Sorting In Swift


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What is Insertion Sort?

Insertion Sort is a sorting algorithm that picks an element from the array (usually the first), takes it out of the index it is currently in, and 'inserts' it in the correct position within a 'sorted sublist'. The elements swap indexes if the first element has a greater value than the second element. If not, the iteration continues with the second element & third element to check if they are in ascending order, while the first element has become a part of the 'sorted sublist'. This process of comparing adjacent elements continues throughout the array until the end has been reached.


Best-Case Complexity: О(n) Worst-Case Complexity: О(n^2)

Psuedo Code:

for i from 1 to N
   key = a[i]
   j = i - 1
   while j >= 0 and a[j] > key
      a[j+1] = a[j]
      j = j - 1
   a[j+1] = key

Insertion Sort

Add the code to sort the array using the Insertion Sort algorithm
Stuck? Check the solution here
func insertionSort(_ array: [Int]) -> [Int] {
    var arr = array
    for x in 1..<arr.count {
        var y = x
        while y > 0 && arr[y] < arr[y - 1] {
            swap(&arr[y - 1], &arr[y])
            y -= 1
    return arr
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