Coloring cube

#include <cstdio>
#include <iostream>
#include <utility>
#include <vector>

using namespace std;

int main(int argc, char *argv[])
{
	// Read the input parameters
	int n;
    cin >> n;

    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            for (int k = 0; k < n; k++) {
                int letter_code = (i + j + k) % 3;
                if (letter_code == 0) cout << "R ";
                if (letter_code == 1) cout << "G ";
                if (letter_code == 2) cout << "B ";
            }
            cout << "\n";
        }
        cout << "\n";
    }

	return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED