Merge Sort Python

PROGRAM TO IMPLEMENT MERGE SORT ALGORITHM

def mergeSort(arr):

    if len(arr) > 1:

 

         # Finding the mid of the array

        mid = len(arr)//2

 

        # Dividing the array elements

        L = arr[:mid]

 

        # into 2 halves

        R = arr[mid:]

 

        # Sorting the first half

        mergeSort(L)

 

        # Sorting the second half

        mergeSort(R)

 

        i = j = k = 0

 

        # Copy data to temp arrays L[] and R[]

        while i < len(L) and j < len(R):

            if L[i] < R[j]:

                arr[k] = L[i]

                i += 1

            else:

                arr[k] = R[j]

                j += 1

            k += 1

 

        # Checking if any element was left

        while i < len(L):

            arr[k] = L[i]

            i += 1

            k += 1

 

        while j < len(R):

            arr[k] = R[j]

            j += 1

            k += 1

 

# Code to print the list

 

 

def printList(arr):

    for i in range(len(arr)):

        print(arr[i], end=" ")

    print()

 

 

# Driver Code

if __name__ == '__main__':

    arr = [12, 11, 13, 5, 6, 7]

    print("Given array is", end="\n")

    printList(arr)

    mergeSort(arr)

    print("Sorted array is: ", end="\n")

    printList(arr)







OUTPUT

Given array is 
12 11 13 5 6 7 
Sorted array is 
5 6 7 11 12 13 

CREDITS: https://www.geeksforgeeks.org/merge-sort/