Base change, recursive and with a default value to 10

base.cpp

#include <iostream>
using namespace std;

void binary (int a, int base = 10);

int main()
{
    int a, base;
    cout << "Enter number and base:";
    cin >> a >> base;
    binary (a, base);
    cout << endl;
    return 0;
}

void binary (int a, int base)
{
    if (a < base)
        cout << a;
    else {
        binary(a / base, base);
        cout << a % base;
    }
}