In this article, we will learn about the solution to the problem statement given below.
Problem statement − We are given an array, we need to sort it using the concept of merge sort
Here we place the maximum element at the end. This is repeated until the array is sorted.
Now let’s observe the solution in the implementation below −
#merge function def merge(arr, l, m, r): n1 = m - l + 1 n2 = r- m # create arrays L =  * (n1) R =  * (n2) # Copy data to arrays for i in range(0 , n1): L[i] = arr[l + i] for j in range(0 , n2): R[j] = arr[m + 1 + j] i = 0 # first half of array j = 0 # second half of array k = l # merges two halves while i < n1 and j < n2 : if L[i] <= R[j]: arr[k] = L[i] i += 1 else: arr[k] = R[j] j += 1 k += 1 # copy the left out elements of left half while i < n1: arr[k] = L[i] i += 1 k += 1 # copy the left out elements of right half while j < n2: arr[k] = R[j] j += 1 k += 1 # sort def mergeSort(arr,l,r): if l < r: # getting the average m = (l+(r-1))/2 # Sort mergeSort(arr, l, m) mergeSort(arr, m+1, r) merge(arr, l, m, r) # main arr = [2,5,3,8,6,5,4,7] n = len(arr) mergeSort(arr,0,n-1) print ("Sorted array is") for i in range(n): print (arr[i],end=" ")
Sorted array is 2 3 4 5 5 6 7 8
All the variables are declared in the local scope and their references are seen in the figure above.
In this article, we have learned about how we can make a Python Program for Merge Sort