C + + combination problem __c++

To get a combination, such as C (16,3), we can find out how many of these are in the formula, but how do we represent these numbers?

Code:

#include <iostream>
#include <stdio.h>
#define MAXN
using namespace std;
int A[MAXN];
int count=0;
void Assem (int m,int k)
{
    int i,j;
    for (i=m;i>=k;i--)
    {
        a[k]=i;
        if (k>1)
            Assem (i-1,k-1);
        else
        {
             count++;
             /* Show number of permutations for
             (j=a[0];j>0;j--)
             {
                cout<<a[j]<< "  ";
             }
             cout<<endl;*/}}
int main ()
{
    int m,r;
    cout<< "m=";
    cin>>m;
    cout<< "r=";
    cin>>r;
    A[0]=r;
    Assem (m,r);
    cout<<count<<endl;
    return 0;
}

For example, we ask C (16,3), we should be first from 16 number of 1 number "into C (16,1)", then from the remaining 15 numbers to take a number "into C (15,1)", and finally from the remaining 14 number of a number "into C (14,1)" was completed. So this process is easy to implement in a recursive way.