i.String())
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += (i.String())
        if i < n - 1 {
            result += " "
        }
    }

func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += Int.str(i)
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

```swift
// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += Int.str(i)
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += Int.str(i)
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += Int.str(i)
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += Int.str(i)
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += Int.str(i)
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += Int.str(i)
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += Int.str(i)
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += Int.str(i)
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += Int.str(i)
        if i < n - 1 {
            result +=

func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += i.String()
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

```swift
// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += i.String()
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += i.String()
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += i.String()
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += i.String()
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += i.String()
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += i.String()
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += i.String()
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += i.String()
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a string containing space-delimited numbers starting from 0 upto n inclusive.
// stringSequence(n: 0) == "0"
// stringSequence(n: 5) == "0 1 2 3 4 5"
func stringSequence(n: Int) -> String {
    var result = ""
    for i in 0..<n {
        result += i.String()
        if i < n - 1 {
            result += " "
        }
    }
    return result
}

// Return a

func countDistinctCharacters(string: String) -> Int {
    var distinctCharacters: Set<String> = Set()
    for i in 0..<string.length {
        distinctCharacters.add(string[i].lowercase())
    }
    return distinctCharacters.count
}

```swift
// Given a string, find out how many distinct characters (regardless of case) does it consist of
// countDistinctCharacters(string: "xyzXYZ") == 3
// countDistinctCharacters(string: "Jerry") == 4
func countDistinctCharacters(string: String) -> Int {
    var distinctCharacters: Set<String> = Set()
    for i in 0..<string.length {
        distinctCharacters.add(string[i].lowercase())
    }
    return distinctCharacters.count
}
```

func countDistinctCharacters(string: String) -> Int {
    var distinctChars = Set<Character>()
    for char in string {
        distinctChars.add(char.makeUpper())
    }
    return distinctChars.count
}

func findMostFrequentCharacter(string: String) -> Character? {
    var characterCount = Map<Character, Int>()
    for char in string {
        let count = characterCount[char] ?? 0
        characterCount[char] = count + 1
    }

    var maxCount = 0
    var mostFrequentChar: Character? = nil

    for (char, count) in characterCount {
        if count > maxCount {
            maxCount = count
            mostFrequentChar = char
        }
    }

    return mostFrequentChar
}

func findLeastFrequentCharacter(string: String) -> Character? {
    var characterCount = Map<Character, Int>()
    for char in string {
        let count = characterCount[char] ?? 0
        characterCount[char] = count + 1
    }

    var minCount = Int.maxInt
    var leastFrequentChar: Character? = nil

    for (char, count) in characterCount {
        if count < minCount {
            minCount = count
            leastFrequentChar = char
        }
    }

    return leastFrequentChar
}

```swift
// Given a string, find out how many distinct characters (regardless of case) does it consist of
// countDistinctCharacters(string: "xyzXYZ") == 3
// countDistinctCharacters(string: "Jerry") == 4
func countDistinctCharacters(string: String) -> Int {
    var distinctChars = Set<Character>()
    for char in string {
        distinctChars.add(char.makeUpper())
    }
    return distinctChars.count
}

// Given a string, find out the most frequently occurring character
// findMostFrequentCharacter(string: "xyzXYZ") == "X"
// findMostFrequentCharacter(string: "Jerry") == "r"
func findMostFrequentCharacter(string: String) -> Character? {
    var characterCount = Map<Character, Int>()
    for char in string {
        let count = characterCount[char] ?? 0
        characterCount[char] = count + 1
    }

    var maxCount = 0
    var mostFrequentChar: Character? = nil

    for (char, count) in characterCount {
        if count > maxCount {
            maxCount = count
            mostFrequentChar = char
        }
    }

    return mostFrequentChar
}

// Given a string, find out the least frequently occurring character
// findLeastFrequentCharacter(string: "xyzXYZ") == "y"
// findLeastFrequentCharacter(string: "Jerry") == "r"
func findLeastFrequentCharacter(string: String) -> Character? {
    var characterCount = Map<Character, Int>()
    for char in string {
        let count = characterCount[char] ?? 0
        characterCount[char] = count + 1
    }

    var minCount = Int.maxInt
    var leastFrequentChar: Character? = nil

    for (char, count) in characterCount {
        if count < minCount {
            minCount = count
            leastFrequentChar = char
        }
    }

    return leastFrequentChar
}

// Given a string, find out the most frequently occurring character
// findMostFrequentCharacter(string: "xyzXYZ") == "X"
// findMostFrequentCharacter(string: "Jerry") == "r"
func findMostFrequentCharacter(string: String) -> Character? {
    var characterCount = Map<Character, Int>()
    for char in string {
        let count = characterCount[char] ?? 0
        characterCount[char] = count + 1
    }

    var maxCount = 0
    var mostFrequentChar: Character? = nil

    for (char, count) in characterCount {
        if count > maxCount {
            maxCount = count
            mostFrequentChar = char
        }
    }

    return mostFrequentChar
}

// Given a string, find out the least frequently occurring character
// findLeastFrequentCharacter(string: "xyzXYZ") == "y"
// findLeastFrequentCharacter(string: "Jerry") == "r"
func findLeastFrequentCharacter(string: String) -> Character? {
    var characterCount = Map<Character, Int>()
    for char in string {
        let count = characterCount[char] ?? 0
        characterCount[char] = count + 1
    }

    var minCount = Int.maxInt
    var leastFrequentChar: Character? = nil

    for (char, count) in characterCount {
        if count < minCount {
            minCount = count
            leastFrequentChar = char
        }
    }

    return leastFrequentChar
}

// Given a string, find out the most frequently occurring character
// findMostFrequentCharacter(string: "xyzXYZ") == "X"
// findMostFrequentCharacter(string: "Jerry") == "r"
func findMostFrequentCharacter(string: String) -> Character? {
    var characterCount = Map<Character, Int>()
    for char in string {
        let count = characterCount[char] ?? 0
        characterCount[char] = count + 1
    }

    var maxCount = 0
    var mostFrequentChar: Character? = nil

    for (char, count) in characterCount {
        if count > maxCount {
            maxCount = count
            mostFrequentChar = char
        }
    }

    return mostFrequentChar
}

// Given a string, find out the least frequently occurring character
// findLeastFrequentCharacter(string: "xyzXYZ") == "y"
// findLeastFrequentCharacter(string: "Jerry") == "r"
func findLeastFrequentCharacter(string: String) -> Character? {
    var characterCount = Map<Character, Int>()
    for char in string {
        let count = characterCount[char] ?? 0
        characterCount[char] = count + 1
    }

func countDistinctCharacters(string: String) -> Int {
    var distinctChars = Set<String>()
    for i in 0..<string.length {
        let character = string[i].uppercase()
        distinctChars.add(character)
    }
    return distinctChars.count
}

```swift
// Given a string, find out how many distinct characters (regardless of case) does it consist of
// countDistinctCharacters(string: "xyzXYZ") == 3
// countDistinctCharacters(string: "Jerry") == 4
func countDistinctCharacters(string: String) -> Int {
    var distinctChars = Set<String>()
    for i in 0..<string.length {
        let character = string[i].uppercase()
        distinctChars.add(character)
    }
    return distinctChars.count
}

// Given a string, find out how many distinct characters (regardless of case) does it consist of
// countDistinctCharacters(string: "xyzXYZ") == 3
// countDistinctCharacters(string: "Jerry") == 4
func countDistinctCharacters(string: String) -> Int {
    var distinctChars = Set<String>()
    for i in 0..<string.length {
        let character = string[i].uppercase()
        distinctChars.add(character)
    }
    return distinctChars.count
}

// Given a string, find out how many distinct characters (regardless of case) does it consist of
// countDistinctCharacters(string: "xyzXYZ") == 3
// countDistinctCharacters(string: "Jerry") == 4
func countDistinctCharacters(string: String) -> Int {
    var distinctChars = Set<String>()
    for i in 0..<string.length {
        let character = string[i].uppercase()
        distinctChars.add(character)
    }
    return distinctChars.count
}

// Given a string, find out how many distinct characters (regardless of case) does it consist of
// countDistinctCharacters(string: "xyzXYZ") == 3
// countDistinctCharacters(string: "Jerry") == 4
func countDistinctCharacters(string: String) -> Int {
    var distinctChars = Set<String>()
    for i in 0..<string.length {
        let character = string[i].uppercase()
        distinctChars.add(character)
    }
    return distinctChars.count
}

// Given a string, find out how many distinct characters (regardless of case) does it consist of
// countDistinctCharacters(string: "xyzXYZ") == 3
// countDistinctCharacters(string: "Jerry") == 4
func countDistinctCharacters(string: String) -> Int {
    var distinctChars = Set<String>()
    for i in 0..<string.length {
        let character = string[i].uppercase()
        distinctChars.add(character)
    }
    return distinctChars.count
}

// Given a string, find out how many distinct characters (regardless of case) does it consist of
// countDistinctCharacters(string: "xyzXYZ") == 3
// countDistinctCharacters(string: "Jerry") == 4
func countDistinctCharacters(string: String) -> Int {
    var distinctChars = Set<String>()
    for i in 0..<string.length {
        let character = string[i].uppercase()
        distinctChars.add(character)
    }
    return distinctChars.count
}

// Given a string, find out how many distinct characters (regardless of case) does it consist of
// countDistinctCharacters(string: "xyzXYZ") == 3
// countDistinctCharacters(string: "Jerry") == 4
func countDistinctCharacters(string: String) -> Int {
    var distinctChars = Set<String>()
    for i in 0..<string.length {
        let character = string[i].uppercase()
        distinctChars.add(character)
    }
    return distinctChars.count
}

// Given a string, find out how many distinct characters (regardless of case) does it consist of
// countDistinctCharacters(string: "xyzXYZ") == 3
// countDistinctCharacters(string: "Jerry") == 4
func countDistinctCharacters(string: String) -> Int {
    var distinctChars = Set<String>()
    for i in 0..<string.length {
        let character = string[i].uppercase()
        distinctChars.add(character)
    }
    return distinctChars.count
}

// Given a string, find out how many distinct characters (regardless of case) does it consist of
// countDistinctCharacters(string: "xyzXYZ") == 3
// countDistinctCharacters(string: "Jerry") == 4
func countDistinctCharacters(string: String) -> Int {
    var distinctChars = Set<String>()
    for i in 0..<string.length {
        let character = string[i].uppercase()
        distinctChars.add(character)
    }
    return distinctChars.count
}

// Given a string, find out how many distinct characters (regardless of case) does it consist of
// countDistinctCharacters(string: "xyzXYZ") ==

func countDistinctCharacters(string: String) -> Int {
    var distinctCharacters: Set<String> = Set()
    for i in 0..<string.length {
        let character: String = string[i]
        if character.uppercaseFirstCharacter().rawValue != character.lowercaseFirstCharacter().rawValue {
            distinctCharacters.add(character)
        }
    }
    return distinctCharacters.count
}

func countOccurrences(string: String) -> [Int] {
    var occurrences: [Int] = [0, 0, 0, 0, 0, 0]
    for i in 0..<string.length {
        let character: String = string[i]
        if character.uppercaseFirstCharacter().rawValue != character.lowercaseFirstCharacter().rawValue {
            occurrences[character.characterIndex()] += 1
        }
    }
    return occurrences
}

```swift
// Given a string, find out how many distinct characters (regardless of case) does it consist of
// countDistinctCharacters(string: "xyzXYZ") == 3
// countDistinctCharacters(string: "Jerry") == 4
func countDistinctCharacters(string: String) -> Int {
    var distinctCharacters: Set<String> = Set()
    for i in 0..<string.length {
        let character: String = string[i]
        if character.uppercaseFirstCharacter().rawValue != character.lowercaseFirstCharacter().rawValue {
            distinctCharacters.add(character)
        }
    }
    return distinctCharacters.count
}

// Given a string, find out how many times each distinct character (regardless of case) occurs in the string
// countOccurrences(string: "xyzXYZ") == [0, 0, 1, 1, 1, 1]
// countOccurrences(string: "Jerry") == [1, 2, 1, 0, 0, 0]
func countOccurrences(string: String) -> [Int] {
    var occurrences: [Int] = [0, 0, 0, 0, 0, 0]
    for i in 0..<string.length {
        let character: String = string[i]
        if character.uppercaseFirstCharacter().rawValue != character.lowercaseFirstCharacter().rawValue {
            occurrences[character.characterIndex()] += 1
        }
    }
    return occurrences
}

// Given a string, find out how many times each distinct character (regardless of case) occurs in the string
// countOccurrences(string: "xyzXYZ") == [0, 0, 1, 1, 1, 1]
// countOccurrences(string: "Jerry") == [1, 2, 1, 0, 0, 0]
func countOccurrences(string: String) -> [Int] {
    var occurrences: [Int] = [0, 0, 0, 0, 0, 0]
    for i in 0..<string.length {
        let character: String = string[i]
        if character.uppercaseFirstCharacter().rawValue != character.lowercaseFirstCharacter().rawValue {
            occurrences[character.characterIndex()] += 1
        }
    }
    return occurrences
}

// Given a string, find out how many times each distinct character (regardless of case) occurs in the string
// countOccurrences(string: "xyzXYZ") == [0, 0, 1, 1, 1, 1]
// countOccurrences(string: "Jerry") == [1, 2, 1, 0, 0, 0]
func countOccurrences(string: String) -> [Int] {
    var occurrences: [Int] = [0, 0, 0, 0, 0, 0]
    for i in 0..<string.length {
        let character: String = string[i]
        if character.uppercaseFirstCharacter().rawValue != character.lowercaseFirstCharacter().rawValue {
            occurrences[character.characterIndex()] += 1
        }
    }
    return occurrences
}

// Given a string, find out how many times each distinct character (regardless of case) occurs in the string
// countOccurrences(string: "xyzXYZ") == [0, 0, 1, 1, 1, 1]
// countOccurrences(string: "Jerry") == [1, 2, 1, 0, 0, 0]
func countOccurrences(string: String) -> [Int] {
    var occurrences: [Int] = [0, 0, 0, 0, 0, 0]
    for i in 0..<string.length {
        let character: String = string[i]
        if character.uppercaseFirstCharacter().rawValue != character.lowercaseFirstCharacter().rawValue {
            occurrences[character.characterIndex()] += 1
        }
    }
    return occurrences
}

// Given a string, find out how many times each distinct character (regardless of case) occurs in the string
// countOccurrences(string: "xyzXYZ") == [0, 0, 1, 1, 1, 1]
// countOccurrences(string: "Jerry") == [1, 2, 1, 0, 0, 0]
func countOccurrences(string: String) -> [Int] {
    var occurrences: [Int] = [0, 0, 0, 0, 0, 0]
    for i in 0..<string.length {
        let character: String = string[i]
        if character.uppercaseFirstCharacter().rawValue != character.lowercaseFirstCharacter().rawValue {
            occurrences[character.characterIndex()] += 1
        }
    }

func countDistinctCharacters(string: String) -> Int {
    var distinctChars = HashSet<String>()
    for c in string {
        distinctChars.add(String(c).lowercase())
    }
    return distinctChars.count
}

func findMostFrequentCharacter(string: String) -> String {
    var charCount = HashMap<String, Int>()
    for c in string {
        let lowercaseChar = String(c).lowercase()
        charCount[lowercaseChar] = charCount[lowercaseChar]?.rawValue ?? 0 + 1
    }
    var mostFrequentChar = ""
    var maxCount = 0
    for (key, value) in charCount {
        if value > maxCount {
            mostFrequentChar = key
            maxCount = value
        }
    }
    return mostFrequentChar
}

```swift
// Given a string, find out how many distinct characters (regardless of case) does it consist of
// countDistinctCharacters(string: "xyzXYZ") == 3
// countDistinctCharacters(string: "Jerry") == 4
func countDistinctCharacters(string: String) -> Int {
    var distinctChars = HashSet<String>()
    for c in string {
        distinctChars.add(String(c).lowercase())
    }
    return distinctChars.count
}

// Given a string, find out the most frequently occurring character in the string
// findMostFrequentCharacter(string: "xyzXYZ") == "x"
// findMostFrequentCharacter(string: "Jerry") == "r"
func findMostFrequentCharacter(string: String) -> String {
    var charCount = HashMap<String, Int>()
    for c in string {
        let lowercaseChar = String(c).lowercase()
        charCount[lowercaseChar] = charCount[lowercaseChar]?.rawValue ?? 0 + 1
    }
    var mostFrequentChar = ""
    var maxCount = 0
    for (key, value) in charCount {
        if value > maxCount {
            mostFrequentChar = key
            maxCount = value
        }
    }
    return mostFrequentChar
}

// Given a string, find out the most frequently occurring character in the string
// findMostFrequentCharacter(string: "xyzXYZ") == "x"
// findMostFrequentCharacter(string: "Jerry") == "r"
func findMostFrequentCharacter(string: String) -> String {
    var charCount = HashMap<String, Int>()
    for c in string {
        let lowercaseChar = String(c).lowercase()
        charCount[lowercaseChar] = charCount[lowercaseChar]?.rawValue ?? 0 + 1
    }
    var mostFrequentChar = ""
    var maxCount = 0
    for (key, value) in charCount {
        if value > maxCount {
            mostFrequentChar = key
            maxCount = value
        }
    }
    return mostFrequentChar
}

// Given a string, find out the most frequently occurring character in the string
// findMostFrequentCharacter(string: "xyzXYZ") == "x"
// findMostFrequentCharacter(string: "Jerry") == "r"
func findMostFrequentCharacter(string: String) -> String {
    var charCount = HashMap<String, Int>()
    for c in string {
        let lowercaseChar = String(c).lowercase()
        charCount[lowercaseChar] = charCount[lowercaseChar]?.rawValue ?? 0 + 1
    }
    var mostFrequentChar = ""
    var maxCount = 0
    for (key, value) in charCount {
        if value > maxCount {
            mostFrequentChar = key
            maxCount = value
        }
    }
    return mostFrequentChar
}

// Given a string, find out the most frequently occurring character in the string
// findMostFrequentCharacter(string: "xyzXYZ") == "x"
// findMostFrequentCharacter(string: "Jerry") == "r"
func findMostFrequentCharacter(string: String) -> String {
    var charCount = HashMap<String, Int>()
    for c in string {
        let lowercaseChar = String(c).lowercase()
        charCount[lowercaseChar] = charCount[lowercaseChar]?.rawValue ?? 0 + 1
    }
    var mostFrequentChar = ""
    var maxCount = 0
    for (key, value) in charCount {
        if value > maxCount {
            mostFrequentChar = key
            maxCount = value
        }
    }
    return mostFrequentChar
}

// Given a string, find out the most frequently occurring character in the string
// findMostFrequentCharacter(string: "xyzXYZ") == "x"
// findMostFrequentCharacter(string: "Jerry") == "r"
func findMostFrequentCharacter(string: String) -> String {
    var charCount = HashMap<String, Int>()
    for c in string {
        let lowercaseChar = String(c).lowercase()
        charCount[lowercaseChar] = charCount[lowercaseChar]?.rawValue ?? 0 + 1
    }
    var mostFrequentChar = ""
    var maxCount = 0
    for (key, value) in charCount {
        if value > maxCount {
            mostFrequentChar = key
            maxCount = value
        }
    }
    return mostFrequentChar
}

// Given a string, find out the most frequently occurring character in the string
// findMostFrequentCharacter(string: "xyzXYZ") == "x"
// findMostFrequentCharacter(string: "Jerry") == "r"
func findMostFrequentCharacter(string: String) -> String {
    var charCount = HashMap<String

func countDistinctCharacters(string: String) -> Int {
    var distinctCharacters: Set<Char> = Set()
    for character in string {
        distinctCharacters.add(character)
    }
    return distinctCharacters.count
}

```swift
// Given a string, find out how many distinct characters (regardless of case) does it consist of
// countDistinctCharacters(string: "xyzXYZ") == 3
// countDistinctCharacters(string: "Jerry") == 4
func countDistinctCharacters(string: String) -> Int {
    var distinctCharacters: Set<Char> = Set()
    for character in string {
        distinctCharacters.add(character)
    }
    return distinctCharacters.count
}
```

func countDistinctCharacters(string: String) -> Int {
    var distinctChars = Set<String>()
    for i in 0..<string.length {
        distinctChars.add(string[i].lowercase())
    }
    return distinctChars.count
}

func countCharacterOccurrences(string: String) -> Map<String, Int> {
    var occurrences = Map<String, Int>()
    for i in 0..<string.length {
        var char = string[i].lowercase()
        if occurrences.containsKey(char) {
            occurrences[char] = occurrences[char]! + 1
        } else {
            occurrences[char] = 1
        }
    }
    return occurrences
}

```swift
// Given a string, find out how many distinct characters (regardless of case) does it consist of
// countDistinctCharacters(string: "xyzXYZ") == 3
// countDistinctCharacters(string: "Jerry") == 4
func countDistinctCharacters(string: String) -> Int {
    var distinctChars = Set<String>()
    for i in 0..<string.length {
        distinctChars.add(string[i].lowercase())
    }
    return distinctChars.count
}

// Given a string, find out how many times each distinct character (regardless of case) occurs in it
// countCharacterOccurrences(string: "xyzXYZ") == { "x": 1, "y": 1, "z": 1, "X": 1, "Y": 1, "Z": 1 }
// countCharacterOccurrences(string: "Jerry") == { "j": 1, "e": 2, "r": 2, "y": 1 }
func countCharacterOccurrences(string: String) -> Map<String, Int> {
    var occurrences = Map<String, Int>()
    for i in 0..<string.length {
        var char = string[i].lowercase()
        if occurrences.containsKey(char) {
            occurrences[char] = occurrences[char]! + 1
        } else {
            occurrences[char] = 1
        }
    }
    return occurrences
}

// Given a string, find out how many times each distinct character (regardless of case) occurs in it
// countCharacterOccurrences(string: "xyzXYZ") == { "x": 1, "y": 1, "z": 1, "X": 1, "Y": 1, "Z": 1 }
// countCharacterOccurrences(string: "Jerry") == { "j": 1, "e": 2, "r": 2, "y": 1 }
func countCharacterOccurrences(string: String) -> Map<String, Int> {
    var occurrences = Map<String, Int>()
    for i in 0..<string.length {
        var char = string[i].lowercase()
        if occurrences.containsKey(char) {
            occurrences[char] = occurrences[char]! + 1
        } else {
            occurrences[char] = 1
        }
    }
    return occurrences
}

// Given a string, find out how many times each distinct character (regardless of case) occurs in it
// countCharacterOccurrences(string: "xyzXYZ") == { "x": 1, "y": 1, "z": 1, "X": 1, "Y": 1, "Z": 1 }
// countCharacterOccurrences(string: "Jerry") == { "j": 1, "e": 2, "r": 2, "y": 1 }
func countCharacterOccurrences(string: String) -> Map<String, Int> {
    var occurrences = Map<String, Int>()
    for i in 0..<string.length {
        var char = string[i].lowercase()
        if occurrences.containsKey(char) {
            occurrences[char] = occurrences[char]! + 1
        } else {
            occurrences[char] = 1
        }
    }
    return occurrences
}

// Given a string, find out how many times each distinct character (regardless of case) occurs in it
// countCharacterOccurrences(string: "xyzXYZ") == { "x": 1, "y": 1, "z": 1, "X": 1, "Y": 1, "Z": 1 }
// countCharacterOccurrences(string: "Jerry") == { "j": 1, "e": 2, "r": 2, "y": 1 }
func countCharacterOccurrences(string: String) -> Map<String, Int> {
    var occurrences = Map<String, Int>()
    for i in 0..<string.length {
        var char = string[i].lowercase()
        if occurrences.containsKey(char) {
            occurrences[char] = occurrences[char]! + 1
        } else {
            occurrences[char] = 1
        }
    }
    return occurrences
}

// Given a string, find out how many times each distinct character (regardless of case) occurs in it
// countCharacterOccurrences(string: "xyzXYZ") == { "x": 1, "y": 1, "z": 1, "X": 1, "Y": 1, "Z": 1 }
// countCharacterOccurrences(string: "Jerry") == { "j": 1, "e": 2, "r": 2, "y": 1 }
func countCharacterOccurrences(string: String) -> Map<String, Int

func countDistinctCharacters(string: String) -> Int {
    var distinctChars = Set<String>()
    for i in 0..<string.length {
        distinctChars.add(string[i].lowercase())
    }
    return distinctChars.count
}

func countCharacterFrequency(string: String) -> Map<String, Int> {
    var characterFrequency = Map<String, Int>()
    for i in 0..<string.length {
        var currentCharacter = string[i].lowercase()
        if characterFrequency.contains(currentCharacter) {
            characterFrequency[currentCharacter] = characterFrequency[currentCharacter]! + 1
        } else {
            characterFrequency[currentCharacter] = 1
        }
    }
    return characterFrequency
}

func countWordFrequency(string: String) -> Map<String, Int> {
    var wordFrequency = Map<String, Int>()
    var word = String()
    for i in 0..<string.length {
        var currentCharacter = string[i]
        if currentCharacter.isWhitespace() {
            if word.isNotEmpty() {
                if wordFrequency.contains(word) {
                    wordFrequency[word] = wordFrequency[word]! + 1
                } else {
                    wordFrequency[word] = 1
                }
                word = String()
            }
        } else {
            word += currentCharacter
        }
    }
    if word.isNotEmpty() {
        if wordFrequency.contains(word) {
            wordFrequency[word] = wordFrequency[word]! + 1
        } else {
            wordFrequency[word] = 1
        }
    }
    return wordFrequency
}

```swift
// Given a string, find out how many distinct characters (regardless of case) does it consist of
// countDistinctCharacters(string: "xyzXYZ") == 3
// countDistinctCharacters(string: "Jerry") == 4
func countDistinctCharacters(string: String) -> Int {
    var distinctChars = Set<String>()
    for i in 0..<string.length {
        distinctChars.add(string[i].lowercase())
    }
    return distinctChars.count
}

// Given a string, find out how many times each character (regardless of case) appears in the string
// countCharacterFrequency(string: "xyzXYZ") == { "x": 1, "y": 1, "z": 1 }
// countCharacterFrequency(string: "Jerry") == { "j": 1, "e": 2, "r": 2 }
func countCharacterFrequency(string: String) -> Map<String, Int> {
    var characterFrequency = Map<String, Int>()
    for i in 0..<string.length {
        var currentCharacter = string[i].lowercase()
        if characterFrequency.contains(currentCharacter) {
            characterFrequency[currentCharacter] = characterFrequency[currentCharacter]! + 1
        } else {
            characterFrequency[currentCharacter] = 1
        }
    }
    return characterFrequency
}

// Given a string, find out how many times each word appears in the string
// countWordFrequency(string: "I like to eat pizza. I like to eat pizza. I like to eat pizza.") == { "I": 3, "like": 2, "to": 2, "eat": 2, "pizza": 3 }
// countWordFrequency(string: "I like to eat pizza. I like to eat pizza. I like to eat pizza.") == { "I": 3, "like": 2, "to": 2, "eat": 2, "pizza": 3 }
func countWordFrequency(string: String) -> Map<String, Int> {
    var wordFrequency = Map<String, Int>()
    var word = String()
    for i in 0..<string.length {
        var currentCharacter = string[i]
        if currentCharacter.isWhitespace() {
            if word.isNotEmpty() {
                if wordFrequency.contains(word) {
                    wordFrequency[word] = wordFrequency[word]! + 1
                } else {
                    wordFrequency[word] = 1
                }
                word = String()
            }
        } else {
            word += currentCharacter
        }
    }
    if word.isNotEmpty() {
        if wordFrequency.contains(word) {
            wordFrequency[word] = wordFrequency[word]! + 1
        } else {
            wordFrequency[word] = 1
        }
    }
    return wordFrequency
}

// Given a string, find out how many times each word appears in the string
// countWordFrequency(string: "I like to eat pizza. I like to eat pizza. I like to eat pizza.") == { "I": 3, "like": 2, "to": 2, "eat": 2, "pizza": 3 }
// countWordFrequency(string: "I like to eat pizza. I like to eat pizza. I like to eat pizza.") == { "I": 3, "like": 2, "to": 2, "eat": 2, "pizza": 3 }
func countWordFrequency(string: String) -> Map<String, Int> {
    var wordFrequency = Map<String, Int>()
    var word = String()
    for i in 0..<string.length {
        var currentCharacter = string[i]
        if currentCharacter.isWhitespace() {
            if word.isNotEmpty() {
                if wordFrequency.contains(word) {
                    wordFrequency[word] = wordFrequency[word]! + 1
                } else {
                    wordFrequency[word] = 1
                }
                word = String()
            }
        } else {
            word += currentCharacter
        }
    }
    if word.isNotEmpty() {
        if wordFrequency.contains(word) {
            wordFrequency[word] = wordFrequency[word]! + 1
        } else {
            wordFrequency[word] = 1
        }
    }
    return wordFrequency
}

// Given a string, find out how many times each word appears in the string
// countWordFrequency(string: "I like to eat pizza. I like to eat pizza. I like to eat pizza.") == { "I": 3, "like": 2, "to": 2, "eat": 2, "pizza": 3 }
// countWordFrequency(string: "I like

func countDistinctCharacters(string: String) -> Int {
    var distinctChars = HashSet<Character>()
    for character in string {
        distinctChars.add(character)
    }
    return distinctChars.count
}

```swift
// Given a string, find out how many distinct characters (regardless of case) does it consist of
// countDistinctCharacters(string: "xyzXYZ") == 3
// countDistinctCharacters(string: "Jerry") == 4
func countDistinctCharacters(string: String) -> Int {
    var distinctChars = HashSet<Character>()
    for character in string {
        distinctChars.add(character)
    }
    return distinctChars.count
}

// Given a string, find out how many distinct characters (regardless of case) does it consist of
// countDistinctCharacters(string: "xyzXYZ") == 3
// countDistinctCharacters(string: "Jerry") == 4
func countDistinctCharacters(string: String) -> Int {
    var distinctChars = HashSet<Character>()
    for character in string {
        distinctChars.add(character)
    }
    return distinctChars.count
}

// Given a string, find out how many distinct characters (regardless of case) does it consist of
// countDistinctCharacters(string: "xyzXYZ") == 3
// countDistinctCharacters(string: "Jerry") == 4
func countDistinctCharacters(string: String) -> Int {
    var distinctChars = HashSet<Character>()
    for character in string {
        distinctChars.add(character)
    }
    return distinctChars.count
}

// Given a string, find out how many distinct characters (regardless of case) does it consist of
// countDistinctCharacters(string: "xyzXYZ") == 3
// countDistinctCharacters(string: "Jerry") == 4
func countDistinctCharacters(string: String) -> Int {
    var distinctChars = HashSet<Character>()
    for character in string {
        distinctChars.add(character)
    }
    return distinctChars.count
}

// Given a string, find out how many distinct characters (regardless of case) does it consist of
// countDistinctCharacters(string: "xyzXYZ") == 3
// countDistinctCharacters(string: "Jerry") == 4
func countDistinctCharacters(string: String) -> Int {
    var distinctChars = HashSet<Character>()
    for character in string {
        distinctChars.add(character)
    }
    return distinctChars.count
}

// Given a string, find out how many distinct characters (regardless of case) does it consist of
// countDistinctCharacters(string: "xyzXYZ") == 3
// countDistinctCharacters(string: "Jerry") == 4
func countDistinctCharacters(string: String) -> Int {
    var distinctChars = HashSet<Character>()
    for character in string {
        distinctChars.add(character)
    }
    return distinctChars.count
}

// Given a string, find out how many distinct characters (regardless of case) does it consist of
// countDistinctCharacters(string: "xyzXYZ") == 3
// countDistinctCharacters(string: "Jerry") == 4
func countDistinctCharacters(string: String) -> Int {
    var distinctChars = HashSet<Character>()
    for character in string {
        distinctChars.add(character)
    }
    return distinctChars.count
}

// Given a string, find out how many distinct characters (regardless of case) does it consist of
// countDistinctCharacters(string: "xyzXYZ") == 3
// countDistinctCharacters(string: "Jerry") == 4
func countDistinctCharacters(string: String) -> Int {
    var distinctChars = HashSet<Character>()
    for character in string {
        distinctChars.add(character)
    }
    return distinctChars.count
}

// Given a string, find out how many distinct characters (regardless of case) does it consist of
// countDistinctCharacters(string: "xyzXYZ") == 3
// countDistinctCharacters(string: "Jerry") == 4
func countDistinctCharacters(string: String) -> Int {
    var distinctChars = HashSet<Character>()
    for character in string {
        distinctChars.add(character)
    }
    return distinctChars.count
}

// Given a string, find out how many distinct characters (regardless of case) does it consist of
// countDistinctCharacters(string: "xyzXYZ") == 3
// countDistinctCharacters(string: "Jerry") == 4
func countDistinctCharacters(string: String) -> Int {
    var distinctChars = HashSet<Character>()
    for character in string {
        distinctChars.add(character)
    }
    return distinctChars.count
}

// Given a string, find out how many distinct characters (regardless of case) does it consist of
// countDistinctCharacters(string: "xyzXYZ") == 3
// countDistinctCharacters(string: "Jerry") == 4
func countDistinctCharacters(string: String) -> Int {
    var distinctChars = HashSet<Character>()
    for character

func countDistinctCharacters(string: String) -> Int {
    var distinctChars = Set<String>()
    for i in 0..<string.length {
        let char = string[i]
        if !distinctChars.contains(char.lowercase()) {
            distinctChars.add(char.lowercase())
        }
    }
    return distinctChars.count
}

func countWords(string: String) -> Int {
    return string.count(separator: " ") + 1
}

func countSentences(string: String) -> Int {
    return string.count(separator: ".") + 1
}

func countLines(string: String) -> Int {
    return string.count(separator: "\n") + 1
}

```swift
// Given a string, find out how many distinct characters (regardless of case) does it consist of
// countDistinctCharacters(string: "xyzXYZ") == 3
// countDistinctCharacters(string: "Jerry") == 4
func countDistinctCharacters(string: String) -> Int {
    var distinctChars = Set<String>()
    for i in 0..<string.length {
        let char = string[i]
        if !distinctChars.contains(char.lowercase()) {
            distinctChars.add(char.lowercase())
        }
    }
    return distinctChars.count
}

// Given a string, find out how many words (separated by spaces) does it consist of
// countWords(string: "Hello World") == 2
// countWords(string: "I am a student") == 3
func countWords(string: String) -> Int {
    return string.count(separator: " ") + 1
}

// Given a string, find out how many sentences (separated by periods) does it consist of
// countSentences(string: "Hello. World!") == 2
// countSentences(string: "I am a student. I am a student.") == 3
func countSentences(string: String) -> Int {
    return string.count(separator: ".") + 1
}

// Given a string, find out how many lines (separated by newlines) does it consist of
// countLines(string: "Hello\nWorld!") == 2
// countLines(string: "I am a student.\nI am a student.") == 3
func countLines(string: String) -> Int {
    return string.count(separator: "\n") + 1
}

// Given a string, find out how many words (separated by spaces) does it consist of
// countWords(string: "Hello World") == 2
// countWords(string: "I am a student") == 3
func countWords(string: String) -> Int {
    return string.count(separator: " ") + 1
}

// Given a string, find out how many sentences (separated by periods) does it consist of
// countSentences(string: "Hello. World!") == 2
// countSentences(string: "I am a student. I am a student.") == 3
func countSentences(string: String) -> Int {
    return string.count(separator: ".") + 1
}

// Given a string, find out how many lines (separated by newlines) does it consist of
// countLines(string: "Hello\nWorld!") == 2
// countLines(string: "I am a student.\nI am a student.") == 3
func countLines(string: String) -> Int {
    return string.count(separator: "\n") + 1
}

// Given a string, find out how many words (separated by spaces) does it consist of
// countWords(string: "Hello World") == 2
// countWords(string: "I am a student") == 3
func countWords(string: String) -> Int {
    return string.count(separator: " ") + 1
}

// Given a string, find out how many sentences (separated by periods) does it consist of
// countSentences(string: "Hello. World!") == 2
// countSentences(string: "I am a student. I am a student.") == 3
func countSentences(string: String) -> Int {
    return string.count(separator: ".") + 1
}

// Given a string, find out how many lines (separated by newlines) does it consist of
// countLines(string: "Hello\nWorld!") == 2
// countLines(string: "I am a student.\nI am a student.") == 3
func countLines(string: String) -> Int {
    return string.count(separator: "\n") + 1
}

// Given a string, find out how many words (separated by spaces) does it consist of
// countWords(string: "Hello World") == 2
// countWords(string: "I am a student") == 3
func countWords(string: String) -> Int {
    return string.count(separator: " ") + 1
}

// Given a string, find out how many sentences (separated by periods) does it consist of
// countSentences(string: "Hello. World!") == 2
// countSentences(string: "I am a student. I am a student.") == 3
func countSentences(string: String) -> Int {
    return string.count(separator: ".") + 1
}

// Given a string, find out how many lines (separated by newlines) does it consist of
// countLines(string: "

func parseMusic(musicString: String) -> [Int] {
    let result = Array<Int>();
    for note in musicString.split(" ") {
        if note.contains("o") {
            result.append(4);
        } else if note.contains("o|") {
            result.append(2);
        } else if note.contains(".") {
            result.append(1);
        } else {
            result.append(0);
        }
    }
    return result;
}

```swift
// Input to this function is a string representing musical notes in a special ASCII format.
// Your task is to parse this string and return array of integers corresponding to how many beats does each
// not last.
// Here is a legend:
// 'o' - whole note, lasts four beats
// 'o|' - half note, lasts two beats
// '.|' - quater note, lasts one beat
// parseMusic(musicString: "o o| .| o| o| .| .| .| .| o o") == [4, 2, 1, 2, 2, 1, 1, 1, 1, 4, 4]
func parseMusic(musicString: String) -> [Int] {
    let result = Array<Int>();
    for note in musicString.split(" ") {
        if note.contains("o") {
            result.append(4);
        } else if note.contains("o|") {
            result.append(2);
        } else if note.contains(".") {
            result.append(1);
        } else {
            result.append(0);
        }
    }
    return result;
}

// Input to this function is a string representing musical notes in a special ASCII format.
// Your task is to parse this string and return array of integers corresponding to how many beats does each
// not last.
// Here is a legend:
// 'o' - whole note, lasts four beats
// 'o|' - half note, lasts two beats
// '.|' - quater note, lasts one beat
// parseMusic(musicString: "o o| .| o| o| .| .| .| .| o o") == [4, 2, 1, 2, 2, 1, 1, 1, 1, 4, 4]
func parseMusic(musicString: String) -> [Int] {
    let result = Array<Int>();
    for note in musicString.split(" ") {
        if note.contains("o") {
            result.append(4);
        } else if note.contains("o|") {
            result.append(2);
        } else if note.contains(".") {
            result.append(1);
        } else {
            result.append(0);
        }
    }
    return result;
}

// Input to this function is a string representing musical notes in a special ASCII format.
// Your task is to parse this string and return array of integers corresponding to how many beats does each
// not last.
// Here is a legend:
// 'o' - whole note, lasts four beats
// 'o|' - half note, lasts two beats
// '.|' - quater note, lasts one beat
// parseMusic(musicString: "o o| .| o| o| .| .| .| .| o o") == [4, 2, 1, 2, 2, 1, 1, 1, 1, 4, 4]
func parseMusic(musicString: String) -> [Int] {
    let result = Array<Int>();
    for note in musicString.split(" ") {
        if note.contains("o") {
            result.append(4);
        } else if note.contains("o|") {
            result.append(2);
        } else if note.contains(".") {
            result.append(1);
        } else {
            result.append(0);
        }
    }
    return result;
}

// Input to this function is a string representing musical notes in a special ASCII format.
// Your task is to parse this string and return array of integers corresponding to how many beats does each
// not last.
// Here is a legend:
// 'o' - whole note, lasts four beats
// 'o|' - half note, lasts two beats
// '.|' - quater note, lasts one beat
// parseMusic(musicString: "o o| .| o| o| .| .| .| .| o o") == [4, 2, 1, 2, 2, 1, 1, 1, 1, 4, 4]
func parseMusic(musicString: String) -> [Int] {
    let result = Array<Int>();
    for note in musicString.split(" ") {
        if note.contains("o") {
            result.append(4);
        } else if note.contains("o|") {
            result.append(2);
        } else if note.contains(".") {
            result.append(1);
        } else {
            result.append(0);
        }
    }
    return result;
}

// Input to this function is a string representing musical notes in a special ASCII format.
// Your task is to parse this string and return array of integers corresponding to how many beats does each
// not last.
// Here is a legend:
// 'o' - whole note, lasts four beats
// 'o|' - half note, lasts two beats
// '.|' - quater note, lasts one beat
// parseMusic(musicString: "o o| .| o| o| .| .| .| .|

func parseMusic(musicString: String) -> [Int] {
    let notes = musicString.split(" ")
    let result = Array<Int>()
    for note in notes {
        match note {
            "o" => result.append(4),
            "o|" => result.append(2),
            ".|" => result.append(1),
            _ => ()
        }
    }
    return result
}

```swift
// Input to this function is a string representing musical notes in a special ASCII format.
// Your task is to parse this string and return array of integers corresponding to how many beats does each
// not last.
// Here is a legend:
// 'o' - whole note, lasts four beats
// 'o|' - half note, lasts two beats
// '.|' - quater note, lasts one beat
// parseMusic(musicString: "o o| .| o| o| .| .| .| .| o o") == [4, 2, 1, 2, 2, 1, 1, 1, 1, 4, 4]
func parseMusic(musicString: String) -> [Int] {
    let notes = musicString.split(" ")
    let result = Array<Int>()
    for note in notes {
        match note {
            "o" => result.append(4),
            "o|" => result.append(2),
            ".|" => result.append(1),
            _ => ()
        }
    }
    return result
}
```

func parseMusic(musicString: String) -> [Int] {
    let beats = [4, 2, 1, 2, 2, 1, 1, 1, 1, 4, 4]
    var result = [Int]()
    for i in 0..<musicString.length {
        if musicString[i] == 'o' {
            result.append(beats[0])
        } else if musicString[i] == '|' {
            result.append(beats[1])
        } else if musicString[i] == '.' {
            result.append(beats[2])
        }
    }
    return result
}

```swift
// Input to this function is a string representing musical notes in a special ASCII format.
// Your task is to parse this string and return array of integers corresponding to how many beats does each
// not last.
// Here is a legend:
// 'o' - whole note, lasts four beats
// 'o|' - half note, lasts two beats
// '.|' - quater note, lasts one beat
// parseMusic(musicString: "o o| .| o| o| .| .| .| .| o o") == [4, 2, 1, 2, 2, 1, 1, 1, 1, 4, 4]
func parseMusic(musicString: String) -> [Int] {
    let beats = [4, 2, 1, 2, 2, 1, 1, 1, 1, 4, 4]
    var result = [Int]()
    for i in 0..<musicString.length {
        if musicString[i] == 'o' {
            result.append(beats[0])
        } else if musicString[i] == '|' {
            result.append(beats[1])
        } else if musicString[i] == '.' {
            result.append(beats[2])
        }
    }
    return result
}
```

func parseMusic(musicString: String) -> [Int] {
    var beats: [Int] = [4, 2, 1, 2, 2, 1, 1, 1, 1, 4, 4]
    var result: [Int] = []
    var note: String = ""
    var i: Int = 0
    while i < musicString.length {
        if musicString[i] == 'o' {
            note = note + "o"
        } else if musicString[i] == '|' {
            note = note + "|"
        } else if musicString[i] == '.' {
            note = note + "."
        }
        if i == musicString.length - 1 {
            result.append(beats[note.count])
        } else if musicString[i + 1] == 'o' || musicString[i + 1] == '|' || musicString[i + 1] == '.' {
            result.append(beats[note.count])
            note = ""
        }
        i = i + 1
    }
    return result
}

```swift
// Input to this function is a string representing musical notes in a special ASCII format.
// Your task is to parse this string and return array of integers corresponding to how many beats does each
// not last.
// Here is a legend:
// 'o' - whole note, lasts four beats
// 'o|' - half note, lasts two beats
// '.|' - quater note, lasts one beat
// parseMusic(musicString: "o o| .| o| o| .| .| .| .| o o") == [4, 2, 1, 2, 2, 1, 1, 1, 1, 4, 4]
func parseMusic(musicString: String) -> [Int] {
    var beats: [Int] = [4, 2, 1, 2, 2, 1, 1, 1, 1, 4, 4]
    var result: [Int] = []
    var note: String = ""
    var i: Int = 0
    while i < musicString.length {
        if musicString[i] == 'o' {
            note = note + "o"
        } else if musicString[i] == '|' {
            note = note + "|"
        } else if musicString[i] == '.' {
            note = note + "."
        }
        if i == musicString.length - 1 {
            result.append(beats[note.count])
        } else if musicString[i + 1] == 'o' || musicString[i + 1] == '|' || musicString[i + 1] == '.' {
            result.append(beats[note.count])
            note = ""
        }
        i = i + 1
    }
    return result
}

// Input to this function is a string representing musical notes in a special ASCII format.
// Your task is to parse this string and return array of integers corresponding to how many beats does each
// not last.
// Here is a legend:
// 'o' - whole note, lasts four beats
// 'o|' - half note, lasts two beats
// '.|' - quater note, lasts one beat
// parseMusic(musicString: "o o| .| o| o| .| .| .| .| o o") == [4, 2, 1, 2, 2, 1, 1, 1, 1, 4, 4]
func parseMusic(musicString: String) -> [Int] {
    var beats: [Int] = [4, 2, 1, 2, 2, 1, 1, 1, 1, 4, 4]
    var result: [Int] = []
    var note: String = ""
    var i: Int = 0
    while i < musicString.length {
        if musicString[i] == 'o' {
            note = note + "o"
        } else if musicString[i] == '|' {
            note = note + "|"
        } else if musicString[i] == '.' {
            note = note + "."
        }
        if i == musicString.length - 1 {
            result.append(beats[note.count])
        } else if musicString[i + 1] == 'o' || musicString[i + 1] == '|' || musicString[i + 1] == '.' {
            result.append(beats[note.count])
            note = ""
        }
        i = i + 1
    }
    return result
}

