Python Program for Recursive Insertion Sort

Insertion sort is a simple sorting algorithm that works the way we sort playing cards in our hands. 
Below is an iterative algorithm for insertion sort
Algorithm

// Sort an arr[] of size n
insertionSort(arr, n) 
    Loop from i = 1 to n-1.
       a) Pick element arr[i] and insert
          it into sorted sequence arr[0..i-1] 

Python

# Recursive Python program for insertion sort

# Recursive function to sort an array using insertion sort
def insertionSortRecursive(arr, n):
    # base case
    if n <= 1:
        return

    # Sort first n-1 elements
    insertionSortRecursive(arr, n - 1)

    # Insert last element at its correct position in sorted array.
    last = arr[n - 1]
    j = n - 2

    # Move elements of arr[0..i-1], that are
    # greater than key, to one position ahead
    # of their current position
    while (j >= 0 and arr[j] > last):
        arr[j + 1] = arr[j]
        j = j - 1
    arr[j + 1] = last


# Driver program to test insertion sort
if __name__ == '__main__':
    A = [-7, 11, 6, 0, -3, 5, 10, 2]
    n = len(A)
    insertionSortRecursive(A, n)
    print(A)

# Contributed by Harsh Valecha,
# Edited by Abraar Masud Nafiz.

Time Complexity: O(n²)

Auxiliary Space: O(n)

Please refer complete article on Recursive Insertion Sort for more details!

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