Merge_Sort.c

#include<stdio.h>
void Merge(int a[],int lb,int mid,int ub)
{
    int b[ub+1],i,j,k;
    i=lb;
    j=mid+1;
    k=lb;
    while(i<=mid && j<=ub)
    {
        if(a[i]<a[j])
        {
            b[k]=a[i];
            i++;
            k++;
        }
        else
        {
            b[k]=a[j];
            j++;
            k++;
        }
    }
    if(i>mid)
    {
        while(j<=ub)
        {
            b[k]=a[j];
            k++;
            j++;
        }
    }
    else
    {
        while(i<=mid)
        {
            b[k]=a[i];
            i++;
            k++;
        }
    }
    for(k=lb;k<=ub;k++)
    a[k]=b[k];
}
void MergeSort(int a[],int lb,int ub)
{
    int mid;
    if(lb<ub)
    {
        mid=(lb+ub)/2;
        MergeSort(a,lb,mid);
        MergeSort(a,mid+1,ub);
        Merge(a,lb,mid,ub);
    }
}
int main()
{
    int i,n,a[100];
    printf("Enter the number of elements : ");
    scanf("%d",&n);
    printf("Enter the elements separated by space : ");
    for(i=0;i<n;i++)
    scanf("%d",&a[i]);
    printf("The unsorted elements are : ");
    for(i=0;i<n;i++)
    printf("%d ",a[i]);
    printf("\n");
    MergeSort(a,0,n-1);
    printf("The sorted elements are : ");
    for(i=0;i<n;i++)
    printf("%d ",a[i]);
    printf("\n");
}