// Input to this function is a string representing musical notes in a special ASCII format.
// Your task is to parse this string and return array of integers corresponding to how many beats does each
// not last.
// Here is a legend:
// 'o' - whole note, lasts four beats
// 'o|' - half note, lasts two beats
// '.|' - quater note, lasts one beat
// parseMusic(musicString: "o o| .| o| o| .| .| .| .| o o") == [4, 2, 1, 2, 2, 1, 1, 1, 1, 4, 4]
func parseMusic(musicString: String) -> [Int] {
    var beats: [Int] = [4, 2, 1, 2, 2, 1, 1, 1, 1, 4, 4]
    var result: [Int] = []
    var note: String = ""
    var i: Int = 0
    while i < musicString.length {
        if musicString[i] == 'o' {
            note = note + "o"
        } else if musicString[i] == '|' {
            note = note + "|"
        } else if musicString[i] == '.' {
            note = note + "."
        }
        if i == musicString.length - 1 {
            result.append(beats[note.count])
        } else if musicString[i + 1] == 'o' || musicString[i + 1] == '

func parseMusic(musicString: String) -> [Int] {
    var beats = [Int]()
    var beatsPerMeasure = 0
    var currentBeat = 0
    for i in 0..<musicString.length {
        if musicString[i] == 'o' {
            beatsPerMeasure += 4
        } else if musicString[i] == '|' {
            beatsPerMeasure += 2
        } else if musicString[i] == '.' {
            beatsPerMeasure += 1
        } else {
            beatsPerMeasure = 0
        }
        currentBeat += beatsPerMeasure
        beats.append(currentBeat)
    }
    return beats
}

```swift
// Input to this function is a string representing musical notes in a special ASCII format.
// Your task is to parse this string and return array of integers corresponding to how many beats does each
// not last.
// Here is a legend:
// 'o' - whole note, lasts four beats
// 'o|' - half note, lasts two beats
// '.|' - quater note, lasts one beat
// parseMusic(musicString: "o o| .| o| o| .| .| .| .| o o") == [4, 2, 1, 2, 2, 1, 1, 1, 1, 4, 4]
func parseMusic(musicString: String) -> [Int] {
    var beats = [Int]()
    var beatsPerMeasure = 0
    var currentBeat = 0
    for i in 0..<musicString.length {
        if musicString[i] == 'o' {
            beatsPerMeasure += 4
        } else if musicString[i] == '|' {
            beatsPerMeasure += 2
        } else if musicString[i] == '.' {
            beatsPerMeasure += 1
        } else {
            beatsPerMeasure = 0
        }
        currentBeat += beatsPerMeasure
        beats.append(currentBeat)
    }
    return beats
}
```

func parseMusic(musicString: String) -> [Int] {
    let notes = musicString.split(" ")
    let beats = [4, 2, 1, 2, 2, 1, 1, 1, 1, 4, 4]
    var result = []
    for note in notes {
        if note == "o" {
            result.append(beats[0])
        } else if note == "o|" {
            result.append(beats[1])
        } else if note == ".|" {
            result.append(beats[2])
        } else if note == "o|" {
            result.append(beats[3])
        }
    }
    return result
}

```swift
// Input to this function is a string representing musical notes in a special ASCII format.
// Your task is to parse this string and return array of integers corresponding to how many beats does each
// not last.
// Here is a legend:
// 'o' - whole note, lasts four beats
// 'o|' - half note, lasts two beats
// '.|' - quater note, lasts one beat
// parseMusic(musicString: "o o| .| o| o| .| .| .| .| o o") == [4, 2, 1, 2, 2, 1, 1, 1, 1, 4, 4]
func parseMusic(musicString: String) -> [Int] {
    let notes = musicString.split(" ")
    let beats = [4, 2, 1, 2, 2, 1, 1, 1, 1, 4, 4]
    var result = []
    for note in notes {
        if note == "o" {
            result.append(beats[0])
        } else if note == "o|" {
            result.append(beats[1])
        } else if note == ".|" {
            result.append(beats[2])
        } else if note == "o|" {
            result.append(beats[3])
        }
    }
    return result
}
```

func parseMusic(musicString: String) -> [Int] {
    let notes = musicString.split("\n")
    var beats = [Int]()
    for note in notes {
        if note.contains("o") {
            beats.append(4)
        } else if note.contains("o|") {
            beats.append(2)
        } else if note.contains(".|") {
            beats.append(1)
        }
    }
    return beats
}

```swift
// Input to this function is a string representing musical notes in a special ASCII format.
// Your task is to parse this string and return array of integers corresponding to how many beats does each
// not last.
// Here is a legend:
// 'o' - whole note, lasts four beats
// 'o|' - half note, lasts two beats
// '.|' - quater note, lasts one beat
// parseMusic(musicString: "o o| .| o| o| .| .| .| .| o o") == [4, 2, 1, 2, 2, 1, 1, 1, 1, 4, 4]
func parseMusic(musicString: String) -> [Int] {
    let notes = musicString.split("\n")
    var beats = [Int]()
    for note in notes {
        if note.contains("o") {
            beats.append(4)
        } else if note.contains("o|") {
            beats.append(2)
        } else if note.contains(".|") {
            beats.append(1)
        }
    }
    return beats
}
```

func parseMusic(musicString: String) -> [Int] {
    var beats: [Int] = [0]
    var note: String = ""
    for c in musicString {
        if c == 'o' {
            beats.append(4)
            note = ""
        } else if c == '|' {
            beats.append(2)
            note = ""
        } else if c == '.' {
            beats.append(1)
            note = ""
        } else {
            note = note + c
            if note.count == 2 {
                beats.append(2)
                note = ""
            } else if note.count == 3 {
                beats.append(4)
                note = ""
            }
        }
    }
    return beats
}

```swift
// Input to this function is a string representing musical notes in a special ASCII format.
// Your task is to parse this string and return array of integers corresponding to how many beats does each
// not last.
// Here is a legend:
// 'o' - whole note, lasts four beats
// 'o|' - half note, lasts two beats
// '.|' - quater note, lasts one beat
// parseMusic(musicString: "o o| .| o| o| .| .| .| .| o o") == [4, 2, 1, 2, 2, 1, 1, 1, 1, 4, 4]
func parseMusic(musicString: String) -> [Int] {
    var beats: [Int] = [0]
    var note: String = ""
    for c in musicString {
        if c == 'o' {
            beats.append(4)
            note = ""
        } else if c == '|' {
            beats.append(2)
            note = ""
        } else if c == '.' {
            beats.append(1)
            note = ""
        } else {
            note = note + c
            if note.count == 2 {
                beats.append(2)
                note = ""
            } else if note.count == 3 {
                beats.append(4)
                note = ""
            }
        }
    }
    return beats
}
```

func parseMusic(musicString: String) -> [Int] {
    var beats = [Int]()
    var note = ""
    var noteCount = 0
    for i in musicString.characters {
        if i == 'o' {
            note = note + "o"
        } else if i == '|' {
            note = note + "o|"
        } else if i == '.' {
            note = note + ".|"
        } else if i == ' ' {
            if note == "o" {
                noteCount = noteCount + 4
            } else if note == "o|" {
                noteCount = noteCount + 2
            } else if note == ".|" {
                noteCount = noteCount + 1
            }
            beats.append(noteCount)
            note = ""
            noteCount = 0
        }
    }
    return beats
}

```swift
// Input to this function is a string representing musical notes in a special ASCII format.
// Your task is to parse this string and return array of integers corresponding to how many beats does each
// not last.
// Here is a legend:
// 'o' - whole note, lasts four beats
// 'o|' - half note, lasts two beats
// '.|' - quater note, lasts one beat
// parseMusic(musicString: "o o| .| o| o| .| .| .| .| o o") == [4, 2, 1, 2, 2, 1, 1, 1, 1, 4, 4]
func parseMusic(musicString: String) -> [Int] {
    var beats = [Int]()
    var note = ""
    var noteCount = 0
    for i in musicString.characters {
        if i == 'o' {
            note = note + "o"
        } else if i == '|' {
            note = note + "o|"
        } else if i == '.' {
            note = note + ".|"
        } else if i == ' ' {
            if note == "o" {
                noteCount = noteCount + 4
            } else if note == "o|" {
                noteCount = noteCount + 2
            } else if note == ".|" {
                noteCount = noteCount + 1
            }
            beats.append(noteCount)
            note = ""
            noteCount = 0
        }
    }
    return beats
}

// Input to this function is a string representing musical notes in a special ASCII format.
// Your task is to parse this string and return array of integers corresponding to how many beats does each
// not last.
// Here is a legend:
// 'o' - whole note, lasts four beats
// 'o|' - half note, lasts two beats
// '.|' - quater note, lasts one beat
// parseMusic(musicString: "o o| .| o| o| .| .| .| .| o o") == [4, 2, 1, 2, 2, 1, 1, 1, 1, 4, 4]
func parseMusic(musicString: String) -> [Int] {
    var beats = [Int]()
    var note = ""
    var noteCount = 0
    for i in musicString.characters {
        if i == 'o' {
            note = note + "o"
        } else if i == '|' {
            note = note + "o|"
        } else if i == '.' {
            note = note + ".|"
        } else if i == ' ' {
            if note == "o" {
                noteCount = noteCount + 4
            } else if note == "o|" {
                noteCount = noteCount + 2
            } else if note == ".|" {
                noteCount = noteCount + 1
            }
            beats.append(noteCount)
            note = ""
            noteCount = 0
        }
    }
    return beats
}

// Input to this function is a string representing musical notes in a special ASCII format.
// Your task is to parse this string and return array of integers corresponding to how many beats does each
// not last.
// Here is a legend:
// 'o' - whole note, lasts four beats
// 'o|' - half note, lasts two beats
// '.|' - quater note, lasts one beat
// parseMusic(musicString: "o o| .| o| o| .| .| .| .| o o") == [4, 2, 1, 2, 2, 1, 1, 1, 1, 4, 4]
func parseMusic(musicString: String) -> [Int] {
    var beats = [Int]()
    var note = ""
    var noteCount = 0
    for i in musicString.characters {
        if i == 'o' {
            note = note + "o"
        } else if i == '|' {
            note = note + "o|"
        } else if i == '.' {
            note = note + ".|"
        } else if i == ' ' {
            if note == "o" {
                noteCount = noteCount + 4
            } else if note == "o|" {
                noteCount = noteCount + 2
            } else if note == ".|" {
                noteCount = noteCount + 1
            }
            beats.append(noteCount)
            note = ""
            noteCount = 0
        }
    }
    return beats
}

// Input to this function is a string representing musical notes in a special ASCII format.
// Your task is to parse this string and return array of integers corresponding to how many beats does each
// not last.
// Here is a legend:
// 'o' - whole note, lasts four beats
// 'o|' - half note, lasts two beats
// '.|' - quater note, lasts one beat
// parseMusic(musicString: "o o| .| o| o| .| .| .| .| o o") == [

```swift
// Input to this function is a string representing musical notes in a special ASCII format.
// Your task is to parse this string and return array of integers corresponding to how many beats does each
// not last.
// Here is a legend:
// 'o' - whole note, lasts four beats
// 'o|' - half note, lasts two beats
// '.|' - quater note, lasts one beat
// parseMusic(musicString: "o o| .| o| o| .| .| .| .| o o") == [4, 2, 1, 2, 2, 1, 1, 1, 1, 4, 4]
func parseMusic(musicString: String) -> [Int] {
    var beats: [Int] = [4, 2, 1, 2, 2, 1, 1, 1, 1, 4, 4]
    var result: [Int] = [0] * 12
    var music: [String] = musicString.split(" ")
    for i in 0..<music.count {
        switch music[i] {
            case "o":
                result[i] = beats[0]
            case "o|":
                result[i] = beats[1]
            case ".|":
                result[i] = beats[2]
            case "o|o":
                result[i] = beats[3]
            case "o|o|":
                result[i] = beats[4]
            case ".|o":
                result[i] = beats[5]
            case ".|o|":
                result[i] = beats[6]
            case ".|o|o":
                result[i] = beats[7]
            case ".|o|o|":
                result[i] = beats[8]
            case ".|o.|":
                result[i] = beats[9]
            case ".|o.|o":
                result[i] = beats[10]
            case ".|o.|o|":
                result[i] = beats[11]
            case ".|o.|o|o":
                result[i] = beats[12]
            case ".|o.|o|o|":
                result[i] = beats[13]
            case ".|o.|o|o|o":
                result[i] = beats[14]
            case ".|o.|o|o|o|":
                result[i] = beats[15]
            case ".|o.|o|o|o|o":
                result[i] = beats[16]
            case ".|o.|o|o|o|o|":
                result[i] = beats[17]
            case ".|o.|o|o|o|o|o":
                result[i] = beats[18]
            case ".|o.|o|o|o|o|o|":
                result[i] = beats[19]
            case ".|o.|o|o|o|o|o|o":
                result[i] = beats[20]
            case ".|o.|o|o|o|o|o|o|":
                result[i] = beats[21]
            case ".|o.|o|o|o|o|o|o|o":
                result[i] = beats[22]
            case ".|o.|o|o|o|o|o|o|o|":
                result[i] = beats[23]
            case ".|o.|o|o|o|o|o|o|o|o":
                result[i] = beats[24]
            case ".|o.|o|o|o|o|o|o|o|o|":
                result[i] = beats[25]
            case ".|o.|o|o|o|o|o|o|o|o|o":
                result[i] = beats[26]
            case ".|o.|o|o|o|o|o|o|o|o|o|":
                result[i] = beats[27]
            case ".|o.|o|o|o|o|o|o|o|o|o|o":
                result[i] = beats[28]
            case ".|o.|o|o|o|o|o|o|o|o|o|o|":
                result[i] = beats[29]
            case ".|o.|o|o|o|o|o|o|o|o|o|o|o":
                result[i] = beats[30]
            case ".|o.|o|o|o|o|o|o|o|o|o|o|o|":
                result[i] = beats[31]
            case ".|o.|o|o|o|o|o|o|o|o|o|o|o|o":
                result[i] = beats[32]
            case ".|o.|

func howManyTimes(string: String, substring: String) -> Int {
    var count = 0
    var index = 0
    while index < string.length {
        var foundIndex = string.index(substring, fromIndex: index)
        if foundIndex != -1 {
            count += 1
            index = foundIndex + substring.length
        } else {
            break
        }
    }
    return count
}

```swift
// Find how many times a given substring can be found in the original string. Count overlaping cases.
// howManyTimes(string: "", substring: "a") == 0
// howManyTimes(string: "aaa", substring: "a") == 3
// howManyTimes(string: "aaaa", substring: "aa") == 3
func howManyTimes(string: String, substring: String) -> Int {
    var count = 0
    var index = 0
    while index < string.length {
        var foundIndex = string.index(substring, fromIndex: index)
        if foundIndex != -1 {
            count += 1
            index = foundIndex + substring.length
        } else {
            break
        }
    }
    return count
}
```

func howManyTimes(string: String, substring: String) -> Int {
    let count = 0
    for i in 0..<string.length {
        if string[i..<string.length].contains(substring) {
            count += 1
        }
    }
    return count
}

```swift
// Find how many times a given substring can be found in the original string. Count overlaping cases.
// howManyTimes(string: "", substring: "a") == 0
// howManyTimes(string: "aaa", substring: "a") == 3
// howManyTimes(string: "aaaa", substring: "aa") == 3
func howManyTimes(string: String, substring: String) -> Int {
    let count = 0
    for i in 0..<string.length {
        if string[i..<string.length].contains(substring) {
            count += 1
        }
    }
    return count
}

// Find the longest substring in the original string that can be found in the original string.
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "aaabaaa") == "aaa"
// longestSubstring(string: "

func howManyTimes(string: String, substring: String) -> Int {
    let result = 0
    let substringLength = substring.length
    let stringLength = string.length
    for i in 0..<stringLength {
        if string.substring(i..<i+substringLength) == substring {
            result += 1
        }
    }
    return result
}

func firstOccurrence(string: String, substring: String) -> Int {
    let substringLength = substring.length
    let stringLength = string.length
    for i in 0..<stringLength {
        if string.substring(i..<i+substringLength) == substring {
            return i
        }
    }
    return -1
}

func lastOccurrence(string: String, substring: String) -> Int {
    let substringLength = substring.length
    let stringLength = string.length
    for i in 0..<stringLength {
        if string.substring(i..<i+substringLength) == substring {
            return i+substringLength-1
        }
    }
    return -1
}

func firstNonOverlapping(string: String, substring: String) -> Int {
    let substringLength = substring.length
    let stringLength = string.length
    for i in 0..<stringLength {
        if string.substring(i..<i+substringLength) == substring {
            return i
        }
    }
    return -1
}

func lastNonOverlapping(string: String, substring: String) -> Int {
    let substringLength = substring.length
    let stringLength = string.length
    for i in 0..<stringLength {
        if string.substring(i..<i+substringLength) == substring {
            return i+substringLength-1
        }
    }
    return -1
}

```swift
// Find how many times a given substring can be found in the original string. Count overlaping cases.
// howManyTimes(string: "", substring: "a") == 0
// howManyTimes(string: "aaa", substring: "a") == 3
// howManyTimes(string: "aaaa", substring: "aa") == 3
func howManyTimes(string: String, substring: String) -> Int {
    let result = 0
    let substringLength = substring.length
    let stringLength = string.length
    for i in 0..<stringLength {
        if string.substring(i..<i+substringLength) == substring {
            result += 1
        }
    }
    return result
}

// Find the first occurrence of a given substring in the original string.
// firstOccurrence(string: "", substring: "a") == -1
// firstOccurrence(string: "aaa", substring: "a") == 0
// firstOccurrence(string: "aaaa", substring: "aa") == 0
// firstOccurrence(string: "aaaa", substring: "a") == 0
// firstOccurrence(string: "aaaa", substring: "b") == -1
func firstOccurrence(string: String, substring: String) -> Int {
    let substringLength = substring.length
    let stringLength = string.length
    for i in 0..<stringLength {
        if string.substring(i..<i+substringLength) == substring {
            return i
        }
    }
    return -1
}

// Find the last occurrence of a given substring in the original string.
// lastOccurrence(string: "", substring: "a") == -1
// lastOccurrence(string: "aaa", substring: "a") == 2
// lastOccurrence(string: "aaaa", substring: "aa") == 3
// lastOccurrence(string: "aaaa", substring: "a") == 3
// lastOccurrence(string: "aaaa", substring: "b") == -1
func lastOccurrence(string: String, substring: String) -> Int {
    let substringLength = substring.length
    let stringLength = string.length
    for i in 0..<stringLength {
        if string.substring(i..<i+substringLength) == substring {
            return i+substringLength-1
        }
    }
    return -1
}

// Find the first non-overlapping occurrence of a given substring in the original string.
// firstNonOverlapping(string: "", substring: "a") == -1
// firstNonOverlapping(string: "aaa", substring: "a") == 0
// firstNonOverlapping(string: "aaaa", substring: "aa") == 0
// firstNonOverlapping(string: "aaaa", substring: "a") == 0
// firstNonOverlapping(string: "aaaa", substring: "b") == 4
func firstNonOverlapping(string: String, substring: String) -> Int {
    let substringLength = substring.length
    let stringLength = string.length
    for i in 0..<stringLength {
        if string.substring(i..<i+substringLength) == substring {
            return i
        }
    }
    return -1
}

// Find the last non-overlapping occurrence of a given substring in the original string.
// lastNonOverlapping(string: "", substring: "a") == -1
// lastNonOverlapping(string: "aaa", substring: "a") == 2
// lastNonOverlapping(string: "aaaa", substring: "aa") == 2
// lastNonOverlapping(string: "aaaa", substring: "a") == 2
// lastNonOverlapping(string: "aaaa", substring: "b") == 4
func lastNonOverlapping(string: String, substring: String) -> Int {
    let substringLength = substring.length
    let stringLength = string.length
    for i in 0..<stringLength {
        if string.substring(i..<i+substringLength) == substring {
            return i+substringLength-1
        }
    }
    return -1
}

// Find the first occurrence of a given substring in the original string.
// firstOccurrence(string: "", substring: "a") == -1
// firstOccurrence(string: "aaa", substring: "a") == 0
// firstOccurrence(string: "aaaa", substring: "aa") == 0
// firstOccurrence(string: "aaaa", substring: "a") == 0
// firstOccurrence(string: "aaaa", substring: "b") == -1
func firstOccurrence(string: String, substring: String) -> Int {
    let substringLength = substring.length
    let stringLength = string.length
    for i in 0..<stringLength {
        if string.substring(i..<i+substringLength) == substring {
            return i
        }
    }
    return -1
}

// Find

func howManyTimes(string: String, substring: String) -> Int {
    var count = 0
    var index = 0
    while index < string.length {
        var substringIndex = string.index(substring: substring, startIndex: index)
        if substringIndex != -1 {
            count += 1
            index = substringIndex + substring.length
        } else {
            break
        }
    }
    return count
}

func longestPalindrome(string: String) -> String {
    var longest = ""
    for i in 0..<string.length {
        for j in i..<string.length {
            var substring = string[i..<j+1]
            if isPalindrome(substring) && substring.length > longest.length {
                longest = substring
            }
        }
    }
    return longest
}

func isPalindrome(string: String) -> Bool {
    var left = 0
    var right = string.length - 1
    while left < right {
        if string[left] != string[right] {
            return false
        }
        left += 1
        right -= 1
    }
    return true
}

```swift
// Find how many times a given substring can be found in the original string. Count overlaping cases.
// howManyTimes(string: "", substring: "a") == 0
// howManyTimes(string: "aaa", substring: "a") == 3
// howManyTimes(string: "aaaa", substring: "aa") == 3
func howManyTimes(string: String, substring: String) -> Int {
    var count = 0
    var index = 0
    while index < string.length {
        var substringIndex = string.index(substring: substring, startIndex: index)
        if substringIndex != -1 {
            count += 1
            index = substringIndex + substring.length
        } else {
            break
        }
    }
    return count
}

// Find the longest substring in the original string that is a palindrome.
// longestPalindrome(string: "") == ""
// longestPalindrome(string: "a") == "a"
// longestPalindrome(string: "aba") == "aba"
// longestPalindrome(string: "abac") == "aba"
// longestPalindrome(string: "abacaba") == "aba"
// longestPalindrome(string: "abacaba") == "aba"
func longestPalindrome(string: String) -> String {
    var longest = ""
    for i in 0..<string.length {
        for j in i..<string.length {
            var substring = string[i..<j+1]
            if isPalindrome(substring) && substring.length > longest.length {
                longest = substring
            }
        }
    }
    return longest
}

func isPalindrome(string: String) -> Bool {
    var left = 0
    var right = string.length - 1
    while left < right {
        if string[left] != string[right] {
            return false
        }
        left += 1
        right -= 1
    }
    return true
}

// Find the longest substring in the original string that is a palindrome.
// longestPalindrome(string: "") == ""
// longestPalindrome(string: "a") == "a"
// longestPalindrome(string: "aba") == "aba"
// longestPalindrome(string: "abac") == "aba"
// longestPalindrome(string: "abacaba") == "aba"
// longestPalindrome(string: "abacaba") == "aba"
func longestPalindrome(string: String) -> String {
    var longest = ""
    for i in 0..<string.length {
        for j in i..<string.length {
            var substring = string[i..<j+1]
            if isPalindrome(substring) && substring.length > longest.length {
                longest = substring
            }
        }
    }
    return longest
}

func isPalindrome(string: String) -> Bool {
    var left = 0
    var right = string.length - 1
    while left < right {
        if string[left] != string[right] {
            return false
        }
        left += 1
        right -= 1
    }
    return true
}

// Find the longest substring in the original string that is a palindrome.
// longestPalindrome(string: "") == ""
// longestPalindrome(string: "a") == "a"
// longestPalindrome(string: "aba") == "aba"
// longestPalindrome(string: "abac") == "aba"
// longestPalindrome(string: "abacaba") == "aba"
// longestPalindrome(string: "abacaba") == "aba"
func longestPalindrome(string: String) -> String {
    var longest = ""
    for i in 0..<string.length {
        for j in i..<string.length {
            var substring = string[i..<j+1]
            if isPalindrome(substring) && substring.length > longest.length {
                longest = substring
            }
        }
    }
    return longest
}

func isPalindrome(string: String) -> Bool {
    var left = 0
    var right = string.length - 1
    while left < right {
        if string[left] != string[right] {
            return false
        }
        left += 1
        right -= 1
    }
    return true
}

// Find the longest substring in the original string that is a palindrome.
// longestPalindrome(string: "") == ""
// longestPalindrome(string: "a") == "a"
// longestPalindrome(string: "aba") == "aba"
// longestPalindrome(string: "abac") == "aba"
// longestPalindrome(string: "abacaba") == "aba"
// longestPalindrome(string: "abacaba") == "aba"
func longestPalindrome(string: String) -> String {
    var longest = ""
    for i in 0..<string.length {

func howManyTimes(string: String, substring: String) -> Int {
    var count = 0
    var index = 0
    while index < string.length {
        var foundIndex = string.index(substring, startIndex: index)
        if foundIndex == -1 {
            break
        }
        count += 1
        index = foundIndex + 1
    }
    return count
}

func longestSubstring(string: String) -> String {
    var longest = ""
    var current = ""
    var index = 0
    while index < string.length {
        var foundIndex = string.index(string[index], startIndex: index + 1)
        if foundIndex == -1 {
            if current.length > longest.length {
                longest = current
            }
            break
        }
        current += string[foundIndex]
        index = foundIndex + 1
    }
    return longest
}

```swift
// Find how many times a given substring can be found in the original string. Count overlaping cases.
// howManyTimes(string: "", substring: "a") == 0
// howManyTimes(string: "aaa", substring: "a") == 3
// howManyTimes(string: "aaaa", substring: "aa") == 3
func howManyTimes(string: String, substring: String) -> Int {
    var count = 0
    var index = 0
    while index < string.length {
        var foundIndex = string.index(substring, startIndex: index)
        if foundIndex == -1 {
            break
        }
        count += 1
        index = foundIndex + 1
    }
    return count
}

// Find the longest substring of the original string that can be found in the original string.
// longestSubstring(string: "abcabcbb") == "abc"
// longestSubstring(string: "bbbbb") == "b"
// longestSubstring(string: "pwwkew") == "wke"
func longestSubstring(string: String) -> String {
    var longest = ""
    var current = ""
    var index = 0
    while index < string.length {
        var foundIndex = string.index(string[index], startIndex: index + 1)
        if foundIndex == -1 {
            if current.length > longest.length {
                longest = current
            }
            break
        }
        current += string[foundIndex]
        index = foundIndex + 1
    }
    return longest
}

// Find the longest substring of the original string that can be found in the original string.
// longestSubstring(string: "abcabcbb") == "abc"
// longestSubstring(string: "bbbbb") == "b"
// longestSubstring(string: "pwwkew") == "wke"
func longestSubstring(string: String) -> String {
    var longest = ""
    var current = ""
    var index = 0
    while index < string.length {
        var foundIndex = string.index(string[index], startIndex: index + 1)
        if foundIndex == -1 {
            if current.length > longest.length {
                longest = current
            }
            break
        }
        current += string[foundIndex]
        index = foundIndex + 1
    }
    return longest
}

// Find the longest substring of the original string that can be found in the original string.
// longestSubstring(string: "abcabcbb") == "abc"
// longestSubstring(string: "bbbbb") == "b"
// longestSubstring(string: "pwwkew") == "wke"
func longestSubstring(string: String) -> String {
    var longest = ""
    var current = ""
    var index = 0
    while index < string.length {
        var foundIndex = string.index(string[index], startIndex: index + 1)
        if foundIndex == -1 {
            if current.length > longest.length {
                longest = current
            }
            break
        }
        current += string[foundIndex]
        index = foundIndex + 1
    }
    return longest
}

// Find the longest substring of the original string that can be found in the original string.
// longestSubstring(string: "abcabcbb") == "abc"
// longestSubstring(string: "bbbbb") == "b"
// longestSubstring(string: "pwwkew") == "wke"
func longestSubstring(string: String) -> String {
    var longest = ""
    var current = ""
    var index = 0
    while index < string.length {
        var foundIndex = string.index(string[index], startIndex: index + 1)
        if foundIndex == -1 {
            if current.length > longest.length {
                longest = current
            }
            break
        }
        current += string[foundIndex]
        index = foundIndex + 1
    }
    return longest
}

// Find the longest substring of the original string that can be found in the original string.
// longestSubstring(string: "abcabcbb") == "abc"
// longestSubstring(string: "bbbbb") == "b"
// longestSubstring(string: "pwwkew") == "wke"
func longestSubstring(string: String) -> String {
    var longest = ""
    var current = ""
    var index = 0
    while index < string.length {
        var foundIndex = string.index(string[index], startIndex: index + 1)
        if foundIndex == -1 {
            if current.length > longest.length {
                longest = current
            }
            break
        }
        current += string[foundIndex]
        index = foundIndex + 1
    }
    

func howManyTimes(string: String, substring: String) -> Int {
    let substrings: [String] = string.components(separatedBy: substring)
    return substrings.count
}

```swift
// Find how many times a given substring can be found in the original string. Count overlaping cases.
// howManyTimes(string: "", substring: "a") == 0
// howManyTimes(string: "aaa", substring: "a") == 3
// howManyTimes(string: "aaaa", substring: "aa") == 3
func howManyTimes(string: String, substring: String) -> Int {
    let substrings: [String] = string.components(separatedBy: substring)
    return substrings.count
}
```

func howManyTimes(string: String, substring: String) -> Int {
    let len = string.length
    let subLen = substring.length
    let mut count = 0
    for i in 0..<len {
        let s = string[i..<len]
        if s.contains(substring) {
            count += 1
        }
    }
    count
}

func indexOf(string: String, substring: String) -> Int {
    let len = string.length
    let subLen = substring.length
    for i in 0..<len {
        let s = string[i..<len]
        if s == substring {
            return i
        }
    }
    -1
}

func lastIndexOf(string: String, substring: String) -> Int {
    let len = string.length
    let subLen = substring.length
    for i in 0..<len {
        let s = string[i..<len]
        if s == substring {
            return i
        }
    }
    -1
}

```swift
// Find how many times a given substring can be found in the original string. Count overlaping cases.
// howManyTimes(string: "", substring: "a") == 0
// howManyTimes(string: "aaa", substring: "a") == 3
// howManyTimes(string: "aaaa", substring: "aa") == 3
func howManyTimes(string: String, substring: String) -> Int {
    let len = string.length
    let subLen = substring.length
    let mut count = 0
    for i in 0..<len {
        let s = string[i..<len]
        if s.contains(substring) {
            count += 1
        }
    }
    count
}

// Find the index of the first occurrence of a given substring in the original string.
// indexOf(string: "", substring: "a") == -1
// indexOf(string: "aaa", substring: "a") == 0
// indexOf(string: "aaaa", substring: "aa") == 0
func indexOf(string: String, substring: String) -> Int {
    let len = string.length
    let subLen = substring.length
    for i in 0..<len {
        let s = string[i..<len]
        if s == substring {
            return i
        }
    }
    -1
}

// Find the index of the last occurrence of a given substring in the original string.
// lastIndexOf(string: "", substring: "a") == -1
// lastIndexOf(string: "aaa", substring: "a") == 2
// lastIndexOf(string: "aaaa", substring: "aa") == 3
func lastIndexOf(string: String, substring: String) -> Int {
    let len = string.length
    let subLen = substring.length
    for i in 0..<len {
        let s = string[i..<len]
        if s == substring {
            return i
        }
    }
    -1
}

// Find the index of the first occurrence of a given substring in the original string.
// Find the index of the last occurrence of a given substring in the original string.
// Find the index of the first occurrence of a given substring in the original string.
// Find the index of the last occurrence of a given substring in the original string.
// Find the index of the first occurrence of a given substring in the original string.
// Find the index of the last occurrence of a given substring in the original string.
// Find the index of the first occurrence of a given substring in the original string.
// Find the index of the last occurrence of a given substring in the original string.
// Find the index of the first occurrence of a given substring in the original string.
// Find the index of the last occurrence of a given substring in the original string.
// Find the index of the first occurrence of a given substring in the original string.
// Find the index of the last occurrence of a given substring in the original string.
// Find the index of the first occurrence of a given substring in the original string.
// Find the index of the last occurrence of a given substring in the original string.
// Find the index of the first occurrence of a given substring in the original string.
// Find the index of the last occurrence of a given substring in the original string.
// Find the index of the first occurrence of a given substring in the original string.
// Find the index of the last occurrence of a given substring in the original string.
// Find the index of the first occurrence of a given substring in the original string.
// Find the index of the last occurrence of a given substring in the original string.
// Find the index of the first occurrence of a given substring in the original string.
// Find the index of the last occurrence of a given substring in the original string.
// Find the index of the first occurrence of a given substring in the original string.
// Find the index of the last occurrence of a given substring in the original string.
// Find the index of the first occurrence of a given substring in the original string.
// Find the index of the last occurrence of a given substring in the original string.
// Find the index of the first occurrence of a given substring in the original string.
// Find the index of the last occurrence of a given substring in the original string.
// Find the index of the first occurrence of a given substring in the original string.
// Find the index of the last occurrence of a given substring in the original string.
// Find the index of the first occurrence of a given substring in the original string.
// Find the index of the last occurrence of a given substring in the original string.
// Find the index of the first occurrence of a given substring in the original string.
// Find the index of the last occurrence of a given substring in the original string.
// Find the index of the first occurrence of a given substring in the original string.
// Find the index of the last occurrence of a given substring in the original string.
// Find the index of the first occurrence of a given substring

func howManyTimes(string: String, substring: String) -> Int {
    var count = 0
    var index = 0
    while index < string.length {
        var foundIndex = string.index(substring, fromIndex: index)
        if foundIndex == -1 {
            break
        }
        count += 1
        index = foundIndex + 1
    }
    return count
}

func findFirstIndex(string: String, substring: String) -> Int {
    var index = 0
    while index < string.length {
        var foundIndex = string.index(substring, fromIndex: index)
        if foundIndex == -1 {
            break
        }
        return foundIndex
        index = foundIndex + 1
    }
    return -1
}

func findLastIndex(string: String, substring: String) -> Int {
    var index = string.length - 1
    while index >= 0 {
        var foundIndex = string.index(substring, fromIndex: index)
        if foundIndex == -1 {
            break
        }
        return foundIndex
        index = foundIndex - 1
    }
    return -1
}

```swift
// Find how many times a given substring can be found in the original string. Count overlaping cases.
// howManyTimes(string: "", substring: "a") == 0
// howManyTimes(string: "aaa", substring: "a") == 3
// howManyTimes(string: "aaaa", substring: "aa") == 3
func howManyTimes(string: String, substring: String) -> Int {
    var count = 0
    var index = 0
    while index < string.length {
        var foundIndex = string.index(substring, fromIndex: index)
        if foundIndex == -1 {
            break
        }
        count += 1
        index = foundIndex + 1
    }
    return count
}

// Find the first index of a given substring in the original string.
// findFirstIndex(string: "", substring: "a") == -1
// findFirstIndex(string: "aaa", substring: "a") == 0
// findFirstIndex(string: "aaaa", substring: "aa") == 0
func findFirstIndex(string: String, substring: String) -> Int {
    var index = 0
    while index < string.length {
        var foundIndex = string.index(substring, fromIndex: index)
        if foundIndex == -1 {
            break
        }
        return foundIndex
        index = foundIndex + 1
    }
    return -1
}

// Find the last index of a given substring in the original string.
// findLastIndex(string: "", substring: "a") == -1
// findLastIndex(string: "aaa", substring: "a") == 2
// findLastIndex(string: "aaaa", substring: "aa") == 3
func findLastIndex(string: String, substring: String) -> Int {
    var index = string.length - 1
    while index >= 0 {
        var foundIndex = string.index(substring, fromIndex: index)
        if foundIndex == -1 {
            break
        }
        return foundIndex
        index = foundIndex - 1
    }
    return -1
}

// Find the first index of a given substring in the original string.
// findLastIndex(string: "", substring: "a") == -1
// findLastIndex(string: "aaa", substring: "a") == 2
// findLastIndex(string: "aaaa", substring: "aa") == 3
func findLastIndex(string: String, substring: String) -> Int {
    var index = string.length - 1
    while index >= 0 {
        var foundIndex = string.index(substring, fromIndex: index)
        if foundIndex == -1 {
            break
        }
        return foundIndex
        index = foundIndex - 1
    }
    return -1
}

// Find the first index of a given substring in the original string.
// findLastIndex(string: "", substring: "a") == -1
// findLastIndex(string: "aaa", substring: "a") == 2
// findLastIndex(string: "aaaa", substring: "aa") == 3
func findLastIndex(string: String, substring: String) -> Int {
    var index = string.length - 1
    while index >= 0 {
        var foundIndex = string.index(substring, fromIndex: index)
        if foundIndex == -1 {
            break
        }
        return foundIndex
        index = foundIndex - 1
    }
    return -1
}

// Find the first index of a given substring in the original string.
// findLastIndex(string: "", substring: "a") == -1
// findLastIndex(string: "aaa", substring: "a") == 2
// findLastIndex(string: "aaaa", substring: "aa") == 3
func findLastIndex(string: String, substring: String) -> Int {
    var index = string.length - 1
    while index >= 0 {
        var foundIndex = string.index(substring, fromIndex: index)
        if foundIndex == -1 {
            break
        }
        return foundIndex
        index = foundIndex - 1
    }
    return -1
}

// Find the first index of a given substring in the original string.
// findLastIndex(string: "", substring: "a") == -1
// findLastIndex(string: "aaa", substring: "a") == 2
// findLastIndex(string: "aaaa", substring: "aa") == 3
func findLastIndex(string: String, substring: String) -> Int {
    var index = string.length - 1
    while index >= 0 {
        var foundIndex = string.index(substring, fromIndex: index)
        if foundIndex == -1 {
            break
        }

func howManyTimes(string: String, substring: String) -> Int {
    var count = 0
    var index = 0
    while index < string.length {
        var substringIndex = string.index(substring: substring, startIndex: index)
        if substringIndex != -1 {
            count += 1
            index = substringIndex + substring.length
        } else {
            break
        }
    }
    return count
}

```swift
// Find how many times a given substring can be found in the original string. Count overlaping cases.
// howManyTimes(string: "", substring: "a") == 0
// howManyTimes(string: "aaa", substring: "a") == 3
// howManyTimes(string: "aaaa", substring: "aa") == 3
func howManyTimes(string: String, substring: String) -> Int {
    var count = 0
    var index = 0
    while index < string.length {
        var substringIndex = string.index(substring: substring, startIndex: index)
        if substringIndex != -1 {
            count += 1
            index = substringIndex + substring.length
        } else {
            break
        }
    }
    return count
}

// Find the longest substring in the original string that can be found in the original string.
// longestSubstring(string: "abc") == "abc"
// longestSubstring(string: "abca") == "abc"
// longestSubstring(string: "abcab") == "abc"
// longestSubstring(string: "abcabca") == "abc"
// longestSubstring(string: "abcabcab") == "abc"
// longestSubstring(string: "abcabcabc") == "abc"
// longestSubstring(string: "abcabcabca") == "abc"
// longestSubstring(string: "abcabcabcab") == "abc"
// longestSubstring(string: "abcabcabcabc") == "abc"
// longestSubstring(string: "abcabcabcabca") == "abc"
// longestSubstring(string: "abcabcabcabcab") == "abc"
// longestSubstring(string: "abcabcabcabcabc") == "abc"
// longestSubstring(string: "abcabcabcabcabca") == "abc"
// longestSubstring(string: "abcabcabcabcabcab") == "abc"
// longestSubstring(string: "abcabcabcabcabcabc") == "abc"
// longestSubstring(string: "abcabcabcabcabcabca") == "abc"
// longestSubstring(string: "abcabcabcabcabcabcab") == "abc"
// longestSubstring(string: "abcabcabcabcabcabcabc") == "abc"
// longestSubstring(string: "abcabcabcabcabcabcabca") == "abc"
// longestSubstring(string: "abcabcabcabcabcabcabcab") == "abc"
// longestSubstring(string: "abcabcabcabcabcabcabcabc") == "abc"
// longestSubstring(string: "abcabcabcabcabcabcabcabca") == "abc"
// longestSubstring(string: "abcabcabcabcabcabcabcabcab") == "abc"
// longestSubstring(string: "abcabcabcabcabcabcabcabcabc") == "abc"
// longestSubstring(string: "abcabcabcabcabcabcabcabcabca") == "abc"
// longestSubstring(string: "abcabcabcabcabcabcabcabcabcab") == "abc"
// longestSubstring(string: "abcabcabcabcabcabcabcabcabcabc") == "abc"
// longestSubstring(string: "abcabcabcabcabcabcabcabcabcabca") == "abc"
// longestSubstring(string: "abcabcabcabcabcabcabcabcabcabcab") == "abc"
// longestSubstring(string: "abcabcabcabcabcabcabcabcabcabcabcabc") == "abc"
// longestSubstring(string: "abcabcabcabcabcabcabcabcabcabcabca") == "abc"
// longestSubstring(string: "abcabcabcabcabcabcabcabcabcabcabcab") == "abc"
// longestSubstring(string: "abcabcabcabcabcabcabcabcabcabcabcabc") == "abc"
// longestSubstring(string: "abcabcabcabcabcabcabcabcabcabcabcabca") == "abc"
// longestSubstring(string: "abcabcabcabcabcabcabcabcabcabcabcabcab") == "abc"
// longestSubstring(string: "abcabcabcabcabcabcabcabcabcabcabcabcabc") == "abc"
// longestSubstring(string: "abcabcabcabcabcabcabcabcabcabcabcabcabca") == "abc"
// longestSubstring(string: "abcabcabcabcabcabcabcabcabcabcabcabcabcabcabca") == "abc"
// longestSubstring(string: "abcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabc") == "abc"
// longestSubstring(string: "abcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabca") == "abc"
// longestSubstring(string: "abcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabca") == "abc"
// longestSubstring(string: "abcabcabcabcabcabcabcab

func howManyTimes(string: String, substring: String) -> Int {
    let result = 0
    let substringLength = substring.length
    for i in 0..<string.length - substringLength + 1 {
        if string[i..<i + substringLength] == substring {
            result += 1
        }
    }
    return result
}

func longestPalindrome(string: String) -> String {
    let result = ""
    let stringLength = string.length
    for i in 0..<stringLength {
        for j in i..<stringLength {
            let substring = string[i..<j + 1]
            if substring == substring.reversed() && substring.length > result.length {
                result = substring
            }
        }
    }
    return result
}

```swift
// Find how many times a given substring can be found in the original string. Count overlaping cases.
// howManyTimes(string: "", substring: "a") == 0
// howManyTimes(string: "aaa", substring: "a") == 3
// howManyTimes(string: "aaaa", substring: "aa") == 3
func howManyTimes(string: String, substring: String) -> Int {
    let result = 0
    let substringLength = substring.length
    for i in 0..<string.length - substringLength + 1 {
        if string[i..<i + substringLength] == substring {
            result += 1
        }
    }
    return result
}

// Find the longest substring in the original string that is a palindrome.
// longestPalindrome(string: "a") == "a"
// longestPalindrome(string: "ab") == "a"
// longestPalindrome(string: "aba") == "aba"
// longestPalindrome(string: "abcba") == "abcba"
// longestPalindrome(string: "abccba") == "abcba"
// longestPalindrome(string: "abcbaabc") == "abcba"
// longestPalindrome(string: "abcbaabcba") == "abcba"
// longestPalindrome(string: "abcbaabcbabc") == "abcba"
func longestPalindrome(string: String) -> String {
    let result = ""
    let stringLength = string.length
    for i in 0..<stringLength {
        for j in i..<stringLength {
            let substring = string[i..<j + 1]
            if substring == substring.reversed() && substring.length > result.length {
                result = substring
            }
        }
    }
    return result
}

// Find the longest substring in the original string that is a palindrome.
// longestPalindrome(string: "a") == "a"
// longestPalindrome(string: "ab") == "a"
// longestPalindrome(string: "aba") == "aba"
// longestPalindrome(string: "abcba") == "abcba"
// longestPalindrome(string: "abccba") == "abcba"
// longestPalindrome(string: "abcbaabc") == "abcba"
// longestPalindrome(string: "abcbaabcba") == "abcba"
// longestPalindrome(string: "abcbaabcbabc") == "abcba"
func longestPalindrome(string: String) -> String {
    let result = ""
    let stringLength = string.length
    for i in 0..<stringLength {
        for j in i..<stringLength {
            let substring = string[i..<j + 1]
            if substring == substring.reversed() && substring.length > result.length {
                result = substring
            }
        }
    }
    return result
}

// Find the longest substring in the original string that is a palindrome.
// longestPalindrome(string: "a") == "a"
// longestPalindrome(string: "ab") == "a"
// longestPalindrome(string: "aba") == "aba"
// longestPalindrome(string: "abcba") == "abcba"
// longestPalindrome(string: "abccba") == "abcba"
// longestPalindrome(string: "abcbaabc") == "abcba"
// longestPalindrome(string: "abcbaabcba") == "abcba"
// longestPalindrome(string: "abcbaabcbabc") == "abcba"
func longestPalindrome(string: String) -> String {
    let result = ""
    let stringLength = string.length
    for i in 0..<stringLength {
        for j in i..<stringLength {
            let substring = string[i..<j + 1]
            if substring == substring.reversed() && substring.length > result.length {
                result = substring
            }
        }
    }
    return result
}

// Find the longest substring in the original string that is a palindrome.
// longestPalindrome(string: "a") == "a"
// longestPalindrome(string: "ab") == "a"
// longestPalindrome(string: "aba") == "aba"
// longestPalindrome(string: "abcba") == "abcba"
// longestPalindrome(string: "abccba") == "abcba"
// longestPalindrome(string: "abcbaabc") == "abcba"
// longestPalindrome(string: "abcbaabcba") == "abcba"
// longestPalindrome(string: "abcbaabcbabc") == "abcba"
func longestPalindrome(string: String) -> String {
    let result = ""
    let stringLength = string.length
    for i in 0..<stringLength {
        for j in i..<stringLength {
            let substring = string[i..<j + 1]
            if substring == substring.reversed() && substring.length > result.length {

func sortNumbers(numbers: String) -> String {
    // Create a dictionary to map each numberal to its corresponding integer value.
    let numberalMap = [
        "zero" : 0,
        "one" : 1,
        "two" : 2,
        "three" : 3,
        "four" : 4,
        "five" : 5,
        "six" : 6,
        "seven" : 7,
        "eight" : 8,
        "nine" : 9
    ];
    
    // Split the input string into an array of numberals.
    let numberals = numbers.split(" ");
    
    // Sort the array of numberals based on their corresponding integer values.
    numberals.sort { &a, &b in
        let aValue = numberalMap[a] ?? 0;
        let bValue = numberalMap[b] ?? 0;
        aValue < bValue
    };
    
    // Join the sorted array of numberals back into a single string.
    return numberals.join(" ");
}

```swift
// Input is a space-delimited string of numberals from 'zero' to 'nine'.
// Valid choices are 'zero', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight' and 'nine'.
// Return the string with numbers sorted from smallest to largest
// sortNumbers(numbers: "three one five") == "one three five"
func sortNumbers(numbers: String) -> String {
    // Create a dictionary to map each numberal to its corresponding integer value.
    let numberalMap = [
        "zero" : 0,
        "one" : 1,
        "two" : 2,
        "three" : 3,
        "four" : 4,
        "five" : 5,
        "six" : 6,
        "seven" : 7,
        "eight" : 8,
        "nine" : 9
    ];
    
    // Split the input string into an array of numberals.
    let numberals = numbers.split(" ");
    
    // Sort the array of numberals based on their corresponding integer values.
    numberals.sort { &a, &b in
        let aValue = numberalMap[a] ?? 0;
        let bValue = numberalMap[b] ?? 0;
        aValue < bValue
    };
    
    // Join the sorted array of numberals back into a single string.
    return numberals.join(" ");
}
```

func sortNumbers(numbers: String) -> String {
    var sortedNumbers = numbers.split(" ").sorted()
    return sortedNumbers.joined(" ")
}

```swift
// Input is a space-delimited string of numberals from 'zero' to 'nine'.
// Valid choices are 'zero', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight' and 'nine'.
// Return the string with numbers sorted from smallest to largest
// sortNumbers(numbers: "three one five") == "one three five"
func sortNumbers(numbers: String) -> String {
    var sortedNumbers = numbers.split(" ").sorted()
    return sortedNumbers.joined(" ")
}
```

func sortNumbers(numbers: String) -> String {
    let numberals = [
        "zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"
    ];
    let sortedNumbers = numbers.split(" ").map {
        let numberalIndex = numberals.index(from: it)
        if numberalIndex != nil {
            numberalIndex
        } else {
            panic("Invalid numberal: $it")
        }
    };
    let sortedNumbersString = sortedNumbers.map(String.fromInt).join(" ");
    return sortedNumbersString
}

func sortWords(words: String) -> String {
    let sortedWords = words.split(" ").sorted()
    let sortedWordsString = sortedWords.join(" ");
    return sortedWordsString
}

func sortWordsReverse(words: String) -> String {
    let sortedWords = words.split(" ").sorted(by: String.compare)
    let sortedWordsString = sortedWords.join(" ");
    return sortedWordsString
}

func sortWordsAndLength(words: String) -> String {
    let sortedWords = words.split(" ").sorted(by: String.compare)
    let sortedWordsString = sortedWords.join(" ");
    return sortedWordsString
}

func sortWordsAndVowels(words: String) -> String {
    let sortedWords = words.split(" ").sorted(by: String.compare)
    let sortedWordsString = sortedWords.join(" ");
    return sortedWordsString
}

func sortWordsAndVowelsReverse(words: String) -> String {
    let sortedWords = words.split(" ").sorted(by: String.compare)
    let sortedWordsString = sortedWords.join(" ");
    return sortedWordsString
}

func sortWordsAndConsonants(words: String) -> String {
    let sortedWords = words.split(" ").sorted(by: String.compare)
    let sortedWordsString = sortedWords.join(" ");
    return sortedWordsString
}

func sortWordsAndConsonantsReverse(words: String) -> String {
    let sortedWords = words.split(" ").sorted(by: String.compare)
    let sortedWordsString = sortedWords.join(" ");
    return sortedWordsString
}

```swift
// Input is a space-delimited string of numberals from 'zero' to 'nine'.
// Valid choices are 'zero', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight' and 'nine'.
// Return the string with numbers sorted from smallest to largest
// sortNumbers(numbers: "three one five") == "one three five"
func sortNumbers(numbers: String) -> String {
    let numberals = [
        "zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"
    ];
    let sortedNumbers = numbers.split(" ").map {
        let numberalIndex = numberals.index(from: it)
        if numberalIndex != nil {
            numberalIndex
        } else {
            panic("Invalid numberal: $it")
        }
    };
    let sortedNumbersString = sortedNumbers.map(String.fromInt).join(" ");
    return sortedNumbersString
}

// Input is a space-delimited string of words.
// Return the string with words sorted from shortest to longest
// sortWords(words: "this is a test") == "a is this test"
func sortWords(words: String) -> String {
    let sortedWords = words.split(" ").sorted()
    let sortedWordsString = sortedWords.join(" ");
    return sortedWordsString
}

// Input is a space-delimited string of words.
// Return the string with words sorted from longest to shortest
// sortWords(words: "this is a test") == "a is this test"
func sortWordsReverse(words: String) -> String {
    let sortedWords = words.split(" ").sorted(by: String.compare)
    let sortedWordsString = sortedWords.join(" ");
    return sortedWordsString
}

// Input is a space-delimited string of words.
// Return the string with words sorted from shortest to longest,
// and then by the number of letters in each word from longest to shortest
// sortWords(words: "this is a test") == "a is this test"
func sortWordsAndLength(words: String) -> String {
    let sortedWords = words.split(" ").sorted(by: String.compare)
    let sortedWordsString = sortedWords.join(" ");
    return sortedWordsString
}

// Input is a space-delimited string of words.
// Return the string with words sorted from shortest to longest,
// and then by the number of vowels in each word from longest to shortest
// sortWords(words: "this is a test") == "a is this test"
func sortWordsAndVowels(words: String) -> String {
    let sortedWords = words.split(" ").sorted(by: String.compare)
    let sortedWordsString = sortedWords.join(" ");
    return sortedWordsString
}

// Input is a space-delimited string of words.
// Return the string with words sorted from longest to shortest,
// and then by the number of vowels in each word from longest to shortest
// sortWords(words: "this is a test") == "a is this test"
func sortWordsAndVowelsReverse(words: String) -> String {
    let sortedWords = words.split(" ").sorted(by: String.compare)
    let sortedWordsString = sortedWords.join(" ");
    return sortedWordsString
}

// Input is a space-delimited string of words.
// Return the string with words sorted from shortest to longest,
// and then by the number of consonants in each word from longest to shortest
// sortWords(words: "this is a test") == "a is this test"
func sortWordsAndConsonants(words: String) -> String {
    let sortedWords = words.split(" ").sorted(by: String.compare)
    let sortedWordsString = sortedWords.join(" ");
    return sortedWordsString
}

// Input is a space-delimited string of words.
// Return the string with words sorted from shortest to longest,
// and then by the number of consonants in each word from longest to shortest
// sortWords(words: "this is a test") == "a is this test"
func sortWordsAndConsonantsReverse(words: String) -> String {
    let sortedWords = words.split(" ").sorted(by: String.compare)
    let sortedWordsString = sortedWords.join(" ");
    return sortedWordsString
}

// Input is a space-delimited string of words.
// Return the string with words sorted from shortest to longest,
// and then by the number of vowels and consonants in each word from longest to shortest
// sortWords(words: "this is a test") == "a is this test"
func sortWordsAndVowelsAndConsonants(words: String) -> String {
    let sortedWords = words.split(" ").sorted(by: String.compare)
    let sortedWordsString = sortedWords.

func sortNumbers(numbers: String) -> String {
    // Create a dictionary with the numberals as keys and their corresponding values as values.
    let numberals = [
        "zero" : 0,
        "one" : 1,
        "two" : 2,
        "three" : 3,
        "four" : 4,
        "five" : 5,
        "six" : 6,
        "seven" : 7,
        "eight" : 8,
        "nine" : 9
    ];
    // Create an array of the numberals in the input string.
    let numberalsArray = numbers.split(" ");
    // Create an array to store the sorted numbers.
    let sortedNumbers = [];
    // Iterate over the numberalsArray and add the corresponding number to the sortedNumbers array.
    for numberal in numberalsArray {
        sortedNumbers.append(numberals[numberal]!);
    }
    // Join the sorted numbers into a single string and return it.
    return sortedNumbers.joinedString();
}

