Introduction

In insertion sort is similar to the sorting methodology we use while playing card games. The given array is split into sorted and unsorted parts and element from unsorted part is picked and moved to correct place in sorted part.

Program

def sort(ip_arr):
    for i in range(1, len(ip_arr)):
        k = ip_arr[i]
        j = i - 1
        while j >= 0 and k < ip_arr[j]:
            ip_arr[j + 1] = ip_arr[j]
            j -= 1
        ip_arr[j + 1] = k
       
ip_arr = [89, 121, 101, 6]
print("The input array is: ", ip_arr)
sort(ip_arr)
print("Sorted array is :")
for i in range(len(ip_arr)):
    print("%d" %ip_arr[i])

Output

Explanation

The below steps are followed for insertion sort:

1. Iterate elements from index[1] to index[n].
2. Compare ele[i] to ele[i-1], if ele[i] < ele[i-1] compare ele[i] and ele[i-2]. Swap with the greater element.
3. Continue the steps 1 and 2 until all the elements are sorted.