Related Articles
C Program for Iterative Merge Sort
• Last Updated : 06 Dec, 2018

Following is a typical recursive implementation of Merge Sort that uses last element as pivot.

 `/* Recursive C program for merge sort */` `#include ` `#include ` ` `  `/* Function to merge the two haves arr[l..m] and arr[m+1..r] of array arr[] */` `void` `merge(``int` `arr[], ``int` `l, ``int` `m, ``int` `r); ` ` `  `/* l is for left index and r is right index of the sub-array ` `  ``of arr to be sorted */` `void` `mergeSort(``int` `arr[], ``int` `l, ``int` `r) ` `{ ` `    ``if` `(l < r) { ` `        ``int` `m = l + (r - l) / 2; ``// Same as (l+r)/2 but avoids overflow for large l & h ` `        ``mergeSort(arr, l, m); ` `        ``mergeSort(arr, m + 1, r); ` `        ``merge(arr, l, m, r); ` `    ``} ` `} ` ` `  `/* Function to merge the two haves arr[l..m] and arr[m+1..r] of array arr[] */` `void` `merge(``int` `arr[], ``int` `l, ``int` `m, ``int` `r) ` `{ ` `    ``int` `i, j, k; ` `    ``int` `n1 = m - l + 1; ` `    ``int` `n2 = r - m; ` ` `  `    ``/* create temp arrays */` `    ``int` `L[n1], R[n2]; ` ` `  `    ``/* Copy data to temp arrays L[] and R[] */` `    ``for` `(i = 0; i < n1; i++) ` `        ``L[i] = arr[l + i]; ` `    ``for` `(j = 0; j < n2; j++) ` `        ``R[j] = arr[m + 1 + j]; ` ` `  `    ``/* Merge the temp arrays back into arr[l..r]*/` `    ``i = 0; ` `    ``j = 0; ` `    ``k = l; ` `    ``while` `(i < n1 && j < n2) { ` `        ``if` `(L[i] <= R[j]) { ` `            ``arr[k] = L[i]; ` `            ``i++; ` `        ``} ` `        ``else` `{ ` `            ``arr[k] = R[j]; ` `            ``j++; ` `        ``} ` `        ``k++; ` `    ``} ` ` `  `    ``/* Copy the remaining elements of L[], if there are any */` `    ``while` `(i < n1) { ` `        ``arr[k] = L[i]; ` `        ``i++; ` `        ``k++; ` `    ``} ` ` `  `    ``/* Copy the remaining elements of R[], if there are any */` `    ``while` `(j < n2) { ` `        ``arr[k] = R[j]; ` `        ``j++; ` `        ``k++; ` `    ``} ` `} ` ` `  `/* Function to print an array */` `void` `printArray(``int` `A[], ``int` `size) ` `{ ` `    ``int` `i; ` `    ``for` `(i = 0; i < size; i++) ` `        ``printf``(``"%d "``, A[i]); ` `    ``printf``(``"\n"``); ` `} ` ` `  `/* Driver program to test above functions */` `int` `main() ` `{ ` `    ``int` `arr[] = { 12, 11, 13, 5, 6, 7 }; ` `    ``int` `arr_size = ``sizeof``(arr) / ``sizeof``(arr[0]); ` ` `  `    ``printf``(``"Given array is \n"``); ` `    ``printArray(arr, arr_size); ` ` `  `    ``mergeSort(arr, 0, arr_size - 1); ` ` `  `    ``printf``(``"\nSorted array is \n"``); ` `    ``printArray(arr, arr_size); ` `    ``return` `0; ` `} `

Output:

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

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

Please refer complete article on Iterative Merge Sort for more details!

Attention reader! Don’t stop learning now. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready.

My Personal Notes arrow_drop_up
Recommended Articles
Page :