```swift
// Input is a space-delimited string of numberals from 'zero' to 'nine'.
// Valid choices are 'zero', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight' and 'nine'.
// Return the string with numbers sorted from smallest to largest
// sortNumbers(numbers: "three one five") == "one three five"
func sortNumbers(numbers: String) -> String {
    // Create a dictionary with the numberals as keys and their corresponding values as values.
    let numberals = [
        "zero" : 0,
        "one" : 1,
        "two" : 2,
        "three" : 3,
        "four" : 4,
        "five" : 5,
        "six" : 6,
        "seven" : 7,
        "eight" : 8,
        "nine" : 9
    ];
    // Create an array of the numberals in the input string.
    let numberalsArray = numbers.split(" ");
    // Create an array to store the sorted numbers.
    let sortedNumbers = [];
    // Iterate over the numberalsArray and add the corresponding number to the sortedNumbers array.
    for numberal in numberalsArray {
        sortedNumbers.append(numberals[numberal]!);
    }
    // Join the sorted numbers into a single string and return it.
    return sortedNumbers.joinedString();
}
```

func sortNumbers(numbers: String) -> String {
    // Create a dictionary of numberals to numbers
    let numberals = [
        "zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"
    ]
    let numbers = numbers.split(" ")
    // Create a dictionary of numbers to numberals
    let numberalsToNumbers = numberals.enumerated().map { (index, numberal) in numberal: index }
    // Create a dictionary of numbers to sorted numbers
    let sortedNumbers = numbers.map { number in numberalsToNumbers[number]! }
    // Return the sorted numbers as a string
    return sortedNumbers.join(" ")
}

func sortNumbers(numbers: String) -> String {
    // Create a list of numbers
    let numbers = numbers.split(",")
    // Sort the numbers
    let sortedNumbers = numbers.sorted()
    // Return the sorted numbers as a string
    return sortedNumbers.join(",")
}

func sortNumbers(numbers: String) -> String {
    // Create a list of numbers
    let numbers = numbers.split(",")
    // Sort the numbers
    let sortedNumbers = numbers.sorted(reverse: true)
    // Return the sorted numbers as a string
    return sortedNumbers.join(",")
}

```swift
// Input is a space-delimited string of numberals from 'zero' to 'nine'.
// Valid choices are 'zero', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight' and 'nine'.
// Return the string with numbers sorted from smallest to largest
// sortNumbers(numbers: "three one five") == "one three five"
func sortNumbers(numbers: String) -> String {
    // Create a dictionary of numberals to numbers
    let numberals = [
        "zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"
    ]
    let numbers = numbers.split(" ")
    // Create a dictionary of numbers to numberals
    let numberalsToNumbers = numberals.enumerated().map { (index, numberal) in numberal: index }
    // Create a dictionary of numbers to sorted numbers
    let sortedNumbers = numbers.map { number in numberalsToNumbers[number]! }
    // Return the sorted numbers as a string
    return sortedNumbers.join(" ")
}

// Input is a string of numbers separated by commas
// Return the string with numbers sorted from smallest to largest
// sortNumbers(numbers: "3, 1, 5") == "1, 3, 5"
func sortNumbers(numbers: String) -> String {
    // Create a list of numbers
    let numbers = numbers.split(",")
    // Sort the numbers
    let sortedNumbers = numbers.sorted()
    // Return the sorted numbers as a string
    return sortedNumbers.join(",")
}

// Input is a string of numbers separated by commas
// Return the string with numbers sorted from largest to smallest
// sortNumbers(numbers: "3, 1, 5") == "5, 3, 1"
func sortNumbers(numbers: String) -> String {
    // Create a list of numbers
    let numbers = numbers.split(",")
    // Sort the numbers
    let sortedNumbers = numbers.sorted(reverse: true)
    // Return the sorted numbers as a string
    return sortedNumbers.join(",")
}

// Input is a string of numbers separated by commas
// Return the string with numbers sorted from smallest to largest
// sortNumbers(numbers: "3, 1, 5") == "5, 3, 1"
func sortNumbers(numbers: String) -> String {
    // Create a list of numbers
    let numbers = numbers.split(",")
    // Sort the numbers
    let sortedNumbers = numbers.sorted()
    // Return the sorted numbers as a string
    return sortedNumbers.join(",")
}

// Input is a string of numbers separated by commas
// Return the string with numbers sorted from largest to smallest
// sortNumbers(numbers: "3, 1, 5") == "5, 3, 1"
func sortNumbers(numbers: String) -> String {
    // Create a list of numbers
    let numbers = numbers.split(",")
    // Sort the numbers
    let sortedNumbers = numbers.sorted(reverse: true)
    // Return the sorted numbers as a string
    return sortedNumbers.join(",")
}

// Input is a string of numbers separated by commas
// Return the string with numbers sorted from smallest to largest
// sortNumbers(numbers: "3, 1, 5") == "5, 3, 1"
func sortNumbers(numbers: String) -> String {
    // Create a list of numbers
    let numbers = numbers.split(",")
    // Sort the numbers
    let sortedNumbers = numbers.sorted()
    // Return the sorted numbers as a string
    return sortedNumbers.join(",")
}

// Input is a string of numbers separated by commas
// Return the string with numbers sorted from largest to smallest
// sortNumbers(numbers: "3, 1, 5") == "5, 3, 1"
func sortNumbers(numbers: String) -> String {
    // Create a list of numbers
    let numbers = numbers.split(",")
    // Sort the numbers
    let sortedNumbers = numbers.sorted(reverse: true)
    // Return the sorted numbers as a string
    return sortedNumbers.join(",")
}

// Input is a string of numbers separated by commas
// Return the string with numbers sorted from smallest to largest
// sortNumbers(numbers: "3, 1, 5") == "5, 3, 1"
func sortNumbers(numbers: String) -> String {
    // Create a list of numbers
    let numbers = numbers.split(",")
    // Sort the numbers
    let sortedNumbers = numbers.sorted()
    // Return the sorted numbers as a string
    return sortedNumbers.join(",")
}

// Input is a string of numbers separated by commas
// Return the string with numbers sorted from largest to smallest
// sortNumbers(numbers: "3, 1, 5") == "5, 3, 1"
func sortNumbers(numbers: String) -> String

func sortNumbers(numbers: String) -> String {
    let numberals = [
        "zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"
    ];
    let numbers = numbers.split(" ");
    let sortedNumbers = numbers.sorted();
    let sortedNumberals = sortedNumbers.map(
        |number| numberals[numberals.index(number)]
    );
    return sortedNumberals.joined(" ");
}

func sortWords(words: String) -> String {
    let words = words.split(" ");
    let sortedWords = words.sorted();
    let sortedWordsByLength = sortedWords.map(
        |word| word.length
    );
    let sortedWordsByLength = sortedWordsByLength.sorted();
    let sortedWordsByLength = sortedWordsByLength.map(
        |length| sortedWords[sortedWordsByLength.index(length)]
    );
    return sortedWordsByLength.joined(" ");
}

func sortWordsByLength(words: String) -> String {
    let words = words.split(" ");
    let sortedWords = words.sorted();
    let sortedWordsByLength = sortedWords.map(
        |word| word.length
    );
    let sortedWordsByLength = sortedWordsByLength.sorted();
    let sortedWordsByLength = sortedWordsByLength.reversed();
    let sortedWordsByLength = sortedWordsByLength.map(
        |length| sortedWords[sortedWordsByLength.index(length)]
    );
    return sortedWordsByLength.joined(" ");
}

func sortWordsByLengthAndAlphabeticalOrder(words: String) -> String {
    let words = words.split(" ");
    let sortedWords = words.sorted();
    let sortedWordsByLength = sortedWords.map(
        |word| word.length
    );
    let sortedWordsByLength = sortedWordsByLength.sorted();
    let sortedWordsByLength = sortedWordsByLength.map(
        |length| sortedWords[sortedWordsByLength.index(length)]
    );
    let sortedWordsByLengthAndAlphabeticalOrder = sortedWordsByLength.sorted();
    let sortedWordsByLengthAndAlphabeticalOrder = sortedWordsByLengthAndAlphabeticalOrder.map(
        |word| word.sorted()
    );
    let sortedWordsByLengthAndAlphabeticalOrder = sortedWordsByLengthAndAlphabeticalOrder.joined(" ");
    return sortedWordsByLengthAndAlphabeticalOrder;
}

func sortWordsByLengthAndAlphabeticalOrderReversed(words: String) -> String {
    let words = words.split(" ");
    let sortedWords = words.sorted();
    let sortedWordsByLength = sortedWords.map(
        |word| word.length
    );
    let sortedWordsByLength = sortedWordsByLength.sorted();
    let sortedWordsByLength = sortedWordsByLength.reversed();
    let sortedWordsByLength = sortedWordsByLength.map(
        |length| sortedWords[sortedWordsByLength.index(length)]
    );
    let sortedWordsByLengthAndAlphabeticalOrder = sortedWordsByLength.sorted();
    let sortedWordsByLengthAndAlphabeticalOrder = sortedWordsByLengthAndAlphabeticalOrder.map(
        |word| word.sorted()
    );
    let sortedWordsByLengthAndAlphabeticalOrder = sortedWordsByLengthAndAlphabeticalOrder.joined(" ");
    return sortedWordsByLengthAndAlphabeticalOrder;
}

```swift
// Input is a space-delimited string of numberals from 'zero' to 'nine'.
// Valid choices are 'zero', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight' and 'nine'.
// Return the string with numbers sorted from smallest to largest
// sortNumbers(numbers: "three one five") == "one three five"
func sortNumbers(numbers: String) -> String {
    let numberals = [
        "zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"
    ];
    let numbers = numbers.split(" ");
    let sortedNumbers = numbers.sorted();
    let sortedNumberals = sortedNumbers.map(
        |number| numberals[numberals.index(number)]
    );
    return sortedNumberals.joined(" ");
}

// Input is a space-delimited string of words.
// Return the string with the words sorted by length, from smallest to largest.
// sortWords(words: "three one five") == "one three five"
func sortWords(words: String) -> String {
    let words = words.split(" ");
    let sortedWords = words.sorted();
    let sortedWordsByLength = sortedWords.map(
        |word| word.length
    );
    let sortedWordsByLength = sortedWordsByLength.sorted();
    let sortedWordsByLength = sortedWordsByLength.map(
        |length| sortedWords[sortedWordsByLength.index(length)]
    );
    return sortedWordsByLength.joined(" ");
}

// Input is a space-delimited string of words.
// Return the string with the words sorted by length, from largest to smallest.
// sortWords(words: "three one five") == "five three one"
func sortWordsByLength(words: String) -> String {
    let words = words.split(" ");
    let sortedWords = words.sorted();
    let sortedWordsByLength = sortedWords.map(
        |word| word.length
    );
    let sortedWordsByLength = sortedWordsByLength.sorted();
    let sortedWordsByLength = sortedWordsByLength.reversed();
    let sortedWordsByLength = sortedWordsByLength.map(
        |length| sortedWords[sortedWordsByLength.index(length)]
    );
    return sortedWordsByLength.joined(" ");
}

// Input is a space-delimited string of words.
// Return the string with the words sorted by length, from smallest to largest,
// and then by alphabetical order, from a to z.
// sortWords(words: "three one five") == "one three five"
func sortWordsByLengthAndAlphabeticalOrder(words: String) -> String {
    let words = words.split(" ");
    let sortedWords = words.sorted();
    let sortedWordsByLength = sortedWords.map(
        |word| word.length
    );
    let sortedWordsByLength = sortedWordsByLength.sorted();
    let sortedWordsByLength = sortedWordsByLength.map(
        |length| sortedWords[sortedWordsByLength.index(length)]
    );
    let sortedWordsByLengthAndAlphabeticalOrder = sortedWordsByLength.sorted();
    let sortedWordsByLengthAndAlphabeticalOrder = sortedWordsByLengthAndAlphabeticalOrder.map(
        |word| word.sorted()
    );
    let sortedWordsByLengthAndAlphabeticalOrder = sortedWordsByLengthAndAlphabeticalOrder.joined(" ");
    return sortedWordsByLengthAndAlphabeticalOrder;
}

// Input is a space-delimited string of words.
// Return the string with the words sorted by length, from largest to smallest,
// and then by alphabetical order, from z to a.
// sortWords(words: "three one five") == "five three one"
func sortWordsByLengthAndAlphabeticalOrderReversed(words: String) -> String {
    let words = words.split(" ");
    let sortedWords = words.sorted();
    let sortedWordsByLength = sortedWords.map(
        |word| word.length
    );
    let sortedWordsByLength = sortedWordsByLength.sorted();
    let sortedWordsByLength = sortedWordsByLength.reversed();
    let sortedWordsByLength = sortedWordsByLength.map(
        |length| sortedWords[sortedWordsByLength.index(length)]
    );
    let sortedWordsByLengthAndAlphabeticalOrder = sortedWordsByLength.sorted();
    let sortedWordsByLengthAndAlphabeticalOrder = sortedWordsByLengthAndAlphabeticalOrder.map(
        |word| word.sorted()
    );
    let sortedWordsByLengthAndAlphabeticalOrder = sortedWordsByLengthAndAlphabeticalOrder.joined(" ");
    return sortedWordsByLengthAndAlphabeticalOrder;
}

// Input is a space-delimited string of words.
// Return the string with the words sorted by

func sortNumbers(numbers: String) -> String {
    var sortedNumbers = numbers.split(" ")
    var sortedNumbers = sortedNumbers.map(func(number) -> Int {
        switch number {
            case "zero": return 0
            case "one": return 1
            case "two": return 2
            case "three": return 3
            case "four": return 4
            case "five": return 5
            case "six": return 6
            case "seven": return 7
            case "eight": return 8
            case "nine": return 9
        }
        return 0
    })
    sortedNumbers.sort()
    return sortedNumbers.map(func(number) -> String {
        switch number {
            case 0: return "zero"
            case 1: return "one"
            case 2: return "two"
            case 3: return "three"
            case 4: return "four"
            case 5: return "five"
            case 6: return "six"
            case 7: return "seven"
            case 8: return "eight"
            case 9: return "nine"
        }
        return ""
    }).join(" ")
}

func sortWords(words: String) -> String {
    var sortedWords = words.split(" ")
    sortedWords.sort()
    return sortedWords.join(" ")
}

func sortWords(words: String) -> String {
    var sortedWords = words.split(" ")
    sortedWords.sort(compare: func(word1: String, word2: String) -> Int {
        return word2.count - word1.count
    })
    return sortedWords.join(" ")
}

func sortWords(words: String) -> String {
    var sortedWords = words.split(" ")
    sortedWords.sort()
    sortedWords.sort(compare: func(word1: String, word2: String) -> Int {
        return word2.count - word1.count
    })
    return sortedWords.join(" ")
}

func sortWords(words: String) -> String {
    var sortedWords = words.split(" ")
    sortedWords.sort(compare: func(word1: String, word2: String) -> Int {
        return word2.count - word1.count
    })
    sortedWords.sort()
    return sortedWords.join(" ")
}

```swift
// Input is a space-delimited string of numberals from 'zero' to 'nine'.
// Valid choices are 'zero', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight' and 'nine'.
// Return the string with numbers sorted from smallest to largest
// sortNumbers(numbers: "three one five") == "one three five"
func sortNumbers(numbers: String) -> String {
    var sortedNumbers = numbers.split(" ")
    var sortedNumbers = sortedNumbers.map(func(number) -> Int {
        switch number {
            case "zero": return 0
            case "one": return 1
            case "two": return 2
            case "three": return 3
            case "four": return 4
            case "five": return 5
            case "six": return 6
            case "seven": return 7
            case "eight": return 8
            case "nine": return 9
        }
        return 0
    })
    sortedNumbers.sort()
    return sortedNumbers.map(func(number) -> String {
        switch number {
            case 0: return "zero"
            case 1: return "one"
            case 2: return "two"
            case 3: return "three"
            case 4: return "four"
            case 5: return "five"
            case 6: return "six"
            case 7: return "seven"
            case 8: return "eight"
            case 9: return "nine"
        }
        return ""
    }).join(" ")
}

// Input is a space-delimited string of words.
// Return the string with words sorted from shortest to longest.
// sortWords(words: "four five six three one two") == "one two three four five six"
func sortWords(words: String) -> String {
    var sortedWords = words.split(" ")
    sortedWords.sort()
    return sortedWords.join(" ")
}

// Input is a space-delimited string of words.
// Return the string with words sorted from longest to shortest.
// sortWords(words: "four five six three one two") == "six five four three two one"
func sortWords(words: String) -> String {
    var sortedWords = words.split(" ")
    sortedWords.sort(compare: func(word1: String, word2: String) -> Int {
        return word2.count - word1.count
    })
    return sortedWords.join(" ")
}

// Input is a space-delimited string of words.
// Return the string with words sorted from shortest to longest,
// and then from longest to shortest, if there are two words of the same length.
// sortWords(words: "four five six three one two") == "one two three four five six"
func sortWords(words: String) -> String {
    var sortedWords = words.split(" ")
    sortedWords.sort()
    sortedWords.sort(compare: func(word1: String, word2: String) -> Int {
        return word2.count - word1.count
    })
    return sortedWords.join(" ")
}

// Input is a space-delimited string of words.
// Return the string with words sorted from longest to shortest,
// and then from shortest to longest, if there are two words of the same length.
// sortWords(words: "four five six three one two") == "six five four three two one"
func sortWords(words: String) -> String {
    var sortedWords = words.split(" ")
    sortedWords.sort(compare: func(word1: String, word2: String) -> Int {
        return word2.count - word1.count
    })
    sortedWords.sort()
    return sortedWords.join(" ")
}

// Input is a space-delimited string of words.
// Return the string with words sorted from shortest to longest,
// and then from longest to shortest, if there are two words of the same length.
// sortWords(words: "four five six three one two") == "six five four three two one"
func sortWords(words: String) -> String {
    var sortedWords = words.split(" ")
    sortedWords.sort(compare: func(word1: String, word2: String) -> Int {
        return word2.count - word1.count
    })
    sortedWords.sort()
    return sortedWords.join(" ")
}

// Input is a space-delimited string of words.
// Return the string with words sorted from shortest to longest,
// and then from longest to shortest, if there are two words of the same length.
// sortWords(words: "four five six three one two") == "six five four three two one"
func sortWords(words: String) -> String {
    var sortedWords

func sortNumbers(numbers: String) -> String {
    var sortedNumbers = [String]()
    var numberals = ["zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"]
    var numbersArray = numbers.split(" ")
    for _, number in numbersArray {
        sortedNumbers.append(numberals[numberals.index(number)])
    }
    return sortedNumbers.join(" ")
}

func sortWords(words: String) -> String {
    var sortedWords = [String]()
    var wordsArray = words.split(" ")
    for _, word in wordsArray {
        sortedWords.append(word)
    }
    sortedWords.sort()
    return sortedWords.join(" ")
}

func sortAlphabetically(words: String) -> String {
    var sortedWords = [String]()
    var wordsArray = words.split(" ")
    for _, word in wordsArray {
        sortedWords.append(word)
    }
    sortedWords.sort()
    return sortedWords.join(" ")
}

func sortWordsByLength(words: String) -> String {
    var sortedWords = [String]()
    var wordsArray = words.split(" ")
    for _, word in wordsArray {
        sortedWords.append(word)
    }
    sortedWords.sort()
    return sortedWords.join(" ")
}

func sortWordsByLengthReverse(words: String) -> String {
    var sortedWords = [String]()
    var wordsArray = words.split(" ")
    for _, word in wordsArray {
        sortedWords.append(word)
    }
    sortedWords.sort()
    sortedWords.reverse()
    return sortedWords.join(" ")
}

```swift
// Input is a space-delimited string of numberals from 'zero' to 'nine'.
// Valid choices are 'zero', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight' and 'nine'.
// Return the string with numbers sorted from smallest to largest
// sortNumbers(numbers: "three one five") == "one three five"
func sortNumbers(numbers: String) -> String {
    var sortedNumbers = [String]()
    var numberals = ["zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"]
    var numbersArray = numbers.split(" ")
    for _, number in numbersArray {
        sortedNumbers.append(numberals[numberals.index(number)])
    }
    return sortedNumbers.join(" ")
}

// Input is a space-delimited string of words.
// Return the string with words sorted by length from shortest to longest.
// sortWords(words: "three one five") == "one three five"
func sortWords(words: String) -> String {
    var sortedWords = [String]()
    var wordsArray = words.split(" ")
    for _, word in wordsArray {
        sortedWords.append(word)
    }
    sortedWords.sort()
    return sortedWords.join(" ")
}

// Input is a space-delimited string of words.
// Return the string with words sorted alphabetically.
// sortWords(words: "three one five") == "five one three"
func sortAlphabetically(words: String) -> String {
    var sortedWords = [String]()
    var wordsArray = words.split(" ")
    for _, word in wordsArray {
        sortedWords.append(word)
    }
    sortedWords.sort()
    return sortedWords.join(" ")
}

// Input is a space-delimited string of words.
// Return the string with words sorted by length from shortest to longest,
// and then alphabetically if the lengths are equal.
// sortWords(words: "three one five") == "one three five"
func sortWordsByLength(words: String) -> String {
    var sortedWords = [String]()
    var wordsArray = words.split(" ")
    for _, word in wordsArray {
        sortedWords.append(word)
    }
    sortedWords.sort()
    return sortedWords.join(" ")
}

// Input is a space-delimited string of words.
// Return the string with words sorted by length from longest to shortest.
// sortWords(words: "three one five") == "five three one"
func sortWordsByLengthReverse(words: String) -> String {
    var sortedWords = [String]()
    var wordsArray = words.split(" ")
    for _, word in wordsArray {
        sortedWords.append(word)
    }
    sortedWords.sort()
    sortedWords.reverse()
    return sortedWords.join(" ")
}

// Input is a space-delimited string of words.
// Return the string with words sorted by length from shortest to longest,
// and then alphabetically if the lengths are equal.
// sortWords(words: "three one five") == "one three five"
func sortWordsByLength(words: String) -> String {
    var sortedWords = [String]()
    var wordsArray = words.split(" ")
    for _, word in wordsArray {
        sortedWords.append(word)
    }
    sortedWords.sort()
    return sortedWords.join(" ")
}

// Input is a space-delimited string of words.
// Return the string with words sorted by length from longest to shortest,
// and then alphabetically if the lengths are equal.
// sortWords(words: "three one five") == "five three one"
func sortWordsByLengthReverse(words: String) -> String {
    var sortedWords = [String]()
    var wordsArray = words.split(" ")
    for _, word in wordsArray {
        sortedWords.append(word)
    }
    sortedWords.sort()
    sortedWords.reverse()
    return sortedWords.join(" ")
}

// Input is a space-delimited string of words.
// Return the string with words sorted by length from shortest to longest,
// and then alphabetically if the lengths are equal.
// sortWords(words: "three one five") == "one three five"
func sortWordsByLength(words: String) -> String {
    var sortedWords = [String]()
    var wordsArray = words.split(" ")
    for _, word in wordsArray {
        sortedWords.append(word)
    }
    sortedWords.sort()
    return sortedWords.join(" ")
}

// Input is a space-delimited string of words.
// Return the string with words sorted by length from longest to shortest,
// and then alphabetically if the lengths are equal.
// sort

func sortNumbers(numbers: String) -> String {
    var sortedNumbers: [String] = []
    for number in numbers.split(" ") {
        sortedNumbers.append(number)
    }
    sortedNumbers.sort()
    return sortedNumbers.joined(" ")
}

func sortNumbersDescending(numbers: String) -> String {
    var sortedNumbers: [String] = []
    for number in numbers.split(" ") {
        sortedNumbers.append(number)
    }
    sortedNumbers.sort(reverse: true)
    return sortedNumbers.joined(" ")
}

func sortNumbersWithZero(numbers: String) -> String {
    var sortedNumbers: [String] = []
    for number in numbers.split(" ") {
        sortedNumbers.append(number)
    }
    sortedNumbers.sort()
    sortedNumbers.append("zero")
    return sortedNumbers.joined(" ")
}

func sortNumbersWithZeroDescending(numbers: String) -> String {
    var sortedNumbers: [String] = []
    for number in numbers.split(" ") {
        sortedNumbers.append(number)
    }
    sortedNumbers.sort(reverse: true)
    sortedNumbers.append("zero")
    return sortedNumbers.joined(" ")
}

func sortNumbersWithZeroAscending(numbers: String) -> String {
    var sortedNumbers: [String] = []
    for number in numbers.split(" ") {
        sortedNumbers.append(number)
    }
    sortedNumbers.sort()
    sortedNumbers.insert(0, "zero")
    return sortedNumbers.joined(" ")
}

func sortNumbersWithZeroDescending(numbers: String) -> String {
    var sortedNumbers: [String] = []
    for number in numbers.split(" ") {
        sortedNumbers.append(number)
    }
    sortedNumbers.sort(reverse: true)
    sortedNumbers.insert(0, "zero")
    return sortedNumbers.joined(" ")
}

```swift
// Input is a space-delimited string of numberals from 'zero' to 'nine'.
// Valid choices are 'zero', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight' and 'nine'.
// Return the string with numbers sorted from smallest to largest
// sortNumbers(numbers: "three one five") == "one three five"
func sortNumbers(numbers: String) -> String {
    var sortedNumbers: [String] = []
    for number in numbers.split(" ") {
        sortedNumbers.append(number)
    }
    sortedNumbers.sort()
    return sortedNumbers.joined(" ")
}

// Input is a space-delimited string of numberals from 'zero' to 'nine'.
// Valid choices are 'zero', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight' and 'nine'.
// Return the string with numbers sorted from largest to smallest
// sortNumbers(numbers: "three one five") == "five three one"
func sortNumbersDescending(numbers: String) -> String {
    var sortedNumbers: [String] = []
    for number in numbers.split(" ") {
        sortedNumbers.append(number)
    }
    sortedNumbers.sort(reverse: true)
    return sortedNumbers.joined(" ")
}

// Input is a space-delimited string of numberals from 'zero' to 'nine'.
// Valid choices are 'zero', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight' and 'nine'.
// Return the string with numbers sorted from smallest to largest, but with the word 'zero' at the end.
// sortNumbersWithZero(numbers: "three one five") == "one three five zero"
func sortNumbersWithZero(numbers: String) -> String {
    var sortedNumbers: [String] = []
    for number in numbers.split(" ") {
        sortedNumbers.append(number)
    }
    sortedNumbers.sort()
    sortedNumbers.append("zero")
    return sortedNumbers.joined(" ")
}

// Input is a space-delimited string of numberals from 'zero' to 'nine'.
// Valid choices are 'zero', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight' and 'nine'.
// Return the string with numbers sorted from largest to smallest, but with the word 'zero' at the end.
// sortNumbersWithZeroDescending(numbers: "three one five") == "five three one zero"
func sortNumbersWithZeroDescending(numbers: String) -> String {
    var sortedNumbers: [String] = []
    for number in numbers.split(" ") {
        sortedNumbers.append(number)
    }
    sortedNumbers.sort(reverse: true)
    sortedNumbers.append("zero")
    return sortedNumbers.joined(" ")
}

// Input is a space-delimited string of numberals from 'zero' to 'nine'.
// Valid choices are 'zero', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight' and 'nine'.
// Return the string with numbers sorted from smallest to largest, but with the word 'zero' at the beginning.
// sortNumbersWithZeroAscending(numbers: "three one five") == "zero one three five"
func sortNumbersWithZeroAscending(numbers: String) -> String {
    var sortedNumbers: [String] = []
    for number in numbers.split(" ") {
        sortedNumbers.append(number)
    }
    sortedNumbers.sort()
    sortedNumbers.insert(0, "zero")
    return sortedNumbers.joined(" ")
}

// Input is a space-delimited string of numberals from 'zero' to 'nine'.
// Valid choices are 'zero', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight' and 'nine'.
// Return the string with numbers sorted from largest to smallest, but with the word 'zero' at the beginning.
// sortNumbersWithZeroDescending(numbers: "three one five") == "zero one three five"
func sortNumbersWithZeroDescending(numbers: String) -> String {
    var sortedNumbers: [String] = []
    for number in numbers.split(" ") {
        sortedNumbers.append(number)
    }
    sortedNumbers.sort(reverse: true)
    sortedNumbers.insert(0, "zero")
    return sortedNumbers.joined(" ")
}

// Input is a space-delimited string of numberals from 'zero' to 'nine'.
// Valid choices are 'zero', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight' and 'nine'.
// Return the string with numbers sorted from smallest to largest, but with the word 'zero' at the beginning and 'nine' at the end.

func sortNumbers(numbers: String) -> String {
    var sortedNumbers = numbers.split(" ").map { it.toInt() }
    sortedNumbers.sort()
    return sortedNumbers.map { it.toString() }.joined(" ")
}

func sortWords(words: String) -> String {
    var sortedWords = words.split(" ").map { it.length }
    sortedWords.sort()
    return sortedWords.map { words.split(" ").filter { it.length == it } }.joined(" ")
}

func sortWordsLongestToShortest(words: String) -> String {
    var sortedWords = words.split(" ").map { it.length }
    sortedWords.sort()
    return sortedWords.map { words.split(" ").filter { it.length == it } }.joined(" ")
}

func sortWordsShortestToLongest(words: String) -> String {
    var sortedWords = words.split(" ").map { it.length }
    sortedWords.sort()
    return sortedWords.map { words.split(" ").filter { it.length == it } }.joined(" ")
}

```swift
// Input is a space-delimited string of numberals from 'zero' to 'nine'.
// Valid choices are 'zero', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight' and 'nine'.
// Return the string with numbers sorted from smallest to largest
// sortNumbers(numbers: "three one five") == "one three five"
func sortNumbers(numbers: String) -> String {
    var sortedNumbers = numbers.split(" ").map { it.toInt() }
    sortedNumbers.sort()
    return sortedNumbers.map { it.toString() }.joined(" ")
}

// Input is a space-delimited string of words.
// Return the string with words sorted from shortest to longest
// sortWords(words: "the quick brown fox") == "fox the quick brown"
func sortWords(words: String) -> String {
    var sortedWords = words.split(" ").map { it.length }
    sortedWords.sort()
    return sortedWords.map { words.split(" ").filter { it.length == it } }.joined(" ")
}

// Input is a space-delimited string of words.
// Return the string with words sorted from longest to shortest
// sortWords(words: "the quick brown fox") == "the quick brown fox"
func sortWordsLongestToShortest(words: String) -> String {
    var sortedWords = words.split(" ").map { it.length }
    sortedWords.sort()
    return sortedWords.map { words.split(" ").filter { it.length == it } }.joined(" ")
}

// Input is a space-delimited string of words.
// Return the string with words sorted from shortest to longest
// sortWords(words: "the quick brown fox") == "the quick brown fox"
func sortWordsShortestToLongest(words: String) -> String {
    var sortedWords = words.split(" ").map { it.length }
    sortedWords.sort()
    return sortedWords.map { words.split(" ").filter { it.length == it } }.joined(" ")
}

// Input is a space-delimited string of words.
// Return the string with words sorted from longest to shortest
// sortWords(words: "the quick brown fox") == "the quick brown fox"
func sortWordsLongestToShortest(words: String) -> String {
    var sortedWords = words.split(" ").map { it.length }
    sortedWords.sort()
    return sortedWords.map { words.split(" ").filter { it.length == it } }.joined(" ")
}

// Input is a space-delimited string of words.
// Return the string with words sorted from shortest to longest
// sortWords(words: "the quick brown fox") == "the quick brown fox"
func sortWordsShortestToLongest(words: String) -> String {
    var sortedWords = words.split(" ").map { it.length }
    sortedWords.sort()
    return sortedWords.map { words.split(" ").filter { it.length == it } }.joined(" ")
}

// Input is a space-delimited string of words.
// Return the string with words sorted from longest to shortest
// sortWords(words: "the quick brown fox") == "the quick brown fox"
func sortWordsLongestToShortest(words: String) -> String {
    var sortedWords = words.split(" ").map { it.length }
    sortedWords.sort()
    return sortedWords.map { words.split(" ").filter { it.length == it } }.joined(" ")
}

// Input is a space-delimited string of words.
// Return the string with words sorted from shortest to longest
// sortWords(words: "the quick brown fox") == "the quick brown fox"
func sortWordsShortestToLongest(words: String) -> String {
    var sortedWords = words.split(" ").map { it.length }
    sortedWords.sort()
    return sortedWords.map { words.split(" ").filter { it.length == it } }.joined(" ")
}

// Input is a space-delimited string of words.
// Return the string with words sorted from longest to shortest
// sortWords(words: "the quick brown fox") == "the quick brown fox"
func sortWordsLongestToShortest(words: String) -> String {
    var sortedWords = words.split(" ").map { it.length }
    sortedWords.sort()
    return sortedWords.map { words.split(" ").filter { it.length == it } }.joined(" ")
}

// Input is a space-delimited string of words.
// Return the string with words sorted from shortest to longest
// sortWords(words: "the quick brown fox") == "the quick brown fox"
func sortWordsShortestToLongest(words: String) -> String {
    var sortedWords = words.split(" ").map { it.length }
    sortedWords.sort()
    return sortedWords.map { words.split("

func findClosestElements(numbers: [Double]) -> (Double, Double) {
    var smallestDiff = Double.max
    var smallestDiffIndex = 0
    var smallestDiffIndex2 = 0
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            var diff = numbers[i] - numbers[j]
            if diff.abs < smallestDiff {
                smallestDiff = diff.abs
                smallestDiffIndex = i
                smallestDiffIndex2 = j
            }
        }
    }
    return (numbers[smallestDiffIndex], numbers[smallestDiffIndex2])
}

```swift
// From a supplied array of numbers (of length at least two) select and return two that are the closest to each
// other and return them in order (smaller number, larger number).
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.2]) == (2.0, 2.2)
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.0]) == (2.0, 2.0)
func findClosestElements(numbers: [Double]) -> (Double, Double) {
    var smallestDiff = Double.max
    var smallestDiffIndex = 0
    var smallestDiffIndex2 = 0
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            var diff = numbers[i] - numbers[j]
            if diff.abs < smallestDiff {
                smallestDiff = diff.abs
                smallestDiffIndex = i
                smallestDiffIndex2 = j
            }
        }
    }
    return (numbers[smallestDiffIndex], numbers[smallestDiffIndex2])
}
```

func findClosestElements(numbers: [Double]) -> (Double, Double) {
    var closestElements: [Double] = [Double.max, Double.max]
    var closestDistance: Double = Double.max
    var closestIndex: Int = 0
    var closestIndex2: Int = 0
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            var distance: Double = numbers[i] - numbers[j]
            if distance.abs < closestDistance {
                closestDistance = distance.abs
                closestIndex = i
                closestIndex2 = j
            }
        }
    }
    return (numbers[closestIndex], numbers[closestIndex2])
}

```swift
// From a supplied array of numbers (of length at least two) select and return two that are the closest to each
// other and return them in order (smaller number, larger number).
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.2]) == (2.0, 2.2)
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.0]) == (2.0, 2.0)
func findClosestElements(numbers: [Double]) -> (Double, Double) {
    var closestElements: [Double] = [Double.max, Double.max]
    var closestDistance: Double = Double.max
    var closestIndex: Int = 0
    var closestIndex2: Int = 0
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            var distance: Double = numbers[i] - numbers[j]
            if distance.abs < closestDistance {
                closestDistance = distance.abs
                closestIndex = i
                closestIndex2 = j
            }
        }
    }
    return (numbers[closestIndex], numbers[closestIndex2])
}

// Given a string, return a new string with the same length where the original string is reversed, but the middle character is moved to the front.
// reverseMiddleCharacter("Hello") == "eHllo"
// reverseMiddleCharacter("abcdef") == "badcfe"
// reverseMiddleCharacter("abcdefg") == "bcdefga"
// reverseMiddleCharacter("abcdefgh") == "cdefgab"
// reverseMiddleCharacter("abcdefghi") == "bcdefghi"
// reverseMiddleCharacter("abcdefghij") == "cdefghij"
// reverseMiddleCharacter("abcdefghijk") == "bcdefghijk"
// reverseMiddleCharacter("abcdefghijkl") == "cdefghijkl"
// reverseMiddleCharacter("abcdefghijklm") == "bcdefghijklm"
// reverseMiddleCharacter("abcdefghijklmn") == "cdefghijklmn"
// reverseMiddleCharacter("abcdefghijklmno") == "bcdefghijklmno"
// reverseMiddleCharacter("abcdefghijklmon") == "cdefghijklmon"
// reverseMiddleCharacter("abcdefghijklmona") == "bcdefghijklmona"
// reverseMiddleCharacter("abcdefghijklmonp") == "cdefghijklmonp"
// reverseMiddleCharacter("abcdefghijklmonpq") == "bcdefghijklmonpq"
// reverseMiddleCharacter("abcdefghijklmonpqr") == "cdefghijklmonpqr"
// reverseMiddleCharacter("abcdefghijklmonpqrst") == "bcdefghijklmonpqrst"
// reverseMiddleCharacter("abcdefghijklmonpqrstuvw") == "bcdefghijklmonpqrstuvw"
// reverseMiddleCharacter("abcdefghijklmonpqrstuvwxy") == "bcdefghijklmonpqrstuvwxy"
// reverseMiddleCharacter("abcdefghijklmonpqrstuvwxyza") == "bcdefghijklmonpqrstuvwxyza"
// reverseMiddleCharacter("abcdefghijklmonpqrstuvwxyzabcd") == "bcdefghijklmonpqrstuvwxyzabcd"
// reverseMiddleCharacter("abcdefghijklmonpqrstuvwxyzabcd") == "bcdefghijklmonpqrstuvwxyzabcd"
// reverseMiddleCharacter("abcdefghijklmonpqrstuvwxyzabcd") == "bcdefghijklmonpqrstuvwxyzabcd"
// reverseMiddleCharacter("abcdefghijklmonpqrstuvwxyzabcd") == "bcdefghijklmonpqrstuvwxyzabcd"
// reverseMiddleCharacter("abcdefghijklmonpqrstuvwxyzabcd") == "bcdefghijklmonpqrstuvwxyzabcd"
// reverseMiddleCharacter("abcdefghijklmonpqrstuvwxyzabcd") == "bcdefghijklmonpqrstuvwxyzabcd"
// reverseMiddleCharacter("abcdefghijklmonpqrstuvwxyzabcd") == "bcdefghijklmonpqrstuvwxyzabcd"
// reverseMiddleCharacter("abcdefghijklmonpqrstuvwxyzabcd") == "bcdefghijklmonpqrstuvwxyzabcd"
// reverseMiddleCharacter("abcdefghijklmonpqrstuvwxyzabcd") == "bcdefghijklmonpqrstuvwxyzabcd"
// reverseMiddleCharacter("abcdefghijklmonpqrstuvwxyzabcd") == "bcdefghijklmonpqrstuvwxyzabcd"
// reverseMiddleCharacter("abcdefghijklmonpqrstuvwxyzabcd") == "bcdefghijklmonpqrstuvwxyzabcd"
// reverseMiddleCharacter("abcdefghijklmonpqrstuvwxyzabcd") == "bcdefghijklmonpqrstuvwxyzabcd"
// reverseMiddleCharacter("abcdefghijklmonpqrstuvwxyzabcd") == "bcdefghijklmonpqrstuvwxyzabcd"
// reverseMiddleCharacter("abcdefghijklmonpqrstuvwxyzabcd") == "bcdefghijklmonpqrstuvwxyzabcd"
// reverseMiddleCharacter("abcdefghijklmonpqrstuvwxyzabcd") == "bcdefghijklmonpqrstuvwxyzabcd"
// reverseMiddleCharacter("abcdefghijklmonpqrstuvwxyzabcd") == "bcdefghijklmonpqrstuvwxyzabcd"
// reverseMiddleCharacter("abcdefghijklmonpqrstuvwxyzabcd") == "bcdefghijklmonpqrstuvwxyza

func findClosestElements(numbers: [Double]) -> (Double, Double) {
    var closestPair: (Double, Double) = (0.0, 0.0)
    var smallestDistance: Double = Double.max
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            var distance: Double = numbers[i] - numbers[j]
            if distance.abs < smallestDistance {
                closestPair = (numbers[i], numbers[j])
                smallestDistance = distance.abs
            }
        }
    }
    return closestPair
}

```swift
// From a supplied array of numbers (of length at least two) select and return two that are the closest to each
// other and return them in order (smaller number, larger number).
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.2]) == (2.0, 2.2)
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.0]) == (2.0, 2.0)
func findClosestElements(numbers: [Double]) -> (Double, Double) {
    var closestPair: (Double, Double) = (0.0, 0.0)
    var smallestDistance: Double = Double.max
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            var distance: Double = numbers[i] - numbers[j]
            if distance.abs < smallestDistance {
                closestPair = (numbers[i], numbers[j])
                smallestDistance = distance.abs
            }
        }
    }
    return closestPair
}

// From a supplied array of numbers (of length at least two) select and return two that are the closest to each
// other and return them in order (smaller number, larger number).
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.2]) == (2.0, 2.2)
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.0]) == (2.0, 2.0)
func findClosestElements(numbers: [Double]) -> (Double, Double) {
    var closestPair: (Double, Double) = (0.0, 0.0)
    var smallestDistance: Double = Double.max
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            var distance: Double = numbers[i] - numbers[j]
            if distance.abs < smallestDistance {
                closestPair = (numbers[i], numbers[j])
                smallestDistance = distance.abs
            }
        }
    }
    return closestPair
}

// From a supplied array of numbers (of length at least two) select and return two that are the closest to each
// other and return them in order (smaller number, larger number).
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.2]) == (2.0, 2.2)
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.0]) == (2.0, 2.0)
func findClosestElements(numbers: [Double]) -> (Double, Double) {
    var closestPair: (Double, Double) = (0.0, 0.0)
    var smallestDistance: Double = Double.max
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            var distance: Double = numbers[i] - numbers[j]
            if distance.abs < smallestDistance {
                closestPair = (numbers[i], numbers[j])
                smallestDistance = distance.abs
            }
        }
    }
    return closestPair
}

// From a supplied array of numbers (of length at least two) select and return two that are the closest to each
// other and return them in order (smaller number, larger number).
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.2]) == (2.0, 2.2)
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.0]) == (2.0, 2.0)
func findClosestElements(numbers: [Double]) -> (Double, Double) {
    var closestPair: (Double, Double) = (0.0, 0.0)
    var smallestDistance: Double = Double.max
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            var distance: Double = numbers[i] - numbers[j]
            if distance.abs < smallestDistance {
                closestPair = (numbers[i], numbers[j])
                smallestDistance = distance.abs
            }
        }
    }
    return closestPair
}

// From a supplied array of numbers (of length at least two) select and return two that are the closest to each
// other and return them in order (smaller number, larger number).
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.

func findClosestElements(numbers: [Double]) -> (Double, Double) {
    var closestElements: [(Double, Double)] = [(numbers[0], numbers[1])]
    for i in 0..<numbers.count - 1 {
        for j in i + 1..<numbers.count {
            var distance: Double = numbers[i] - numbers[j]
            closestElements.append((numbers[i], numbers[j]))
            closestElements.sort()
        }
    }
    return closestElements[0]
}

```swift
// From a supplied array of numbers (of length at least two) select and return two that are the closest to each
// other and return them in order (smaller number, larger number).
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.2]) == (2.0, 2.2)
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.0]) == (2.0, 2.0)
func findClosestElements(numbers: [Double]) -> (Double, Double) {
    var closestElements: [(Double, Double)] = [(numbers[0], numbers[1])]
    for i in 0..<numbers.count - 1 {
        for j in i + 1..<numbers.count {
            var distance: Double = numbers[i] - numbers[j]
            closestElements.append((numbers[i], numbers[j]))
            closestElements.sort()
        }
    }
    return closestElements[0]
}

// From a supplied array of numbers (of length at least two) select and return two that are the closest to each
// other and return them in order (smaller number, larger number).
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.2]) == (2.0, 2.2)
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.0]) == (2.0, 2.0)
func findClosestElements(numbers: [Double]) -> (Double, Double) {
    var closestElements: [(Double, Double)] = [(numbers[0], numbers[1])]
    for i in 0..<numbers.count - 1 {
        for j in i + 1..<numbers.count {
            var distance: Double = numbers[i] - numbers[j]
            closestElements.append((numbers[i], numbers[j]))
            closestElements.sort()
        }
    }
    return closestElements[0]
}

// From a supplied array of numbers (of length at least two) select and return two that are the closest to each
// other and return them in order (smaller number, larger number).
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.2]) == (2.0, 2.2)
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.0]) == (2.0, 2.0)
func findClosestElements(numbers: [Double]) -> (Double, Double) {
    var closestElements: [(Double, Double)] = [(numbers[0], numbers[1])]
    for i in 0..<numbers.count - 1 {
        for j in i + 1..<numbers.count {
            var distance: Double = numbers[i] - numbers[j]
            closestElements.append((numbers[i], numbers[j]))
            closestElements.sort()
        }
    }
    return closestElements[0]
}

// From a supplied array of numbers (of length at least two) select and return two that are the closest to each
// other and return them in order (smaller number, larger number).
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.2]) == (2.0, 2.2)
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.0]) == (2.0, 2.0)
func findClosestElements(numbers: [Double]) -> (Double, Double) {
    var closestElements: [(Double, Double)] = [(numbers[0], numbers[1])]
    for i in 0..<numbers.count - 1 {
        for j in i + 1..<numbers.count {
            var distance: Double = numbers[i] - numbers[j]
            closestElements.append((numbers[i], numbers[j]))
            closestElements.sort()
        }
    }
    return closestElements[0]
}

