【PAT甲级】1027.Colors in Mars (20)

#include<iostream>
#include<stdio.h>
#include<string>
using namespace std;

string change_13(string s) {
if (s == "10")
s = "A";
else if (s == "11")
s = "B";
else if (s == "12")
s = "C";
return s;
}

string change(int i){
string b = to_string(i % 13);
string a = to_string((i - i % 13) / 13);
return change_13(a) + change_13(b);
}

int main() {
int r, g, b;
cin >> r >> g >> b;
cout << "#" << change(r) << change(g) << change(b);
return 0;
}