Rotate an array (k) positions

rotateArray

/*:
 
 ## Given an array, rotate the array to the right by k steps, where k is non-negative.
```
Example 1:

Input: [1,2,3,4,5,6,7] and k = 3
Output: [5,6,7,1,2,3,4]
Explanation:
rotate 1 steps to the right: [7,1,2,3,4,5,6]
rotate 2 steps to the right: [6,7,1,2,3,4,5]
rotate 3 steps to the right: [5,6,7,1,2,3,4]
 ```
 ```
Example 2:

Input: [-1,-100,3,99] and k = 2
Output: [3,99,-1,-100]
Explanation:
rotate 1 steps to the right: [99,-1,-100,3]
rotate 2 steps to the right: [3,99,-1,-100]
 ```
*/
func rotate<a>(arr: inout[a], steps k: Int) {
    if k > 0 {
        for _ in 1...k { //do the following k times
            let last = arr.last! //save the last position of the array to move it to the first position
            for i in (1..<arr.count).reversed() { //loop through the array backwards
                arr[i] = arr[i - 1] //shift 1 position to the right
            }
            arr[0] = last //replace the first array position with the original last array position
        }
    } else {
        print("Enter a positive integer")
    }
}

var arr = [0,1,2,3,4,5]
rotate(arr: &arr, steps: 3)

var letterArr = ["a","b","c"]
rotate(arr: &letterArr, steps: 1)