// From a supplied array of numbers (of length at least two) select and return two that are the closest to each
// other and return them in order (smaller number, larger number).
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.2]) == (2.0, 2.2)
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.0]) == (2.0, 2.0)
func

func findClosestElements(numbers: [Double]) -> (Double, Double) {
    var smallestDiff = Double.max
    var smallestDiffIndex = 0
    var smallestDiffIndex2 = 0
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if i == j {
                continue
            }
            var diff = numbers[i] - numbers[j]
            if diff.abs < smallestDiff {
                smallestDiff = diff.abs
                smallestDiffIndex = i
                smallestDiffIndex2 = j
            }
        }
    }
    return (numbers[smallestDiffIndex], numbers[smallestDiffIndex2])
}

func findClosestElements2(numbers: [Double]) -> (Double, Double) {
    var smallestDiff = Double.max
    var smallestDiffIndex = 0
    var smallestDiffIndex2 = 0
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if i == j {
                continue
            }
            var diff = numbers[i] - numbers[j]
            if diff.abs < smallestDiff {
                smallestDiff = diff.abs
                smallestDiffIndex = i
                smallestDiffIndex2 = j
            }
        }
    }
    return (numbers[smallestDiffIndex], numbers[smallestDiffIndex2])
}

func findClosestElements3(numbers: [Double]) -> (Double, Double) {
    var smallestDiff = Double.max
    var smallestDiffIndex = 0
    var smallestDiffIndex2 = 0
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if i == j {
                continue
            }
            var diff = numbers[i] - numbers[j]
            if diff.abs < smallestDiff {
                smallestDiff = diff.abs
                smallestDiffIndex = i
                smallestDiffIndex2 = j
            }
        }
    }
    return (numbers[smallestDiffIndex], numbers[smallestDiffIndex2])
}

```swift
// From a supplied array of numbers (of length at least two) select and return two that are the closest to each
// other and return them in order (smaller number, larger number).
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.2]) == (2.0, 2.2)
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.0]) == (2.0, 2.0)
func findClosestElements(numbers: [Double]) -> (Double, Double) {
    var smallestDiff = Double.max
    var smallestDiffIndex = 0
    var smallestDiffIndex2 = 0
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if i == j {
                continue
            }
            var diff = numbers[i] - numbers[j]
            if diff.abs < smallestDiff {
                smallestDiff = diff.abs
                smallestDiffIndex = i
                smallestDiffIndex2 = j
            }
        }
    }
    return (numbers[smallestDiffIndex], numbers[smallestDiffIndex2])
}

// From a supplied array of numbers (of length at least two) select and return two that are the closest to each
// other and return them in order (smaller number, larger number).
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.2]) == (2.0, 2.2)
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.0]) == (2.0, 2.0)
func findClosestElements2(numbers: [Double]) -> (Double, Double) {
    var smallestDiff = Double.max
    var smallestDiffIndex = 0
    var smallestDiffIndex2 = 0
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if i == j {
                continue
            }
            var diff = numbers[i] - numbers[j]
            if diff.abs < smallestDiff {
                smallestDiff = diff.abs
                smallestDiffIndex = i
                smallestDiffIndex2 = j
            }
        }
    }
    return (numbers[smallestDiffIndex], numbers[smallestDiffIndex2])
}

// From a supplied array of numbers (of length at least two) select and return two that are the closest to each
// other and return them in order (smaller number, larger number).
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.2]) == (2.0, 2.2)
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.0]) == (2.0, 2.0)
func findClosestElements3(numbers: [Double]) -> (Double, Double) {
    var smallestDiff = Double.max
    var smallestDiffIndex = 0
    var smallestDiffIndex2 = 0
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if i == j {
                continue
            }
            var diff = numbers[i] - numbers[j]
            if diff.abs < smallestDiff {
                smallestDiff = diff.abs
                smallestDiffIndex = i
                smallestDiffIndex2 = j
            }
        }
    }
    return (numbers[smallestDiffIndex], numbers[smallestDiffIndex2])
}

// From a supplied array of numbers (of length at least two) select and return two that are the closest to each
// other and return them in order (smaller number, larger number).
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.2]) == (2.0, 2.2)
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.0]) == (2.0, 2.0)
func findClosestElements4(numbers: [Double]) -> (Double, Double) {
    var smallestDiff = Double.max
    var smallestDiffIndex = 0
    var smallestDiffIndex2 = 0
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if i == j {
                continue
            }
            var diff = numbers[i] - numbers[j]
            if diff.abs < smallestDiff {
                smallestDiff = diff.abs
                smallestDiffIndex = i
                smallestDiffIndex2 = j
            }
        }
    }
    return (numbers[smallestDiffIndex], numbers[smallestDiffIndex2

func findClosestElements(numbers: [Double]) -> (Double, Double) {
    var closestElements: [(Double, Double)] = [(numbers[0], numbers[1])]
    for i in 0..<numbers.count - 1 {
        for j in i + 1..<numbers.count {
            var distance1: Double = numbers[i] - numbers[j]
            var distance2: Double = numbers[j] - numbers[i]
            if distance1.absoluteValue < distance2.absoluteValue {
                closestElements.append((numbers[i], numbers[j]))
            } else {
                closestElements.append((numbers[j], numbers[i]))
            }
        }
    }
    return closestElements[0]
}

```swift
// From a supplied array of numbers (of length at least two) select and return two that are the closest to each
// other and return them in order (smaller number, larger number).
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.2]) == (2.0, 2.2)
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.0]) == (2.0, 2.0)
func findClosestElements(numbers: [Double]) -> (Double, Double) {
    var closestElements: [(Double, Double)] = [(numbers[0], numbers[1])]
    for i in 0..<numbers.count - 1 {
        for j in i + 1..<numbers.count {
            var distance1: Double = numbers[i] - numbers[j]
            var distance2: Double = numbers[j] - numbers[i]
            if distance1.absoluteValue < distance2.absoluteValue {
                closestElements.append((numbers[i], numbers[j]))
            } else {
                closestElements.append((numbers[j], numbers[i]))
            }
        }
    }
    return closestElements[0]
}
```

func findClosestElements(numbers: [Double]) -> (Double, Double) {
    var closestElements: [(Double, Double)] = [(numbers[0], numbers[1])]
    for i in 0..<numbers.count - 1 {
        for j in i + 1..<numbers.count {
            var currentClosestElements: [(Double, Double)] = [(numbers[i], numbers[j])]
            closestElements = closestElements + currentClosestElements
        }
    }
    closestElements.sort()
    return closestElements[0]
}

func largestProduct(numbers: [Double]) -> Double {
    var largestProduct: Double = 0.0
    for i in 0..<numbers.count - 1 {
        for j in i + 1..<numbers.count {
            var currentProduct: Double = numbers[i] * numbers[j]
            if currentProduct > largestProduct {
                largestProduct = currentProduct
            }
        }
    }
    return largestProduct
}

func secondLargest(numbers: [Double]) -> Double {
    var secondLargest: Double = 0.0
    for i in 0..<numbers.count - 1 {
        for j in i + 1..<numbers.count {
            if numbers[i] < numbers[j] && numbers[j] > secondLargest {
                secondLargest = numbers[j]
            }
        }
    }
    return secondLargest
}

func sumOf(numbers: [Double]) -> Double {
    var sum: Double = 0.0
    for _, number in numbers {
        sum += number
    }
    return sum
}

func averageOf(numbers: [Double]) -> Double {
    return sumOf(numbers) / Double(numbers.count)
}

func medianOf(numbers: [Double]) -> Double {
    var sortedNumbers: [Double] = numbers.sorted()
    var middleIndex: Int = (sortedNumbers.count - 1) / 2
    if sortedNumbers.count % 2 == 0 {
        return (sortedNumbers[middleIndex] + sortedNumbers[middleIndex + 1]) / 2.0
    } else {
        return sortedNumbers[middleIndex]
    }
}

```swift
// From a supplied array of numbers (of length at least two) select and return two that are the closest to each
// other and return them in order (smaller number, larger number).
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.2]) == (2.0, 2.2)
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.0]) == (2.0, 2.0)
func findClosestElements(numbers: [Double]) -> (Double, Double) {
    var closestElements: [(Double, Double)] = [(numbers[0], numbers[1])]
    for i in 0..<numbers.count - 1 {
        for j in i + 1..<numbers.count {
            var currentClosestElements: [(Double, Double)] = [(numbers[i], numbers[j])]
            closestElements = closestElements + currentClosestElements
        }
    }
    closestElements.sort()
    return closestElements[0]
}

// Given an array of numbers, return the largest product that can be made from two of the numbers in the array.
// largestProduct([1, 2, 3, 4, 5, 6]) == 24
// largestProduct([1, 2, 3, 4, 5, 6, 7, 8]) == 56
func largestProduct(numbers: [Double]) -> Double {
    var largestProduct: Double = 0.0
    for i in 0..<numbers.count - 1 {
        for j in i + 1..<numbers.count {
            var currentProduct: Double = numbers[i] * numbers[j]
            if currentProduct > largestProduct {
                largestProduct = currentProduct
            }
        }
    }
    return largestProduct
}

// Given an array of numbers, return the second largest number in the array.
// secondLargest([1, 2, 3, 4, 5, 6]) == 5
// secondLargest([1, 2, 3, 4, 5, 6, 7, 8]) == 7
func secondLargest(numbers: [Double]) -> Double {
    var secondLargest: Double = 0.0
    for i in 0..<numbers.count - 1 {
        for j in i + 1..<numbers.count {
            if numbers[i] < numbers[j] && numbers[j] > secondLargest {
                secondLargest = numbers[j]
            }
        }
    }
    return secondLargest
}

// Given an array of numbers, return the sum of the numbers in the array.
// sumOf([1, 2, 3, 4, 5, 6]) == 21
// sumOf([1, 2, 3, 4, 5, 6, 7, 8]) == 36
func sumOf(numbers: [Double]) -> Double {
    var sum: Double = 0.0
    for _, number in numbers {
        sum += number
    }
    return sum
}

// Given an array of numbers, return the average of the numbers in the array.
// averageOf([1, 2, 3, 4, 5, 6]) == 3.5
// averageOf([1, 2, 3, 4, 5, 6, 7, 8]) == 4.5
func averageOf(numbers: [Double]) -> Double {
    return sumOf(numbers) / Double(numbers.count)
}

// Given an array of numbers, return the median of the numbers in the array.
// medianOf([1, 2, 3, 4, 5, 6]) == 3.5
// medianOf([1, 2, 3, 4, 5, 6, 7, 8]) == 4.5
func medianOf(numbers: [Double]) -> Double {
    var sortedNumbers: [Double] = numbers.sorted()
    var middleIndex: Int = (sortedNumbers.count - 1) / 2
    if sortedNumbers.count % 2 == 0 {
        return (sortedNumbers[middleIndex] + sortedNumbers[middleIndex + 1]) / 2.0
    } else {
        return sortedNumbers[middleIndex]
    }
}

// Given an array of numbers, return the mode of the numbers in the array.
// modeOf([1, 2, 3, 4, 5, 6]) == 3.5
// modeOf([1, 2, 3, 4, 5, 6, 7, 8]) == 4.5
func modeOf(numbers: [Double]) -> Double {
    var mode: Double = 0.0
    var modeCount: Int = 0
    var currentCount: Int = 0
    var currentNumber: Double = numbers[0]
    for _, number in numbers {
        if number

func findClosestElements(numbers: [Double]) -> (Double, Double) {
    var closest: Double = Double.max
    var closest1: Double = Double.max
    var closest2: Double = Double.max
    var closest1Index: Int = 0
    var closest2Index: Int = 0
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            var diff: Double = numbers[i] - numbers[j]
            if diff.abs < closest {
                closest = diff.abs
                closest1 = numbers[i]
                closest2 = numbers[j]
                closest1Index = i
                closest2Index = j
            }
        }
    }
    return (closest1, closest2)
}

```swift
// From a supplied array of numbers (of length at least two) select and return two that are the closest to each
// other and return them in order (smaller number, larger number).
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.2]) == (2.0, 2.2)
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.0]) == (2.0, 2.0)
func findClosestElements(numbers: [Double]) -> (Double, Double) {
    var closest: Double = Double.max
    var closest1: Double = Double.max
    var closest2: Double = Double.max
    var closest1Index: Int = 0
    var closest2Index: Int = 0
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            var diff: Double = numbers[i] - numbers[j]
            if diff.abs < closest {
                closest = diff.abs
                closest1 = numbers[i]
                closest2 = numbers[j]
                closest1Index = i
                closest2Index = j
            }
        }
    }
    return (closest1, closest2)
}

// From a supplied array of numbers (of length at least two) select and return two that are the closest to each
// other and return them in order (smaller number, larger number).
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.2]) == (2.0, 2.2)
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.0]) == (2.0, 2.0)
func findClosestElements(numbers: [Double]) -> (Double, Double) {
    var closest: Double = Double.max
    var closest1: Double = Double.max
    var closest2: Double = Double.max
    var closest1Index: Int = 0
    var closest2Index: Int = 0
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            var diff: Double = numbers[i] - numbers[j]
            if diff.abs < closest {
                closest = diff.abs
                closest1 = numbers[i]
                closest2 = numbers[j]
                closest1Index = i
                closest2Index = j
            }
        }
    }
    return (closest1, closest2)
}

// From a supplied array of numbers (of length at least two) select and return two that are the closest to each
// other and return them in order (smaller number, larger number).
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.2]) == (2.0, 2.2)
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.0]) == (2.0, 2.0)
func findClosestElements(numbers: [Double]) -> (Double, Double) {
    var closest: Double = Double.max
    var closest1: Double = Double.max
    var closest2: Double = Double.max
    var closest1Index: Int = 0
    var closest2Index: Int = 0
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            var diff: Double = numbers[i] - numbers[j]
            if diff.abs < closest {
                closest = diff.abs
                closest1 = numbers[i]
                closest2 = numbers[j]
                closest1Index = i
                closest2Index = j
            }
        }
    }
    return (closest1, closest2)
}

// From a supplied array of numbers (of length at least two) select and return two that are the closest to each
// other and return them in order (smaller number, larger number).
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.2]) == (2.0, 2.2)
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.0]) == (2.0, 2.0)
func findClosestElements(numbers: [Double]) -> (Double, Double) {
    var closest: Double = Double.max
    var closest1: Double = Double.max
    var closest2: Double = Double.max
    var closest1Index: Int = 0
    var closest2Index: Int = 0
    for i in 0..<numbers.count {
        for j

```swift
// From a supplied array of numbers (of length at least two) select and return two that are the closest to each
// other and return them in order (smaller number, larger number).
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.2]) == (2.0, 2.2)
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.0]) == (2.0, 2.0)
func findClosestElements(numbers: [Double]) -> (Double, Double) {
    var smallestDifference: Double = Double.max
    var smallestDifferenceIndex: Int = 0
    var smallestDifferenceIndex2: Int = 0
    var smallestDifferenceIndex3: Int = 0
    var smallestDifferenceIndex4: Int = 0
    var smallestDifferenceIndex5: Int = 0
    var smallestDifferenceIndex6: Int = 0
    var smallestDifferenceIndex7: Int = 0
    var smallestDifferenceIndex8: Int = 0
    var smallestDifferenceIndex9: Int = 0
    var smallestDifferenceIndex10: Int = 0
    var smallestDifferenceIndex11: Int = 0
    var smallestDifferenceIndex12: Int = 0
    var smallestDifferenceIndex13: Int = 0
    var smallestDifferenceIndex14: Int = 0
    var smallestDifferenceIndex15: Int = 0
    var smallestDifferenceIndex16: Int = 0
    var smallestDifferenceIndex17: Int = 0
    var smallestDifferenceIndex18: Int = 0
    var smallestDifferenceIndex19: Int = 0
    var smallestDifferenceIndex20: Int = 0
    var smallestDifferenceIndex21: Int = 0
    var smallestDifferenceIndex22: Int = 0
    var smallestDifferenceIndex23: Int = 0
    var smallestDifferenceIndex24: Int = 0
    var smallestDifferenceIndex25: Int = 0
    var smallestDifferenceIndex26: Int = 0
    var smallestDifferenceIndex27: Int = 0
    var smallestDifferenceIndex28: Int = 0
    var smallestDifferenceIndex29: Int = 0
    var smallestDifferenceIndex30: Int = 0
    var smallestDifferenceIndex31: Int = 0
    var smallestDifferenceIndex32: Int = 0
    var smallestDifferenceIndex33: Int = 0
    var smallestDifferenceIndex34: Int = 0
    var smallestDifferenceIndex35: Int = 0
    var smallestDifferenceIndex36: Int = 0
    var smallestDifferenceIndex37: Int = 0
    var smallestDifferenceIndex38: Int = 0
    var smallestDifferenceIndex39: Int = 0
    var smallestDifferenceIndex40: Int = 0
    var smallestDifferenceIndex41: Int = 0
    var smallestDifferenceIndex42: Int = 0
    var smallestDifferenceIndex43: Int = 0
    var smallestDifferenceIndex44: Int = 0
    var smallestDifferenceIndex45: Int = 0
    var smallestDifferenceIndex46: Int = 0
    var smallestDifferenceIndex47: Int = 0
    var smallestDifferenceIndex48: Int = 0
    var smallestDifferenceIndex49: Int = 0
    var smallestDifferenceIndex50: Int = 0
    var smallestDifferenceIndex51: Int = 0
    var smallestDifferenceIndex52: Int = 0
    var smallestDifferenceIndex53: Int = 0
    var smallestDifferenceIndex54: Int = 0
    var smallestDifferenceIndex55: Int = 0
    var smallestDifferenceIndex56: Int = 0
    var smallestDifferenceIndex57: Int = 0
    var smallestDifferenceIndex58: Int = 0
    var smallestDifferenceIndex59: Int = 0
    var smallestDifferenceIndex60: Int = 0
    var smallestDifferenceIndex61: Int = 0
    var smallestDifferenceIndex62: Int = 0
    var smallestDifferenceIndex63: Int = 0
    var smallestDifferenceIndex64: Int = 0
    var smallestDifferenceIndex65: Int = 0
    var smallestDifferenceIndex66: Int = 0
    var smallestDifferenceIndex67: Int = 0
    var smallestDifferenceIndex68: Int = 0
    var smallestDifferenceIndex69: Int = 0
    var smallestDifferenceIndex70: Int = 0
    var smallestDifferenceIndex71: Int = 0
    var smallestDifferenceIndex72: Int = 0
    var smallestDifferenceIndex73: Int = 0
    var smallestDifferenceIndex74: Int = 0
    var smallestDifferenceIndex75: Int = 0
    var smallestDifferenceIndex76: Int = 0
    var smallestDifferenceIndex77: Int = 0
    var smallestDifferenceIndex78: Int = 0
    var smallestDifferenceIndex79:

func findClosestElements(numbers: [Double]) -> (Double, Double) {
    var closestPair: (Double, Double) = (numbers[0], numbers[1])
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if (numbers[i] - numbers[j]).absoluteValue < (closestPair.0 - closestPair.1).absoluteValue {
                closestPair = (numbers[i], numbers[j])
            }
        }
    }
    return closestPair
}

func countDivisors(numbers: [Double], k: Double) -> Int {
    var count: Int = 0
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if (numbers[i] + numbers[j]).modulo(k) == 0 {
                count += 1
            }
        }
    }
    return count
}

```swift
// From a supplied array of numbers (of length at least two) select and return two that are the closest to each
// other and return them in order (smaller number, larger number).
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.2]) == (2.0, 2.2)
// findClosestElements(numbers: [1.0, 2.0, 3.0, 4.0, 5.0, 2.0]) == (2.0, 2.0)
func findClosestElements(numbers: [Double]) -> (Double, Double) {
    var closestPair: (Double, Double) = (numbers[0], numbers[1])
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if (numbers[i] - numbers[j]).absoluteValue < (closestPair.0 - closestPair.1).absoluteValue {
                closestPair = (numbers[i], numbers[j])
            }
        }
    }
    return closestPair
}

// Given an array of numbers, return the number of pairs of indices (i, j) such that i < j and a[i] + a[j] is
// divisible by k.
// countDivisors([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], 2) == 8
// countDivisors([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], 3) == 5
func countDivisors(numbers: [Double], k: Double) -> Int {
    var count: Int = 0
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if (numbers[i] + numbers[j]).modulo(k) == 0 {
                count += 1
            }
        }
    }
    return count
}

// Given an array of numbers, return the number of pairs of indices (i, j) such that i < j and a[i] + a[j] is
// divisible by k.
// countDivisors([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], 2) == 8
// countDivisors([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], 3) == 5
func countDivisors(numbers: [Double], k: Double) -> Int {
    var count: Int = 0
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if (numbers[i] + numbers[j]).modulo(k) == 0 {
                count += 1
            }
        }
    }
    return count
}

// Given an array of numbers, return the number of pairs of indices (i, j) such that i < j and a[i] + a[j] is
// divisible by k.
// countDivisors([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], 2) == 8
// countDivisors([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], 3) == 5
func countDivisors(numbers: [Double], k: Double) -> Int {
    var count: Int = 0
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if (numbers[i] + numbers[j]).modulo(k) == 0 {
                count += 1
            }
        }
    }
    return count
}

// Given an array of numbers, return the number of pairs of indices (i, j) such that i < j and a[i] + a[j] is
// divisible by k.
// countDivisors([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], 2) == 8
// countDivisors([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], 3) == 5
func countDivisors(numbers: [Double], k: Double) -> Int {
    var count: Int = 0
    for i in 0..<numbers.count {
        for j in i..<numbers.count {
            if (numbers[i] + numbers[j]).modulo(k) == 0 {
                count += 1
            }
        }
    }
    return count
}

// Given an array of numbers, return the number of pairs of indices (i, j) such that i < j and a[i] + a[j] is

func rescaleToUnit(numbers: [Double]) -> [Double] {
    let min = numbers.min()
    let max = numbers.max()
    let result = numbers.map({
        |x| {
            if (x == min) {
                return 0.0
            } else if (x == max) {
                return 1.0
            } else {
                return (x - min) / (max - min)
            }
        }
    })
    return result
}

```swift
// Given array of numbers (of at least two elements), apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToUnit(numbers: [Double]) -> [Double] {
    let min = numbers.min()
    let max = numbers.max()
    let result = numbers.map({
        |x| {
            if (x == min) {
                return 0.0
            } else if (x == max) {
                return 1.0
            } else {
                return (x - min) / (max - min)
            }
        }
    })
    return result
}
```

func rescaleToUnit(numbers: [Double]) -> [Double] {
    let min = numbers.min()
    let max = numbers.max()
    let result = numbers.map({
        let x = it - min
        let y = max - min
        x / y
    })
    return result
}

func rescaleToZeroOne(numbers: [Double]) -> [Double] {
    let min = numbers.min()
    let max = numbers.max()
    let result = numbers.map({
        let x = it - min
        let y = max - min
        x / y
    })
    return result
}

```swift
// Given array of numbers (of at least two elements), apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToUnit(numbers: [Double]) -> [Double] {
    let min = numbers.min()
    let max = numbers.max()
    let result = numbers.map({
        let x = it - min
        let y = max - min
        x / y
    })
    return result
}

// Given an array of numbers, apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToZeroOne(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToZeroOne(numbers: [Double]) -> [Double] {
    let min = numbers.min()
    let max = numbers.max()
    let result = numbers.map({
        let x = it - min
        let y = max - min
        x / y
    })
    return result
}

// Given an array of numbers, apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToZeroOne(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToZeroOne(numbers: [Double]) -> [Double] {
    let min = numbers.min()
    let max = numbers.max()
    let result = numbers.map({
        let x = it - min
        let y = max - min
        x / y
    })
    return result
}

// Given an array of numbers, apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToZeroOne(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToZeroOne(numbers: [Double]) -> [Double] {
    let min = numbers.min()
    let max = numbers.max()
    let result = numbers.map({
        let x = it - min
        let y = max - min
        x / y
    })
    return result
}

// Given an array of numbers, apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToZeroOne(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToZeroOne(numbers: [Double]) -> [Double] {
    let min = numbers.min()
    let max = numbers.max()
    let result = numbers.map({
        let x = it - min
        let y = max - min
        x / y
    })
    return result
}

// Given an array of numbers, apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToZeroOne(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToZeroOne(numbers: [Double]) -> [Double] {
    let min = numbers.min()
    let max = numbers.max()
    let result = numbers.map({
        let x = it - min
        let y = max - min
        x / y
    })
    return result
}

// Given an array of numbers, apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToZeroOne(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToZeroOne(numbers:

func rescaleToUnit(numbers: [Double]) -> [Double] {
    let min = numbers.min()
    let max = numbers.max()
    let result = numbers.map({
        let x = it - min
        let y = max - min
        x / y
    })
    return result
}

```swift
// Given array of numbers (of at least two elements), apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToUnit(numbers: [Double]) -> [Double] {
    let min = numbers.min()
    let max = numbers.max()
    let result = numbers.map({
        let x = it - min
        let y = max - min
        x / y
    })
    return result
}
```

func rescaleToUnit(numbers: [Double]) -> [Double] {
    let min = numbers.min()!
    let max = numbers.max()!
    return numbers.map { (it - min) / (max - min) }
}

```swift
// Given array of numbers (of at least two elements), apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToUnit(numbers: [Double]) -> [Double] {
    let min = numbers.min()!
    let max = numbers.max()!
    return numbers.map { (it - min) / (max - min) }
}
```

func rescaleToUnit(numbers: [Double]) -> [Double] {
    var min = Double.max
    var max = Double.min
    for _, num in numbers {
        if num < min {
            min = num
        }
        if num > max {
            max = num
        }
    }
    var rescaled = [Double](repeating: 0, count: numbers.count)
    for i, num in enumerate(numbers) {
        rescaled[i] = (num - min) / (max - min)
    }
    return rescaled
}

```swift
// Given array of numbers (of at least two elements), apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToUnit(numbers: [Double]) -> [Double] {
    var min = Double.max
    var max = Double.min
    for _, num in numbers {
        if num < min {
            min = num
        }
        if num > max {
            max = num
        }
    }
    var rescaled = [Double](repeating: 0, count: numbers.count)
    for i, num in enumerate(numbers) {
        rescaled[i] = (num - min) / (max - min)
    }
    return rescaled
}

// Given array of numbers (of at least two elements), apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToUnit(numbers: [Double]) -> [Double] {
    var min = Double.max
    var max = Double.min
    for _, num in numbers {
        if num < min {
            min = num
        }
        if num > max {
            max = num
        }
    }
    var rescaled = [Double](repeating: 0, count: numbers.count)
    for i, num in enumerate(numbers) {
        rescaled[i] = (num - min) / (max - min)
    }
    return rescaled
}

// Given array of numbers (of at least two elements), apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToUnit(numbers: [Double]) -> [Double] {
    var min = Double.max
    var max = Double.min
    for _, num in numbers {
        if num < min {
            min = num
        }
        if num > max {
            max = num
        }
    }
    var rescaled = [Double](repeating: 0, count: numbers.count)
    for i, num in enumerate(numbers) {
        rescaled[i] = (num - min) / (max - min)
    }
    return rescaled
}

// Given array of numbers (of at least two elements), apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToUnit(numbers: [Double]) -> [Double] {
    var min = Double.max
    var max = Double.min
    for _, num in numbers {
        if num < min {
            min = num
        }
        if num > max {
            max = num
        }
    }
    var rescaled = [Double](repeating: 0, count: numbers.count)
    for i, num in enumerate(numbers) {
        rescaled[i] = (num - min) / (max - min)
    }
    return rescaled
}

// Given array of numbers (of at least two elements), apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToUnit(numbers: [Double]) -> [Double] {
    var min = Double.max
    var max = Double.min
    for _, num in numbers {
        if num < min {
            min = num
        }
        if num > max {
            max = num
        }
    }
    var rescaled = [Double](repeating: 0, count: numbers.

func rescaleToUnit(numbers: [Double]) -> [Double] {
    var min = Double.max
    var max = Double.min
    for _, num in numbers {
        if num < min {
            min = num
        }
        if num > max {
            max = num
        }
    }
    var rescale = (max - min)
    var rescaled = Array(0..<numbers.count)
    for i, num in enumerate(numbers) {
        var scaled = (num - min) / rescale
        rescaled[i] = scaled
    }
    return rescaled
}

func rescaleToUnit2(numbers: [Double]) -> [Double] {
    var min = Double.max
    var max = Double.min
    for _, num in numbers {
        if num < min {
            min = num
        }
        if num > max {
            max = num
        }
    }
    var rescale = (max - min)
    var rescaled = Array(0..<numbers.count)
    for i, num in enumerate(numbers) {
        var scaled = (num - min) / rescale
        rescaled[i] = scaled
    }
    return rescaled
}

func rescaleToUnit3(numbers: [Double]) -> [Double] {
    var min = Double.max
    var max = Double.min
    for _, num in numbers {
        if num < min {
            min = num
        }
        if num > max {
            max = num
        }
    }
    var rescale = (max - min)
    var rescaled = Array(0..<numbers.count)
    for i, num in enumerate(numbers) {
        var scaled = (num - min) / rescale
        rescaled[i] = scaled
    }
    return rescaled
}

func rescaleToUnit4(numbers: [Double]) -> [Double] {
    var min = Double.max
    var max = Double.min
    for _, num in numbers {
        if num < min {
            min = num
        }
        if num > max {
            max = num
        }
    }
    var rescale = (max - min)
    var rescaled = Array(0..<numbers.count)
    for i, num in enumerate(numbers) {
        var scaled = (num - min) / rescale
        rescaled[i] = scaled
    }
    return rescaled
}

```swift
// Given array of numbers (of at least two elements), apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToUnit(numbers: [Double]) -> [Double] {
    var min = Double.max
    var max = Double.min
    for _, num in numbers {
        if num < min {
            min = num
        }
        if num > max {
            max = num
        }
    }
    var rescale = (max - min)
    var rescaled = Array(0..<numbers.count)
    for i, num in enumerate(numbers) {
        var scaled = (num - min) / rescale
        rescaled[i] = scaled
    }
    return rescaled
}

// Given array of numbers (of at least two elements), apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToUnit2(numbers: [Double]) -> [Double] {
    var min = Double.max
    var max = Double.min
    for _, num in numbers {
        if num < min {
            min = num
        }
        if num > max {
            max = num
        }
    }
    var rescale = (max - min)
    var rescaled = Array(0..<numbers.count)
    for i, num in enumerate(numbers) {
        var scaled = (num - min) / rescale
        rescaled[i] = scaled
    }
    return rescaled
}

// Given array of numbers (of at least two elements), apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToUnit3(numbers: [Double]) -> [Double] {
    var min = Double.max
    var max = Double.min
    for _, num in numbers {
        if num < min {
            min = num
        }
        if num > max {
            max = num
        }
    }
    var rescale = (max - min)
    var rescaled = Array(0..<numbers.count)
    for i, num in enumerate(numbers) {
        var scaled = (num - min) / rescale
        rescaled[i] = scaled
    }
    return rescaled
}

// Given array of numbers (of at least two elements), apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToUnit4(numbers: [Double]) -> [Double] {
    var min = Double.max
    var max = Double.min
    for _, num in numbers {
        if num < min {
            min = num
        }
        if num > max {
            max = num
        }
    }
    var rescale = (max - min)
    var rescaled = Array(0..<numbers.count)
    for i, num in enumerate(numbers) {
        var scaled = (num - min) / rescale
        rescaled[i] = scaled
    }
    return rescaled
}

// Given array of numbers (of at least two elements), apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToUnit5(numbers: [Double]) -> [Double] {
    var min = Double.max
    var max = Double.min
    for _, num in numbers {
        if num < min {
            min = num
        }
        if num >

func rescaleToUnit(numbers: [Double]) -> [Double] {
    let min = numbers.min()
    let max = numbers.max()
    let diff = max - min
    let rescaled = numbers.map({
        |x| (x - min) / diff
    })
    return rescaled
}

```swift
// Given array of numbers (of at least two elements), apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToUnit(numbers: [Double]) -> [Double] {
    let min = numbers.min()
    let max = numbers.max()
    let diff = max - min
    let rescaled = numbers.map({
        |x| (x - min) / diff
    })
    return rescaled
}

// Given array of numbers (of at least two elements), apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToUnit(numbers: [Double]) -> [Double] {
    let min = numbers.min()
    let max = numbers.max()
    let diff = max - min
    let rescaled = numbers.map({
        |x| (x - min) / diff
    })
    return rescaled
}

// Given array of numbers (of at least two elements), apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToUnit(numbers: [Double]) -> [Double] {
    let min = numbers.min()
    let max = numbers.max()
    let diff = max - min
    let rescaled = numbers.map({
        |x| (x - min) / diff
    })
    return rescaled
}

// Given array of numbers (of at least two elements), apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToUnit(numbers: [Double]) -> [Double] {
    let min = numbers.min()
    let max = numbers.max()
    let diff = max - min
    let rescaled = numbers.map({
        |x| (x - min) / diff
    })
    return rescaled
}

// Given array of numbers (of at least two elements), apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToUnit(numbers: [Double]) -> [Double] {
    let min = numbers.min()
    let max = numbers.max()
    let diff = max - min
    let rescaled = numbers.map({
        |x| (x - min) / diff
    })
    return rescaled
}

// Given array of numbers (of at least two elements), apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToUnit(numbers: [Double]) -> [Double] {
    let min = numbers.min()
    let max = numbers.max()
    let diff = max - min
    let rescaled = numbers.map({
        |x| (x - min) / diff
    })
    return rescaled
}

// Given array of numbers (of at least two elements), apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 

func rescaleToUnit(numbers: [Double]) -> [Double] {
    var min = Double.max
    var max = Double.min
    for i in 0..<numbers.count {
        if numbers[i] < min {
            min = numbers[i]
        }
        if numbers[i] > max {
            max = numbers[i]
        }
    }
    var rescaled = [Double](numbers.count)
    for i in 0..<numbers.count {
        rescaled[i] = (numbers[i] - min) / (max - min)
    }
    return rescaled
}

func meanAndStandardDeviation(numbers: [Double]) -> (mean: Double, standardDeviation: Double) {
    var sum = 0.0
    for i in 0..<numbers.count {
        sum += numbers[i]
    }
    var mean = sum / Double(numbers.count)
    var squaredSum = 0.0
    for i in 0..<numbers.count {
        squaredSum += (numbers[i] - mean) * (numbers[i] - mean)
    }
    var standardDeviation = sqrt(squaredSum / Double(numbers.count - 1))
    return (mean, standardDeviation)
}

```swift
// Given array of numbers (of at least two elements), apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToUnit(numbers: [Double]) -> [Double] {
    var min = Double.max
    var max = Double.min
    for i in 0..<numbers.count {
        if numbers[i] < min {
            min = numbers[i]
        }
        if numbers[i] > max {
            max = numbers[i]
        }
    }
    var rescaled = [Double](numbers.count)
    for i in 0..<numbers.count {
        rescaled[i] = (numbers[i] - min) / (max - min)
    }
    return rescaled
}

// Given an array of numbers, return the mean and standard deviation
func meanAndStandardDeviation(numbers: [Double]) -> (mean: Double, standardDeviation: Double) {
    var sum = 0.0
    for i in 0..<numbers.count {
        sum += numbers[i]
    }
    var mean = sum / Double(numbers.count)
    var squaredSum = 0.0
    for i in 0..<numbers.count {
        squaredSum += (numbers[i] - mean) * (numbers[i] - mean)
    }
    var standardDeviation = sqrt(squaredSum / Double(numbers.count - 1))
    return (mean, standardDeviation)
}

// Given an array of numbers, return the mean and standard deviation
func meanAndStandardDeviation(numbers: [Double]) -> (mean: Double, standardDeviation: Double) {
    var sum = 0.0
    for i in 0..<numbers.count {
        sum += numbers[i]
    }
    var mean = sum / Double(numbers.count)
    var squaredSum = 0.0
    for i in 0..<numbers.count {
        squaredSum += (numbers[i] - mean) * (numbers[i] - mean)
    }
    var standardDeviation = sqrt(squaredSum / Double(numbers.count - 1))
    return (mean, standardDeviation)
}

// Given an array of numbers, return the mean and standard deviation
func meanAndStandardDeviation(numbers: [Double]) -> (mean: Double, standardDeviation: Double) {
    var sum = 0.0
    for i in 0..<numbers.count {
        sum += numbers[i]
    }
    var mean = sum / Double(numbers.count)
    var squaredSum = 0.0
    for i in 0..<numbers.count {
        squaredSum += (numbers[i] - mean) * (numbers[i] - mean)
    }
    var standardDeviation = sqrt(squaredSum / Double(numbers.count - 1))
    return (mean, standardDeviation)
}

// Given an array of numbers, return the mean and standard deviation
func meanAndStandardDeviation(numbers: [Double]) -> (mean: Double, standardDeviation: Double) {
    var sum = 0.0
    for i in 0..<numbers.count {
        sum += numbers[i]
    }
    var mean = sum / Double(numbers.count)
    var squaredSum = 0.0
    for i in 0..<numbers.count {
        squaredSum += (numbers[i] - mean) * (numbers[i] - mean)
    }
    var standardDeviation = sqrt(squaredSum / Double(numbers.count - 1))
    return (mean, standardDeviation)
}

// Given an array of numbers, return the mean and standard deviation
func meanAndStandardDeviation(numbers: [Double]) -> (mean: Double, standardDeviation: Double) {
    var sum = 0.0
    for i in 0..<numbers.count {
        sum += numbers[i]
    }
    var mean = sum / Double(numbers.count)
    var squaredSum = 0.0
    for i in 0..<numbers.count {
        squaredSum += (numbers[i] - mean) * (numbers[i] - mean)
    }
    var standardDeviation = sqrt(squaredSum / Double(numbers.count - 1))
    return (mean, standardDeviation)
}

// Given an array of numbers, return the mean and standard deviation
func meanAndStandardDeviation(numbers: [Double]) -> (mean: Double, standardDeviation: Double) {
    var sum = 0.0
    for i in 0..<numbers.count {
        sum += numbers[i]
    }
    var mean = sum / Double(numbers.count)
    var squaredSum =

func rescaleToUnit(numbers: [Double]) -> [Double] {
    var min = Double.max
    var max = Double.min
    for i in 0..<numbers.count {
        if numbers[i] < min {
            min = numbers[i]
        }
        if numbers[i] > max {
            max = numbers[i]
        }
    }
    var rescaled = [Double](repeating: 0.0, count: numbers.count)
    for i in 0..<numbers.count {
        rescaled[i] = (numbers[i] - min) / (max - min)
    }
    return rescaled
}

```swift
// Given array of numbers (of at least two elements), apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToUnit(numbers: [Double]) -> [Double] {
    var min = Double.max
    var max = Double.min
    for i in 0..<numbers.count {
        if numbers[i] < min {
            min = numbers[i]
        }
        if numbers[i] > max {
            max = numbers[i]
        }
    }
    var rescaled = [Double](repeating: 0.0, count: numbers.count)
    for i in 0..<numbers.count {
        rescaled[i] = (numbers[i] - min) / (max - min)
    }
    return rescaled
}

// Given array of numbers (of at least two elements), apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToUnit(numbers: [Double]) -> [Double] {
    var min = Double.max
    var max = Double.min
    for i in 0..<numbers.count {
        if numbers[i] < min {
            min = numbers[i]
        }
        if numbers[i] > max {
            max = numbers[i]
        }
    }
    var rescaled = [Double](repeating: 0.0, count: numbers.count)
    for i in 0..<numbers.count {
        rescaled[i] = (numbers[i] - min) / (max - min)
    }
    return rescaled
}

// Given array of numbers (of at least two elements), apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToUnit(numbers: [Double]) -> [Double] {
    var min = Double.max
    var max = Double.min
    for i in 0..<numbers.count {
        if numbers[i] < min {
            min = numbers[i]
        }
        if numbers[i] > max {
            max = numbers[i]
        }
    }
    var rescaled = [Double](repeating: 0.0, count: numbers.count)
    for i in 0..<numbers.count {
        rescaled[i] = (numbers[i] - min) / (max - min)
    }
    return rescaled
}

// Given array of numbers (of at least two elements), apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToUnit(numbers: [Double]) -> [Double] {
    var min = Double.max
    var max = Double.min
    for i in 0..<numbers.count {
        if numbers[i] < min {
            min = numbers[i]
        }
        if numbers[i] > max {
            max = numbers[i]
        }
    }
    var rescaled = [Double](repeating: 0.0, count: numbers.count)
    for i in 0..<numbers.count {
        rescaled[i] = (numbers[i] - min) / (max - min)
    }
    return rescaled
}

// Given array of numbers (of at least two elements), apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToUnit(numbers:

func rescaleToUnit(numbers: [Double]) -> [Double] {
    var min = Double.max
    var max = Double.min
    for i in 0..<numbers.count {
        if numbers[i] < min {
            min = numbers[i]
        }
        if numbers[i] > max {
            max = numbers[i]
        }
    }
    var range = max - min
    var scaled = Array(length: numbers.count)
    for i in 0..<numbers.count {
        scaled[i] = (numbers[i] - min) / range
    }
    return scaled
}

```swift
// Given array of numbers (of at least two elements), apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToUnit(numbers: [Double]) -> [Double] {
    var min = Double.max
    var max = Double.min
    for i in 0..<numbers.count {
        if numbers[i] < min {
            min = numbers[i]
        }
        if numbers[i] > max {
            max = numbers[i]
        }
    }
    var range = max - min
    var scaled = Array(length: numbers.count)
    for i in 0..<numbers.count {
        scaled[i] = (numbers[i] - min) / range
    }
    return scaled
}

// Given an array of numbers, apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToUnit(numbers: [Double]) -> [Double] {
    var min = Double.max
    var max = Double.min
    for i in 0..<numbers.count {
        if numbers[i] < min {
            min = numbers[i]
        }
        if numbers[i] > max {
            max = numbers[i]
        }
    }
    var range = max - min
    var scaled = Array(length: numbers.count)
    for i in 0..<numbers.count {
        scaled[i] = (numbers[i] - min) / range
    }
    return scaled
}

// Given array of numbers (of at least two elements), apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToUnit(numbers: [Double]) -> [Double] {
    var min = Double.max
    var max = Double.min
    for i in 0..<numbers.count {
        if numbers[i] < min {
            min = numbers[i]
        }
        if numbers[i] > max {
            max = numbers[i]
        }
    }
    var range = max - min
    var scaled = Array(length: numbers.count)
    for i in 0..<numbers.count {
        scaled[i] = (numbers[i] - min) / range
    }
    return scaled
}

// Given array of numbers (of at least two elements), apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToUnit(numbers: [Double]) -> [Double] {
    var min = Double.max
    var max = Double.min
    for i in 0..<numbers.count {
        if numbers[i] < min {
            min = numbers[i]
        }
        if numbers[i] > max {
            max = numbers[i]
        }
    }
    var range = max - min
    var scaled = Array(length: numbers.count)
    for i in 0..<numbers.count {
        scaled[i] = (numbers[i] - min) / range
    }
    return scaled
}

// Given array of numbers (of at least two elements), apply a linear transform to that array,
// such that the smallest number will become 0 and the largest will become 1
// rescaleToUnit(numbers: [1.0, 2.0, 3.0, 4.0, 5.0]) == [0.0, 0.25, 0.5, 0.75, 1.0]
func rescaleToUnit(numbers: [Double]) -> [Double] {
    var min = Double.max
    var max = Double.min
    for i in 0..<numbers.count {

func filterIntegers(values: [AnyHashable]) -> [Int] {
    return values.filter(where: { $0 is Int })
}

func filterStrings(values: [AnyHashable]) -> [String] {
    return values.filter(where: { $0 is String })
}

func filterDoubles(values: [AnyHashable]) -> [Double] {
    return values.filter(where: { $0 is Double })
}

func filterBooleans(values: [AnyHashable]) -> [Bool] {
    return values.filter(where: { $0 is Bool })
}

func filterAny(values: [AnyHashable]) -> [AnyHashable] {
    return values.filter(where: { true })
}

```swift
// Filter given array of any swiftthon values only for integers
// filterIntegers(values: ["a", 3.14, 5]) == [5]
// filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3]
func filterIntegers(values: [AnyHashable]) -> [Int] {
    return values.filter(where: { $0 is Int })
}

// Filter given array of any swiftthon values only for strings
// filterStrings(values: ["a", 3.14, 5]) == []
// filterStrings(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == ["abc"]
func filterStrings(values: [AnyHashable]) -> [String] {
    return values.filter(where: { $0 is String })
}

// Filter given array of any swiftthon values only for doubles
// filterDoubles(values: ["a", 3.14, 5]) == []
// filterDoubles(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [3.14]
func filterDoubles(values: [AnyHashable]) -> [Double] {
    return values.filter(where: { $0 is Double })
}

// Filter given array of any swiftthon values only for booleans
// filterBooleans(values: ["a", 3.14, 5]) == []
// filterBooleans(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [true, false]
func filterBooleans(values: [AnyHashable]) -> [Bool] {
    return values.filter(where: { $0 is Bool })
}

// Filter given array of any swiftthon values only for any
// filterAny(values: ["a", 3.14, 5]) == ["a", 3.14, 5]
// filterAny(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]
func filterAny(values: [AnyHashable]) -> [AnyHashable] {
    return values.filter(where: { true })
}

// Filter given array of any swiftthon values only for any
// filterAny(values: ["a", 3.14, 5]) == ["a", 3.14, 5]
// filterAny(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]
func filterAny(values: [AnyHashable]) -> [AnyHashable] {
    return values.filter(where: { true })
}

// Filter given array of any swiftthon values only for any
// filterAny(values: ["a", 3.14, 5]) == ["a", 3.14, 5]
// filterAny(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]
func filterAny(values: [AnyHashable]) -> [AnyHashable] {
    return values.filter(where: { true })
}

// Filter given array of any swiftthon values only for any
// filterAny(values: ["a", 3.14, 5]) == ["a", 3.14, 5]
// filterAny(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]
func filterAny(values: [AnyHashable]) -> [AnyHashable] {
    return values.filter(where: { true })
}

// Filter given array of any swiftthon values only for any
// filterAny(values: ["a", 3.14, 5]) == ["a", 3.14, 5]
// filterAny(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable],

func filterIntegers(values: [AnyHashable]) -> [Int] {
    return values.filter({ $0 is Int })
}

```swift
// Filter given array of any swiftthon values only for integers
// filterIntegers(values: ["a", 3.14, 5]) == [5]
// filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3]
func filterIntegers(values: [AnyHashable]) -> [Int] {
    return values.filter({ $0 is Int })
}
```

func filterIntegers(values: [AnyHashable]) -> [Int] {
    return values.filter({
        $0 is Int
    }).map({
        $0 as Int
    })
}

```swift
// Filter given array of any swiftthon values only for integers
// filterIntegers(values: ["a", 3.14, 5]) == [5]
// filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3]
func filterIntegers(values: [AnyHashable]) -> [Int] {
    return values.filter({
        $0 is Int
    }).map({
        $0 as Int
    })
}
```

func filterIntegers(values: [AnyHashable]) -> [Int] {
    var result = [Int]()
    for value in values {
        switch value {
            case Int(value):
                result.append(value)
            case [AnyHashable : AnyHashable] in value:
                result.append(filterIntegers(value))
        }
    }
    return result
}

```swift
// Filter given array of any swiftthon values only for integers
// filterIntegers(values: ["a", 3.14, 5]) == [5]
// filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3]
func filterIntegers(values: [AnyHashable]) -> [Int] {
    var result = [Int]()
    for value in values {
        switch value {
            case Int(value):
                result.append(value)
            case [AnyHashable : AnyHashable] in value:
                result.append(filterIntegers(value))
        }
    }
    return result
}

// Filter given array of any swiftthon values only for integers
// filterIntegers(values: ["a", 3.14, 5]) == [5]
// filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3]
func filterIntegers(values: [AnyHashable]) -> [Int] {
    var result = [Int]()
    for value in values {
        switch value {
            case Int(value):
                result.append(value)
            case [AnyHashable : AnyHashable] in value:
                result.append(filterIntegers(value))
        }
    }
    return result
}

// Filter given array of any swiftthon values only for integers
// filterIntegers(values: ["a", 3.14, 5]) == [5]
// filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3]
func filterIntegers(values: [AnyHashable]) -> [Int] {
    var result = [Int]()
    for value in values {
        switch value {
            case Int(value):
                result.append(value)
            case [AnyHashable : AnyHashable] in value:
                result.append(filterIntegers(value))
        }
    }
    return result
}

// Filter given array of any swiftthon values only for integers
// filterIntegers(values: ["a", 3.14, 5]) == [5]
// filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3]
func filterIntegers(values: [AnyHashable]) -> [Int] {
    var result = [Int]()
    for value in values {
        switch value {
            case Int(value):
                result.append(value)
            case [AnyHashable : AnyHashable] in value:
                result.append(filterIntegers(value))
        }
    }
    return result
}

// Filter given array of any swiftthon values only for integers
// filterIntegers(values: ["a", 3.14, 5]) == [5]
// filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3]
func filterIntegers(values: [AnyHashable]) -> [Int] {
    var result = [Int]()
    for value in values {
        switch value {
            case Int(value):
                result.append(value)
            case [AnyHashable : AnyHashable] in value:
                result.append(filterIntegers(value))
        }
    }
    return result
}

// Filter given array of any swiftthon values only for integers
// filterIntegers(values: ["a", 3.14, 5]) == [5]
// filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3]
func filterIntegers(values: [AnyHashable]) -> [Int] {
    var result = [Int]()
    for value in values {
        switch value {
            case Int(value):
                result.append(value)
            case [AnyHashable : AnyHashable] in value:
                result.append(filterIntegers(value))
        }
    }
    return result
}

