Merge sorting in c

C Program to Implement MERGE SORT

Merge Sort

#include<stdio.h>

#include<stdlib.h>

void Merge(int a[], int tmp[], int lpos, int rpos, int rend)

{

    int i, lend, n, tmppos;

    lend = rpos - 1;

    tmppos = lpos;

    n = rend - lpos + 1;

    while(lpos <= lend && rpos <= rend)

    {

        if(a[lpos] <= a[rpos])

            tmp[tmppos++] = a[lpos++];

        else

            tmp[tmppos++] = a[rpos++];




    }

    while(lpos <= lend)

        tmp[tmppos++] = a[lpos++];

    while(rpos <= rend)

        tmp[tmppos++] = a[rpos++];

    for(i = 0; i < n; i++, rend--)

        a[rend] = tmp[rend];

}

void MSort(int a[], int tmp[], int left, int right)

{

    int center;

    if(left < right)

    {

        center = (left + right) / 2;

        MSort(a, tmp, left, center);

        MSort(a, tmp, center + 1, right);

        Merge(a, tmp, left, center + 1, right);

    }

}

void MergeSort(int a[], int n)

{

    int *tmparray;

    tmparray = malloc(sizeof(int) * n);

    MSort(a, tmparray, 0, n-1);

    free(tmparray);

}

main()

{

    int i, n, a[10];

    printf("Enter the number of elements :: ");

    scanf("%d",&n);

    printf("Enter the elements :: ");

    for(i = 0; i < n; i++)

    {

        scanf("%d",&a[i]);

    }

    MergeSort(a,n);

    printf("The sorted elements are ::  ");

    for(i = 0; i < n; i++)

        printf("%d  ",a[i]);

    printf("\n");

}

OUTPUT:

Enter the number of elements :: 7
Enter the elements :: 70 60 50 40 10 20 30
The sorted elements are ::  10  20  30  40  50  60  70