Program for Recursive Merge Sort using Python

Introduction

In previous article we understood the python code for merge sort. Now we will understand the recursive implementation of merge sort.

The last element in the given array is treated as the pivot element

Program

```def merge_arr(left, right):

if not len(left) or not len(right):

return left or right

output = []

x , y = 0, 0

while (len(output) < len(left) + len(right)):

if left[x] < right[y]:

output.append(left[x])

x += 1

else:

output.append(right[y])

y += 1

if x == len(left) or y == len(right):

output.extend(left[x:] or right[y:])

break

return output

def sort(arr):

if len(arr) < 2:

return arr

mid = int(len(arr)/2)

left = sort(arr[:mid])

right = sort(arr[mid:])

return merge_arr(left, right)

ip_arr = [12, 11, 13, 5, 6, 7]

print("The sorted array is :")

print(sort(ip_arr))

```

Author

• A Full Stack Developer with 10+ years of experience in different domain including SAP, Blockchain, AI and Web Development.