[C++] 백준2675 문자열 반복

#include <iostream>
using namespace std;
int main() {
	int t, r;
	char s[21];

	cin >> t;
	for (int i = 0; i < t; i++) {
		cin >> r >> s;
		for (int k = 0; k < 20; k++) {
			if (s[k] == '\0') break;
			for (int j = 0; j < r; j++)
				cout << s[k];
		}
		cout << '\n';
	}

	return 0;
}