merge with insertion

#include<bits/stdc++.h>

using namespace std;
int arr[100];


void insertionSort(int arr[], int n  ){
        int i , j ,key ;
        for(i=1 ;i<n ; i++){
           key=arr[i] ;
           j= i-1 ;

           while (j >= 0 && arr[j] > key)
       {
           arr[j+1] = arr[j];
           j = j-1;
       }
       arr[j+1] = key;
   }
}




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

    int L[n1], R[n2];

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

    i = 0;
    j = 0;
    k = l;
    while (i < n1 && j < n2)
    {
        if (L[i] <= R[j])
        {
            arr[k] = L[i];
            i++;
        }
        else
        {
            arr[k] = R[j];
            j++;
        }
        k++;
    }


    while (i < n1)
    {
        arr[k] = L[i];
        i++;
        k++;
    }


    while (j < n2)
    {
        arr[k] = R[j];
        j++;
        k++;
    }
}

void mergeSort(int arr[], int l, int r)
{
    if (l < r)
    {

        int m = l+(r-l)/2;

        mergeSort(arr, l, m);
        mergeSort(arr, m+1, r);

        merge(arr, l, m, r);
    }
}



int main()
{


     int i , n;
    cout<<"Enter number :";
    cin>>n;
    for(i=0 ; i<n ; i++){
        cin>>arr[i];
    }

        if(n<16)
            insertionSort(arr,n);
        else
        mergeSort(arr,0,n-1);

    cout<<"Sorted array is :";
    //printArray(arr, n);
     for(i=0 ; i<n ; i++){
        cout<<arr[i]<<" ";
    }
    return 0;
}