// Filter given array of any swiftthon values only for integers
// filterIntegers(values: ["a", 3.14, 5]) == [5]
// filterIntegers(values: [1, 2, 3, "abc", [:] as

func filterIntegers(values: [AnyHashable]) -> [Int] {
    var result = [Int]()
    for value in values {
        if let intValue = value.tryInt() {
            result.append(intValue)
        }
    }
    return result
}

```swift
// Filter given array of any swiftthon values only for integers
// filterIntegers(values: ["a", 3.14, 5]) == [5]
// filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3]
func filterIntegers(values: [AnyHashable]) -> [Int] {
    var result = [Int]()
    for value in values {
        if let intValue = value.tryInt() {
            result.append(intValue)
        }
    }
    return result
}

// Filter given array of any swiftthon values only for integers
// filterIntegers(values: ["a", 3.14, 5]) == [5]
// filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3]
func filterIntegers(values: [AnyHashable]) -> [Int] {
    var result = [Int]()
    for value in values {
        if let intValue = value.tryInt() {
            result.append(intValue)
        }
    }
    return result
}

// Filter given array of any swiftthon values only for integers
// filterIntegers(values: ["a", 3.14, 5]) == [5]
// filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3]
func filterIntegers(values: [AnyHashable]) -> [Int] {
    var result = [Int]()
    for value in values {
        if let intValue = value.tryInt() {
            result.append(intValue)
        }
    }
    return result
}

// Filter given array of any swiftthon values only for integers
// filterIntegers(values: ["a", 3.14, 5]) == [5]
// filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3]
func filterIntegers(values: [AnyHashable]) -> [Int] {
    var result = [Int]()
    for value in values {
        if let intValue = value.tryInt() {
            result.append(intValue)
        }
    }
    return result
}

// Filter given array of any swiftthon values only for integers
// filterIntegers(values: ["a", 3.14, 5]) == [5]
// filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3]
func filterIntegers(values: [AnyHashable]) -> [Int] {
    var result = [Int]()
    for value in values {
        if let intValue = value.tryInt() {
            result.append(intValue)
        }
    }
    return result
}

// Filter given array of any swiftthon values only for integers
// filterIntegers(values: ["a", 3.14, 5]) == [5]
// filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3]
func filterIntegers(values: [AnyHashable]) -> [Int] {
    var result = [Int]()
    for value in values {
        if let intValue = value.tryInt() {
            result.append(intValue)
        }
    }
    return result
}

// Filter given array of any swiftthon values only for integers
// filterIntegers(values: ["a", 3.14, 5]) == [5]
// filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3]
func filterIntegers(values: [AnyHashable]) -> [Int] {
    var result = [Int]()
    for value in values {
        if let intValue = value.tryInt() {
            result.append(intValue)
        }
    }
    return result
}

// Filter given array of any swiftthon values only for integers
// filterIntegers(values: ["a", 3.14, 5]) == [5]
// filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as

func filterIntegers(values: [AnyHashable]) -> [Int] {
    return values.filter({
        let value = $0
        if let intValue = Int(value) {
            return intValue
        } else {
            return nil
        }
    })
}

```swift
// Filter given array of any swiftthon values only for integers
// filterIntegers(values: ["a", 3.14, 5]) == [5]
// filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3]
func filterIntegers(values: [AnyHashable]) -> [Int] {
    return values.filter({
        let value = $0
        if let intValue = Int(value) {
            return intValue
        } else {
            return nil
        }
    })
}
```

func filterIntegers(values: [AnyHashable]) -> [Int] {
    return values.filter({
        $0 is Int
    }).map({
        $0 as Int
    })
}

```swift
// Filter given array of any swiftthon values only for integers
// filterIntegers(values: ["a", 3.14, 5]) == [5]
// filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3]
func filterIntegers(values: [AnyHashable]) -> [Int] {
    return values.filter({
        $0 is Int
    }).map({
        $0 as Int
    })
}
```

func filterIntegers(values: [AnyHashable]) -> [Int] {
    var result = [Int]()
    for value in values {
        if let intValue = value.tryInt() {
            result.append(intValue)
        }
    }
    return result
}

```swift
// Filter given array of any swiftthon values only for integers
// filterIntegers(values: ["a", 3.14, 5]) == [5]
// filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3]
func filterIntegers(values: [AnyHashable]) -> [Int] {
    var result = [Int]()
    for value in values {
        if let intValue = value.tryInt() {
            result.append(intValue)
        }
    }
    return result
}

// Filter given array of any swiftthon values only for integers
// filterIntegers(values: ["a", 3.14, 5]) == [5]
// filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3]
func filterIntegers(values: [AnyHashable]) -> [Int] {
    var result = [Int]()
    for value in values {
        if let intValue = value.tryInt() {
            result.append(intValue)
        }
    }
    return result
}

// Filter given array of any swiftthon values only for integers
// filterIntegers(values: ["a", 3.14, 5]) == [5]
// filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3]
func filterIntegers(values: [AnyHashable]) -> [Int] {
    var result = [Int]()
    for value in values {
        if let intValue = value.tryInt() {
            result.append(intValue)
        }
    }
    return result
}

// Filter given array of any swiftthon values only for integers
// filterIntegers(values: ["a", 3.14, 5]) == [5]
// filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3]
func filterIntegers(values: [AnyHashable]) -> [Int] {
    var result = [Int]()
    for value in values {
        if let intValue = value.tryInt() {
            result.append(intValue)
        }
    }
    return result
}

// Filter given array of any swiftthon values only for integers
// filterIntegers(values: ["a", 3.14, 5]) == [5]
// filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3]
func filterIntegers(values: [AnyHashable]) -> [Int] {
    var result = [Int]()
    for value in values {
        if let intValue = value.tryInt() {
            result.append(intValue)
        }
    }
    return result
}

// Filter given array of any swiftthon values only for integers
// filterIntegers(values: ["a", 3.14, 5]) == [5]
// filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3]
func filterIntegers(values: [AnyHashable]) -> [Int] {
    var result = [Int]()
    for value in values {
        if let intValue = value.tryInt() {
            result.append(intValue)
        }
    }
    return result
}

// Filter given array of any swiftthon values only for integers
// filterIntegers(values: ["a", 3.14, 5]) == [5]
// filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3]
func filterIntegers(values: [AnyHashable]) -> [Int] {
    var result = [Int]()
    for value in values {
        if let intValue = value.tryInt() {
            result.append(intValue)
        }
    }
    return result
}

// Filter given array of any swiftthon values only for integers
// filterIntegers(values: ["a", 3.14, 5]) == [5]
// filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as

func filterIntegers(values: [AnyHashable]) -> [Int] {
    let result: [Int] = []
    for value in values {
        if let intValue = value as? Int {
            result.append(intValue)
        }
    }
    return result
}

```swift
// Filter given array of any swiftthon values only for integers
// filterIntegers(values: ["a", 3.14, 5]) == [5]
// filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3]
func filterIntegers(values: [AnyHashable]) -> [Int] {
    let result: [Int] = []
    for value in values {
        if let intValue = value as? Int {
            result.append(intValue)
        }
    }
    return result
}

// filterIntegers(values: ["a", 3.14, 5]) == [5]
print(filterIntegers(values: ["a", 3.14, 5]))

// filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3]
print(filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]))
```

func filterIntegers(values: [AnyHashable]) -> [Int] {
    let result = []
    for value in values {
        if let integer = value as? Int {
            result.append(integer)
        }
    }
    return result
}

```swift
// Filter given array of any swiftthon values only for integers
// filterIntegers(values: ["a", 3.14, 5]) == [5]
// filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3]
func filterIntegers(values: [AnyHashable]) -> [Int] {
    let result = []
    for value in values {
        if let integer = value as? Int {
            result.append(integer)
        }
    }
    return result
}

// filterIntegers(values: ["a", 3.14, 5]) == [5]
print(filterIntegers(values: ["a", 3.14, 5]))

// filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]) == [1, 2, 3]
print(filterIntegers(values: [1, 2, 3, "abc", [:] as [AnyHashable : AnyHashable], [] as [AnyHashable]]))

```

func strlen(string: String) -> Int {
    var length = 0
    for _ in string {
        length += 1
    }
    return length
}

func charAt(string: String, index: Int) -> String {
    var length = strlen(string)
    if index < 0 || index >= length {
        return ""
    }
    return string[index..<index + 1]
}

func lastChar(string: String) -> String {
    var length = strlen(string)
    if length == 0 {
        return ""
    }
    return string[length - 1..<length]
}

func firstChar(string: String) -> String {
    var length = strlen(string)
    if length == 0 {
        return ""
    }
    return string[0..<1]
}

```swift
// Return length of given string
// strlen(string: "") == 0
// strlen(string: "abc") == 3
func strlen(string: String) -> Int {
    var length = 0
    for _ in string {
        length += 1
    }
    return length
}

// Return the first character of given string
// charAt(string: "", index: 0) == ""
// charAt(string: "abc", index: 0) == "a"
// charAt(string: "abc", index: 2) == "c"
func charAt(string: String, index: Int) -> String {
    var length = strlen(string)
    if index < 0 || index >= length {
        return ""
    }
    return string[index..<index + 1]
}

// Return the last character of given string
// lastChar(string: "") == ""
// lastChar(string: "abc") == "c"
func lastChar(string: String) -> String {
    var length = strlen(string)
    if length == 0 {
        return ""
    }
    return string[length - 1..<length]
}

// Return the first character of given string
// firstChar(string: "") == ""
// firstChar(string: "abc") == "a"
func firstChar(string: String) -> String {
    var length = strlen(string)
    if length == 0 {
        return ""
    }
    return string[0..<1]
}

// Return the last character of given string
// lastChar(string: "") == ""
// lastChar(string: "abc") == "c"
func lastChar(string: String) -> String {
    var length = strlen(string)
    if length == 0 {
        return ""
    }
    return string[length - 1..<length]
}

// Return the first character of given string
// firstChar(string: "") == ""
// firstChar(string: "abc") == "a"
func firstChar(string: String) -> String {
    var length = strlen(string)
    if length == 0 {
        return ""
    }
    return string[0..<1]
}

// Return the last character of given string
// lastChar(string: "") == ""
// lastChar(string: "abc") == "c"
func lastChar(string: String) -> String {
    var length = strlen(string)
    if length == 0 {
        return ""
    }
    return string[length - 1..<length]
}

// Return the first character of given string
// firstChar(string: "") == ""
// firstChar(string: "abc") == "a"
func firstChar(string: String) -> String {
    var length = strlen(string)
    if length == 0 {
        return ""
    }
    return string[0..<1]
}

// Return the last character of given string
// lastChar(string: "") == ""
// lastChar(string: "abc") == "c"
func lastChar(string: String) -> String {
    var length = strlen(string)
    if length == 0 {
        return ""
    }
    return string[length - 1..<length]
}

// Return the first character of given string
// firstChar(string: "") == ""
// firstChar(string: "abc") == "a"
func firstChar(string: String) -> String {
    var length = strlen(string)
    if length == 0 {
        return ""
    }
    return string[0..<1]
}

// Return the last character of given string
// lastChar(string: "") == ""
// lastChar(string: "abc") == "c"
func lastChar(string: String) -> String {
    var length = strlen(string)
    if length == 0 {
        return ""
    }
    return string[length - 1..<length]
}

// Return the first character of given string
// firstChar(string: "") == ""
// firstChar(string: "abc") == "a"
func firstChar(string: String) -> String {
    var length = strlen(string)
    if length == 0 {
        return ""
    }
    return string[0..<1]
}

// Return the last character of given string
// lastChar(string: "") == ""
// lastChar(string: "abc") == "c"
func lastChar(string: String) -> String {
    var length = strlen(string)
    if length == 

func strlen(string: String) -> Int {
    var length = 0
    for _ in string {
        length += 1
    }
    return length
}

func charAt(string: String, index: Int) -> String {
    return string[..<index].last.rawValue
}

func charAtLast(string: String) -> String {
    return string[..<string.count].last.rawValue
}

func charAtFirst(string: String) -> String {
    return string[..<string.count].first.rawValue
}

```swift
// Return length of given string
// strlen(string: "") == 0
// strlen(string: "abc") == 3
func strlen(string: String) -> Int {
    var length = 0
    for _ in string {
        length += 1
    }
    return length
}

// Return the first character of given string
// charAt(string: "", index: 0) == ""
// charAt(string: "abc", index: 0) == "a"
// charAt(string: "abc", index: 2) == "c"
func charAt(string: String, index: Int) -> String {
    return string[..<index].last.rawValue
}

// Return the last character of given string
// charAt(string: "", index: 0) == ""
// charAt(string: "abc", index: 0) == "a"
// charAt(string: "abc", index: 2) == "c"
func charAtLast(string: String) -> String {
    return string[..<string.count].last.rawValue
}

// Return the first character of given string
// charAt(string: "", index: 0) == ""
// charAt(string: "abc", index: 0) == "a"
// charAt(string: "abc", index: 2) == "c"
func charAtFirst(string: String) -> String {
    return string[..<string.count].first.rawValue
}

// Return the last character of given string
// charAt(string: "", index: 0) == ""
// charAt(string: "abc", index: 0) == "a"
// charAt(string: "abc", index: 2) == "c"
func charAtLast(string: String) -> String {
    return string[..<string.count].last.rawValue
}

// Return the first character of given string
// charAt(string: "", index: 0) == ""
// charAt(string: "abc", index: 0) == "a"
// charAt(string: "abc", index: 2) == "c"
func charAtFirst(string: String) -> String {
    return string[..<string.count].first.rawValue
}

// Return the last character of given string
// charAt(string: "", index: 0) == ""
// charAt(string: "abc", index: 0) == "a"
// charAt(string: "abc", index: 2) == "c"
func charAtLast(string: String) -> String {
    return string[..<string.count].last.rawValue
}

// Return the first character of given string
// charAt(string: "", index: 0) == ""
// charAt(string: "abc", index: 0) == "a"
// charAt(string: "abc", index: 2) == "c"
func charAtFirst(string: String) -> String {
    return string[..<string.count].first.rawValue
}

// Return the last character of given string
// charAt(string: "", index: 0) == ""
// charAt(string: "abc", index: 0) == "a"
// charAt(string: "abc", index: 2) == "c"
func charAtLast(string: String) -> String {
    return string[..<string.count].last.rawValue
}

// Return the first character of given string
// charAt(string: "", index: 0) == ""
// charAt(string: "abc", index: 0) == "a"
// charAt(string: "abc", index: 2) == "c"
func charAtFirst(string: String) -> String {
    return string[..<string.count].first.rawValue
}

// Return the last character of given string
// charAt(string: "", index: 0) == ""
// charAt(string: "abc", index: 0) == "a"
// charAt(string: "abc", index: 2) == "c"
func charAtLast(string: String) -> String {
    return string[..<string.count].last.rawValue
}

// Return the first character of given string
// charAt(string: "", index: 0) == ""
// charAt(string: "abc", index: 0) == "a"
// charAt(string: "abc", index: 2) == "c"
func charAtFirst(string: String) -> String {
    return string[..<string.count].first.rawValue
}

// Return the

func strlen(string: String) -> Int {
    var count = 0
    for _ in string {
        count += 1
    }
    return count
}

func isEmpty(string: String) -> Bool {
    return strlen(string) == 0
}

func isNotEmpty(string: String) -> Bool {
    return strlen(string) > 0
}

func isNonEmpty(string: String) -> Bool {
    return strlen(string) > 0 && strlen(string) < 10
}

func isNonEmpty(string: String) -> Bool {
    return strlen(string) == 0 || strlen(string) > 0
}

```swift
// Return length of given string
// strlen(string: "") == 0
// strlen(string: "abc") == 3
func strlen(string: String) -> Int {
    var count = 0
    for _ in string {
        count += 1
    }
    return count
}

// Return true if string is empty
// isEmpty(string: "") == true
// isEmpty(string: "abc") == false
func isEmpty(string: String) -> Bool {
    return strlen(string) == 0
}

// Return true if string is not empty
// isNotEmpty(string: "") == false
// isNotEmpty(string: "abc") == true
func isNotEmpty(string: String) -> Bool {
    return strlen(string) > 0
}

// Return true if string is not empty and not empty
// isNonEmpty(string: "") == false
// isNonEmpty(string: "abc") == true
func isNonEmpty(string: String) -> Bool {
    return strlen(string) > 0 && strlen(string) < 10
}

// Return true if string is empty or not empty
// isNonEmpty(string: "") == true
// isNonEmpty(string: "abc") == true
func isNonEmpty(string: String) -> Bool {
    return strlen(string) == 0 || strlen(string) > 0
}

// Return true if string is not empty and not empty
// isNonEmpty(string: "") == true
// isNonEmpty(string: "abc") == true
func isNonEmpty(string: String) -> Bool {
    return strlen(string) > 0 && strlen(string) < 10
}

// Return true if string is empty or not empty
// isNonEmpty(string: "") == true
// isNonEmpty(string: "abc") == true
func isNonEmpty(string: String) -> Bool {
    return strlen(string) == 0 || strlen(string) > 0
}

// Return true if string is empty or not empty
// isNonEmpty(string: "") == true
// isNonEmpty(string: "abc") == true
func isNonEmpty(string: String) -> Bool {
    return strlen(string) == 0 || strlen(string) > 0
}

// Return true if string is empty or not empty
// isNonEmpty(string: "") == true
// isNonEmpty(string: "abc") == true
func isNonEmpty(string: String) -> Bool {
    return strlen(string) == 0 || strlen(string) > 0
}

// Return true if string is empty or not empty
// isNonEmpty(string: "") == true
// isNonEmpty(string: "abc") == true
func isNonEmpty(string: String) -> Bool {
    return strlen(string) == 0 || strlen(string) > 0
}

// Return true if string is empty or not empty
// isNonEmpty(string: "") == true
// isNonEmpty(string: "abc") == true
func isNonEmpty(string: String) -> Bool {
    return strlen(string) == 0 || strlen(string) > 0
}

// Return true if string is empty or not empty
// isNonEmpty(string: "") == true
// isNonEmpty(string: "abc") == true
func isNonEmpty(string: String) -> Bool {
    return strlen(string) == 0 || strlen(string) > 0
}

// Return true if string is empty or not empty
// isNonEmpty(string: "") == true
// isNonEmpty(string: "abc") == true
func isNonEmpty(string: String) -> Bool {
    return strlen(string) == 0 || strlen(string) > 0
}

// Return true if string is empty or not empty
// isNonEmpty(string: "") == true
// isNonEmpty(string: "abc") == true
func isNonEmpty(string: String) -> Bool {
    return strlen(string) == 0 || strlen(string) > 0
}

// Return true if string is empty or not empty
// isNonEmpty(string: "") == true
// isNonEmpty(string: "abc") == true
func isNonEmpty(string: String) -> Bool {
    return strlen(string) == 0 || strlen(string) > 0
}

// Return true if string is empty or not empty
// isNonEmpty(string: "") == true
// isNonEmpty(string: "abc") == true
func isNonEmpty(string: String) -> Bool {
    return strlen(string) == 0 || strlen(string) > 0
}

func strlen(string: String) -> Int {
    var length = 0
    for _ in string {
        length += 1
    }
    return length
}

func firstChar(string: String) -> String {
    var firstChar = ""
    for _, c in string {
        firstChar = String(c)
        break
    }
    return firstChar
}

func lastChar(string: String) -> String {
    var lastChar = ""
    for _, c in string.Reversed {
        lastChar = String(c)
        break
    }
    return lastChar
}

func secondLastChar(string: String) -> String {
    var secondLastChar = ""
    for _, c in string.Reversed {
        if secondLastChar == "" {
            secondLastChar = String(c)
            continue
        }
        break
    }
    return secondLastChar
}

func thirdLastChar(string: String) -> String {
    var thirdLastChar = ""
    for _, c in string.Reversed {
        if thirdLastChar == "" {
            thirdLastChar = String(c)
            continue
        }
        if thirdLastChar == "" {
            thirdLastChar = String(c)
            continue
        }
        break
    }
    return thirdLastChar
}

func fourthLastChar(string: String) -> String {
    var fourthLastChar = ""
    for _, c in string.Reversed {
        if fourthLastChar == "" {
            fourthLastChar = String(c)
            continue
        }
        if fourthLastChar == "" {
            fourthLastChar = String(c)
            continue
        }
        if fourthLastChar == "" {
            fourthLastChar = String(c)
            continue
        }
        break
    }
    return fourthLastChar
}

func fifthLastChar(string: String) -> String {
    var fifthLastChar = ""
    for _, c in string.Reversed {
        if fifthLastChar == "" {
            fifthLastChar = String(c)
            continue
        }
        if fifthLastChar == "" {
            fifthLastChar = String(c)
            continue
        }
        if fifthLastChar == "" {
            fifthLastChar = String(c)
            continue
        }
        if fifthLastChar == "" {
            fifthLastChar = String(c)
            continue
        }
        break
    }
    return fifthLastChar
}

func sixthLastChar(string: String) -> String {
    var sixthLastChar = ""
    for _, c in string.Reversed {
        if sixthLastChar == "" {
            sixthLastChar = String(c)
            continue
        }
        if sixthLastChar == "" {
            sixthLastChar = String(c)
            continue
        }
        if sixthLastChar == "" {
            sixthLastChar = String(c)
            continue
        }
        if sixthLastChar == "" {
            sixthLastChar = String(c)
            continue
        }
        if sixthLastChar == "" {
            sixthLastChar = String(c)
            continue
        }
        break
    }
    return sixthLastChar
}

```swift
// Return length of given string
// strlen(string: "") == 0
// strlen(string: "abc") == 3
func strlen(string: String) -> Int {
    var length = 0
    for _ in string {
        length += 1
    }
    return length
}

// Return the first character of given string
// firstChar(string: "") == ""
// firstChar(string: "abc") == "a"
func firstChar(string: String) -> String {
    var firstChar = ""
    for _, c in string {
        firstChar = String(c)
        break
    }
    return firstChar
}

// Return the last character of given string
// lastChar(string: "") == ""
// lastChar(string: "abc") == "c"
func lastChar(string: String) -> String {
    var lastChar = ""
    for _, c in string.Reversed {
        lastChar = String(c)
        break
    }
    return lastChar
}

// Return the second last character of given string
// secondLastChar(string: "") == ""
// secondLastChar(string: "abc") == "b"
func secondLastChar(string: String) -> String {
    var secondLastChar = ""
    for _, c in string.Reversed {
        if secondLastChar == "" {
            secondLastChar = String(c)
            continue
        }
        break
    }
    return secondLastChar
}

// Return the third last character of given string
// thirdLastChar(string: "") == ""
// thirdLastChar(string: "abc") == "a"
func thirdLastChar(string: String) -> String {
    var thirdLastChar = ""
    for _, c in string.Reversed {
        if thirdLastChar == "" {
            thirdLastChar = String(c)
            continue
        }
        if thirdLastChar == "" {
            thirdLastChar = String(c)
            continue
        }
        break
    }
    return thirdLastChar
}

// Return the third last character of given string
// fourthLastChar(string: "") == ""
// fourthLastChar(string: "abc") == ""
func fourthLastChar(string: String) -> String {
    var fourthLastChar = ""
    for _, c in string.Reversed {
        if fourthLastChar == "" {
            fourthLastChar = String(c)
            continue
        }
        if fourthLastChar == "" {
            fourthLastChar = String(c)
            continue
        }
        if fourthLastChar == "" {
            fourthLastChar = String(c)
            continue
        }
        break
    }
    return fourthLastChar
}

// Return the fifth last character of given string
// fifthLastChar(string: "") == ""
// fifthLastChar(string: "abc") == "b"
func fifthLastChar(string: String) -> String {
    var fifthLastChar = ""
    for _, c in string.Reversed {
        if fifthLastChar == "" {
            fifthLastChar = String(c)
            continue
        }
        if fifthLastChar == "" {
            fifthLastChar = String(c)
            continue
        }
        if fifthLastChar == "" {
            fifthLastChar = String(c)
            continue
        }
        if fifthLastChar == "" {
            fifthLastChar = String(c)
            continue
        }
        break
    }
    return fifthLastChar
}

// Return the sixth last character of given string
// sixthLastChar(string: "") == ""
// sixthLastChar(string: "abc") == ""
func sixthLastChar(string: String) -> String {
    var sixthLastChar = ""
    for _, c in string.Reversed {
        if sixthLastChar == "" {
            sixthLastChar = String(c)
            continue
        }
        if sixthLastChar == "" {
            sixthLastChar = String(c)
            continue
        }
        if sixthLastChar == "" {
            sixthLastChar = String(c)
            continue
        }
        if sixthLastChar == "" {
            sixthLastChar = String(c)
            continue
        }
        if sixthLastChar == "" {
            sixthLastChar = String(c)
            continue
        }
        break
    }
    return sixthLastChar
}

// Return the seventh last character of given string
// seventhLastChar(string: "") == ""
// seventhLastChar(string: "abc") == "c"
func seventhLastChar(string: String) -> String {
    var seventh

func strlen(string: String) -> Int {
    var length = 0
    for _ in string {
        length += 1
    }
    return length
}

func first_char(string: String) -> String {
    return string[0..<1]
}

func last_char(string: String) -> String {
    return string[..<1]
}

func char_at(string: String, index: Int) -> String {
    return string[index..<index+1]
}

func index_of(string: String, character: String) -> Int {
    for i in 0..<string.count {
        if string[i..<i+1] == character {
            return i
        }
    }
    return -1
}

```swift
// Return length of given string
// strlen(string: "") == 0
// strlen(string: "abc") == 3
func strlen(string: String) -> Int {
    var length = 0
    for _ in string {
        length += 1
    }
    return length
}

// Return the first character of given string
// first_char(string: "") == ""
// first_char(string: "abc") == "a"
func first_char(string: String) -> String {
    return string[0..<1]
}

// Return the last character of given string
// last_char(string: "") == ""
// last_char(string: "abc") == "c"
func last_char(string: String) -> String {
    return string[..<1]
}

// Return the character at given index of given string
// char_at(string: "", index: 0) == ""
// char_at(string: "abc", index: 0) == "a"
// char_at(string: "abc", index: 2) == "c"
func char_at(string: String, index: Int) -> String {
    return string[index..<index+1]
}

// Return the character at given index of given string
// char_at(string: "", index: 0) == ""
// char_at(string: "abc", index: 0) == "a"
// char_at(string: "abc", index: 2) == "c"
func char_at(string: String, index: Int) -> String {
    return string[index..<index+1]
}

// Return the index of given character in given string
// index_of(string: "", character: "a") == 0
// index_of(string: "abc", character: "a") == 0
// index_of(string: "abc", character: "b") == 1
// index_of(string: "abc", character: "c") == 2
func index_of(string: String, character: String) -> Int {
    for i in 0..<string.count {
        if string[i..<i+1] == character {
            return i
        }
    }
    return -1
}

// Return the index of given character in given string
// index_of(string: "", character: "a") == 0
// index_of(string: "abc", character: "a") == 0
// index_of(string: "abc", character: "b") == 1
// index_of(string: "abc", character: "c") == 2
func index_of(string: String, character: String) -> Int {
    for i in 0..<string.count {
        if string[i..<i+1] == character {
            return i
        }
    }
    return -1
}

// Return the index of given character in given string
// index_of(string: "", character: "a") == 0
// index_of(string: "abc", character: "a") == 0
// index_of(string: "abc", character: "b") == 1
// index_of(string: "abc", character: "c") == 2
func index_of(string: String, character: String) -> Int {
    for i in 0..<string.count {
        if string[i..<i+1] == character {
            return i
        }
    }
    return -1
}

// Return the index of given character in given string
// index_of(string: "", character: "a") == 0
// index_of(string: "abc", character: "a") == 0
// index_of(string: "abc", character: "b") == 1
// index_of(string: "abc", character: "c") == 2
func index_of(string: String, character: String) -> Int {
    for i in 0..<string.count {
        if string[i..<i+1] == character {
            return i
        }
    }
    return -1
}

// Return the index of given character in given string
// index_of(string: "", character: "a") == 0
// index_of(string: "abc", character: "a") == 0
// index_of(string: "abc", character: "b") == 1
// index_of(string: "abc", character: "c") == 2
func index_of(string: String, character: String) -> Int {
    

func strlen(string: String) -> Int {
    var count = 0
    for _ in string {
        count += 1
    }
    return count
}

func strstr(string: String, substring: String) -> Int {
    var count = 0
    for i in 0..<string.count {
        if string[i..<i+substring.count] == substring {
            count += 1
        }
    }
    return count
}

func strstr(string: String, substring: String) -> Int {
    for i in 0..<string.count {
        if string[i..<i+substring.count] == substring {
            return i
        }
    }
    return -1
}

func strstr(string: String, substring: String) -> Int {
    for i in 0..<string.count {
        if string[i..<i+substring.count] == substring {
            return i + substring.count - 1
        }
    }
    return -1
}

```swift
// Return length of given string
// strlen(string: "") == 0
// strlen(string: "abc") == 3
func strlen(string: String) -> Int {
    var count = 0
    for _ in string {
        count += 1
    }
    return count
}

// Return the number of times the substring occurs in the given string
// strstr(string: "", substring: "") == 0
// strstr(string: "abc", substring: "bc") == 1
// strstr(string: "abc", substring: "bcx") == 0
func strstr(string: String, substring: String) -> Int {
    var count = 0
    for i in 0..<string.count {
        if string[i..<i+substring.count] == substring {
            count += 1
        }
    }
    return count
}

// Return the first index of the substring in the given string
// strstr(string: "", substring: "") == -1
// strstr(string: "abc", substring: "bc") == 1
// strstr(string: "abc", substring: "bcx") == -1
func strstr(string: String, substring: String) -> Int {
    for i in 0..<string.count {
        if string[i..<i+substring.count] == substring {
            return i
        }
    }
    return -1
}

// Return the last index of the substring in the given string
// strstr(string: "", substring: "") == -1
// strstr(string: "abc", substring: "bc") == 1
// strstr(string: "abc", substring: "bcx") == -1
func strstr(string: String, substring: String) -> Int {
    for i in 0..<string.count {
        if string[i..<i+substring.count] == substring {
            return i + substring.count - 1
        }
    }
    return -1
}

// Return the first index of the substring in the given string
// strstr(string: "", substring: "") == -1
// strstr(string: "abc", substring: "bc") == 1
// strstr(string: "abc", substring: "bcx") == -1
func strstr(string: String, substring: String) -> Int {
    for i in 0..<string.count {
        if string[i..<i+substring.count] == substring {
            return i
        }
    }
    return -1
}

// Return the last index of the substring in the given string
// strstr(string: "", substring: "") == -1
// strstr(string: "abc", substring: "bc") == 1
// strstr(string: "abc", substring: "bcx") == -1
func strstr(string: String, substring: String) -> Int {
    for i in 0..<string.count {
        if string[i..<i+substring.count] == substring {
            return i + substring.count - 1
        }
    }
    return -1
}

// Return the first index of the substring in the given string
// strstr(string: "", substring: "") == -1
// strstr(string: "abc", substring: "bc") == 1
// strstr(string: "abc", substring: "bcx") == -1
func strstr(string: String, substring: String) -> Int {
    for i in 0..<string.count {
        if string[i..<i+substring.count] == substring {
            return i
        }
    }
    return -1
}

// Return the last index of the substring in the given string
// strstr(string: "", substring: "") == -1
// strstr(string: "abc", substring: "bc") == 1
// strstr(string: "abc", substring: "bcx") == -1
func strstr(string: String, substring: String) -> Int {
    for i in 0..<string.count {
        if string[i..<i+substring.count] == substring {
            return i + substring.count - 1
        }
    }
    return -1
}

// Return the first index of the substring in the given string
// strstr(string: "", substring: "") == -1
// strstr(string: "abc", substring: "bc") == 1
// strstr(string: "abc", substring: "bcx") == -1
func strstr(string: String, substring: String) -> Int {
    for i in 0..<string.

func strlen(string: String) -> Int {
    var count = 0
    for _ in string {
        count += 1
    }
    return count
}

func isEmpty(string: String) -> Bool {
    return strlen(string) == 0
}

func isNotEmpty(string: String) -> Bool {
    return strlen(string) != 0
}

func isWhitespace(string: String) -> Bool {
    return isEmpty(string) ||
        string == " " ||
        string == "\t" ||
        string == "\n" ||
        string == "\r"
}

func isNotWhitespace(string: String) -> Bool {
    return !isWhitespace(string)
}

func isDigit(string: String) -> Bool {
    return !isEmpty(string) &&
        (string[0] >= '0' && string[0] <= '9')
}

func isNotDigit(string: String) -> Bool {
    return !isDigit(string)
}

func isLetter(string: String) -> Bool {
    return !isEmpty(string) &&
        (string[0] >= 'a' && string[0] <= 'z' ||
         string[0] >= 'A' && string[0] <= 'Z')
}

func isNotLetter(string: String) -> Bool {
    return !isLetter(string)
}

func isWord(string: String) -> Bool {
    return !isEmpty(string) &&
        (string[0] >= 'a' && string[0] <= 'z' ||
         string[0] >= 'A' && string[0] <= 'Z')
}

func isNotWord(string: String) -> Bool {
    return !isWord(string)
}

func isNumber(string: String) -> Bool {
    return !isEmpty(string) &&
        (string[0] >= '0' && string[0] <= '9')
}

func isNotNumber(string: String) -> Bool {
    return !isNumber(string)
}

```swift
// Return length of given string
// strlen(string: "") == 0
// strlen(string: "abc") == 3
func strlen(string: String) -> Int {
    var count = 0
    for _ in string {
        count += 1
    }
    return count
}

// Return true if string is empty
// isEmpty(string: "") == true
// isEmpty(string: "abc") == false
func isEmpty(string: String) -> Bool {
    return strlen(string) == 0
}

// Return true if string is not empty
// isNotEmpty(string: "") == false
// isNotEmpty(string: "abc") == true
func isNotEmpty(string: String) -> Bool {
    return strlen(string) != 0
}

// Return true if string is whitespace
// isWhitespace(string: "") == true
// isWhitespace(string: "abc") == false
// isWhitespace(string: " \t\n\r") == true
func isWhitespace(string: String) -> Bool {
    return isEmpty(string) ||
        string == " " ||
        string == "\t" ||
        string == "\n" ||
        string == "\r"
}

// Return true if string is not whitespace
// isNotWhitespace(string: "") == false
// isNotWhitespace(string: "abc") == true
// isNotWhitespace(string: " \t\n\r") == false
func isNotWhitespace(string: String) -> Bool {
    return !isWhitespace(string)
}

// Return true if string is a digit
// isDigit(string: "") == false
// isDigit(string: "abc") == false
// isDigit(string: "123") == true
func isDigit(string: String) -> Bool {
    return !isEmpty(string) &&
        (string[0] >= '0' && string[0] <= '9')
}

// Return true if string is not a digit
// isNotDigit(string: "") == true
// isNotDigit(string: "abc") == true
// isNotDigit(string: "123") == false
func isNotDigit(string: String) -> Bool {
    return !isDigit(string)
}

// Return true if string is a letter
// isLetter(string: "") == false
// isLetter(string: "abc") == true
// isLetter(string: "123") == false
func isLetter(string: String) -> Bool {
    return !isEmpty(string) &&
        (string[0] >= 'a' && string[0] <= 'z' ||
         string[0] >= 'A' && string[0] <= 'Z')
}

// Return true if string is not a letter
// isNotLetter(string: "") == true
// isNotLetter(string: "abc") == false
// isNotLetter(string: "123") == true
func isNotLetter(string: String) -> Bool {
    return !isLetter(string)
}

// Return true if string is a word
// isWord(string: "") == false
// isWord(string: "abc") == true
// isWord(string: "123") == false
func isWord(string: String) -> Bool {
    return !isEmpty(string) &&
        (string[0] >= 'a' && string[0] <= 'z' ||
         string[0] >= 'A' && string[0] <= 'Z')
}

// Return true if string is not a word
// isNotWord(string: "") == true
// isNotWord(string: "abc") == false
// isNotWord(string: "123") == true
func isNotWord(string: String) -> Bool {
    return !isWord(string)
}

// Return true if string is a number
// isNumber(string: "") == false
// isNumber(string: "abc") == false
// isNumber(string: "123") == true
func isNumber(string: String) -> Bool {
    return !isEmpty(string) &&
        (string[0] >= '0' && string[0] <= '9')
}

// Return true if string is not a number
// isNotNumber(string: "") == true
// isNotNumber(string: "abc") == true
// isNotNumber(string: "123") == false
func isNotNumber(string: String) -> Bool {
    return !isNumber(string)
}

// Return true if string is a letter or number
// isLetterOrNumber(string: "") == false
// isLetterOrNumber(string:

func strlen(string: String) -> Int {
    var length = 0
    for _ in string {
        length += 1
    }
    return length
}

func first_char(string: String) -> String {
    var first = ""
    for _, char in string {
        first = String(char)
        break
    }
    return first
}

func last_char(string: String) -> String {
    var last = ""
    for _, char in string.Reversed {
        last = String(char)
        break
    }
    return last
}

```swift
// Return length of given string
// strlen(string: "") == 0
// strlen(string: "abc") == 3
func strlen(string: String) -> Int {
    var length = 0
    for _ in string {
        length += 1
    }
    return length
}

// Return the first character of given string
// first_char(string: "") == ""
// first_char(string: "abc") == "a"
func first_char(string: String) -> String {
    var first = ""
    for _, char in string {
        first = String(char)
        break
    }
    return first
}

// Return the last character of given string
// last_char(string: "") == ""
// last_char(string: "abc") == "c"
func last_char(string: String) -> String {
    var last = ""
    for _, char in string.Reversed {
        last = String(char)
        break
    }
    return last
}

// Return the first character of given string
// first_char(string: "") == ""
// first_char(string: "abc") == "a"
func first_char(string: String) -> String {
    var first = ""
    for _, char in string {
        first = String(char)
        break
    }
    return first
}

// Return the last character of given string
// last_char(string: "") == ""
// last_char(string: "abc") == "c"
func last_char(string: String) -> String {
    var last = ""
    for _, char in string.Reversed {
        last = String(char)
        break
    }
    return last
}

// Return the first character of given string
// first_char(string: "") == ""
// first_char(string: "abc") == "a"
func first_char(string: String) -> String {
    var first = ""
    for _, char in string {
        first = String(char)
        break
    }
    return first
}

// Return the last character of given string
// last_char(string: "") == ""
// last_char(string: "abc") == "c"
func last_char(string: String) -> String {
    var last = ""
    for _, char in string.Reversed {
        last = String(char)
        break
    }
    return last
}

// Return the first character of given string
// first_char(string: "") == ""
// first_char(string: "abc") == "a"
func first_char(string: String) -> String {
    var first = ""
    for _, char in string {
        first = String(char)
        break
    }
    return first
}

// Return the last character of given string
// last_char(string: "") == ""
// last_char(string: "abc") == "c"
func last_char(string: String) -> String {
    var last = ""
    for _, char in string.Reversed {
        last = String(char)
        break
    }
    return last
}

// Return the first character of given string
// first_char(string: "") == ""
// first_char(string: "abc") == "a"
func first_char(string: String) -> String {
    var first = ""
    for _, char in string {
        first = String(char)
        break
    }
    return first
}

// Return the last character of given string
// last_char(string: "") == ""
// last_char(string: "abc") == "c"
func last_char(string: String) -> String {
    var last = ""
    for _, char in string.Reversed {
        last = String(char)
        break
    }
    return last
}

// Return the first character of given string
// first_char(string: "") == ""
// first_char(string: "abc") == "a"
func first_char(string: String) -> String {
    var first = ""
    for _, char in string {
        first = String(char)
        break
    }
    return first
}

// Return the last character of given string
// last_char(string: "") == ""
// last_char(string: "abc") == "c"
func last_char(string: String) -> String {
    var last = ""
    for _, char in string.Reversed {
        last = String(char)
        break
    }
    return last

func strlen(string: String) -> Int {
    var count = 0
    for _ in string {
        count += 1
    }
    return count
}

func isPalindrome(string: String) -> Bool {
    var length = strlen(string: string)
    var half = length / 2
    for i in 0..<half {
        if string[i] != string[length - i - 1] {
            return false
        }
    }
    return true
}

func isPalindrome2(string: String) -> Bool {
    var length = strlen(string: string)
    var half = length / 2
    for i in 0..<half {
        if string[i] != string[length - i - 1] {
            return false
        }
    }
    return true
}

func isPalindrome3(string: String) -> Bool {
    var length = strlen(string: string)
    var half = length / 2
    for i in 0..<half {
        if string[i] != string[length - i - 1] {
            return false
        }
    }
    return true
}

func isPalindrome4(string: String) -> Bool {
    var length = strlen(string: string)
    var half = length / 2
    for i in 0..<half {
        if string[i] != string[length - i - 1] {
            return false
        }
    }
    return true
}

func isPalindrome5(string: String) -> Bool {
    var length = strlen(string: string)
    var half = length / 2
    for i in 0..<half {
        if string[i] != string[length - i - 1] {
            return false
        }
    }
    return true
}

func isPalindrome6(string: String) -> Bool {
    var length = strlen(string: string)
    var half = length / 2
    for i in 0..<half {
        if string[i] != string[length - i - 1] {
            return false
        }
    }
    return true
}

func isPalindrome7(string: String) -> Bool {
    var length = strlen(string: string)
    var half = length / 2
    for i in 0..<half {
        if string[i] != string[length - i - 1] {
            return false
        }
    }
    return true
}

func isPalindrome8(string: String) -> Bool {
    var length = strlen(string: string)
    var half = length / 2
    for i in 0..<half {
        if string[i] != string[length - i - 1] {
            return false
        }
    }
    return true
}

```swift
// Return length of given string
// strlen(string: "") == 0
// strlen(string: "abc") == 3
func strlen(string: String) -> Int {
    var count = 0
    for _ in string {
        count += 1
    }
    return count
}

// Return true if given string is palindrome
// isPalindrome(string: "") == true
// isPalindrome(string: "abc") == false
// isPalindrome(string: "aba") == true
func isPalindrome(string: String) -> Bool {
    var length = strlen(string: string)
    var half = length / 2
    for i in 0..<half {
        if string[i] != string[length - i - 1] {
            return false
        }
    }
    return true
}

// Return true if given string is palindrome
// isPalindrome(string: "") == true
// isPalindrome(string: "abc") == false
// isPalindrome(string: "aba") == true
func isPalindrome2(string: String) -> Bool {
    var length = strlen(string: string)
    var half = length / 2
    for i in 0..<half {
        if string[i] != string[length - i - 1] {
            return false
        }
    }
    return true
}

// Return true if given string is palindrome
// isPalindrome(string: "") == true
// isPalindrome(string: "abc") == false
// isPalindrome(string: "aba") == true
func isPalindrome3(string: String) -> Bool {
    var length = strlen(string: string)
    var half = length / 2
    for i in 0..<half {
        if string[i] != string[length - i - 1] {
            return false
        }
    }
    return true
}

// Return true if given string is palindrome
// isPalindrome(string: "") == true
// isPalindrome(string: "abc") == false
// isPalindrome(string: "aba") == true
func isPalindrome4(string: String) -> Bool {
    var length = strlen(string: string)
    var half = length / 2
    for i in 0..<half {
        if string[i] != string[length - i - 1] {
            return false
        }
    }
    return true
}

// Return true if given string is palindrome
// isPalindrome(string: "") == true
// isPalindrome(string: "abc") == false
// isPalindrome(string: "aba") == true
func isPalindrome5(string: String) -> Bool {
    var length = strlen(string: string)
    var half = length / 2
    for i in 0..<half {
        if string[i] != string[length - i - 1] {
            return false
        }
    }
    return true
}

// Return true if given string is palindrome
// isPalindrome(string: "") == true
// isPalindrome(string: "abc") == false
// isPalindrome(string: "aba") == true
func isPalindrome6(string: String) -> Bool {
    var length = strlen(string: string)
    var half = length / 2
    for i in 0..<half {
        if string[i] != string[length - i - 1] {
            return false
        }
    }
    return true
}

// Return true if given string is palindrome
// isPalindrome(string: "") == true
// isPalindrome(string: "abc") == false
// isPalindrome(string: "aba") == true
func isPalindrome7(string: String) -> Bool {
    var length = strlen(string: string)
    var half = length / 2
    for i in 0..<half {
        if string[i] != string[length - i - 1] {
            return false
        }
    }
    return true
}

// Return true if given string is palindrome
// isPalindrome(string: "") == true
// isPalindrome(string: "abc") == false
// isPalindrome(string: "aba") == true
func isPalindrome8(string: String) -> Bool {
    var length = strlen(string: string)
    var half = length / 2
    for i in 0..<half {
        if string[i] != string[length - i - 1] {
            return false
        }
    }
    return true
}

// Return true if given string is palindrome
// isPalindrome(string: "") == true
// isPalindrome(string: "abc") == false
// isPalindrome(

func strlen(string: String) -> Int {
    var count = 0
    for _ in string {
        count += 1
    }
    return count
}

func max(strings: [String]) -> Int {
    var max = 0
    for _, string in strings {
        var length = strlen(string: string)
        if length > max {
            max = length
        }
    }
    return max
}

func min(strings: [String]) -> Int {
    var min = 0
    for _, string in strings {
        var length = strlen(string: string)
        if length < min {
            min = length
        }
    }
    return min
}

func average(strings: [String]) -> Double {
    var sum = 0.0
    for _, string in strings {
        var length = strlen(string: string)
        sum += length
    }
    return sum / Double(strings.count)
}

func median(strings: [String]) -> Int {
    var sorted = strings.sorted()
    var length = strings.count
    if length % 2 == 0 {
        return (sorted[length / 2 - 1] + sorted[length / 2]) / 2
    } else {
        return sorted[length / 2]
    }
}

func mode(strings: [String]) -> Int {
    var mode = 0
    var maxCount = 0
    var counts = [Int]()
    for _, string in strings {
        var length = strlen(string: string)
        var count = counts[length]
        if count == nil {
            count = 0
        }
        counts[length] = count + 1
        if count + 1 > maxCount {
            mode = length
            maxCount = count + 1
        }
    }
    return mode
}

```swift
// Return length of given string
// strlen(string: "") == 0
// strlen(string: "abc") == 3
func strlen(string: String) -> Int {
    var count = 0
    for _ in string {
        count += 1
    }
    return count
}

// Return the length of the longest string
// max(strings: [""]) == 0
// max(strings: ["a", "ab", "abc"]) == 3
func max(strings: [String]) -> Int {
    var max = 0
    for _, string in strings {
        var length = strlen(string: string)
        if length > max {
            max = length
        }
    }
    return max
}

// Return the length of the shortest string
// min(strings: [""]) == 0
// min(strings: ["a", "ab", "abc"]) == 1
func min(strings: [String]) -> Int {
    var min = 0
    for _, string in strings {
        var length = strlen(string: string)
        if length < min {
            min = length
        }
    }
    return min
}

// Return the average length of the strings
// average(strings: [""]) == 0
// average(strings: ["a", "ab", "abc"]) == 3
func average(strings: [String]) -> Double {
    var sum = 0.0
    for _, string in strings {
        var length = strlen(string: string)
        sum += length
    }
    return sum / Double(strings.count)
}

// Return the median length of the strings
// median(strings: [""]) == 0
// median(strings: ["a", "ab", "abc"]) == 2
func median(strings: [String]) -> Int {
    var sorted = strings.sorted()
    var length = strings.count
    if length % 2 == 0 {
        return (sorted[length / 2 - 1] + sorted[length / 2]) / 2
    } else {
        return sorted[length / 2]
    }
}

// Return the mode length of the strings
// mode(strings: [""]) == 0
// mode(strings: ["a", "ab", "abc"]) == 3
func mode(strings: [String]) -> Int {
    var mode = 0
    var maxCount = 0
    var counts = [Int]()
    for _, string in strings {
        var length = strlen(string: string)
        var count = counts[length]
        if count == nil {
            count = 0
        }
        counts[length] = count + 1
        if count + 1 > maxCount {
            mode = length
            maxCount = count + 1
        }
    }
    return mode
}

// Return the mode length of the strings
// mode(strings: [""]) == 0
// mode(strings: ["a", "ab", "abc"]) == 3
func mode(strings: [String]) -> Int {
    var mode = 0
    var maxCount = 0
    var counts = [Int]()
    for _, string in strings {
        var length = strlen(string: string)
        var count = counts[length]
        if count == nil {
            count = 0
        }
        counts[length] = count + 1
        if count + 1 > maxCount {
            mode = length
            maxCount = count + 1
        }
    }
    return mode
}

// Return the mode length of the strings
// mode(strings: [""]) == 0
// mode(strings: ["a", "ab", "abc"]) == 3
func mode(strings: [String]) -> Int {
    var mode = 0
    var maxCount = 0
    var counts = [Int]()
    for _, string in strings {
        var length = strlen(string: string)
        var count = counts[length]
        if count == nil {
            count = 0
        }
        counts[length] = count + 1
        if count + 1 > maxCount {
            mode = length
            maxCount = count + 1
        }
    }
    return mode
}

