欧几里得算法求最大公约数

#include <iostream>
using namespace std;

int gcd(int m , int n)
{
    int r;
    while(n!=0)
    {
        r = m%n;
        m = n;
        n = r;
        gcd(m,n);
    }
    return m;
}

int main(int argc, char* argv[])
{
    cout << gcd(4,2) << endl;
    return 0;
}