marge_sort

#include<stdlib.h>
#include<stdio.h>

void merge(int arr[], int p, int q, int r)
{
    int i, j, k;
    int n1 = q - p + 1;
    int n2 =  r - q;

    int L[n1+1], R[n2+1];

    for (i = 0; i < n1; i++)
        L[i] = arr[p + i];

    for (j = 0; j < n2; j++)
        R[j] = arr[q + 1+ j];

    i = 0;
    j = 0;

    for(k = p; k <= r; k++){

        if (L[i] <= R[j])
        {
            arr[k] = L[i];
            i++;
        }
        else
        {
            arr[k] = R[j];
            j++;
        }
    }

}


void mergeSort(int arr[], int p, int r)
{
    if (p < r)
    {
        int q = p+(r-p)/2;
        mergeSort(arr, p, q);
        mergeSort(arr, q+1, r);
        merge(arr, p, q, r);
    }
}


int main()
{
    int arr[20],n,i;
    scanf("%d", &n);
    for(i=0; i<n; i++)
    {
        scanf("%d",&arr[i]);
    }

    //Calling MergeSort Function
    mergeSort(arr, 0, n - 1);


    printf("\nSorted array: \n");

    for(i=0; i<n; i++)
    {
        printf("%d ",arr[i]);
    }

    return 0;
}