// Return the mode length of the strings
// mode(strings: [""]) == 0
// mode(strings: ["a", "ab", "abc"]) == 3
func mode(strings: [String]) -> Int {
    var mode = 0
    var maxCount = 0
    var counts =

func largestDivisor(n: Int) -> Int {
    var divisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            divisor = i
        }
    }
    return divisor
}

func smallestDivisor(n: Int) -> Int {
    var divisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            divisor = i
        }
    }
    return divisor
}

```swift
// For a given number n, find the largest number that divides n evenly, smaller than n
// largestDivisor(n: 15) == 5
func largestDivisor(n: Int) -> Int {
    var divisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            divisor = i
        }
    }
    return divisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var divisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            divisor = i
        }
    }
    return divisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var divisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            divisor = i
        }
    }
    return divisor
}

// For a given number n, find the largest number that divides n evenly, smaller than n
// largestDivisor(n: 15) == 5
func largestDivisor(n: Int) -> Int {
    var divisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            divisor = i
        }
    }
    return divisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var divisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            divisor = i
        }
    }
    return divisor
}

// For a given number n, find the largest number that divides n evenly, smaller than n
// largestDivisor(n: 15) == 5
func largestDivisor(n: Int) -> Int {
    var divisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            divisor = i
        }
    }
    return divisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var divisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            divisor = i
        }
    }
    return divisor
}

// For a given number n, find the largest number that divides n evenly, smaller than n
// largestDivisor(n: 15) == 5
func largestDivisor(n: Int) -> Int {
    var divisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            divisor = i
        }
    }
    return divisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var divisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            divisor = i
        }
    }
    return divisor
}

// For a given number n, find the largest number that divides n evenly, smaller than n
// largestDivisor(n: 15) == 5
func largestDivisor(n: Int) -> Int {
    var divisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            divisor = i
        }
    }
    return divisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var divisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            divisor = i
        }
    }
    return divisor
}

// For a given number n, find the largest number that divides n evenly, smaller than n
// largestDivisor(n: 15)

func largestDivisor(n: Int) -> Int {
    var result: Int = 0
    for i in 1 .. n {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

func smallestDivisor(n: Int) -> Int {
    var result: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

```swift
// For a given number n, find the largest number that divides n evenly, smaller than n
// largestDivisor(n: 15) == 5
func largestDivisor(n: Int) -> Int {
    var result: Int = 0
    for i in 1 .. n {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var result: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var result: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var result: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var result: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var result: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var result: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var result: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var result: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var result: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var result: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n:

func largestDivisor(n: Int) -> Int {
    var largestDivisor = 1
    for i in 1 .. n {
        if n % i == 0 {
            largestDivisor = i
        }
    }
    return largestDivisor
}

func smallestDivisor(n: Int) -> Int {
    var smallestDivisor = n
    for i in 1 .. n {
        if n % i == 0 {
            smallestDivisor = i
        }
    }
    return smallestDivisor
}

func smallestDivisor2(n: Int) -> Int {
    var smallestDivisor = n
    for i in n .. 1 {
        if n % i == 0 {
            smallestDivisor = i
        }
    }
    return smallestDivisor
}

func smallestDivisor3(n: Int) -> Int {
    var smallestDivisor = n
    for i in n .. 1 {
        if n % i == 0 {
            smallestDivisor = i
        }
    }
    return smallestDivisor
}

func smallestDivisor4(n: Int) -> Int {
    var smallestDivisor = n
    for i in n .. 1 {
        if n % i == 0 {
            smallestDivisor = i
        }
    }
    return smallestDivisor
}

func smallestDivisor5(n: Int) -> Int {
    var smallestDivisor = n
    for i in n .. 1 {
        if n % i == 0 {
            smallestDivisor = i
        }
    }
    return smallestDivisor
}

func smallestDivisor6(n: Int) -> Int {
    var smallestDivisor = n
    for i in n .. 1 {
        if n % i == 0 {
            smallestDivisor = i
        }
    }
    return smallestDivisor
}

func smallestDivisor7(n: Int) -> Int {
    var smallestDivisor = n
    for i in n .. 1 {
        if n % i == 0 {
            smallestDivisor = i
        }
    }
    return smallestDivisor
}

func smallestDivisor8(n: Int) -> Int {
    var smallestDivisor = n
    for i in n .. 1 {
        if n % i == 0 {
            smallestDivisor = i
        }
    }
    return smallestDivisor
}

func smallestDivisor9(n: Int) -> Int {
    var smallestDivisor = n
    for i in n .. 1 {
        if n % i == 0 {
            smallestDivisor = i
        }
    }
    return smallestDivisor
}

```swift
// For a given number n, find the largest number that divides n evenly, smaller than n
// largestDivisor(n: 15) == 5
func largestDivisor(n: Int) -> Int {
    var largestDivisor = 1
    for i in 1 .. n {
        if n % i == 0 {
            largestDivisor = i
        }
    }
    return largestDivisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var smallestDivisor = n
    for i in 1 .. n {
        if n % i == 0 {
            smallestDivisor = i
        }
    }
    return smallestDivisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 5
func smallestDivisor2(n: Int) -> Int {
    var smallestDivisor = n
    for i in n .. 1 {
        if n % i == 0 {
            smallestDivisor = i
        }
    }
    return smallestDivisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 5
func smallestDivisor3(n: Int) -> Int {
    var smallestDivisor = n
    for i in n .. 1 {
        if n % i == 0 {
            smallestDivisor = i
        }
    }
    return smallestDivisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 5
func smallestDivisor4(n: Int) -> Int {
    var smallestDivisor = n
    for i in n .. 1 {
        if n % i == 0 {
            smallestDivisor = i
        }
    }
    return smallestDivisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 5
func smallestDivisor5(n: Int) -> Int {
    var smallestDivisor = n
    for i in n .. 1 {
        if n % i == 0 {
            smallestDivisor = i
        }
    }
    return smallestDivisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 5
func smallestDivisor6(n: Int) -> Int {
    var smallestDivisor = n
    for i in n .. 1 {
        if n % i == 0 {
            smallestDivisor = i
        }
    }
    return smallestDivisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 5
func smallestDivisor7(n: Int) -> Int {
    var smallestDivisor = n
    for i in n .. 1 {
        if n % i == 0 {
            smallestDivisor = i
        }
    }
    return smallestDivisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 5
func smallestDivisor8(n: Int) -> Int {
    var smallestDivisor = n
    for i in n .. 1 {
        if n % i == 0 {
            smallestDivisor = i
        }
    }
    return smallestDivisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 5
func smallestDivisor9(n: Int) -> Int {
    var smallestDivisor = n
    for i in n .. 1 {
        if n % i == 0 {
            smallestDivisor = i
        }
    }
    return smallestDivisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 5
func smallestDivisor10(n: Int) -> Int {
    var smallestDivisor = n
    for i in n .. 1 {
        if n % i == 0 {
            smallestDivisor = i
        }
    }

func largestDivisor(n: Int) -> Int {
    var largest: Int = 1
    for i in 1 .. n {
        if n % i == 0 && i > largest {
            largest = i
        }
    }
    return largest
}

func smallestDivisor(n: Int) -> Int {
    var smallest: Int = n
    for i in 1 .. n {
        if n % i == 0 && i < smallest {
            smallest = i
        }
    }
    return smallest
}

func smallestDivisor(n: Int) -> Int {
    var smallest: Int = n
    for i in 1 .. n {
        if n % i == 0 && i > smallest {
            smallest = i
        }
    }
    return smallest
}

```swift
// For a given number n, find the largest number that divides n evenly, smaller than n
// largestDivisor(n: 15) == 5
func largestDivisor(n: Int) -> Int {
    var largest: Int = 1
    for i in 1 .. n {
        if n % i == 0 && i > largest {
            largest = i
        }
    }
    return largest
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var smallest: Int = n
    for i in 1 .. n {
        if n % i == 0 && i < smallest {
            smallest = i
        }
    }
    return smallest
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 5
func smallestDivisor(n: Int) -> Int {
    var smallest: Int = n
    for i in 1 .. n {
        if n % i == 0 && i > smallest {
            smallest = i
        }
    }
    return smallest
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 5
func smallestDivisor(n: Int) -> Int {
    var smallest: Int = n
    for i in 1 .. n {
        if n % i == 0 && i < smallest {
            smallest = i
        }
    }
    return smallest
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 5
func smallestDivisor(n: Int) -> Int {
    var smallest: Int = n
    for i in 1 .. n {
        if n % i == 0 && i > smallest {
            smallest = i
        }
    }
    return smallest
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 5
func smallestDivisor(n: Int) -> Int {
    var smallest: Int = n
    for i in 1 .. n {
        if n % i == 0 && i > smallest {
            smallest = i
        }
    }
    return smallest
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 5
func smallestDivisor(n: Int) -> Int {
    var smallest: Int = n
    for i in 1 .. n {
        if n % i == 0 && i > smallest {
            smallest = i
        }
    }
    return smallest
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 5
func smallestDivisor(n: Int) -> Int {
    var smallest: Int = n
    for i in 1 .. n {
        if n % i == 0 && i > smallest {
            smallest = i
        }
    }
    return smallest
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 5
func smallestDivisor(n: Int) -> Int {
    var smallest: Int = n
    for i in 1 .. n {
        if n % i == 0 && i > smallest {
            smallest = i
        }
    }
    return smallest
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 5
func smallestDivisor(n: Int) -> Int {
    var smallest: Int = n
    for i in 1 .. n {
        if n % i == 0 && i > smallest {
            smallest = i
        }
    }
    return smallest
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 5
func smallestDivisor(n: Int) -> Int {
    var smallest: Int = n
    for i in 1 .. n {
        if n % i == 0 && i > smallest {
            smallest = i
        }
    }
    return smallest
}

// For

func largestDivisor(n: Int) -> Int {
    var largestDivisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            largestDivisor = i
        }
    }
    return largestDivisor
}

func smallestDivisor(n: Int) -> Int {
    var smallestDivisor: Int = n
    for i in 1 .. n {
        if n % i == 0 {
            smallestDivisor = i
        }
    }
    return smallestDivisor
}

func sumOfDigits(n: Int) -> Int {
    var sum: Int = 0
    var n: Int = n
    while n > 0 {
        sum += n % 10
        n = n / 10
    }
    return sum
}

func numberOfDigits(n: Int) -> Int {
    var numberOfDigits: Int = 0
    var n: Int = n
    while n > 0 {
        numberOfDigits += 1
        n = n / 10
    }
    return numberOfDigits
}

```swift
// For a given number n, find the largest number that divides n evenly, smaller than n
// largestDivisor(n: 15) == 5
func largestDivisor(n: Int) -> Int {
    var largestDivisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            largestDivisor = i
        }
    }
    return largestDivisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var smallestDivisor: Int = n
    for i in 1 .. n {
        if n % i == 0 {
            smallestDivisor = i
        }
    }
    return smallestDivisor
}

// For a given number n, find the sum of the digits of n
// sumOfDigits(n: 123) == 6
func sumOfDigits(n: Int) -> Int {
    var sum: Int = 0
    var n: Int = n
    while n > 0 {
        sum += n % 10
        n = n / 10
    }
    return sum
}

// For a given number n, find the number of digits in n
// numberOfDigits(n: 123) == 3
func numberOfDigits(n: Int) -> Int {
    var numberOfDigits: Int = 0
    var n: Int = n
    while n > 0 {
        numberOfDigits += 1
        n = n / 10
    }
    return numberOfDigits
}

// For a given number n, find the number of digits in n
// numberOfDigits(n: 123) == 3
func numberOfDigits(n: Int) -> Int {
    var numberOfDigits: Int = 0
    var n: Int = n
    while n > 0 {
        numberOfDigits += 1
        n = n / 10
    }
    return numberOfDigits
}

// For a given number n, find the number of digits in n
// numberOfDigits(n: 123) == 3
func numberOfDigits(n: Int) -> Int {
    var numberOfDigits: Int = 0
    var n: Int = n
    while n > 0 {
        numberOfDigits += 1
        n = n / 10
    }
    return numberOfDigits
}

// For a given number n, find the number of digits in n
// numberOfDigits(n: 123) == 3
func numberOfDigits(n: Int) -> Int {
    var numberOfDigits: Int = 0
    var n: Int = n
    while n > 0 {
        numberOfDigits += 1
        n = n / 10
    }
    return numberOfDigits
}

// For a given number n, find the number of digits in n
// numberOfDigits(n: 123) == 3
func numberOfDigits(n: Int) -> Int {
    var numberOfDigits: Int = 0
    var n: Int = n
    while n > 0 {
        numberOfDigits += 1
        n = n / 10
    }
    return numberOfDigits
}

// For a given number n, find the number of digits in n
// numberOfDigits(n: 123) == 3
func numberOfDigits(n: Int) -> Int {
    var numberOfDigits: Int = 0
    var n: Int = n
    while n > 0 {
        numberOfDigits += 1
        n = n / 10
    }
    return numberOfDigits
}

// For a given number n, find the number of digits in n
// numberOfDigits(n: 123) == 3
func numberOfDigits(n: Int) -> Int {
    var numberOfDigits: Int = 0
    var n: Int = n
    while n > 0 {
        numberOfDigits += 1
        n = n / 10
    }
    return numberOfDigits
}

// For a given number n, find the number of digits in n
// numberOfDigits(n: 123) == 3
func numberOfDigits(n: Int) -> Int {
    var numberOfDigits: Int = 0
    var n: Int = n
    while n > 0 {
        numberOfDigits += 1
        n = n / 10
    }
    return numberOfDigits
}

// For a given number n, find the number of digits in n
// numberOfDigits(n: 

func largestDivisor(n: Int) -> Int {
    var divisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            divisor = i
        }
    }
    return divisor
}

func smallestDivisor(n: Int) -> Int {
    var divisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            divisor = i
        }
    }
    return divisor
}

```swift
// For a given number n, find the largest number that divides n evenly, smaller than n
// largestDivisor(n: 15) == 5
func largestDivisor(n: Int) -> Int {
    var divisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            divisor = i
        }
    }
    return divisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var divisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            divisor = i
        }
    }
    return divisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var divisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            divisor = i
        }
    }
    return divisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var divisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            divisor = i
        }
    }
    return divisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var divisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            divisor = i
        }
    }
    return divisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var divisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            divisor = i
        }
    }
    return divisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var divisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            divisor = i
        }
    }
    return divisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var divisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            divisor = i
        }
    }
    return divisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var divisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            divisor = i
        }
    }
    return divisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var divisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            divisor = i
        }
    }
    return divisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var divisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            divisor = i
        }
    }
    return divisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n:

func largestDivisor(n: Int) -> Int {
    var divisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            divisor = i
        }
    }
    return divisor
}

func smallestDivisor(n: Int) -> Int {
    var divisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            divisor = i
        }
    }
    return divisor
}

func sumDigits(n: Int) -> Int {
    var sum: Int = 0
    var digits: String = n.toString()
    for i in 0 .. digits.count - 1 {
        sum += Int(digits[i])
    }
    return sum
}

func countDigits(n: Int) -> Int {
    var digits: String = n.toString()
    return digits.count
}

func countEvenDigits(n: Int) -> Int {
    var digits: String = n.toString()
    var count: Int = 0
    for i in 0 .. digits.count - 1 {
        if Int(digits[i]) % 2 == 0 {
            count += 1
        }
    }
    return count
}

func countOddDigits(n: Int) -> Int {
    var digits: String = n.toString()
    var count: Int = 0
    for i in 0 .. digits.count - 1 {
        if Int(digits[i]) % 2 != 0 {
            count += 1
        }
    }
    return count
}

func countPrimeDigits(n: Int) -> Int {
    var digits: String = n.toString()
    var count: Int = 0
    for i in 0 .. digits.count - 1 {
        if isPrime(Int(digits[i])) {
            count += 1
        }
    }
    return count
}

func countCompositeDigits(n: Int) -> Int {
    var digits: String = n.toString()
    var count: Int = 0
    for i in 0 .. digits.count - 1 {
        if !isPrime(Int(digits[i])) {
            count += 1
        }
    }
    return count
}

func countFactorialDigits(n: Int) -> Int {
    var factorial: Int = 1
    for i in 1 .. n {
        factorial *= i
    }
    var digits: String = factorial.toString()
    return digits.count
}

func countFactorialSumDigits(n: Int) -> Int {
    var sum: Int = 0
    var digits: String = n.toString()
    for i in 0 .. digits.count - 1 {
        sum += factorial(Int(digits[i]))
    }
    var digits2: String = sum.toString()
    return digits2.count
}

```swift
// For a given number n, find the largest number that divides n evenly, smaller than n
// largestDivisor(n: 15) == 5
func largestDivisor(n: Int) -> Int {
    var divisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            divisor = i
        }
    }
    return divisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var divisor: Int = 1
    for i in 1 .. n {
        if n % i == 0 {
            divisor = i
        }
    }
    return divisor
}

// For a given number n, find the sum of the digits of n
// sumDigits(n: 12345) == 1 + 2 + 3 + 4 + 5 == 15
func sumDigits(n: Int) -> Int {
    var sum: Int = 0
    var digits: String = n.toString()
    for i in 0 .. digits.count - 1 {
        sum += Int(digits[i])
    }
    return sum
}

// For a given number n, find the number of digits in n
// countDigits(n: 12345) == 5
func countDigits(n: Int) -> Int {
    var digits: String = n.toString()
    return digits.count
}

// For a given number n, find the number of even digits in n
// countEvenDigits(n: 12345) == 2
func countEvenDigits(n: Int) -> Int {
    var digits: String = n.toString()
    var count: Int = 0
    for i in 0 .. digits.count - 1 {
        if Int(digits[i]) % 2 == 0 {
            count += 1
        }
    }
    return count
}

// For a given number n, find the number of odd digits in n
// countOddDigits(n: 12345) == 3
func countOddDigits(n: Int) -> Int {
    var digits: String = n.toString()
    var count: Int = 0
    for i in 0 .. digits.count - 1 {
        if Int(digits[i]) % 2 != 0 {
            count += 1
        }
    }
    return count
}

// For a given number n, find the number of prime digits in n
// countPrimeDigits(n: 12345) == 2
func countPrimeDigits(n: Int) -> Int {
    var digits: String = n.toString()
    var count: Int = 0
    for i in 0 .. digits.count - 1 {
        if isPrime(Int(digits[i])) {
            count += 1
        }
    }
    return count
}

// For a given number n, find the number of composite digits in n
// countCompositeDigits(n: 12345) == 3
func countCompositeDigits(n: Int) -> Int {
    var digits: String = n.toString()
    var count: Int = 0
    for i in 0 .. digits.count - 1 {
        if !isPrime(Int(digits[i])) {
            count += 1
        }
    }
    return count
}

// For a given number n, find the number of digits in the factorial of n
// countFactorialDigits(n: 12345) == 12
func countFactorialDigits(n: Int) -> Int {
    var factorial: Int = 1
    for i in 1 .. n {
        factorial *= i
    }
    var digits: String = factorial.toString()
    return digits.count
}

// For a given number n, find the number of digits in the sum of the factorial of all the digits of n
// countFactorialSumDigits(n: 12345) == 15
func countFactorialSumDigits(n: Int) -> Int {
    var sum: Int = 0
    var digits: String = n.toString()
    for i in 0 .. digits.count - 1 {
        sum += factorial(Int(digits[i]))
    }
    var digits2: String = sum.toString()
    return digits2.count
}

// For a given number n, find the number of digits in the sum of

func largestDivisor(n: Int) -> Int {
    var largestDivisor: Int = 0
    for i in 1..<n {
        if n % i == 0 {
            largestDivisor = i
        }
    }
    return largestDivisor
}

func smallestDivisor(n: Int) -> Int {
    var smallestDivisor: Int = 0
    for i in 1..<n {
        if n % i == 0 {
            smallestDivisor = i
        }
    }
    return smallestDivisor
}

func smallestDivisor2(n: Int) -> Int {
    var smallestDivisor: Int = 0
    for i in 1..<n {
        if n % i == 0 {
            smallestDivisor = i
        }
    }
    return smallestDivisor
}

func largestDivisor2(n: Int) -> Int {
    var largestDivisor: Int = 0
    for i in 1..<n {
        if n % i == 0 {
            largestDivisor = i
        }
    }
    return largestDivisor
}

func smallestDivisor3(n: Int) -> Int {
    var smallestDivisor: Int = 0
    for i in 1..<n {
        if n % i == 0 {
            smallestDivisor = i
        }
    }
    return smallestDivisor
}

func largestDivisor3(n: Int) -> Int {
    var largestDivisor: Int = 0
    for i in 1..<n {
        if n % i == 0 {
            largestDivisor = i
        }
    }
    return largestDivisor
}

func smallestDivisor4(n: Int) -> Int {
    var smallestDivisor: Int = 0
    for i in 1..<n {
        if n % i == 0 {
            smallestDivisor = i
        }
    }
    return smallestDivisor
}

func largestDivisor4(n: Int) -> Int {
    var largestDivisor: Int = 0
    for i in 1..<n {
        if n % i == 0 {
            largestDivisor = i
        }
    }
    return largestDivisor
}

func smallestDivisor5(n: Int) -> Int {
    var smallestDivisor: Int = 0
    for i in 1..<n {
        if n % i == 0 {
            smallestDivisor = i
        }
    }
    return smallestDivisor
}

func largestDivisor5(n: Int) -> Int {
    var largestDivisor: Int = 0
    for i in 1..<n {
        if n % i == 0 {
            largestDivisor = i
        }
    }
    return largestDivisor
}

```swift
// For a given number n, find the largest number that divides n evenly, smaller than n
// largestDivisor(n: 15) == 5
func largestDivisor(n: Int) -> Int {
    var largestDivisor: Int = 0
    for i in 1..<n {
        if n % i == 0 {
            largestDivisor = i
        }
    }
    return largestDivisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var smallestDivisor: Int = 0
    for i in 1..<n {
        if n % i == 0 {
            smallestDivisor = i
        }
    }
    return smallestDivisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 3
func smallestDivisor2(n: Int) -> Int {
    var smallestDivisor: Int = 0
    for i in 1..<n {
        if n % i == 0 {
            smallestDivisor = i
        }
    }
    return smallestDivisor
}

// For a given number n, find the largest number that divides n evenly, smaller than n
// largestDivisor(n: 15) == 3
func largestDivisor2(n: Int) -> Int {
    var largestDivisor: Int = 0
    for i in 1..<n {
        if n % i == 0 {
            largestDivisor = i
        }
    }
    return largestDivisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor3(n: Int) -> Int {
    var smallestDivisor: Int = 0
    for i in 1..<n {
        if n % i == 0 {
            smallestDivisor = i
        }
    }
    return smallestDivisor
}

// For a given number n, find the largest number that divides n evenly, smaller than n
// largestDivisor(n: 15) == 3
func largestDivisor3(n: Int) -> Int {
    var largestDivisor: Int = 0
    for i in 1..<n {
        if n % i == 0 {
            largestDivisor = i
        }
    }
    return largestDivisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 5
func smallestDivisor4(n: Int) -> Int {
    var smallestDivisor: Int = 0
    for i in 1..<n {
        if n % i == 0 {
            smallestDivisor = i
        }
    }
    return smallestDivisor
}

// For a given number n, find the largest number that divides n evenly, smaller than n
// largestDivisor(n: 15) == 15
func largestDivisor4(n: Int) -> Int {
    var largestDivisor: Int = 0
    for i in 1..<n {
        if n % i == 0 {
            largestDivisor = i
        }
    }
    return largestDivisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor5(n: Int) -> Int {
    var smallestDivisor: Int = 0
    for i in 1..<n {
        if n % i == 0 {
            smallestDivisor = i
        }
    }
    return smallestDivisor
}

// For a given number n, find the largest number that divides n evenly, smaller than n
// largestDivisor(n: 15) == 3
func largestDivisor5(n: Int) -> Int {
    var largestDivisor: Int = 0
    for i in 1..<n {
        if n % i == 0 {
            largestDivisor = i
        }
    }
    return largestDivisor
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor6(n: Int) -> Int {
    var smallestDivisor: Int = 

func largestDivisor(n: Int) -> Int {
    var result = 1
    for i in 1 .. n {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

func smallestDivisor(n: Int) -> Int {
    var result = n
    for i in 1 .. n {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

func smallestDivisor2(n: Int) -> Int {
    var result = n
    for i in n .. 1 {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

func smallestDivisor3(n: Int) -> Int {
    var result = n
    for i in n .. 1 {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

func smallestDivisor4(n: Int) -> Int {
    var result = n
    for i in n .. 1 {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

func smallestDivisor5(n: Int) -> Int {
    var result = n
    for i in n .. 1 {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

func smallestDivisor6(n: Int) -> Int {
    var result = n
    for i in n .. 1 {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

func smallestDivisor7(n: Int) -> Int {
    var result = n
    for i in n .. 1 {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

func smallestDivisor8(n: Int) -> Int {
    var result = n
    for i in n .. 1 {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

func smallestDivisor9(n: Int) -> Int {
    var result = n
    for i in n .. 1 {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

func smallestDivisor10(n: Int) -> Int {
    var result = n
    for i in n .. 1 {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

```swift
// For a given number n, find the largest number that divides n evenly, smaller than n
// largestDivisor(n: 15) == 5
func largestDivisor(n: Int) -> Int {
    var result = 1
    for i in 1 .. n {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor(n: Int) -> Int {
    var result = n
    for i in 1 .. n {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor2(n: Int) -> Int {
    var result = n
    for i in n .. 1 {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor3(n: Int) -> Int {
    var result = n
    for i in n .. 1 {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor4(n: Int) -> Int {
    var result = n
    for i in n .. 1 {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor5(n: Int) -> Int {
    var result = n
    for i in n .. 1 {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor6(n: Int) -> Int {
    var result = n
    for i in n .. 1 {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor7(n: Int) -> Int {
    var result = n
    for i in n .. 1 {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor8(n: Int) -> Int {
    var result = n
    for i in n .. 1 {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor9(n: Int) -> Int {
    var result = n
    for i in n .. 1 {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor10(n: Int) -> Int {
    var result = n
    for i in n .. 1 {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 15
func smallestDivisor11(n: Int) -> Int

func largestDivisor(n: Int) -> Int {
    var result = 1
    for i in 1 .. n {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

func smallestDivisor(n: Int) -> Int {
    var result = n
    for i in 1 .. n {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

```swift
// For a given number n, find the largest number that divides n evenly, smaller than n
// largestDivisor(n: 15) == 5
func largestDivisor(n: Int) -> Int {
    var result = 1
    for i in 1 .. n {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 25
func smallestDivisor(n: Int) -> Int {
    var result = n
    for i in 1 .. n {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 25
func smallestDivisor(n: Int) -> Int {
    var result = n
    for i in 1 .. n {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 25
func smallestDivisor(n: Int) -> Int {
    var result = n
    for i in 1 .. n {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 25
func smallestDivisor(n: Int) -> Int {
    var result = n
    for i in 1 .. n {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 25
func smallestDivisor(n: Int) -> Int {
    var result = n
    for i in 1 .. n {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 25
func smallestDivisor(n: Int) -> Int {
    var result = n
    for i in 1 .. n {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 25
func smallestDivisor(n: Int) -> Int {
    var result = n
    for i in 1 .. n {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 25
func smallestDivisor(n: Int) -> Int {
    var result = n
    for i in 1 .. n {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 25
func smallestDivisor(n: Int) -> Int {
    var result = n
    for i in 1 .. n {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 25
func smallestDivisor(n: Int) -> Int {
    var result = n
    for i in 1 .. n {
        if n % i == 0 {
            result = i
        }
    }
    return result
}

// For a given number n, find the smallest number that divides n evenly, larger than n
// smallestDivisor(n: 15) == 25
func smallestDivisor(n: Int) -> Int {
    var result = n
    for i in

func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while i <= n {
        if n % i == 0 {
            factors.append(i)
            n = n / i
        } else {
            i += 1
        }
    }
    return factors
}

```swift
// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while i <= n {
        if n % i == 0 {
            factors.append(i)
            n = n / i
        } else {
            i += 1
        }
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while i <= n {
        if n % i == 0 {
            factors.append(i)
            n = n / i
        } else {
            i += 1
        }
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while i <= n {
        if n % i == 0 {
            factors.append(i)
            n = n / i
        } else {
            i += 1
        }
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while i <= n {
        if n % i == 0 {
            factors.append(i)
            n = n / i
        } else {
            i += 1
        }
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while i <= n {
        if n % i == 0 {
            factors.append(i)
            n = n / i
        } else {
            i += 1
        }
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2

func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while (i <= n) {
        if (n % i == 0) {
            factors.append(i)
            n = n / i
        } else {
            i += 1
        }
    }
    return factors
}

```swift
// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while (i <= n) {
        if (n % i == 0) {
            factors.append(i)
            n = n / i
        } else {
            i += 1
        }
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while (i <= n) {
        if (n % i == 0) {
            factors.append(i)
            n = n / i
        } else {
            i += 1
        }
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while (i <= n) {
        if (n % i == 0) {
            factors.append(i)
            n = n / i
        } else {
            i += 1
        }
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while (i <= n) {
        if (n % i == 0) {
            factors.append(i)
            n = n / i
        } else {
            i += 1
        }
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while (i <= n) {
        if (n % i == 0) {
            factors.append(i)
            n = n / i
        } else {
            i += 1
        }
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int]

func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while (i <= n) {
        if (n % i == 0) {
            factors.append(i)
            n = n / i
        } else {
            i += 1
        }
    }
    return factors
}

```swift
// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while (i <= n) {
        if (n % i == 0) {
            factors.append(i)
            n = n / i
        } else {
            i += 1
        }
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while (i <= n) {
        if (n % i == 0) {
            factors.append(i)
            n = n / i
        } else {
            i += 1
        }
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while (i <= n) {
        if (n % i == 0) {
            factors.append(i)
            n = n / i
        } else {
            i += 1
        }
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while (i <= n) {
        if (n % i == 0) {
            factors.append(i)
            n = n / i
        } else {
            i += 1
        }
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while (i <= n) {
        if (n % i == 0) {
            factors.append(i)
            n = n / i
        } else {
            i += 1
        }
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int]

func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while n > 1 {
        while n % i == 0 {
            factors.append(i)
            n = n / i
        }
        i = i + 1
    }
    return factors
}

```swift
// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while n > 1 {
        while n % i == 0 {
            factors.append(i)
            n = n / i
        }
        i = i + 1
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while n > 1 {
        while n % i == 0 {
            factors.append(i)
            n = n / i
        }
        i = i + 1
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while n > 1 {
        while n % i == 0 {
            factors.append(i)
            n = n / i
        }
        i = i + 1
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while n > 1 {
        while n % i == 0 {
            factors.append(i)
            n = n / i
        }
        i = i + 1
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while n > 1 {
        while n % i == 0 {
            factors.append(i)
            n = n / i
        }
        i = i + 1
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while n > 1 {
        

func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while (i <= n) {
        if (n % i == 0) {
            factors.append(i)
            n = n / i
            i = 2
        } else {
            i = i + 1
        }
    }
    return factors
}

```swift
// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while (i <= n) {
        if (n % i == 0) {
            factors.append(i)
            n = n / i
            i = 2
        } else {
            i = i + 1
        }
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while (i <= n) {
        if (n % i == 0) {
            factors.append(i)
            n = n / i
            i = 2
        } else {
            i = i + 1
        }
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while (i <= n) {
        if (n % i == 0) {
            factors.append(i)
            n = n / i
            i = 2
        } else {
            i = i + 1
        }
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while (i <= n) {
        if (n % i == 0) {
            factors.append(i)
            n = n / i
            i = 2
        } else {
            i = i + 1
        }
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while (i <= n) {
        if (n % i == 0) {
            factors.append(i)
            n = n / i
            i = 2
        } else {
            i = i + 1
        }
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) ==

func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while n > 1 {
        while n % i == 0 {
            factors.append(i)
            n = n / i
        }
        i = i + 1
    }
    return factors
}

```swift
// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while n > 1 {
        while n % i == 0 {
            factors.append(i)
            n = n / i
        }
        i = i + 1
    }
    return factors
}
```

func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while i <= n {
        if n % i == 0 {
            factors.append(i)
            n = n / i
            i = 2
        } else {
            i += 1
        }
    }
    return factors
}

```swift
// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while i <= n {
        if n % i == 0 {
            factors.append(i)
            n = n / i
            i = 2
        } else {
            i += 1
        }
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while i <= n {
        if n % i == 0 {
            factors.append(i)
            n = n / i
            i = 2
        } else {
            i += 1
        }
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while i <= n {
        if n % i == 0 {
            factors.append(i)
            n = n / i
            i = 2
        } else {
            i += 1
        }
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while i <= n {
        if n % i == 0 {
            factors.append(i)
            n = n / i
            i = 2
        } else {
            i += 1
        }
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while i <= n {
        if n % i == 0 {
            factors.append(i)
            n = n / i
            i = 2
        } else {
            i += 1
        }
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factor

func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while n > 1 {
        while n % i == 0 {
            factors.append(i)
            n = n / i
        }
        i = i + 1
    }
    return factors
}

```swift
// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while n > 1 {
        while n % i == 0 {
            factors.append(i)
            n = n / i
        }
        i = i + 1
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while n > 1 {
        while n % i == 0 {
            factors.append(i)
            n = n / i
        }
        i = i + 1
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while n > 1 {
        while n % i == 0 {
            factors.append(i)
            n = n / i
        }
        i = i + 1
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while n > 1 {
        while n % i == 0 {
            factors.append(i)
            n = n / i
        }
        i = i + 1
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while n > 1 {
        while n % i == 0 {
            factors.append(i)
            n = n / i
        }
        i = i + 1
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while n > 1 {
        

func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while (i <= n) {
        if (n % i == 0) {
            factors.append(i)
            n = n / i
            i = 2
        } else {
            i += 1
        }
    }
    return factors
}

```swift
// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while (i <= n) {
        if (n % i == 0) {
            factors.append(i)
            n = n / i
            i = 2
        } else {
            i += 1
        }
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while (i <= n) {
        if (n % i == 0) {
            factors.append(i)
            n = n / i
            i = 2
        } else {
            i += 1
        }
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while (i <= n) {
        if (n % i == 0) {
            factors.append(i)
            n = n / i
            i = 2
        } else {
            i += 1
        }
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while (i <= n) {
        if (n % i == 0) {
            factors.append(i)
            n = n / i
            i = 2
        } else {
            i += 1
        }
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while (i <= n) {
        if (n % i == 0) {
            factors.append(i)
            n = n / i
            i = 2
        } else {
            i += 1
        }
    }
    return factors
}

// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize

func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while n > 1 {
        while n % i == 0 {
            factors.append(i)
            n = n / i
        }
        i = i + 1
    }
    return factors
}

```swift
// Return array of prime factors of given integer in the order from smallest to largest.
// Each of the factors should be arrayed number of times corresponding to how many times it appeares in factorization.
// Input number should be equal to the product of all factors
// factorize(n: 8) == [2, 2, 2]
// factorize(n: 25) == [5, 5]
// factorize(n: 70) == [2, 5, 7]
func factorize(n: Int) -> [Int] {
    var factors: [Int] = []
    var i: Int = 2
    while n > 1 {
        while n % i == 0 {
            factors.append(i)
            n = n / i
        }
        i = i + 1
    }
    return factors
}
```

func removeDuplicates(numbers: [Int]) -> [Int] {
    var result: [Int] = []
    var seen: Set<Int> = Set()
    for number in numbers {
        if !seen.contains(number) {
            result.append(number)
            seen.add(number)
        }
    }
    return result
}

func removeNonAlphabetic(text: String) -> String {
    var result: String = ""
    for character in text {
        if character.isAlphabetic() {
            result += character.lowercase()
        }
    }
    return result
}

func findSecondLargest(numbers: [Int]) -> Int {
    var largest: Int = Int.min
    var secondLargest: Int = Int.min
    for number in numbers {
        if number > largest {
            secondLargest = largest
            largest = number
        } else if number > secondLargest && number != largest {
            secondLargest = number
        }
    }
    return secondLargest
}

func findSmallestLargest(numbers: [Int]) -> Int {
    var smallest: Int = Int.max
    var largest: Int = Int.min
    for number in numbers {
        if number < smallest {
            largest = smallest
            smallest = number
        } else if number > largest {
            largest = number
        }
    }
    return largest
}

func sumOfNumbers(numbers: [Int]) -> Int {
    var sum: Int = 0
    for number in numbers {
        sum += number
    }
    return sum
}

func productOfNumbers(numbers: [Int]) -> Int {
    var product: Int = 1
    for number in numbers {
        product *= number
    }
    return product
}

func averageOfNumbers(numbers: [Int]) -> Double {
    var sum: Int = 0
    for number in numbers {
        sum += number
    }
    return Double(sum) / Double(numbers.count)
}

func medianOfNumbers(numbers: [Int]) -> Int {
    var sortedNumbers: [Int] = numbers.sorted()
    var middleIndex: Int = (sortedNumbers.count - 1) / 2
    if (sortedNumbers.count % 2) == 0 {
        return (sortedNumbers[middleIndex] + sortedNumbers[middleIndex + 1]) / 2
    } else {
        return sortedNumbers[middleIndex]
    }
}

```swift
// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var result: [Int] = []
    var seen: Set<Int> = Set()
    for number in numbers {
        if !seen.contains(number) {
            result.append(number)
            seen.add(number)
        }
    }
    return result
}

// From a string, remove all non-alphabetic characters and convert to lowercase.
// removeNonAlphabetic(text: "Hello, World!") == "hello"
func removeNonAlphabetic(text: String) -> String {
    var result: String = ""
    for character in text {
        if character.isAlphabetic() {
            result += character.lowercase()
        }
    }
    return result
}

// From a list of integers, find the second-largest number.
// findSecondLargest(numbers: [1, 2, 3, 4, 5]) == 4
func findSecondLargest(numbers: [Int]) -> Int {
    var largest: Int = Int.min
    var secondLargest: Int = Int.min
    for number in numbers {
        if number > largest {
            secondLargest = largest
            largest = number
        } else if number > secondLargest && number != largest {
            secondLargest = number
        }
    }
    return secondLargest
}

// From a list of integers, find the largest number that is also the smallest.
// findSmallestLargest(numbers: [1, 2, 3, 4, 5]) == 1
func findSmallestLargest(numbers: [Int]) -> Int {
    var smallest: Int = Int.max
    var largest: Int = Int.min
    for number in numbers {
        if number < smallest {
            largest = smallest
            smallest = number
        } else if number > largest {
            largest = number
        }
    }
    return largest
}

// From a list of integers, find the sum of all elements.
// sumOfNumbers(numbers: [1, 2, 3, 4, 5]) == 15
func sumOfNumbers(numbers: [Int]) -> Int {
    var sum: Int = 0
    for number in numbers {
        sum += number
    }
    return sum
}

// From a list of integers, find the product of all elements.
// productOfNumbers(numbers: [1, 2, 3, 4, 5]) == 120
func productOfNumbers(numbers: [Int]) -> Int {
    var product: Int = 1
    for number in numbers {
        product *= number
    }
    return product
}

// From a list of integers, find the average of all elements.
// averageOfNumbers(numbers: [1, 2, 3, 4, 5]) == 3
func averageOfNumbers(numbers: [Int]) -> Double {
    var sum: Int = 0
    for number in numbers {
        sum += number
    }
    return Double(sum) / Double(numbers.count)
}

// From a list of integers, find the median of all elements.
// medianOfNumbers(numbers: [1, 2, 3, 4, 5]) == 3
func medianOfNumbers(numbers: [Int]) -> Int {
    var sortedNumbers: [Int] = numbers.sorted()
    var middleIndex: Int = (sortedNumbers.count - 1) / 2
    if (sortedNumbers.count % 2) == 0 {
        return (sortedNumbers[middleIndex] + sortedNumbers[middleIndex + 1]) / 2
    } else {
        return sortedNumbers[middleIndex]
    }
}

// From a list of integers, find the mode of all elements.
// modeOfNumbers(numbers: [1, 2, 2, 3, 3, 3, 4, 4, 4, 4]) == 3
func modeOfNumbers(numbers: [Int]) -> Int {
    var counts: Map<Int, Int> = Map()
    for number in numbers {
        if counts.contains(number) {
            counts[number] += 1
        } else {
            counts[number] = 1
        }
    }
    var maxCount: Int = 0
    var mode: Int = 0
    for (number, count) in counts {
        if count > maxCount {
            maxCount = count
            mode = number
        }
    

func removeDuplicates(numbers: [Int]) -> [Int] {
    var result: [Int] = []
    var seen: Set<Int> = Set()
    for num in numbers {
        if !seen.contains(num) {
            result.append(num)
            seen.add(num)
        }
    }
    return result
}

```swift
// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var result: [Int] = []
    var seen: Set<Int> = Set()
    for num in numbers {
        if !seen.contains(num) {
            result.append(num)
            seen.add(num)
        }
    }
    return result
}

// Test the function
let numbers = [1, 2, 3, 2, 4]
let result = removeDuplicates(numbers)
print(result) // prints [1, 3, 4]
```

func removeDuplicates(numbers: [Int]) -> [Int] {
    var result: [Int] = []
    var seen: Set<Int> = Set()
    for i in 0..<numbers.count {
        if !seen.contains(numbers[i]) {
            result.append(numbers[i])
            seen.add(numbers[i])
        }
    }
    return result
}

```swift
// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var result: [Int] = []
    var seen: Set<Int> = Set()
    for i in 0..<numbers.count {
        if !seen.contains(numbers[i]) {
            result.append(numbers[i])
            seen.add(numbers[i])
        }
    }
    return result
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var result: [Int] = []
    var seen: Set<Int> = Set()
    for i in 0..<numbers.count {
        if !seen.contains(numbers[i]) {
            result.append(numbers[i])
            seen.add(numbers[i])
        }
    }
    return result
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var result: [Int] = []
    var seen: Set<Int> = Set()
    for i in 0..<numbers.count {
        if !seen.contains(numbers[i]) {
            result.append(numbers[i])
            seen.add(numbers[i])
        }
    }
    return result
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var result: [Int] = []
    var seen: Set<Int> = Set()
    for i in 0..<numbers.count {
        if !seen.contains(numbers[i]) {
            result.append(numbers[i])
            seen.add(numbers[i])
        }
    }
    return result
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var result: [Int] = []
    var seen: Set<Int> = Set()
    for i in 0..<numbers.count {
        if !seen.contains(numbers[i]) {
            result.append(numbers[i])
            seen.add(numbers[i])
        }
    }
    return result
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var result: [Int] = []
    var seen: Set<Int> = Set()
    for i in 0..<numbers.count {
        if !seen.contains(numbers[i]) {
            result.append(numbers[i])
            seen.add(numbers[i])
        }
    }
    return result
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var result: [Int] = []
    var seen: Set<Int> = Set()
    for i in 0..<numbers.count {
        if !seen.contains(numbers[i]) {
            result.append(numbers[i])
            seen.add(numbers[i])
        }
    }
    return result
}

// From

func removeDuplicates(numbers: [Int]) -> [Int] {
    var uniqueNumbers: [Int] = []
    var seenNumbers: [Int] = []
    for number in numbers {
        if !seenNumbers.contains(number) {
            uniqueNumbers.append(number)
            seenNumbers.append(number)
        }
    }
    return uniqueNumbers
}

func removeNonAlphaNumeric(input: String) -> String {
    var result: String = ""
    for character in input {
        if character.isAlphanumeric {
            result += character
        }
    }
    return result.lowercase()
}

```swift
// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var uniqueNumbers: [Int] = []
    var seenNumbers: [Int] = []
    for number in numbers {
        if !seenNumbers.contains(number) {
            uniqueNumbers.append(number)
            seenNumbers.append(number)
        }
    }
    return uniqueNumbers
}

// From a string, remove all non-alphanumeric characters and convert to lowercase.
// removeNonAlphaNumeric(input: "Hello, World!") == "hello world"
func removeNonAlphaNumeric(input: String) -> String {
    var result: String = ""
    for character in input {
        if character.isAlphanumeric {
            result += character
        }
    }
    return result.lowercase()
}

// From a string, remove all non-alphanumeric characters and convert to lowercase.
// removeNonAlphaNumeric(input: "Hello, World!") == "hello world"
func removeNonAlphaNumeric(input: String) -> String {
    var result: String = ""
    for character in input {
        if character.isAlphanumeric {
            result += character
        }
    }
    return result.lowercase()
}

// From a string, remove all non-alphanumeric characters and convert to lowercase.
// removeNonAlphaNumeric(input: "Hello, World!") == "hello world"
func removeNonAlphaNumeric(input: String) -> String {
    var result: String = ""
    for character in input {
        if character.isAlphanumeric {
            result += character
        }
    }
    return result.lowercase()
}

// From a string, remove all non-alphanumeric characters and convert to lowercase.
// removeNonAlphaNumeric(input: "Hello, World!") == "hello world"
func removeNonAlphaNumeric(input: String) -> String {
    var result: String = ""
    for character in input {
        if character.isAlphanumeric {
            result += character
        }
    }
    return result.lowercase()
}

// From a string, remove all non-alphanumeric characters and convert to lowercase.
// removeNonAlphaNumeric(input: "Hello, World!") == "hello world"
func removeNonAlphaNumeric(input: String) -> String {
    var result: String = ""
    for character in input {
        if character.isAlphanumeric {
            result += character
        }
    }
    return result.lowercase()
}

// From a string, remove all non-alphanumeric characters and convert to lowercase.
// removeNonAlphaNumeric(input: "Hello, World!") == "hello world"
func removeNonAlphaNumeric(input: String) -> String {
    var result: String = ""
    for character in input {
        if character.isAlphanumeric {
            result += character
        }
    }
    return result.lowercase()
}

// From a string, remove all non-alphanumeric characters and convert to lowercase.
// removeNonAlphaNumeric(input: "Hello, World!") == "hello world"
func removeNonAlphaNumeric(input: String) -> String {
    var result: String = ""
    for character in input {
        if character.isAlphanumeric {
            result += character
        }
    }
    return result.lowercase()
}

// From a string, remove all non-alphanumeric characters and convert to lowercase.
// removeNonAlphaNumeric(input: "Hello, World!") == "hello world"
func removeNonAlphaNumeric(input: String) -> String {
    var result: String = ""
    for character in input {
        if character.isAlphanumeric {
            result += character
        }
    }
    return result.lowercase()
}

// From a string, remove all non-alphanumeric characters and convert to lowercase.
// removeNonAlphaNumeric(input: "Hello, World!") == "hello world"
func removeNonAlphaNumeric(input: String) -> String {
    var result: String = ""
    for character in input {
        if character.isAlphanumeric {
            result += character
        }
    }
    return result.lowercase()
}

// From a string, remove all non-alphanumeric characters and convert to lowercase.
// removeNonAlphaNumeric(input: "Hello, World!") == "hello world"
func removeNonAlphaNumeric(input: String) -> String {
    var result: String = ""
    for character in input {
        if character.isAlphanumeric {
            result += character
        }
    }
    return result.lowercase()
}

//

func removeDuplicates(numbers: [Int]) -> [Int] {
    var result: [Int] = []
    var seen: Set<Int> = Set()
    for i in 0..<numbers.count {
        if !seen.contains(numbers[i]) {
            result.append(numbers[i])
            seen.add(numbers[i])
        }
    }
    return result
}

```swift
// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var result: [Int] = []
    var seen: Set<Int> = Set()
    for i in 0..<numbers.count {
        if !seen.contains(numbers[i]) {
            result.append(numbers[i])
            seen.add(numbers[i])
        }
    }
    return result
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var result: [Int] = []
    var seen: Set<Int> = Set()
    for i in 0..<numbers.count {
        if !seen.contains(numbers[i]) {
            result.append(numbers[i])
            seen.add(numbers[i])
        }
    }
    return result
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var result: [Int] = []
    var seen: Set<Int> = Set()
    for i in 0..<numbers.count {
        if !seen.contains(numbers[i]) {
            result.append(numbers[i])
            seen.add(numbers[i])
        }
    }
    return result
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var result: [Int] = []
    var seen: Set<Int> = Set()
    for i in 0..<numbers.count {
        if !seen.contains(numbers[i]) {
            result.append(numbers[i])
            seen.add(numbers[i])
        }
    }
    return result
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var result: [Int] = []
    var seen: Set<Int> = Set()
    for i in 0..<numbers.count {
        if !seen.contains(numbers[i]) {
            result.append(numbers[i])
            seen.add(numbers[i])
        }
    }
    return result
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var result: [Int] = []
    var seen: Set<Int> = Set()
    for i in 0..<numbers.count {
        if !seen.contains(numbers[i]) {
            result.append(numbers[i])
            seen.add(numbers[i])
        }
    }
    return result
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var result: [Int] = []
    var seen: Set<Int> = Set()
    for i in 0..<numbers.count {
        if !seen.contains(numbers[i]) {
            result.append(numbers[i])
            seen.add(numbers[i])
        }
    }
    return result
}

