Explanation

• Insertion Sort is a simple sorting algorithm that builds the final sorted array one item at a time. It works by gradually taking each element from the unsorted portion and inserting it into its correct position within the sorted portion of the array.

Steps:

• The first element is considered already sorted.
• The next element is taken and inserted into the correct position in the sorted portion of the list.
• This process is repeated for each element until the entire list is sorted.

Time Complexity:

• Best Case (Already Sorted): O(n)
• Average and Worst Case (Unsorted List): O(n^2)**

def insertion_sort(arr):
    # Traverse through 1 to len(arr)
    for i in range(1, len(arr)):
        key = arr[i]
        j = i - 1
        # Move elements of arr[0..i-1] that are greater than key
        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 is:", arr)