Print all possible combinations of r elements in a given array of size n

#include<bits/stdc++.h>
using namespace std;
 
void combinationUtil(int arr[], int data[],int start, int end,int index, int r);
void printCombination(int arr[], int n, int r)
{  int data[r];
   combinationUtil(arr, data, 0, n-1, 0, r);
}
void combinationUtil(int arr[], int data[],int start, int end,int index, int r)
{
    if (index == r)
    {
        for (int j = 0; j < r; j++)
            cout << data[j] << " ";
        cout << endl;
        return;
    }
    for (int i = start; i <= end && end - i + 1 >= r - index; i++)
    {
        data[index] = arr[i];
        combinationUtil(arr, data, i+1,end, index+1, r);
    }
}
 
// Driver code
int main()
{
    int arr[] = {1, 2, 3, 4, 5};
    int r = 3;
    int n = sizeof(arr)/sizeof(arr[0]);
    printCombination(arr, n, r);
}