Convert Decimal to (Binary, Octal, Hexadecimal)

#include <iostream>
using namespace std;

int binary(int dec) {
    int bin = 0;
    int rem;
    for(int i = 1; dec; i *= 10) {
        rem = dec % 2;
        dec /= 2;
        bin += rem * i;
    }
    return bin;
}

int main() {
    int n;

    cin >> n;

    cout << "Binary: " << binary(n) << endl;
    cout << "Octal: " << oct << n << endl;
    cout << "Hexa-decimal: " << hex << n << endl;

    return 0;
}