def insertion_sort(arr): for i in range(1, len(arr)): key = arr[i] j = i - 1 while j >= 0 and key < arr[j]: arr[j + 1] = arr[j] j -= 1 arr[j + 1] = key # Example usage: arr = [12, 11, 13, 5, 6] insertion_sort(arr) print("Sorted array:", arr)