Exercise_4.py

# Python program for implementation of MergeSort
def mergeSort(arr):

    # write your code here
    if len(arr) > 1:
        mid = len(arr)//2

        left = arr[:mid]

        right = arr[mid:]

        mergeSort(left)
        mergeSort(right)

        i = j = k = 0

        while i < len(left) and j < len(right):
            if left[i] <= right[j]:
                arr[k] = left[i]
                i += 1
            else:
                arr[k] = right[j]
                j += 1
            k += 1

        while i < len(left):
            arr[k] = left[i]
            i += 1
            k += 1

        while j < len(right):
            arr[k] = right[j]
            j += 1
            k += 1
# Code to print the list


def printList(arr):

    # write your code here
    for i in range(len(arr)):
        print(arr[i], end="")
    print()

    # driver code to test the above 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)