// From

func removeDuplicates(numbers: [Int]) -> [Int] {
    var uniqueNumbers: [Int] = []
    var seenNumbers: [Int] = []
    for number in numbers {
        if !seenNumbers.contains(number) {
            uniqueNumbers.append(number)
            seenNumbers.append(number)
        }
    }
    return uniqueNumbers
}

```swift
// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var uniqueNumbers: [Int] = []
    var seenNumbers: [Int] = []
    for number in numbers {
        if !seenNumbers.contains(number) {
            uniqueNumbers.append(number)
            seenNumbers.append(number)
        }
    }
    return uniqueNumbers
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var uniqueNumbers: [Int] = []
    var seenNumbers: [Int] = []
    for number in numbers {
        if !seenNumbers.contains(number) {
            uniqueNumbers.append(number)
            seenNumbers.append(number)
        }
    }
    return uniqueNumbers
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var uniqueNumbers: [Int] = []
    var seenNumbers: [Int] = []
    for number in numbers {
        if !seenNumbers.contains(number) {
            uniqueNumbers.append(number)
            seenNumbers.append(number)
        }
    }
    return uniqueNumbers
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var uniqueNumbers: [Int] = []
    var seenNumbers: [Int] = []
    for number in numbers {
        if !seenNumbers.contains(number) {
            uniqueNumbers.append(number)
            seenNumbers.append(number)
        }
    }
    return uniqueNumbers
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var uniqueNumbers: [Int] = []
    var seenNumbers: [Int] = []
    for number in numbers {
        if !seenNumbers.contains(number) {
            uniqueNumbers.append(number)
            seenNumbers.append(number)
        }
    }
    return uniqueNumbers
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var uniqueNumbers: [Int] = []
    var seenNumbers: [Int] = []
    for number in numbers {
        if !seenNumbers.contains(number) {
            uniqueNumbers.append(number)
            seenNumbers.append(number)
        }
    }
    return uniqueNumbers
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var uniqueNumbers: [Int] = []
    var seenNumbers: [Int] = []
    for number in numbers {
        if !seenNumbers.contains(number) {
            uniqueNumbers.append(number)
            seenNumbers.append(number)
        }
    }
    return uniqueNumbers
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4

func removeDuplicates(numbers: [Int]) -> [Int] {
    var result = [Int]()
    var seen = [Int]()
    for number in numbers {
        if !seen.contains(number) {
            result.append(number)
            seen.append(number)
        }
    }
    return result
}

func reverseString(s: String) -> String {
    var reversed = ""
    for i in s.indicesReversed {
        reversed += s[i]
    }
    return reversed
}

func sortString(s: String) -> String {
    var characters = s.characters
    characters.sort()
    return String(characters)
}

func countHi(s: String) -> Int {
    var count = 0
    for i in 0..<s.length - 1 {
        if s[i..<i+2] == "hi" {
            count += 1
        }
    }
    return count
}

```swift
// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var result = [Int]()
    var seen = [Int]()
    for number in numbers {
        if !seen.contains(number) {
            result.append(number)
            seen.append(number)
        }
    }
    return result
}

// Given a string, return a string with the characters in reverse order.
// reverseString("hello") == "olleh"
func reverseString(s: String) -> String {
    var reversed = ""
    for i in s.indicesReversed {
        reversed += s[i]
    }
    return reversed
}

// Given a string, return a string with the characters in alphabetical order.
// sortString("hello") == "ehllo"
func sortString(s: String) -> String {
    var characters = s.characters
    characters.sort()
    return String(characters)
}

// Given a string, return the number of times the string "hi" appears anywhere in the string.
// countHi("abc hi ho") == 1
// countHi("ABChi hi") == 2
// countHi("hihi") == 2
func countHi(s: String) -> Int {
    var count = 0
    for i in 0..<s.length - 1 {
        if s[i..<i+2] == "hi" {
            count += 1
        }
    }
    return count
}

// Given a string, return the number of times the string "hi" appears anywhere in the string.
// countHi("abc hi ho") == 1
// countHi("ABChi hi") == 2
// countHi("hihi") == 2
func countHi(s: String) -> Int {
    var count = 0
    for i in 0..<s.length - 1 {
        if s[i..<i+2] == "hi" {
            count += 1
        }
    }
    return count
}

// Given a string, return the number of times the string "hi" appears anywhere in the string.
// countHi("abc hi ho") == 1
// countHi("ABChi hi") == 2
// countHi("hihi") == 2
func countHi(s: String) -> Int {
    var count = 0
    for i in 0..<s.length - 1 {
        if s[i..<i+2] == "hi" {
            count += 1
        }
    }
    return count
}

// Given a string, return the number of times the string "hi" appears anywhere in the string.
// countHi("abc hi ho") == 1
// countHi("ABChi hi") == 2
// countHi("hihi") == 2
func countHi(s: String) -> Int {
    var count = 0
    for i in 0..<s.length - 1 {
        if s[i..<i+2] == "hi" {
            count += 1
        }
    }
    return count
}

// Given a string, return the number of times the string "hi" appears anywhere in the string.
// countHi("abc hi ho") == 1
// countHi("ABChi hi") == 2
// countHi("hihi") == 2
func countHi(s: String) -> Int {
    var count = 0
    for i in 0..<s.length - 1 {
        if s[i..<i+2] == "hi" {
            count += 1
        }
    }
    return count
}

// Given a string, return the number of times the string "hi" appears anywhere in the string.
// countHi("abc hi ho") == 1
// countHi("ABChi hi") == 2
// countHi("hihi") == 2
func countHi(s: String) -> Int {
    var count = 0
    for i in 0..<s.length - 1 {
        if s[i..<i+2] == "hi" {
            count += 1
        }
    }
    return count
}

// Given a string, return the number of times the string "hi" appears anywhere in the string.
// countHi("abc hi ho") == 1
// countHi("ABChi hi") == 2
// countHi("hihi") == 2
func countHi(s: String) -> Int {
    var count = 0
    for i in 0

func removeDuplicates(numbers: [Int]) -> [Int] {
    var uniqueNumbers = [Int]()
    var seenNumbers = [Int]()
    for number in numbers {
        if !seenNumbers.contains(number) {
            uniqueNumbers.append(number)
            seenNumbers.append(number)
        }
    }
    return uniqueNumbers
}

```swift
// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var uniqueNumbers = [Int]()
    var seenNumbers = [Int]()
    for number in numbers {
        if !seenNumbers.contains(number) {
            uniqueNumbers.append(number)
            seenNumbers.append(number)
        }
    }
    return uniqueNumbers
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var uniqueNumbers = [Int]()
    var seenNumbers = [Int]()
    for number in numbers {
        if !seenNumbers.contains(number) {
            uniqueNumbers.append(number)
            seenNumbers.append(number)
        }
    }
    return uniqueNumbers
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var uniqueNumbers = [Int]()
    var seenNumbers = [Int]()
    for number in numbers {
        if !seenNumbers.contains(number) {
            uniqueNumbers.append(number)
            seenNumbers.append(number)
        }
    }
    return uniqueNumbers
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var uniqueNumbers = [Int]()
    var seenNumbers = [Int]()
    for number in numbers {
        if !seenNumbers.contains(number) {
            uniqueNumbers.append(number)
            seenNumbers.append(number)
        }
    }
    return uniqueNumbers
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var uniqueNumbers = [Int]()
    var seenNumbers = [Int]()
    for number in numbers {
        if !seenNumbers.contains(number) {
            uniqueNumbers.append(number)
            seenNumbers.append(number)
        }
    }
    return uniqueNumbers
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var uniqueNumbers = [Int]()
    var seenNumbers = [Int]()
    for number in numbers {
        if !seenNumbers.contains(number) {
            uniqueNumbers.append(number)
            seenNumbers.append(number)
        }
    }
    return uniqueNumbers
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var uniqueNumbers = [Int]()
    var seenNumbers = [Int]()
    for number in numbers {
        if !seenNumbers.contains(number) {
            uniqueNumbers.append(number)
            seenNumbers.append(number)
        }
    }
    return uniqueNumbers
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    

func removeDuplicates(numbers: [Int]) -> [Int] {
    var result = [Int]()
    var seen = [Int]()
    for number in numbers {
        if !seen.contains(number) {
            result.append(number)
            seen.append(number)
        }
    }
    return result
}

func main() {
    assert(removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4])
    assert(removeDuplicates(numbers: [1, 1, 1]) == [1])
    assert(removeDuplicates(numbers: [1]) == [1])
}

```swift
// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var result = [Int]()
    var seen = [Int]()
    for number in numbers {
        if !seen.contains(number) {
            result.append(number)
            seen.append(number)
        }
    }
    return result
}

// Test cases
func main() {
    assert(removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4])
    assert(removeDuplicates(numbers: [1, 1, 1]) == [1])
    assert(removeDuplicates(numbers: [1]) == [1])
}

```

func removeDuplicates(numbers: [Int]) -> [Int] {
    var result = [Int]()
    var seen = [Int]()
    for i in 0..<numbers.count {
        if !seen.contains(numbers[i]) {
            result.append(numbers[i])
            seen.append(numbers[i])
        }
    }
    return result
}

```swift
// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var result = [Int]()
    var seen = [Int]()
    for i in 0..<numbers.count {
        if !seen.contains(numbers[i]) {
            result.append(numbers[i])
            seen.append(numbers[i])
        }
    }
    return result
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var result = [Int]()
    var seen = [Int]()
    for i in 0..<numbers.count {
        if !seen.contains(numbers[i]) {
            result.append(numbers[i])
            seen.append(numbers[i])
        }
    }
    return result
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var result = [Int]()
    var seen = [Int]()
    for i in 0..<numbers.count {
        if !seen.contains(numbers[i]) {
            result.append(numbers[i])
            seen.append(numbers[i])
        }
    }
    return result
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var result = [Int]()
    var seen = [Int]()
    for i in 0..<numbers.count {
        if !seen.contains(numbers[i]) {
            result.append(numbers[i])
            seen.append(numbers[i])
        }
    }
    return result
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var result = [Int]()
    var seen = [Int]()
    for i in 0..<numbers.count {
        if !seen.contains(numbers[i]) {
            result.append(numbers[i])
            seen.append(numbers[i])
        }
    }
    return result
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var result = [Int]()
    var seen = [Int]()
    for i in 0..<numbers.count {
        if !seen.contains(numbers[i]) {
            result.append(numbers[i])
            seen.append(numbers[i])
        }
    }
    return result
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 3, 2, 4]) == [1, 3, 4]
func removeDuplicates(numbers: [Int]) -> [Int] {
    var result = [Int]()
    var seen = [Int]()
    for i in 0..<numbers.count {
        if !seen.contains(numbers[i]) {
            result.append(numbers[i])
            seen.append(numbers[i])
        }
    }
    return result
}

// From an array of integers, remove all elements that occur more than once.
// Keep order of elements left the same as in the input.
// removeDuplicates(numbers: [1, 2, 

func flipCase(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if char.isUpper {
            result += char.lowercase
        } else {
            result += char.uppercase
        }
    }
    return result
}

func removeVowels(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if !char.isVowel {
            result += char
        }
    }
    return result
}

func firstNonRepeatedCharacter(string: String) -> String {
    var charCounts = map<Char, Int>()
    for _, char in string.characters {
        charCounts[char] = charCounts.get(char, 0) + 1
    }
    for _, char in string.characters {
        if charCounts[char] == 1 {
            return char.toString()
        }
    }
    return ""
}

func firstRepeatedCharacter(string: String) -> String {
    var charCounts = map<Char, Int>()
    for _, char in string.characters {
        charCounts[char] = charCounts.get(char, 0) + 1
    }
    for _, char in string.characters {
        if charCounts[char] > 1 {
            return char.toString()
        }
    }
    return ""
}

```swift
// For a given string, flip lowercase characters to uppercase and uppercase to lowercase.
// flipCase(string: "Hello") == "hELLO"
func flipCase(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if char.isUpper {
            result += char.lowercase
        } else {
            result += char.uppercase
        }
    }
    return result
}

// For a given string, remove all vowels.
// removeVowels(string: "Hello") == "Hll"
func removeVowels(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if !char.isVowel {
            result += char
        }
    }
    return result
}

// For a given string, return the first non-repeated character.
// firstNonRepeatedCharacter(string: "Hello") == "H"
func firstNonRepeatedCharacter(string: String) -> String {
    var charCounts = map<Char, Int>()
    for _, char in string.characters {
        charCounts[char] = charCounts.get(char, 0) + 1
    }
    for _, char in string.characters {
        if charCounts[char] == 1 {
            return char.toString()
        }
    }
    return ""
}

// For a given string, return the first repeated character.
// firstRepeatedCharacter(string: "Hello") == "l"
func firstRepeatedCharacter(string: String) -> String {
    var charCounts = map<Char, Int>()
    for _, char in string.characters {
        charCounts[char] = charCounts.get(char, 0) + 1
    }
    for _, char in string.characters {
        if charCounts[char] > 1 {
            return char.toString()
        }
    }
    return ""
}

// For a given string, return the first character that is repeated.
// firstRepeatedCharacter(string: "Hello") == "l"
func firstRepeatedCharacter(string: String) -> String {
    var charCounts = map<Char, Int>()
    for _, char in string.characters {
        charCounts[char] = charCounts.get(char, 0) + 1
    }
    for _, char in string.characters {
        if charCounts[char] > 1 {
            return char.toString()
        }
    }
    return ""
}

// For a given string, return the first character that is repeated.
// firstRepeatedCharacter(string: "Hello") == "l"
func firstRepeatedCharacter(string: String) -> String {
    var charCounts = map<Char, Int>()
    for _, char in string.characters {
        charCounts[char] = charCounts.get(char, 0) + 1
    }
    for _, char in string.characters {
        if charCounts[char] > 1 {
            return char.toString()
        }
    }
    return ""
}

// For a given string, return the first character that is repeated.
// firstRepeatedCharacter(string: "Hello") == "l"
func firstRepeatedCharacter(string: String) -> String {
    var charCounts = map<Char, Int>()
    for _, char in string.characters {
        charCounts[char] = charCounts.get(char, 0) + 1
    }
    for _, char in string.characters {
        if charCounts[char] > 1 {
            return char.toString()
        }
    }
    return ""
}

// For a given string, return the first character that is repeated.
// firstRepeatedCharacter(string: "Hello") == "l"
func firstRepeatedCharacter(string: String) -> String {
    var charCounts = map<Char, Int>()
    for _, char in string.characters {
        charCounts[char] = charCounts.get(char, 0) + 1
    }
    for _, char in string.characters {
        if charCounts[char] > 1 {
            return char.toString()
        }
    }
    return ""
}

// For a given string, return the first character that is repeated.
// firstRepeatedCharacter(string: "Hello") == "l"
func firstRepeatedCharacter(string: String) -> String {
    var charCounts = map<Char, Int>()
    for _, char in string.characters {
        charCounts[char] = charCounts.get(char, 0) + 1
    }
    for _, char in string.characters {
        if charCounts[char

func flipCase(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if char.isUpper {
            result += char.lowercase
        } else {
            result += char.uppercase
        }
    }
    return result
}

func removeVowels(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if !char.isVowel {
            result += char
        }
    }
    return result
}

func countVowels(string: String) -> Int {
    var count = 0
    for _, char in string.characters {
        if char.isVowel {
            count++
        }
    }
    return count
}

func countConsonants(string: String) -> Int {
    var count = 0
    for _, char in string.characters {
        if !char.isVowel {
            count++
        }
    }
    return count
}

func countWords(string: String) -> Int {
    var count = 1
    for _, char in string.characters {
        if char == " " {
            count++
        }
    }
    return count
}

func countCharacters(string: String) -> Int {
    return string.count
}

func countDigits(string: String) -> Int {
    var count = 0
    for _, char in string.characters {
        if char.isDigit {
            count++
        }
    }
    return count
}

func countSymbols(string: String) -> Int {
    var count = 0
    for _, char in string.characters {
        if !char.isLetter || !char.isDigit {
            count++
        }
    }
    return count
}

func countWordsStartingWithVowel(string: String) -> Int {
    var count = 0
    for _, word in string.split(" ") {
        if word.firstCharacter.isVowel {
            count++
        }
    }
    return count
}

func countWordsStartingWithConsonant(string: String) -> Int {
    var count = 0
    for _, word in string.split(" ") {
        if !word.firstCharacter.isVowel {
            count++
        }
    }
    return count
}

func countWordsEndingWithVowel(string: String) -> Int {
    var count = 0
    for _, word in string.split(" ") {
        if word.lastCharacter.isVowel {
            count++
        }
    }
    return count
}

func countWordsEndingWithConsonant(string: String) -> Int {
    var count = 0
    for _, word in string.split(" ") {
        if !word.lastCharacter.isVowel {
            count++
        }
    }
    return count
}

```swift
// For a given string, flip lowercase characters to uppercase and uppercase to lowercase.
// flipCase(string: "Hello") == "hELLO"
func flipCase(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if char.isUpper {
            result += char.lowercase
        } else {
            result += char.uppercase
        }
    }
    return result
}

// For a given string, remove all vowels.
// removeVowels(string: "Hello") == "Hll"
func removeVowels(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if !char.isVowel {
            result += char
        }
    }
    return result
}

// For a given string, return the number of vowels.
// countVowels(string: "Hello") == 2
func countVowels(string: String) -> Int {
    var count = 0
    for _, char in string.characters {
        if char.isVowel {
            count++
        }
    }
    return count
}

// For a given string, return the number of consonants.
// countConsonants(string: "Hello") == 3
func countConsonants(string: String) -> Int {
    var count = 0
    for _, char in string.characters {
        if !char.isVowel {
            count++
        }
    }
    return count
}

// For a given string, return the number of words.
// countWords(string: "Hello World") == 2
func countWords(string: String) -> Int {
    var count = 1
    for _, char in string.characters {
        if char == " " {
            count++
        }
    }
    return count
}

// For a given string, return the number of characters.
// countCharacters(string: "Hello") == 5
func countCharacters(string: String) -> Int {
    return string.count
}

// For a given string, return the number of digits.
// countDigits(string: "Hello 123") == 3
func countDigits(string: String) -> Int {
    var count = 0
    for _, char in string.characters {
        if char.isDigit {
            count++
        }
    }
    return count
}

// For a given string, return the number of symbols.
// countSymbols(string: "Hello!") == 3
func countSymbols(string: String) -> Int {
    var count = 0
    for _, char in string.characters {
        if !char.isLetter || !char.isDigit {
            count++
        }
    }
    return count
}

// For a given string, return the number of words that start with a vowel.
// countWordsStartingWithVowel(string: "Hello World") == 1
func countWordsStartingWithVowel(string: String) -> Int {
    var count = 0
    for _, word in string.split(" ") {
        if word.firstCharacter.isVowel {
            count++
        }
    }
    return count
}

// For a given string, return the number of words that start with a consonant.
// countWordsStartingWithConsonant(string: "Hello World") == 1
func countWordsStartingWithConsonant(string: String) -> Int {
    var count = 0
    for _, word in string.split(" ") {
        if !word.firstCharacter.isVowel {
            count++
        }
    }
    return count
}

// For a given string, return the number of words that end with a vowel.
// countWordsEndingWithVowel(string: "Hello World") == 1
func countWordsEndingWithVowel(string: String) -> Int {
    var count = 0
    for _, word in string.split(" ") {
        if word.lastCharacter.isVowel {
            count++
        }
    }
    return count
}

// For a given string, return the number of words that end with a consonant.
// countWordsEndingWithConsonant(string: "Hello World") == 1
func countWordsEndingWithConsonant(string: String) -> Int {
    var count = 0
    for _, word in string.split(" ") {
        if !word.lastCharacter.isVowel {
            count++
        }
    }
    return count
}

// For a given string, return the number of words that contain a vowel.
// countWordsContainingVowel(string

func flipCase(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if char.isUpper {
            result += char.lowercase
        } else if char.isLower {
            result += char.uppercase
        } else {
            result += char
        }
    }
    return result
}

func countFoo(string: String) -> Int {
    var count = 0
    var index = 0
    while index < string.length {
        var fooIndex = string.index(of: "foo", from: index)
        if fooIndex != -1 {
            count++
            index = fooIndex + 3
        } else {
            break
        }
    }
    return count
}

func capitalizeFirst(string: String) -> String {
    var result = ""
    var capitalizeNext = true
    for _, char in string.characters {
        if char.isWhitespace {
            capitalizeNext = true
        } else if capitalizeNext {
            result += char.uppercase
            capitalizeNext = false
        } else {
            result += char
        }
    }
    return result
}

func capitalizeLast(string: String) -> String {
    var result = ""
    var capitalizeNext = false
    for _, char in string.characters {
        if char.isWhitespace {
            capitalizeNext = true
        } else if capitalizeNext {
            result += char.uppercase
            capitalizeNext = false
        } else {
            result += char
        }
    }
    return result
}

```swift
// For a given string, flip lowercase characters to uppercase and uppercase to lowercase.
// flipCase(string: "Hello") == "hELLO"
func flipCase(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if char.isUpper {
            result += char.lowercase
        } else if char.isLower {
            result += char.uppercase
        } else {
            result += char
        }
    }
    return result
}

// For a given string, return the number of times the string "foo" appears.
// countFoo("foo bar foo") == 2
func countFoo(string: String) -> Int {
    var count = 0
    var index = 0
    while index < string.length {
        var fooIndex = string.index(of: "foo", from: index)
        if fooIndex != -1 {
            count++
            index = fooIndex + 3
        } else {
            break
        }
    }
    return count
}

// For a given string, return the string with the first character of each word capitalized.
// capitalizeFirst("hello world") == "Hello World"
func capitalizeFirst(string: String) -> String {
    var result = ""
    var capitalizeNext = true
    for _, char in string.characters {
        if char.isWhitespace {
            capitalizeNext = true
        } else if capitalizeNext {
            result += char.uppercase
            capitalizeNext = false
        } else {
            result += char
        }
    }
    return result
}

// For a given string, return the string with the last character of each word capitalized.
// capitalizeLast("hello world") == "Hello World"
func capitalizeLast(string: String) -> String {
    var result = ""
    var capitalizeNext = false
    for _, char in string.characters {
        if char.isWhitespace {
            capitalizeNext = true
        } else if capitalizeNext {
            result += char.uppercase
            capitalizeNext = false
        } else {
            result += char
        }
    }
    return result
}

// For a given string, return the string with the first character of each word capitalized.
// capitalizeFirst("hello world") == "Hello World"
func capitalizeFirst(string: String) -> String {
    var result = ""
    var capitalizeNext = true
    for _, char in string.characters {
        if char.isWhitespace {
            capitalizeNext = true
        } else if capitalizeNext {
            result += char.uppercase
            capitalizeNext = false
        } else {
            result += char
        }
    }
    return result
}

// For a given string, return the string with the last character of each word capitalized.
// capitalizeLast("hello world") == "Hello World"
func capitalizeLast(string: String) -> String {
    var result = ""
    var capitalizeNext = false
    for _, char in string.characters {
        if char.isWhitespace {
            capitalizeNext = true
        } else if capitalizeNext {
            result += char.uppercase
            capitalizeNext = false
        } else {
            result += char
        }
    }
    return result
}

// For a given string, return the string with the first character of each word capitalized.
// capitalizeFirst("hello world") == "Hello World"
func capitalizeFirst(string: String) -> String {
    var result = ""
    var capitalizeNext = true
    for _, char in string.characters {
        if char.isWhitespace {
            capitalizeNext = true
        } else if capitalizeNext {
            result += char.uppercase
            capitalizeNext = false
        } else {
            result += char
        }
    }
    return result
}

// For a given string, return the string with the last character of each word capitalized.
// capitalizeLast("hello world") == "Hello World"
func capitalizeLast(string: String) -> String {
    var result = ""
    var capitalizeNext = false
    for _, char in string.characters {
        if char.isWhitespace {
            capitalizeNext = true
        } else if capitalizeNext {
            result += char.uppercase
            capitalizeNext = false
        } else {
            result += char
        }
    }
    return result
}

// For a given string, return the string with the first character of each word capitalized.
// capitalizeFirst("hello world") == "Hello World"
func capitalizeFirst(string: String) -> String {
    var result = ""
    var capitalizeNext = true
    for _, char in string.characters {
        if char.isWhitespace {
            capitalizeNext = true
        

func flipCase(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if char.isUpper {
            result += char.lowercase
        } else {
            result += char.uppercase
        }
    }
    return result
}

func removeVowels(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if !char.isVowel {
            result += char
        }
    }
    return result
}

func removeConsonants(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if char.isConsonant {
            result += char
        }
    }
    return result
}

func removePunctuation(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if !char.isPunctuation {
            result += char
        }
    }
    return result
}

func removeDigits(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if !char.isDigit {
            result += char
        }
    }
    return result
}

func removeWhitespace(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if !char.isWhitespace {
            result += char
        }
    }
    return result
}

func removeNonAlphanumeric(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if char.isAlphanumeric {
            result += char
        }
    }
    return result
}

```swift
// For a given string, flip lowercase characters to uppercase and uppercase to lowercase.
// flipCase(string: "Hello") == "hELLO"
func flipCase(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if char.isUpper {
            result += char.lowercase
        } else {
            result += char.uppercase
        }
    }
    return result
}

// For a given string, remove all vowels.
// removeVowels(string: "Hello") == "Hll"
func removeVowels(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if !char.isVowel {
            result += char
        }
    }
    return result
}

// For a given string, remove all consonants.
// removeConsonants(string: "Hello") == "Hll"
func removeConsonants(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if char.isConsonant {
            result += char
        }
    }
    return result
}

// For a given string, remove all punctuation.
// removePunctuation(string: "Hello, World!") == "Hello World"
func removePunctuation(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if !char.isPunctuation {
            result += char
        }
    }
    return result
}

// For a given string, remove all digits.
// removeDigits(string: "Hello, World!") == "Hll, Wrd!"
func removeDigits(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if !char.isDigit {
            result += char
        }
    }
    return result
}

// For a given string, remove all whitespace.
// removeWhitespace(string: "Hello, World!") == "Hello, World!"
func removeWhitespace(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if !char.isWhitespace {
            result += char
        }
    }
    return result
}

// For a given string, remove all non-alphanumeric characters.
// removeNonAlphanumeric(string: "Hello, World!") == "Hello World"
func removeNonAlphanumeric(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if char.isAlphanumeric {
            result += char
        }
    }
    return result
}

// For a given string, remove all non-alphanumeric characters.
// removeNonAlphanumeric(string: "Hello, World!") == "Hello World"
func removeNonAlphanumeric(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if char.isAlphanumeric {
            result += char
        }
    }
    return result
}

// For a given string, remove all non-alphanumeric characters.
// removeNonAlphanumeric(string: "Hello, World!") == "Hello World"
func removeNonAlphanumeric(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if char.isAlphanumeric {
            result += char
        }
    }
    return result
}

// For a given string, remove all non-alphanumeric characters.
// removeNonAlphanumeric(string: "Hello, World!") == "Hello World"
func removeNonAlphanumeric(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if char.isAlphanumeric {
            result += char
        }
    }
    return result
}

// For a given string, remove all non-alphanumeric characters.
// removeNonAlphanumeric(string: "Hello, World!") == "Hello World"
func removeNonAlphanumeric(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if char.isAlphanumeric {
            result += char
        }
    }
    return result
}

// For a given string, remove all non-alphanumeric characters.
// removeNonAlphanumeric(string: "Hello, World!") == "Hello World"
func removeNonAlphanumeric(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if char.isAlphanumeric {
            result += char
        }
    }
    return result
}

// For a given string, remove all

func flipCase(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if char.isUpper {
            result += char.lowercase
        } else {
            result += char.uppercase
        }
    }
    return result
}

func removeVowels(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if !char.isVowel {
            result += char
        }
    }
    return result
}

func longestVowelSubstring(string: String) -> String {
    var longest = ""
    var current = ""
    for _, char in string.characters {
        if char.isVowel {
            current += char
        } else {
            if current.count > longest.count {
                longest = current
            }
            current = ""
        }
    }
    if current.count > longest.count {
        longest = current
    }
    return longest
}

func firstNonRepeatingCharacter(string: String) -> String {
    var counts = [String: Int]()
    for _, char in string.characters {
        if counts.contains(char) {
            counts[char] += 1
        } else {
            counts[char] = 1
        }
    }
    for _, char in string.characters {
        if counts[char] == 1 {
            return char
        }
    }
    return ""
}

func firstRepeatingCharacter(string: String) -> String {
    var counts = [String: Int]()
    for _, char in string.characters {
        if counts.contains(char) {
            return char
        } else {
            counts[char] = 1
        }
    }
    return ""
}

```swift
// For a given string, flip lowercase characters to uppercase and uppercase to lowercase.
// flipCase(string: "Hello") == "hELLO"
func flipCase(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if char.isUpper {
            result += char.lowercase
        } else {
            result += char.uppercase
        }
    }
    return result
}

// For a given string, remove all vowels.
// removeVowels(string: "Hello") == "Hll"
func removeVowels(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if !char.isVowel {
            result += char
        }
    }
    return result
}

// For a given string, return the longest substring of consecutive vowels.
// longestVowelSubstring(string: "Hello") == "oo"
func longestVowelSubstring(string: String) -> String {
    var longest = ""
    var current = ""
    for _, char in string.characters {
        if char.isVowel {
            current += char
        } else {
            if current.count > longest.count {
                longest = current
            }
            current = ""
        }
    }
    if current.count > longest.count {
        longest = current
    }
    return longest
}

// For a given string, return the first non-repeating character.
// firstNonRepeatingCharacter(string: "Hello") == "H"
func firstNonRepeatingCharacter(string: String) -> String {
    var counts = [String: Int]()
    for _, char in string.characters {
        if counts.contains(char) {
            counts[char] += 1
        } else {
            counts[char] = 1
        }
    }
    for _, char in string.characters {
        if counts[char] == 1 {
            return char
        }
    }
    return ""
}

// For a given string, return the first repeating character.
// firstRepeatingCharacter(string: "Hello") == "l"
func firstRepeatingCharacter(string: String) -> String {
    var counts = [String: Int]()
    for _, char in string.characters {
        if counts.contains(char) {
            return char
        } else {
            counts[char] = 1
        }
    }
    return ""
}

// For a given string, return the first character that appears twice.
// firstRepeatingCharacter(string: "Hello") == "l"
func firstRepeatingCharacter(string: String) -> String {
    var counts = [String: Int]()
    for _, char in string.characters {
        if counts.contains(char) {
            return char
        } else {
            counts[char] = 1
        }
    }
    return ""
}

// For a given string, return the first character that appears twice.
// firstRepeatingCharacter(string: "Hello") == "l"
func firstRepeatingCharacter(string: String) -> String {
    var counts = [String: Int]()
    for _, char in string.characters {
        if counts.contains(char) {
            return char
        } else {
            counts[char] = 1
        }
    }
    return ""
}

// For a given string, return the first character that appears twice.
// firstRepeatingCharacter(string: "Hello") == "l"
func firstRepeatingCharacter(string: String) -> String {
    var counts = [String: Int]()
    for _, char in string.characters {
        if counts.contains(char) {
            return char
        } else {
            counts[char] = 1
        }
    }
    return ""
}

// For a given string, return the first character that appears twice.
// firstRepeatingCharacter(string: "Hello") == "l"
func firstRepeatingCharacter(string: String) -> String {
    var counts = [String: Int]()
    for _, char in string.characters {
        if counts.contains(char) {
            return char
        } else {
            counts[char] = 1
        }
    }
    return ""
}

// For a given string, return the first character that appears twice.
// firstRepeatingCharacter(string: "Hello") == "l"
func firstRepeatingCharacter(string: String) -> String {
    var counts = [String: Int]()
    for _, char in string.characters {
        if counts.contains(char) {
            return char
        } else {
            counts[char] = 

func flipCase(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if char.isUpper {
            result += char.lowercase
        } else {
            result += char.uppercase
        }
    }
    return result
}

func removeVowels(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if !char.isVowel {
            result += char
        }
    }
    return result
}

func reverse(string: String) -> String {
    var result = ""
    for _, char in string.characters.reversed {
        result += char
    }
    return result
}

func removeNonAlphabetic(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if char.isAlphabetic {
            result += char
        }
    }
    return result
}

func isPalindrome(string: String) -> Bool {
    var reversed = reverse(string)
    return string == reversed
}

func countOccurrences(string: String, character: Char) -> Int {
    var count = 0
    for _, char in string.characters {
        if char == character {
            count++
        }
    }
    return count
}

func findFirstOccurrence(string: String, character: Char) -> Int {
    for index, char in string.characters.enumerated {
        if char == character {
            return index
        }
    }
    return -1
}

func findLastOccurrence(string: String, character: Char) -> Int {
    for index in string.characters.count downTo 0 {
        if string[index] == character {
            return index
        }
    }
    return -1
}

func longestSubstringWithoutRepeatingCharacters(string: String) -> String {
    var longest = ""
    var current = ""
    for _, char in string.characters {
        if !current.contains(char) {
            current += char
        } else {
            if current.count > longest.count {
                longest = current
            }
            current = char
        }
    }
    if current.count > longest.count {
        longest = current
    }
    return longest
}

```swift
// For a given string, flip lowercase characters to uppercase and uppercase to lowercase.
// flipCase(string: "Hello") == "hELLO"
func flipCase(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if char.isUpper {
            result += char.lowercase
        } else {
            result += char.uppercase
        }
    }
    return result
}

// For a given string, remove all vowels.
// removeVowels(string: "Hello") == "Hll"
func removeVowels(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if !char.isVowel {
            result += char
        }
    }
    return result
}

// For a given string, reverse the order of its characters.
// reverse(string: "Hello") == "olleH"
func reverse(string: String) -> String {
    var result = ""
    for _, char in string.characters.reversed {
        result += char
    }
    return result
}

// For a given string, remove all non-alphabetic characters.
// removeNonAlphabetic(string: "Hello, World!") == "HelloWorld"
func removeNonAlphabetic(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if char.isAlphabetic {
            result += char
        }
    }
    return result
}

// For a given string, check if it is a palindrome.
// isPalindrome(string: "racecar") == true
// isPalindrome(string: "hello") == false
func isPalindrome(string: String) -> Bool {
    var reversed = reverse(string)
    return string == reversed
}

// For a given string, count the number of occurrences of a given character.
// countOccurrences(string: "Hello, World!", character: 'l') == 2
func countOccurrences(string: String, character: Char) -> Int {
    var count = 0
    for _, char in string.characters {
        if char == character {
            count++
        }
    }
    return count
}

// For a given string, find the first occurrence of a given character.
// findFirstOccurrence(string: "Hello, World!", character: 'l') == 2
// findFirstOccurrence(string: "Hello, World!", character: 'x') == -1
func findFirstOccurrence(string: String, character: Char) -> Int {
    for index, char in string.characters.enumerated {
        if char == character {
            return index
        }
    }
    return -1
}

// For a given string, find the last occurrence of a given character.
// findLastOccurrence(string: "Hello, World!", character: 'l') == 8
// findLastOccurrence(string: "Hello, World!", character: 'x') == -1
func findLastOccurrence(string: String, character: Char) -> Int {
    for index in string.characters.count downTo 0 {
        if string[index] == character {
            return index
        }
    }
    return -1
}

// For a given string, find the longest substring without repeating characters.
// longestSubstringWithoutRepeatingCharacters(string: "abcabcbb") == "abc"
// longestSubstringWithoutRepeatingCharacters(string: "bbbbb") == "b"
// longestSubstringWithoutRepeatingCharacters(string: "pwwkew") == "wke"
func longestSubstringWithoutRepeatingCharacters(string: String) -> String {
    var longest = ""
    var current = ""
    for _, char in string.characters {
        if !current.contains(char) {
            current += char
        } else {
            if current.count > longest.count {
                longest = current
            }
            current = char
        }
    }
    if current.count > longest.count {
        longest = current
    }
    return longest
}

// For a given string, find the first non-repeating character.
// firstNonRepeatingCharacter(string: "abcabcbb") == 'd'
// firstNonRepeatingCharacter(string: "bbbbb") == 'b'
// firstNonRepeatingCharacter(string: "pwwkew") == 'k'
func firstNonRepeatingCharacter(string: String) -> Char? {
    var seen = Map<Char, Int>()
    for index, char in string.characters.enumerated {
        if seen.contains(char) {
            seen[char] = seen[char]! + 1
        } else {
            seen[char] = 1

func flipCase(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if char.isUpper {
            result += char.lowercase
        } else if char.isLower {
            result += char.uppercase
        } else {
            result += char
        }
    }
    return result
}

func capitalizeFirstLetters(string: String) -> String {
    var result = ""
    var capitalizeNext = true
    for _, char in string.characters {
        if char.isWhitespace {
            capitalizeNext = true
        } else if capitalizeNext {
            result += char.uppercase
            capitalizeNext = false
        } else {
            result += char
        }
    }
    return result
}

func capitalizeLastLetters(string: String) -> String {
    var result = ""
    var capitalizeNext = true
    for _, char in string.characters.reversed {
        if char.isWhitespace {
            capitalizeNext = true
        } else if capitalizeNext {
            result += char.uppercase
            capitalizeNext = false
        } else {
            result += char
        }
    }
    return result.reversed
}

```swift
// For a given string, flip lowercase characters to uppercase and uppercase to lowercase.
// flipCase(string: "Hello") == "hELLO"
func flipCase(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if char.isUpper {
            result += char.lowercase
        } else if char.isLower {
            result += char.uppercase
        } else {
            result += char
        }
    }
    return result
}

// For a given string, return a string of the same length with the first character of each word capitalized.
// capitalizeFirstLetters(string: "hello world") == "Hello World"
func capitalizeFirstLetters(string: String) -> String {
    var result = ""
    var capitalizeNext = true
    for _, char in string.characters {
        if char.isWhitespace {
            capitalizeNext = true
        } else if capitalizeNext {
            result += char.uppercase
            capitalizeNext = false
        } else {
            result += char
        }
    }
    return result
}

// For a given string, return a string of the same length with the last character of each word capitalized.
// capitalizeLastLetters(string: "hello world") == "Hello World"
func capitalizeLastLetters(string: String) -> String {
    var result = ""
    var capitalizeNext = true
    for _, char in string.characters.reversed {
        if char.isWhitespace {
            capitalizeNext = true
        } else if capitalizeNext {
            result += char.uppercase
            capitalizeNext = false
        } else {
            result += char
        }
    }
    return result.reversed
}

// For a given string, return a string of the same length with the first character of each word capitalized.
// capitalizeFirstLetters(string: "hello world") == "Hello World"
func capitalizeFirstLetters(string: String) -> String {
    var result = ""
    var capitalizeNext = true
    for _, char in string.characters {
        if char.isWhitespace {
            capitalizeNext = true
        } else if capitalizeNext {
            result += char.uppercase
            capitalizeNext = false
        } else {
            result += char
        }
    }
    return result
}

// For a given string, return a string of the same length with the last character of each word capitalized.
// capitalizeLastLetters(string: "hello world") == "Hello World"
func capitalizeLastLetters(string: String) -> String {
    var result = ""
    var capitalizeNext = true
    for _, char in string.characters.reversed {
        if char.isWhitespace {
            capitalizeNext = true
        } else if capitalizeNext {
            result += char.uppercase
            capitalizeNext = false
        } else {
            result += char
        }
    }
    return result.reversed
}

// For a given string, return a string of the same length with the first character of each word capitalized.
// capitalizeFirstLetters(string: "hello world") == "Hello World"
func capitalizeFirstLetters(string: String) -> String {
    var result = ""
    var capitalizeNext = true
    for _, char in string.characters {
        if char.isWhitespace {
            capitalizeNext = true
        } else if capitalizeNext {
            result += char.uppercase
            capitalizeNext = false
        } else {
            result += char
        }
    }
    return result
}

// For a given string, return a string of the same length with the last character of each word capitalized.
// capitalizeLastLetters(string: "hello world") == "Hello World"
func capitalizeLastLetters(string: String) -> String {
    var result = ""
    var capitalizeNext = true
    for _, char in string.characters.reversed {
        if char.isWhitespace {
            capitalizeNext = true
        } else if capitalizeNext {
            result += char.uppercase
            capitalizeNext = false
        } else {
            result += char
        }
    }
    return result.reversed
}

// For a given string, return a string of the same length with the first character of each word capitalized.
// capitalizeFirstLetters(string: "hello world") == "Hello World"
func capitalizeFirstLetters(string: String) -> String {
    var result = ""
    var capitalizeNext = true
    for _, char in string.characters {
        if char.isWhitespace {
            capitalizeNext = true
        } else if capitalizeNext {
            result += char.uppercase
            capitalizeNext = false
        } else {
            result += char
        }
    }
    return result
}

// For a given string, return a string of

func flipCase(string: String) -> String {
    var result = ""
    for _, char in string.characterByCharacter {
        if char.isUpper {
            result += char.lowercase
        } else {
            result += char.uppercase
        }
    }
    return result
}

func countVowels(string: String) -> Int {
    var count = 0
    for _, char in string.characterByCharacter {
        if char.isVowel {
            count += 1
        }
    }
    return count
}

func countConsonants(string: String) -> Int {
    var count = 0
    for _, char in string.characterByCharacter {
        if char.isConsonant {
            count += 1
        }
    }
    return count
}

func countDigits(string: String) -> Int {
    var count = 0
    for _, char in string.characterByCharacter {
        if char.isDigit {
            count += 1
        }
    }
    return count
}

func countWhitespace(string: String) -> Int {
    var count = 0
    for _, char in string.characterByCharacter {
        if char.isWhitespace {
            count += 1
        }
    }
    return count
}

func countPunctuation(string: String) -> Int {
    var count = 0
    for _, char in string.characterByCharacter {
        if char.isPunctuation {
            count += 1
        }
    }
    return count
}

func countSymbols(string: String) -> Int {
    var count = 0
    for _, char in string.characterByCharacter {
        if char.isSymbol {
            count += 1
        }
    }
    return count
}

```swift
// For a given string, flip lowercase characters to uppercase and uppercase to lowercase.
// flipCase(string: "Hello") == "hELLO"
func flipCase(string: String) -> String {
    var result = ""
    for _, char in string.characterByCharacter {
        if char.isUpper {
            result += char.lowercase
        } else {
            result += char.uppercase
        }
    }
    return result
}

// For a given string, return the number of vowels.
// countVowels(string: "Hello") == 2
func countVowels(string: String) -> Int {
    var count = 0
    for _, char in string.characterByCharacter {
        if char.isVowel {
            count += 1
        }
    }
    return count
}

// For a given string, return the number of consonants.
// countConsonants(string: "Hello") == 3
func countConsonants(string: String) -> Int {
    var count = 0
    for _, char in string.characterByCharacter {
        if char.isConsonant {
            count += 1
        }
    }
    return count
}

// For a given string, return the number of digits.
// countDigits(string: "Hello") == 0
func countDigits(string: String) -> Int {
    var count = 0
    for _, char in string.characterByCharacter {
        if char.isDigit {
            count += 1
        }
    }
    return count
}

// For a given string, return the number of whitespace characters.
// countWhitespace(string: "Hello") == 0
func countWhitespace(string: String) -> Int {
    var count = 0
    for _, char in string.characterByCharacter {
        if char.isWhitespace {
            count += 1
        }
    }
    return count
}

// For a given string, return the number of punctuation characters.
// countPunctuation(string: "Hello") == 0
func countPunctuation(string: String) -> Int {
    var count = 0
    for _, char in string.characterByCharacter {
        if char.isPunctuation {
            count += 1
        }
    }
    return count
}

// For a given string, return the number of symbols.
// countSymbols(string: "Hello") == 0
func countSymbols(string: String) -> Int {
    var count = 0
    for _, char in string.characterByCharacter {
        if char.isSymbol {
            count += 1
        }
    }
    return count
}

// For a given string, return the number of whitespace characters.
// countWhitespace(string: "Hello") == 0
func countWhitespace(string: String) -> Int {
    var count = 0
    for _, char in string.characterByCharacter {
        if char.isWhitespace {
            count += 1
        }
    }
    return count
}

// For a given string, return the number of symbols.
// countSymbols(string: "Hello") == 0
func countSymbols(string: String) -> Int {
    var count = 0
    for _, char in string.characterByCharacter {
        if char.isSymbol {
            count += 1
        }
    }
    return count
}

// For a given string, return the number of symbols.
// countSymbols(string: "Hello") == 0
func countSymbols(string: String) -> Int {
    var count = 0
    for _, char in string.characterByCharacter {
        if char.isSymbol {
            count += 1
        }
    }
    return count
}

// For a given string, return the number of symbols.
// countSymbols(string: "Hello") == 0
func countSymbols(string: String) -> Int {
    var count = 0
    for _, char in string.characterByCharacter {
        if char.isSymbol {
            count += 1
        }
    }
    return count
}

// For a given string, return the number of symbols.
// countSymbols(string: "Hello") == 0
func countSymbols(string: String) -> Int {
    var count = 0
    for _, char in string.characterByCharacter {
        if char.isSymbol {
            count += 1
        }
    }
    return count
}

// For a given string, return the number of symbols.
// countSymbols(string: "Hello") == 0
func countSymbols(string: String) -> Int {
    

func flipCase(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if char.isUpper {
            result += char.lowercase
        } else if char.isLower {
            result += char.uppercase
        } else {
            result += char
        }
    }
    return result
}

func findLongestWord(string: String) -> String {
    var words = string.components(separatedBy: " ")
    var longestWord = ""
    for _, word in words {
        if word.count > longestWord.count {
            longestWord = word
        }
    }
    return longestWord
}

func countVowels(string: String) -> Int {
    var vowels = "aeiouAEIOU"
    var count = 0
    for _, char in string.characters {
        if vowels.contains(char) {
            count += 1
        }
    }
    return count
}

func countConsonants(string: String) -> Int {
    var consonants = "bcdfghjklmnpqrstvwxyzBCDFGHJKLMNPQRSTVWXYZ"
    var count = 0
    for _, char in string.characters {
        if consonants.contains(char) {
            count += 1
        }
    }
    return count
}

func countWords(string: String) -> Int {
    return string.components(separatedBy: " ").count
}

func countSentences(string: String) -> Int {
    var sentences = string.components(separatedBy: ".")
    return sentences.count
}

func countParagraphs(string: String) -> Int {
    var paragraphs = string.components(separatedBy: "\n\n")
    return paragraphs.count
}

func countLines(string: String) -> Int {
    return string.components(separatedBy: "\n").count
}

func countCharacters(string: String) -> Int {
    return string.characters.count
}

func countWordsWithLengthGreaterThan5(string: String) -> Int {
    var words = string.components(separatedBy: " ")
    var count = 0
    for _, word in words {
        if word.count > 5 {
            count += 1
        }
    }
    return count
}

func countWordsWithLengthLessThan5(string: String) -> Int {
    var words = string.components(separatedBy: " ")
    var count = 0
    for _, word in words {
        if word.count < 5 {
            count += 1
        }
    }
    return count
}

```swift
// For a given string, flip lowercase characters to uppercase and uppercase to lowercase.
// flipCase(string: "Hello") == "hELLO"
func flipCase(string: String) -> String {
    var result = ""
    for _, char in string.characters {
        if char.isUpper {
            result += char.lowercase
        } else if char.isLower {
            result += char.uppercase
        } else {
            result += char
        }
    }
    return result
}

// For a given string, find the longest word.
// findLongestWord(string: "Hello, world!") == "world"
func findLongestWord(string: String) -> String {
    var words = string.components(separatedBy: " ")
    var longestWord = ""
    for _, word in words {
        if word.count > longestWord.count {
            longestWord = word
        }
    }
    return longestWord
}

// For a given string, find the number of vowels.
// countVowels(string: "Hello") == 2
func countVowels(string: String) -> Int {
    var vowels = "aeiouAEIOU"
    var count = 0
    for _, char in string.characters {
        if vowels.contains(char) {
            count += 1
        }
    }
    return count
}

// For a given string, find the number of consonants.
// countConsonants(string: "Hello") == 3
func countConsonants(string: String) -> Int {
    var consonants = "bcdfghjklmnpqrstvwxyzBCDFGHJKLMNPQRSTVWXYZ"
    var count = 0
    for _, char in string.characters {
        if consonants.contains(char) {
            count += 1
        }
    }
    return count
}

// For a given string, find the number of words.
// countWords(string: "Hello, world!") == 2
func countWords(string: String) -> Int {
    return string.components(separatedBy: " ").count
}

// For a given string, find the number of sentences.
// countSentences(string: "Hello, world! How are you?") == 2
func countSentences(string: String) -> Int {
    var sentences = string.components(separatedBy: ".")
    return sentences.count
}

// For a given string, find the number of paragraphs.
// countParagraphs(string: "Hello, world!\n\nHow are you?") == 2
func countParagraphs(string: String) -> Int {
    var paragraphs = string.components(separatedBy: "\n\n")
    return paragraphs.count
}

// For a given string, find the number of lines.
// countLines(string: "Hello, world!\n\nHow are you?") == 3
func countLines(string: String) -> Int {
    return string.components(separatedBy: "\n").count
}

// For a given string, find the number of characters.
// countCharacters(string: "Hello, world!") == 13
func countCharacters(string: String) -> Int {
    return string.characters.count
}

// For a given string, find the number of words with a length greater than 5.
// countWordsWithLengthGreaterThan5(string: "Hello, world!") == 2
func countWordsWithLengthGreaterThan5(string: String) -> Int {
    var words = string.components(separatedBy: " ")
    var count = 0
    for _, word in words {
        if word.count > 5 {
            count += 1
        }
    }
    return count
}

// For a given string, find the number of words with a length less than 5.
// countWordsWithLengthLessThan5(string: "Hello, world!") == 2
func countWordsWithLengthLessThan5(string: String) -> Int {
    var words = string.components(separatedBy: " ")
    var count = 0
    for _, word in words {
        if word.count < 5 {
            count += 1
        }
    }
    return count
}

// For a given string, find the number of words with a length between 5 and 10.
// countWordsWithLengthBetween5And10(string: "Hello, world!") == 2
func countWordsWithLengthBetween5And10(string: String) -> Int {
    var words = string.components(separatedBy: " ")
    var count = 0
    for _, word in words {
        if word.count >= 5 && word.count <= 1

func flipCase(string: String) -> String {
    var result = ""
    for _, char in string.characterByCharacter {
        if char.isUpper {
            result += char.lowercase
        } else {
            result += char.uppercase
        }
    }
    return result
}

func countVowels(string: String) -> Int {
    var count = 0
    for _, char in string.characterByCharacter {
        if char.isVowel {
            count++
        }
    }
    return count
}

func countConsonants(string: String) -> Int {
    var count = 0
    for _, char in string.characterByCharacter {
        if char.isConsonant {
            count++
        }
    }
    return count
}

func countDigits(string: String) -> Int {
    var count = 0
    for _, char in string.characterByCharacter {
        if char.isDigit {
            count++
        }
    }
    return count
}

func countSpaces(string: String) -> Int {
    var count = 0
    for _, char in string.characterByCharacter {
        if char.isSpace {
            count++
        }
    }
    return count
}

func countNonWhitespace(string: String) -> Int {
    var count = 0
    for _, char in string.characterByCharacter {
        if !char.isWhitespace {
            count++
        }
    }
    return count
}

func countWords(string: String) -> Int {
    var count = 1
    for _, char in string.characterByCharacter {
        if char.isWhitespace {
            count++
        }
    }
    return count
}

func countSentences(string: String) -> Int {
    var count = 0
    for _, char in string.characterByCharacter {
        if char.isSentenceTerminator {
            count++
        }
    }
    return count
}

func countParagraphs(string: String) -> Int {
    var count = 1
    for _, char in string.characterByCharacter {
        if char.isParagraphTerminator {
            count++
        }
    }
    return count
}

func countLines(string: String) -> Int {
    var count = 1
    for _, char in string.characterByCharacter {
        if char.isLineTerminator {
            count++
        }
    }
    return count
}

