Merge Sort
Medium Accuracy: 41.46% Submissions: 67643 Points: 4

Given an array arr[], its starting position l and its ending position r. Sort the array using merge sort algorithm.
Example 1:

Input:
N = 5
arr[] = {4 1 3 9 7}
Output:
1 3 4 7 9

Example 2:

Input:
N = 10
arr[] = {10 9 8 7 6 5 4 3 2 1}
Output:
1 2 3 4 5 6 7 8 9 10

Your Task:
You don't need to take the input or print anything. Your task is to complete the function merge() which takes arr[], l, m, r as its input parameters and modifies arr[] in-place such that it is sorted from position l to position r, and function mergeSort() which uses merge() to sort the array in ascending order using merge sort algorithm.


Expected Time Complexity: O(nlogn) 
Expected Auxiliary Space: O(n)


Constraints:
1 <= N <= 105
1 <= arr[i] <= 103

We are replacing the old Disqus forum with the new Discussions section given below.
Click here to view old Disqus comments.


to report an issue on this page.

Editorial

We strongly recommend solving this problem on your own before viewing its editorial. Do you still want to view the editorial?

Yes

All Submissions

My Submissions:

Login to access your submissions.

Merge Sort

Output Window