merge sort

#include<stdio.h>


int main()
{
    int n,i,arr[50];

    printf("Enter the size of array\n");
    scanf("%d",&n);
    printf("Enter the elements:");
    for(i=0; i<n; i++)
        scanf("%d",&arr[i]);

    mergesort(arr,0,n-1);

    printf("Sorted array:");
    for(i=0; i<n; i++)
        printf("\t%d",arr[i]);

    return 0;
}

void mergesort(int arr[],int low,int high)
{
    int mid;
    if(low<high)
    {
        mid=(low+high)/2;

        mergesort(arr,low,mid);
        mergesort(arr,mid+1,high);
        merge(arr,low,mid,high);
    }
}

void merge(int arr[],int l,int m,int h)
{
    int arr1[25],arr2[25];
    int n1,n2,i,j,k;
    n1=m-l+1;
    n2=h-m;

    for(i=0; i<n1; i++)
        arr1[i]=arr[l+i];
    for(j=0; j<n2; j++)
        arr2[j]=arr[m+j+1];

    arr1[i]=9999;
    arr2[j]=9999;

    i=0;
    j=0;

    for(k=l; k<=h; k++)
    {
        if(arr1[i]<=arr2[j])
        {
            arr[k]=arr1[i];
            i++;
        }
        else
        {
            arr[k]=arr2[j];
            j++;
        }
    }
}