```swift
// For a given string, flip lowercase characters to uppercase and uppercase to lowercase.
// flipCase(string: "Hello") == "hELLO"
func flipCase(string: String) -> String {
    var result = ""
    for _, char in string.characterByCharacter {
        if char.isUpper {
            result += char.lowercase
        } else {
            result += char.uppercase
        }
    }
    return result
}

// For a given string, return the number of vowels in the string.
// countVowels(string: "Hello") == 2
func countVowels(string: String) -> Int {
    var count = 0
    for _, char in string.characterByCharacter {
        if char.isVowel {
            count++
        }
    }
    return count
}

// For a given string, return the number of consonants in the string.
// countConsonants(string: "Hello") == 3
func countConsonants(string: String) -> Int {
    var count = 0
    for _, char in string.characterByCharacter {
        if char.isConsonant {
            count++
        }
    }
    return count
}

// For a given string, return the number of digits in the string.
// countDigits(string: "Hello") == 0
func countDigits(string: String) -> Int {
    var count = 0
    for _, char in string.characterByCharacter {
        if char.isDigit {
            count++
        }
    }
    return count
}

// For a given string, return the number of spaces in the string.
// countSpaces(string: "Hello") == 1
func countSpaces(string: String) -> Int {
    var count = 0
    for _, char in string.characterByCharacter {
        if char.isSpace {
            count++
        }
    }
    return count
}

// For a given string, return the number of non-whitespace characters in the string.
// countNonWhitespace(string: "Hello") == 5
func countNonWhitespace(string: String) -> Int {
    var count = 0
    for _, char in string.characterByCharacter {
        if !char.isWhitespace {
            count++
        }
    }
    return count
}

// For a given string, return the number of words in the string.
// countWords(string: "Hello world") == 2
func countWords(string: String) -> Int {
    var count = 1
    for _, char in string.characterByCharacter {
        if char.isWhitespace {
            count++
        }
    }
    return count
}

// For a given string, return the number of sentences in the string.
// countSentences(string: "Hello. world!") == 2
func countSentences(string: String) -> Int {
    var count = 0
    for _, char in string.characterByCharacter {
        if char.isSentenceTerminator {
            count++
        }
    }
    return count
}

// For a given string, return the number of paragraphs in the string.
// countParagraphs(string: "Hello.\n\nworld!") == 2
func countParagraphs(string: String) -> Int {
    var count = 1
    for _, char in string.characterByCharacter {
        if char.isParagraphTerminator {
            count++
        }
    }
    return count
}

// For a given string, return the number of lines in the string.
// countLines(string: "Hello.\n\nworld!") == 3
func countLines(string: String) -> Int {
    var count = 1
    for _, char in string.characterByCharacter {
        if char.isLineTerminator {
            count++
        }
    }
    return count
}

// For a given string, return the number of words in the string.
// countWords(string: "Hello world") == 2
func countWords(string: String) -> Int {
    var count = 1
    for _, char in string.characterByCharacter {
        if char.isWhitespace {
            count++
        }
    }
    return count
}

// For a given string, return the number of sentences in the string.
// countSentences(string: "Hello. world!") == 2
func countSentences(string: String) -> Int {
    var count = 0
    for _, char in string.characterByCharacter {
        if char.isSentenceTerminator {
            count++
        }
    }
    return count
}

// For

func concatenate(strings: [String]) -> String {
    var result = ""
    for _, string in strings {
        result += string
    }
    return result
}

func concatenate(integers: [Int]) -> String {
    var result = ""
    for _, integer in integers {
        result += integer.String()
    }
    return result
}

func concatenate(floats: [Double]) -> String {
    var result = ""
    for _, float in floats {
        result += float.String()
    }
    return result
}

func concatenate(booleans: [Bool]) -> String {
    var result = ""
    for _, boolean in booleans {
        result += boolean.String()
    }
    return result
}

func concatenate(characters: [Char]) -> String {
    var result = ""
    for _, character in characters {
        result += character.String()
    }
    return result
}

func concatenate(dates: [Date]) -> String {
    var result = ""
    for _, date in dates {
        result += date.String()
    }
    return result
}

func concatenate(urls: [URL]) -> String {
    var result = ""
    for _, url in urls {
        result += url.String()
    }
    return result
}

func concatenate(uuids: [UUID]) -> String {
    var result = ""
    for _, uuid in uuids {
        result += uuid.String()
    }
    return result
}

func concatenate(numbers: [Number]) -> String {
    var result = ""
    for _, number in numbers {
        result += number.String()
    }
    return result
}

```swift
// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    var result = ""
    for _, string in strings {
        result += string
    }
    return result
}

// Concatenate array of integers into a single string
// concatenate(integers: [] as [Int]) == ""
// concatenate(integers: [1, 2, 3]) == "123"
func concatenate(integers: [Int]) -> String {
    var result = ""
    for _, integer in integers {
        result += integer.String()
    }
    return result
}

// Concatenate array of floats into a single string
// concatenate(floats: [] as [Double]) == ""
// concatenate(floats: [1.0, 2.0, 3.0]) == "1.02.0"
func concatenate(floats: [Double]) -> String {
    var result = ""
    for _, float in floats {
        result += float.String()
    }
    return result
}

// Concatenate array of booleans into a single string
// concatenate(booleans: [] as [Bool]) == ""
// concatenate(booleans: [true, false]) == "truefalse"
func concatenate(booleans: [Bool]) -> String {
    var result = ""
    for _, boolean in booleans {
        result += boolean.String()
    }
    return result
}

// Concatenate array of characters into a single string
// concatenate(characters: [] as [Char]) == ""
// concatenate(characters: ["a", "b", "c"]) == "abc"
func concatenate(characters: [Char]) -> String {
    var result = ""
    for _, character in characters {
        result += character.String()
    }
    return result
}

// Concatenate array of dates into a single string
// concatenate(dates: [] as [Date]) == ""
// concatenate(dates: [Date(year: 2021, month: 1, day: 1), Date(year: 2022, month: 1, day: 1)]) == "2021-01-012022-01-01"
func concatenate(dates: [Date]) -> String {
    var result = ""
    for _, date in dates {
        result += date.String()
    }
    return result
}

// Concatenate array of URLs into a single string
// concatenate(urls: [] as [URL]) == ""
// concatenate(urls: [URL(string: "http://www.example.com"), URL(string: "https://www.google.com")]) == "http://www.example.comhttps://www.google.com"
func concatenate(urls: [URL]) -> String {
    var result = ""
    for _, url in urls {
        result += url.String()
    }
    return result
}

// Concatenate array of UUIDs into a single string
// concatenate(uuids: [] as [UUID]) == ""
// concatenate(uuids: [UUID(string: "123e4567-e89b-12d3-a456-426614174000"), UUID(string: "123e4567-e89b-12d3-a456-426614174001")]) == "123e4567e89b12d3a456426614174000123e4567e89b12d3a456426614174001"
func concatenate(uuids: [UUID]) -> String {
    var result = ""
    for _, uuid in uuids {
        result += uuid.String()
    }
    return result
}

// Concatenate array of numbers into a single string
// concatenate(numbers: [] as [Number]) == ""
// concatenate(numbers: [1, 2, 3]) == "123"
func concatenate(numbers: [Number]) -> String {
    var result = ""
    for _, number in numbers {
        result += number.String()
    }
    return result
}

// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String

func concatenate(strings: [String]) -> String {
    return strings.reduce(initial: "", block: (acc: String, s: String) -> String {
        return acc + s
    })
}

func split(string: String, separator: String) -> [String] {
    return string.split(separator: separator)
}

func remove(string: String, substring: String) -> String {
    return string.replace(regex: substring, with: "")
}

func index(string: String, substring: String) -> Int {
    return string.index(of: substring)
}

func lastIndex(string: String, substring: String) -> Int {
    return string.lastIndex(of: substring)
}

func length(string: String) -> Int {
    return string.count
}

func count(string: String, substring: String) -> Int {
    return string.count(of: substring)
}

func position(string: String, substring: String) -> Int {
    return string.position(of: substring)
}

func lastPosition(string: String, substring: String) -> Int {
    return string.lastPosition(of: substring)
}

func find(string: String, substring: String) -> Int {
    return string.find(of: substring)
}

func lastFind(string: String, substring: String) -> Int {
    return string.lastFind(of: substring)
}

func startsWith(string: String, prefix: String) -> Bool {
    return string.startsWith(prefix: prefix)
}

func endsWith(string: String, suffix: String) -> Bool {
    return string.endsWith(suffix: suffix)
}

func contains(string: String, substring: String) -> Bool {
    return string.contains(substring: substring)
}

```swift
// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    return strings.reduce(initial: "", block: (acc: String, s: String) -> String {
        return acc + s
    })
}

// Split a string into an array of substrings
// split(string: "", separator: ",") == []
// split(string: "a,b,c", separator: ",") == ["a", "b", "c"]
func split(string: String, separator: String) -> [String] {
    return string.split(separator: separator)
}

// Remove a substring from a string
// remove(string: "abc", substring: "b") == "ac"
// remove(string: "abc", substring: "d") == "abc"
func remove(string: String, substring: String) -> String {
    return string.replace(regex: substring, with: "")
}

// Find the index of the first occurrence of a substring in a string
// index(string: "abc", substring: "b") == 1
// index(string: "abc", substring: "d") == -1
func index(string: String, substring: String) -> Int {
    return string.index(of: substring)
}

// Find the index of the last occurrence of a substring in a string
// lastIndex(string: "abc", substring: "b") == 1
// lastIndex(string: "abc", substring: "d") == -1
func lastIndex(string: String, substring: String) -> Int {
    return string.lastIndex(of: substring)
}

// Find the length of a string
// length(string: "abc") == 3
// length(string: "") == 0
func length(string: String) -> Int {
    return string.count
}

// Find the number of times a substring occurs in a string
// count(string: "abcabcabc", substring: "abc") == 3
// count(string: "abcabcabc", substring: "xyz") == 0
func count(string: String, substring: String) -> Int {
    return string.count(of: substring)
}

// Find the position of the first occurrence of a substring in a string
// position(string: "abc", substring: "b") == 1
// position(string: "abc", substring: "d") == -1
func position(string: String, substring: String) -> Int {
    return string.position(of: substring)
}

// Find the position of the last occurrence of a substring in a string
// lastPosition(string: "abc", substring: "b") == 1
// lastPosition(string: "abc", substring: "d") == -1
func lastPosition(string: String, substring: String) -> Int {
    return string.lastPosition(of: substring)
}

// Find the first occurrence of a substring in a string
// find(string: "abc", substring: "b") == 1
// find(string: "abc", substring: "d") == -1
func find(string: String, substring: String) -> Int {
    return string.find(of: substring)
}

// Find the last occurrence of a substring in a string
// lastFind(string: "abc", substring: "b") == 1
// lastFind(string: "abc", substring: "d") == -1
func lastFind(string: String, substring: String) -> Int {
    return string.lastFind(of: substring)
}

// Find the first occurrence of a substring in a string
// startsWith(string: "abc", prefix: "a") == true
// startsWith(string: "abc", prefix: "b") == false
func startsWith(string: String, prefix: String) -> Bool {
    return string.startsWith(prefix: prefix)
}

// Find the last occurrence of a substring in a string
// endsWith(string: "abc", suffix: "c") == true
// endsWith(string: "abc", suffix: "d") == false
func endsWith(string: String, suffix: String) -> Bool {
    return string.endsWith(suffix: suffix)
}

// Find the first occurrence of a substring in a string
// contains(string: "abc", substring: "b") == true
// contains(string: "abc", substring: "d") == false
func contains(string: String, substring: String) -> Bool {
    return string.contains(substring: substring)
}

// Find the last occurrence of a substring in a string
//

func concatenate(strings: [String]) -> String {
    var result = ""
    for _, s in strings {
        result += s
    }
    return result
}

func reverse(s: String) -> String {
    var reversed = ""
    for _, c in s.Reversed {
        reversed += c
    }
    return reversed
}

func capitalize(s: String) -> String {
    if s.Length == 0 {
        return s
    }
    return s[0].Uppercased() + s[1..]
}

func removeFirst(s: String, c: Char) -> String {
    var result = ""
    var found = false
    for _, c in s {
        if !found && c == c {
            found = true
        } else {
            result += c
        }
    }
    return result
}

func removeLast(s: String, c: Char) -> String {
    var result = ""
    var found = false
    for _, c in s.Reversed {
        if !found && c == c {
            found = true
        } else {
            result += c
        }
    }
    return result.Reversed
}

func removeAll(s: String, c: Char) -> String {
    var result = ""
    for _, c in s {
        if c != c {
            result += c
        }
    }
    return result
}

```swift
// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    var result = ""
    for _, s in strings {
        result += s
    }
    return result
}

// Reverse a string
// reverse("abc") == "cba"
func reverse(s: String) -> String {
    var reversed = ""
    for _, c in s.Reversed {
        reversed += c
    }
    return reversed
}

// Capitalize the first letter of a string
// capitalize("hello") == "Hello"
func capitalize(s: String) -> String {
    if s.Length == 0 {
        return s
    }
    return s[0].Uppercased() + s[1..]
}

// Remove the first occurrence of a character from a string
// removeFirst("hello", 'l') == "heo"
func removeFirst(s: String, c: Char) -> String {
    var result = ""
    var found = false
    for _, c in s {
        if !found && c == c {
            found = true
        } else {
            result += c
        }
    }
    return result
}

// Remove the last occurrence of a character from a string
// removeLast("hello", 'l') == "hel"
func removeLast(s: String, c: Char) -> String {
    var result = ""
    var found = false
    for _, c in s.Reversed {
        if !found && c == c {
            found = true
        } else {
            result += c
        }
    }
    return result.Reversed
}

// Remove all occurrences of a character from a string
// removeAll("hello", 'l') == "heo"
func removeAll(s: String, c: Char) -> String {
    var result = ""
    for _, c in s {
        if c != c {
            result += c
        }
    }
    return result
}

// Remove all occurrences of a character from a string
// removeFirst("hello", 'l') == "heo"
func removeFirst(s: String, c: Char) -> String {
    var result = ""
    var found = false
    for _, c in s {
        if !found && c == c {
            found = true
        } else {
            result += c
        }
    }
    return result
}

// Remove all occurrences of a character from a string
// removeLast("hello", 'l') == "hel"
func removeLast(s: String, c: Char) -> String {
    var result = ""
    var found = false
    for _, c in s.Reversed {
        if !found && c == c {
            found = true
        } else {
            result += c
        }
    }
    return result.Reversed
}

// Remove all occurrences of a character from a string
// removeAll("hello", 'l') == "heo"
func removeAll(s: String, c: Char) -> String {
    var result = ""
    for _, c in s {
        if c != c {
            result += c
        }
    }
    return result
}

// Remove all occurrences of a character from a string
// removeFirst("hello", 'l') == "heo"
func removeFirst(s: String, c: Char) -> String {
    var result = ""
    var found = false
    for _, c in s {
        if !found && c == c {
            found = true
        } else {
            result += c
        }
    }
    return result
}

// Remove all occurrences of a character from a string
// removeLast("hello", 'l') == "hel"
func removeLast(s: String, c: Char) -> String {
    var result = ""
    var found = false
    for _, c in s.Reversed {
        if !found && c == c {
            found = true
        } else {
            result += c
        }
    }
    return result.Reversed
}

// Remove all occurrences of a character from a string
// removeAll("hello", 'l') == "heo"
func removeAll(s: String, c: Char) -> String {
    var result = ""
    for _, c in s {
        if c != c {
            result += c
        }
    }
    return result
}

// Remove all occurrences of a character from a string
// removeFirst("hello", 'l') == "heo"
func removeFirst(s: String, c

func concatenate(strings: [String]) -> String {
    var result = ""
    for _, string in strings {
        result += string
    }
    return result
}

func concatenate(integers: [Int]) -> String {
    var result = ""
    for _, integer in integers {
        result += integer.String()
    }
    return result
}

func concatenate(doubles: [Double]) -> String {
    var result = ""
    for _, double in doubles {
        result += double.String()
    }
    return result
}

func concatenate(booleans: [Bool]) -> String {
    var result = ""
    for _, boolean in booleans {
        result += boolean.String()
    }
    return result
}

func concatenate(values: [Any]) -> String {
    var result = ""
    for _, value in values {
        result += value.String()
    }
    return result
}

```swift
// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    var result = ""
    for _, string in strings {
        result += string
    }
    return result
}

// Concatenate array of integers into a single string
// concatenate(integers: [] as [Int]) == ""
// concatenate(integers: [1, 2, 3]) == "123"
func concatenate(integers: [Int]) -> String {
    var result = ""
    for _, integer in integers {
        result += integer.String()
    }
    return result
}

// Concatenate array of doubles into a single string
// concatenate(doubles: [] as [Double]) == ""
// concatenate(doubles: [1.0, 2.0, 3.0]) == "1.02.03.0"
func concatenate(doubles: [Double]) -> String {
    var result = ""
    for _, double in doubles {
        result += double.String()
    }
    return result
}

// Concatenate array of booleans into a single string
// concatenate(booleans: [] as [Bool]) == ""
// concatenate(booleans: [true, false, true]) == "truefalsetrue"
func concatenate(booleans: [Bool]) -> String {
    var result = ""
    for _, boolean in booleans {
        result += boolean.String()
    }
    return result
}

// Concatenate array of any type into a single string
// concatenate(values: [] as [Any]) == ""
// concatenate(values: ["a", 1, true]) == "a1true"
func concatenate(values: [Any]) -> String {
    var result = ""
    for _, value in values {
        result += value.String()
    }
    return result
}

// Concatenate array of any type into a single string
// concatenate(values: [] as [Any]) == ""
// concatenate(values: ["a", 1, true]) == "a1true"
func concatenate(values: [Any]) -> String {
    var result = ""
    for _, value in values {
        result += value.String()
    }
    return result
}

// Concatenate array of any type into a single string
// concatenate(values: [] as [Any]) == ""
// concatenate(values: ["a", 1, true]) == "a1true"
func concatenate(values: [Any]) -> String {
    var result = ""
    for _, value in values {
        result += value.String()
    }
    return result
}

// Concatenate array of any type into a single string
// concatenate(values: [] as [Any]) == ""
// concatenate(values: ["a", 1, true]) == "a1true"
func concatenate(values: [Any]) -> String {
    var result = ""
    for _, value in values {
        result += value.String()
    }
    return result
}

// Concatenate array of any type into a single string
// concatenate(values: [] as [Any]) == ""
// concatenate(values: ["a", 1, true]) == "a1true"
func concatenate(values: [Any]) -> String {
    var result = ""
    for _, value in values {
        result += value.String()
    }
    return result
}

// Concatenate array of any type into a single string
// concatenate(values: [] as [Any]) == ""
// concatenate(values: ["a", 1, true]) == "a1true"
func concatenate(values: [Any]) -> String {
    var result = ""
    for _, value in values {
        result += value.String()
    }
    return result
}

// Concatenate array of any type into a single string
// concatenate(values: [] as [Any]) == ""
// concatenate(values: ["a", 1, true]) == "a1true"
func concatenate(values: [Any]) -> String {
    var result = ""
    for _, value in values {
        result += value.String()
    }
    return result
}

// Concatenate array of any type into a single string
// concatenate(values: [] as [Any]) == ""
// concatenate(values: ["a", 1, true]) == "a1true"
func concatenate(values: [Any]) -> String {
    var result = ""
    for _, value in values {
        result += value.String()
    }
    return result
}

//

func concatenate(strings: [String]) -> String {
    var result = ""
    for _, string in strings {
        result += string
    }
    return result
}

func reverse(string: String) -> String {
    var reversed = ""
    for _, character in string.characters.reversed {
        reversed += character
    }
    return reversed
}

func isPalindrome(string: String) -> Bool {
    var reversed = reverse(string)
    return string == reversed
}

```swift
// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    var result = ""
    for _, string in strings {
        result += string
    }
    return result
}

// Reverse a string
// reverse("") == ""
// reverse("abc") == "cba"
func reverse(string: String) -> String {
    var reversed = ""
    for _, character in string.characters.reversed {
        reversed += character
    }
    return reversed
}

// Check if a string is a palindrome
// isPalindrome("") == true
// isPalindrome("a") == true
// isPalindrome("aba") == true
// isPalindrome("abac") == false
func isPalindrome(string: String) -> Bool {
    var reversed = reverse(string)
    return string == reversed
}

// Check if a string is a palindrome
// isPalindrome("") == true
// isPalindrome("a") == true
// isPalindrome("aba") == true
// isPalindrome("abac") == false
func isPalindrome(string: String) -> Bool {
    var reversed = reverse(string)
    return string == reversed
}

// Check if a string is a palindrome
// isPalindrome("") == true
// isPalindrome("a") == true
// isPalindrome("aba") == true
// isPalindrome("abac") == false
func isPalindrome(string: String) -> Bool {
    var reversed = reverse(string)
    return string == reversed
}

// Check if a string is a palindrome
// isPalindrome("") == true
// isPalindrome("a") == true
// isPalindrome("aba") == true
// isPalindrome("abac") == false
func isPalindrome(string: String) -> Bool {
    var reversed = reverse(string)
    return string == reversed
}

// Check if a string is a palindrome
// isPalindrome("") == true
// isPalindrome("a") == true
// isPalindrome("aba") == true
// isPalindrome("abac") == false
func isPalindrome(string: String) -> Bool {
    var reversed = reverse(string)
    return string == reversed
}

// Check if a string is a palindrome
// isPalindrome("") == true
// isPalindrome("a") == true
// isPalindrome("aba") == true
// isPalindrome("abac") == false
func isPalindrome(string: String) -> Bool {
    var reversed = reverse(string)
    return string == reversed
}

// Check if a string is a palindrome
// isPalindrome("") == true
// isPalindrome("a") == true
// isPalindrome("aba") == true
// isPalindrome("abac") == false
func isPalindrome(string: String) -> Bool {
    var reversed = reverse(string)
    return string == reversed
}

// Check if a string is a palindrome
// isPalindrome("") == true
// isPalindrome("a") == true
// isPalindrome("aba") == true
// isPalindrome("abac") == false
func isPalindrome(string: String) -> Bool {
    var reversed = reverse(string)
    return string == reversed
}

// Check if a string is a palindrome
// isPalindrome("") == true
// isPalindrome("a") == true
// isPalindrome("aba") == true
// isPalindrome("abac") == false
func isPalindrome(string: String) -> Bool {
    var reversed = reverse(string)
    return string == reversed
}

// Check if a string is a palindrome
// isPalindrome("") == true
// isPalindrome("a") == true
// isPalindrome("aba") == true
// isPalindrome("abac") == false
func isPalindrome(string: String) -> Bool {
    var reversed = reverse(string)
    return string == reversed
}

// Check if a string is a palindrome
// isPalindrome("") == true
// isPalindrome("a") == true
// isPalindrome("aba") == true
// isPalindrome("abac") == false
func isPalindrome(string: String) -> Bool {
    var reversed = reverse(string)
    return string == reversed
}

// Check if a string is a palindrome
// isPalindrome("") == true
// isPalindrome("a") == true
// isPalindrome("aba") == true
// isPalindrome("abac") == false
func isPalindrome(string: String) -> Bool {
    var reversed = reverse(string)
    return string == reversed
}

// Check if a string is a palindrome
// isPalindrome("") == true
// isPalindrome("a") == true
// isPalindrome("aba") == true
// isPalindrome("abac") == false
func isPalindrome(string: String) -> Bool {

func concatenate(strings: [String]) -> String {
    let result = ""
    for string in strings {
        result += string
    }
    return result
}

```swift
// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    let result = ""
    for string in strings {
        result += string
    }
    return result
}

// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    let result = ""
    for string in strings {
        result += string
    }
    return result
}

// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    let result = ""
    for string in strings {
        result += string
    }
    return result
}

// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    let result = ""
    for string in strings {
        result += string
    }
    return result
}

// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    let result = ""
    for string in strings {
        result += string
    }
    return result
}

// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    let result = ""
    for string in strings {
        result += string
    }
    return result
}

// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    let result = ""
    for string in strings {
        result += string
    }
    return result
}

// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    let result = ""
    for string in strings {
        result += string
    }
    return result
}

// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    let result = ""
    for string in strings {
        result += string
    }
    return result
}

// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    let result = ""
    for string in strings {
        result += string
    }
    return result
}

// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    let result = ""
    for string in strings {
        result += string
    }
    return result
}

// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    let result = ""
    for string in strings {
        result += string
    }
    return result
}

// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    let result = ""
    for string in strings {
        result += string
    }
    return result
}

func concatenate(strings: [String]) -> String {
    return strings.reduce(initial: "", block: { (acc, s) in
        return acc + s
    })
}

func concatenateNumbers(numbers: [Int]) -> String {
    return numbers.reduce(initial: "", block: { (acc, n) in
        return acc + String(n)
    })
}

func concatenateNumbers(numbers: [Double]) -> String {
    return numbers.reduce(initial: "", block: { (acc, n) in
        return acc + String(n)
    })
}

func concatenateNumbers(numbers: [Float]) -> String {
    return numbers.reduce(initial: "", block: { (acc, n) in
        return acc + String(n)
    })
}

func concatenateNumbers(numbers: [UInt]) -> String {
    return numbers.reduce(initial: "", block: { (acc, n) in
        return acc + String(n)
    })
}

func concatenateNumbers(numbers: [ULong]) -> String {
    return numbers.reduce(initial: "", block: { (acc, n) in
        return acc + String(n)
    })
}

func concatenateNumbers(numbers: [ULongLong]) -> String {
    return numbers.reduce(initial: "", block: { (acc, n) in
        return acc + String(n)
    })
}

func concatenateNumbers(numbers: [UShort]) -> String {
    return numbers.reduce(initial: "", block: { (acc, n) in
        return acc + String(n)
    })
}

func concatenateNumbers(numbers: [Short]) -> String {
    return numbers.reduce(initial: "", block: { (acc, n) in
        return acc + String(n)
    })
}

func concatenateNumbers(numbers: [Long]) -> String {
    return numbers.reduce(initial: "", block: { (acc, n) in
        return acc + String(n)
    })
}

func concatenateNumbers(numbers: [LongLong]) -> String {
    return numbers.reduce(initial: "", block: { (acc, n) in
        return acc + String(n)
    })
}

```swift
// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    return strings.reduce(initial: "", block: { (acc, s) in
        return acc + s
    })
}

// Concatenate array of numbers into a single string
// concatenateNumbers(numbers: [] as [Int]) == ""
// concatenateNumbers(numbers: [1, 2, 3]) == "123"
func concatenateNumbers(numbers: [Int]) -> String {
    return numbers.reduce(initial: "", block: { (acc, n) in
        return acc + String(n)
    })
}

// Concatenate array of numbers into a single string
// concatenateNumbers(numbers: [] as [Double]) == ""
// concatenateNumbers(numbers: [1.1, 2.2, 3.3]) == "1.12.23.3"
func concatenateNumbers(numbers: [Double]) -> String {
    return numbers.reduce(initial: "", block: { (acc, n) in
        return acc + String(n)
    })
}

// Concatenate array of numbers into a single string
// concatenateNumbers(numbers: [] as [Float]) == ""
// concatenateNumbers(numbers: [1.1, 2.2, 3.3]) == "1.12.23.3"
func concatenateNumbers(numbers: [Float]) -> String {
    return numbers.reduce(initial: "", block: { (acc, n) in
        return acc + String(n)
    })
}

// Concatenate array of numbers into a single string
// concatenateNumbers(numbers: [] as [UInt]) == ""
// concatenateNumbers(numbers: [1, 2, 3]) == "123"
func concatenateNumbers(numbers: [UInt]) -> String {
    return numbers.reduce(initial: "", block: { (acc, n) in
        return acc + String(n)
    })
}

// Concatenate array of numbers into a single string
// concatenateNumbers(numbers: [] as [ULong]) == ""
// concatenateNumbers(numbers: [1, 2, 3]) == "123"
func concatenateNumbers(numbers: [ULong]) -> String {
    return numbers.reduce(initial: "", block: { (acc, n) in
        return acc + String(n)
    })
}

// Concatenate array of numbers into a single string
// concatenateNumbers(numbers: [] as [ULongLong]) == ""
// concatenateNumbers(numbers: [1, 2, 3]) == "123"
func concatenateNumbers(numbers: [ULongLong]) -> String {
    return numbers.reduce(initial: "", block: { (acc, n) in
        return acc + String(n)
    })
}

// Concatenate array of numbers into a single string
// concatenateNumbers(numbers: [] as [UShort]) == ""
// concatenateNumbers(numbers: [1, 2, 3]) == "123"
func concatenateNumbers(numbers: [UShort]) -> String {
    return numbers.reduce(initial: "", block: { (acc, n) in
        return acc + String(n)
    })
}

// Concatenate array of numbers into a single string
// concatenateNumbers(numbers: [] as [Short]) == ""
// concatenateNumbers(numbers: [1, 2, 3]) == "123"
func concatenateNumbers(numbers: [Short]) -> String {
    return numbers.reduce(initial: "", block: { (acc, n) in
        return acc + String(n)
    })
}

// Concatenate array of numbers into a single string
// concatenateNumbers(numbers: [] as [Long]) == ""
// concatenateNumbers(numbers: [1, 2, 3]) == "123"
func concatenateNumbers(numbers: [Long]) -> String {
    return numbers.reduce(initial: "", block: { (acc, n) in
        return acc + String(n)
    })
}

// Concatenate array of numbers into a single string
// concatenateNumbers(numbers: [] as [LongLong]) == ""
// concatenateNumbers(numbers: [1, 2, 3]) == "123"
func concatenateNumbers(numbers: [LongLong]) -> String {
    return numbers.reduce(initial: "", block: { (acc, n) in
        return acc + String(n)
    })
}

// Concatenate array of numbers into a single string
// concatenateNumbers(numbers: []

func concatenate(strings: [String]) -> String {
    return strings.reduce(
        initial: "",
        block: (acc: String, s: String) -> String {
            return acc + s
        }
    )
}

func firstElement<T>(array: [T]) -> T? {
    return array.first
}

func lastElement<T>(array: [T]) -> T? {
    return array.last
}

```swift
// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    return strings.reduce(
        initial: "",
        block: (acc: String, s: String) -> String {
            return acc + s
        }
    )
}

// Return the first element of an array, or nil if the array is empty
// firstElement(array: [] as [String]) == nil
// firstElement(array: ["a", "b", "c"]) == "a"
func firstElement<T>(array: [T]) -> T? {
    return array.first
}

// Return the last element of an array, or nil if the array is empty
// lastElement(array: [] as [String]) == nil
// lastElement(array: ["a", "b", "c"]) == "c"
func lastElement<T>(array: [T]) -> T? {
    return array.last
}

// Return the first element of an array, or nil if the array is empty
// firstElement(array: [] as [String]) == nil
// firstElement(array: ["a", "b", "c"]) == "a"
func firstElement<T>(array: [T]) -> T? {
    return array.first
}

// Return the last element of an array, or nil if the array is empty
// lastElement(array: [] as [String]) == nil
// lastElement(array: ["a", "b", "c"]) == "c"
func lastElement<T>(array: [T]) -> T? {
    return array.last
}

// Return the first element of an array, or nil if the array is empty
// firstElement(array: [] as [String]) == nil
// firstElement(array: ["a", "b", "c"]) == "a"
func firstElement<T>(array: [T]) -> T? {
    return array.first
}

// Return the last element of an array, or nil if the array is empty
// lastElement(array: [] as [String]) == nil
// lastElement(array: ["a", "b", "c"]) == "c"
func lastElement<T>(array: [T]) -> T? {
    return array.last
}

// Return the first element of an array, or nil if the array is empty
// firstElement(array: [] as [String]) == nil
// firstElement(array: ["a", "b", "c"]) == "a"
func firstElement<T>(array: [T]) -> T? {
    return array.first
}

// Return the last element of an array, or nil if the array is empty
// lastElement(array: [] as [String]) == nil
// lastElement(array: ["a", "b", "c"]) == "c"
func lastElement<T>(array: [T]) -> T? {
    return array.last
}

// Return the first element of an array, or nil if the array is empty
// firstElement(array: [] as [String]) == nil
// firstElement(array: ["a", "b", "c"]) == "a"
func firstElement<T>(array: [T]) -> T? {
    return array.first
}

// Return the last element of an array, or nil if the array is empty
// lastElement(array: [] as [String]) == nil
// lastElement(array: ["a", "b", "c"]) == "c"
func lastElement<T>(array: [T]) -> T? {
    return array.last
}

// Return the first element of an array, or nil if the array is empty
// firstElement(array: [] as [String]) == nil
// firstElement(array: ["a", "b", "c"]) == "a"
func firstElement<T>(array: [T]) -> T? {
    return array.first
}

// Return the last element of an array, or nil if the array is empty
// lastElement(array: [] as [String]) == nil
// lastElement(array: ["a", "b", "c"]) == "c"
func lastElement<T>(array: [T]) -> T? {
    return array.last
}

// Return the first element of an array, or nil if the array is empty
// firstElement(array: [] as [String]) == nil
// firstElement(array: ["a", "b", "c"]) == "a"
func firstElement<T>(array: [T]) -> T? {
    return array.first
}

// Return the last element of

func concatenate(strings: [String]) -> String {
    return strings.join(separator: "")
}

```swift
// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    return strings.join(separator: "")
}

// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    return strings.join(separator: "")
}

// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    return strings.join(separator: "")
}

// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    return strings.join(separator: "")
}

// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    return strings.join(separator: "")
}

// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    return strings.join(separator: "")
}

// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    return strings.join(separator: "")
}

// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    return strings.join(separator: "")
}

// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    return strings.join(separator: "")
}

// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    return strings.join(separator: "")
}

// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    return strings.join(separator: "")
}

// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    return strings.join(separator: "")
}

// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    return strings.join(separator: "")
}

// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    return strings.join(separator: "")
}

// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    return strings.join(separator: "")
}

// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    return strings

func concatenate(strings: [String]) -> String {
    let mut result = String()
    for string in strings {
        result += string
    }
    return result
}

func concatenate(integers: [Int]) -> String {
    let mut result = String()
    for integer in integers {
        result += integer.toString()
    }
    return result
}

func concatenate(floats: [Float]) -> String {
    let mut result = String()
    for float in floats {
        result += float.toString()
    }
    return result
}

func concatenate(booleans: [Bool]) -> String {
    let mut result = String()
    for boolean in booleans {
        result += boolean.toString()
    }
    return result
}

func concatenate(dates: [Date]) -> String {
    let mut result = String()
    for date in dates {
        result += date.toString()
    }
    return result
}

func concatenate(times: [Time]) -> String {
    let mut result = String()
    for time in times {
        result += time.toString()
    }
    return result
}

func concatenate(datesAndTimes: [Date, Time]) -> String {
    let mut result = String()
    for dateAndTime in datesAndTimes {
        result += dateAndTime.toString()
    }
    return result
}

func concatenate(numbers: [Number]) -> String {
    let mut result = String()
    for number in numbers {
        result += number.toString()
    }
    return result
}

```swift
// Concatenate array of strings into a single string
// concatenate(strings: [] as [String]) == ""
// concatenate(strings: ["a", "b", "c"]) == "abc"
func concatenate(strings: [String]) -> String {
    let mut result = String()
    for string in strings {
        result += string
    }
    return result
}

// Concatenate array of integers into a single string
// concatenate(integers: [] as [Int]) == ""
// concatenate(integers: [1, 2, 3]) == "123"
func concatenate(integers: [Int]) -> String {
    let mut result = String()
    for integer in integers {
        result += integer.toString()
    }
    return result
}

// Concatenate array of floats into a single string
// concatenate(floats: [] as [Float]) == ""
// concatenate(floats: [1.0, 2.0, 3.0]) == "1.02.0"
func concatenate(floats: [Float]) -> String {
    let mut result = String()
    for float in floats {
        result += float.toString()
    }
    return result
}

// Concatenate array of booleans into a single string
// concatenate(booleans: [] as [Bool]) == ""
// concatenate(booleans: [true, false, true]) == "truefalsetrue"
func concatenate(booleans: [Bool]) -> String {
    let mut result = String()
    for boolean in booleans {
        result += boolean.toString()
    }
    return result
}

// Concatenate array of dates into a single string
// concatenate(dates: [] as [Date]) == ""
// concatenate(dates: [Date(year: 2022, month: 1, day: 1), Date(year: 2022, month: 1, day: 2)]) == "2022-01-012022-01-02"
func concatenate(dates: [Date]) -> String {
    let mut result = String()
    for date in dates {
        result += date.toString()
    }
    return result
}

// Concatenate array of times into a single string
// concatenate(times: [] as [Time]) == ""
// concatenate(times: [Time(hour: 12, minute: 30, second: 45), Time(hour: 13, minute: 45, second: 15)]) == "12:30:4513:45:15"
func concatenate(times: [Time]) -> String {
    let mut result = String()
    for time in times {
        result += time.toString()
    }
    return result
}

// Concatenate array of dates and times into a single string
// concatenate(datesAndTimes: [] as [Date, Time]) == ""
// concatenate(datesAndTimes: [Date(year: 2022, month: 1, day: 1), Time(hour: 12, minute: 30, second: 45)]) == "2022-01-0112:30:45"
func concatenate(datesAndTimes: [Date, Time]) -> String {
    let mut result = String()
    for dateAndTime in datesAndTimes {
        result += dateAndTime.toString()
    }
    return result
}

// Concatenate array of numbers into a single string
// concatenate(numbers: [] as [Number]) == ""
// concatenate(numbers: [1, 2, 3, 4, 5]) == "12345"
func concatenate(numbers: [Number]) -> String {
    let mut result = String()
    for number in numbers {
        result += number.toString()
    }
    return result
}

// Concatenate array of numbers into a single string
// concatenate(numbers: [] as [Number]) == ""
// concatenate(numbers: [1, 2, 3, 4, 5]) == "12345"
func concatenate(numbers: [Number]) -> String {
    let mut result = String()
    for number in numbers {
        result += number.toString()
    }
    return result
}

// Concatenate array of numbers into a single string
// concatenate(numbers: [] as [Number]) == ""
// concatenate(numbers: [1, 2, 3, 4, 5]) == "12345"
func concatenate(numbers: [Number]) -> String {
    let mut result = String()
    for number in numbers {
        result +=

func filterByPrefix(strings: [String], prefix: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if string.starts(with: prefix) {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

func filterBySuffix(strings: [String], suffix: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if string.ends(with: suffix) {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

func filterBySubstring(strings: [String], substring: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if string.contains(substring) {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

func filterByRegex(strings: [String], regex: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if string.matches(regex) {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

func filterByValue(strings: [String], value: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if string == value {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

func filterByNotValue(strings: [String], value: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if string != value {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

func filterByGreaterThan(strings: [String], value: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if string > value {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

```swift
// Filter an input array of strings only for ones that start with a given prefix.
// filterByPrefix(strings: [] as [String], prefix: "a") == [] as [String]
// filterByPrefix(strings: ["abc", "bcd", "cde", "array"], prefix: "a") == ["abc", "array"]
func filterByPrefix(strings: [String], prefix: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if string.starts(with: prefix) {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

// Filter an input array of strings only for ones that end with a given suffix.
// filterBySuffix(strings: [] as [String], suffix: "c") == [] as [String]
// filterBySuffix(strings: ["abc", "bcd", "cde", "array"], suffix: "c") == ["cde", "array"]
func filterBySuffix(strings: [String], suffix: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if string.ends(with: suffix) {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

// Filter an input array of strings only for ones that contain a given substring.
// filterBySubstring(strings: [] as [String], substring: "c") == [] as [String]
// filterBySubstring(strings: ["abc", "bcd", "cde", "array"], substring: "c") == ["abc", "cde"]
func filterBySubstring(strings: [String], substring: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if string.contains(substring) {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

// Filter an input array of strings only for ones that match a given regular expression.
// filterByRegex(strings: [] as [String], regex: "c") == [] as [String]
// filterByRegex(strings: ["abc", "bcd", "cde", "array"], regex: "c") == ["abc", "cde"]
func filterByRegex(strings: [String], regex: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if string.matches(regex) {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

// Filter an input array of strings only for ones that are equal to a given value.
// filterByValue(strings: [] as [String], value: "c") == [] as [String]
// filterByValue(strings: ["abc", "bcd", "cde", "array"], value: "c") == ["abc", "cde"]
func filterByValue(strings: [String], value: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if string == value {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

// Filter an input array of strings only for ones that are not equal to a given value.
// filterByNotValue(strings: [] as [String], value: "c") == [] as [String]
// filterByNotValue(strings: ["abc", "bcd", "cde", "array"], value: "c") == ["abc", "bcd", "array"]
func filterByNotValue(strings: [String], value: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if string != value {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

// Filter an input array of strings only for ones that are greater than a given value.
// filterByGreaterThan(strings: [] as [String], value: "c") == [] as [String]
// filterByGreaterThan(strings: ["abc", "bcd", "cde", "array"], value: "c") == ["abc", "bcd", "cde", "array"]
func filterByGreaterThan(strings: [String], value: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if string > value {
            filteredStrings.append(string)
        }
    }
    return filteredStrings
}

// Filter an input array of strings only for ones that are less than a given value.
// filterByLessThan(strings: [] as [String], value: "c") == [] as [String]
// filterByLessThan(strings: ["abc", "bcd", "cde", "array"], value: "c") == ["abc", "bcd"]
func filterByLessThan(strings: [String], value: String) -> [String] {
    var filteredStrings = [String]()
    for string in strings {
        if

func filterByPrefix(strings: [String], prefix: String) -> [String] {
    var result = [String]()
    for string in strings {
        if string.startsWith(prefix) {
            result.append(string)
        }
    }
    return result
}

func filterByThreshold(numbers: [Int], threshold: Int) -> [Int] {
    var result = [Int]()
    for number in numbers {
        if number > threshold {
            result.append(number)
        }
    }
    return result
}

func filterByKeyValue(dictionaries: [Dictionary<Any, Any>], key: String, value: Any) -> [Dictionary<Any, Any>] {
    var result = [Dictionary<Any, Any>]()
    for dictionary in dictionaries {
        if dictionary[key] == value {
            result.append(dictionary)
        }
    }
    return result
}

func filterByProperty(objects: [Any], property: String, value: Any) -> [Any] {
    var result = [Any]()
    for object in objects {
        if object[property] == value {
            result.append(object)
        }
    }
    return result
}

func filterByKeyValue(tuples: [Tuple<Any, Any>], key: String, value: Any) -> [Tuple<Any, Any>] {
    var result = [Tuple<Any, Any>]()
    for tuple in tuples {
        if tuple.0 == key && tuple.1 == value {
            result.append(tuple)
        }
    }
    return result
}

func filterByKeyValue(sets: [Set<Any>], key: String, value: Any) -> [Set<Any>] {
    var result = [Set<Any>]()
    for set in sets {
        if set.contains(value) {
            result.append(set)
        }
    }
    return result
}

```swift
// Filter an input array of strings only for ones that start with a given prefix.
// filterByPrefix(strings: [] as [String], prefix: "a") == [] as [String]
// filterByPrefix(strings: ["abc", "bcd", "cde", "array"], prefix: "a") == ["abc", "array"]
func filterByPrefix(strings: [String], prefix: String) -> [String] {
    var result = [String]()
    for string in strings {
        if string.startsWith(prefix) {
            result.append(string)
        }
    }
    return result
}

// Filter an input array of numbers only for ones that are greater than a given threshold.
// filterByThreshold(numbers: [] as [Int], threshold: 10) == [] as [Int]
// filterByThreshold(numbers: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15], threshold: 10) == [11, 12, 13, 14, 15]
func filterByThreshold(numbers: [Int], threshold: Int) -> [Int] {
    var result = [Int]()
    for number in numbers {
        if number > threshold {
            result.append(number)
        }
    }
    return result
}

// Filter an input array of dictionaries only for ones that have a specific key with a given value.
// filterByKeyValue(dictionaries: [] as [Dictionary<Any, Any>], key: "name", value: "John") == [] as [Dictionary<Any, Any>]
// filterByKeyValue(dictionaries: [{name: "John", age: 30}, {name: "Jane", age: 25}], key: "name", value: "John") == [{name: "John", age: 30}]
func filterByKeyValue(dictionaries: [Dictionary<Any, Any>], key: String, value: Any) -> [Dictionary<Any, Any>] {
    var result = [Dictionary<Any, Any>]()
    for dictionary in dictionaries {
        if dictionary[key] == value {
            result.append(dictionary)
        }
    }
    return result
}

// Filter an input array of objects only for ones that have a specific property with a given value.
// filterByProperty(objects: [] as [Any], property: "name", value: "John") == [] as [Any]
// filterByProperty(objects: [{name: "John", age: 30}, {name: "Jane", age: 25}], property: "name", value: "John") == [{name: "John", age: 30}]
func filterByProperty(objects: [Any], property: String, value: Any) -> [Any] {
    var result = [Any]()
    for object in objects {
        if object[property] == value {
            result.append(object)
        }
    }
    return result
}

// Filter an input array of tuples only for ones that have a specific key with a given value.
// filterByKeyValue(tuples: [] as [Tuple<Any, Any>], key: "name", value: "John") == [] as [Tuple<Any, Any>]
// filterByKeyValue(tuples: [("name", "John"), ("age", 30), ("city", "New York")], key: "name", value: "John") == [("name", "John"), ("city", "New York")]
func filterByKeyValue(tuples: [Tuple<Any, Any>], key: String, value: Any) -> [Tuple<Any, Any>] {
    var result = [Tuple<Any, Any>]()
    for tuple in tuples {
        if tuple.0 == key && tuple.1 == value {
            result.append(tuple)
        }
    }
    return result
}

// Filter an input array of sets only for ones that have a specific key with a given value.
// filterByKeyValue(sets: [] as [Set<Any>], key: "name", value: "John") == [] as [Set<Any>]
// filterByKeyValue(sets: [Set(["John"]), Set(["Jane"]), Set(["John", "Jane"])], key: "name", value: "John") == [Set(["John"]), Set(["John", "Jane"])]
func filterByKeyValue(sets: [Set<Any>], key: String, value: Any) -> [Set<Any>] {
    var result = [Set<Any>]()
    for set in sets {
        if set.contains(value) {
            result.append(set)
        }
    }
    return result
}

// Filter an input array of ranges only for ones that have a specific key with a given value.
// filterByKeyValue(ranges: []