/* Recursive Merge Sort in C Programming */
#include<stdio.h>
merge(int a[],int l,int mid,int h)
{
int i=l,j=mid+1,k=l,c[50];
while((i<=mid)&&(j<=h))
{
if(a[i]<=a[j])
c[k++]=a[i++];
else
c[k++]=a[j++]; // l=low
} // h=high
while(i<=mid)
c[k++]=a[i++];
while(j<=h)
c[k++]=a[j++];
for(i=l;i<k;i++) // necessary loop
a[i]=c[i];
}
merge_sort(int a[],int l,int h)
{
int mid;
if(l<h)
{ mid=(l+h)/2;
merge_sort(a,l,mid);
merge_sort(a,mid+1,h);
merge(a,l,mid,h);
}
}
main()
{
int i,n;
printf("\nProgram to sort an array using merge sort : \n");
printf("Enter array capacity : \n");
scanf("%d",&n);
int a[n];
for(i=0;i<n;i++)
a[i]=rand()%100;
printf("Initial array : ");
for(i=0;i<n;i++)
printf("%4d",a[i]);
printf("\n");
merge_sort(a,0,n-1); // merge function
printf("\nSorted array : ");
for(i=0;i<n;i++)
printf("%4d",a[i]);
printf("\n");
}
Recursive Merge Sort
