COMBINATION.CPP FILE FOR FINDING THE COMBINATIONS IN CALCULATOR

/*COMBINATION.CPP*/
#include "calculator.h"
#include <iostream>
using namespace std;
void comb(int n, int r, int *arr, int sz)
{
    for(int i = n; i >= r; i--)
 {
        // choose the first element
        arr[r - 1] = i;
        if (r > 1)
  {
   // if still needs to choose
            // recursive into smaller problem
            comb(i - 1, r - 1, arr, sz);
        }
  else
  {
            // print out one solution
            for (int i = 0; i < sz; i++)
   {
                cout<<arr[i]<<" ";
            }
            cout<<endl;
        }
    }
}
void ScientificCalculator::combination()
{
 const int N = 5;
    const int M = 3;
    int *arr = new int[M];
    comb(N, M, arr, M);
}