백준(2675) JAVA - 문자열 반복

import java.util.Scanner;

public class Main {
	
	/**
	 *  (2675) - 문자열 반복
	 */
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		
		for(int i = 0 ; i < N ; i++) {
			String P = "";
			int R = sc.nextInt();
			String S = sc.next();
			char[] ar = S.toCharArray();
			
			for(int j = 0 ; j < ar.length ; j++) {
				for(int k = 0 ; k < R ; k++) {
					
					P = P.concat(Character.toString(ar[j]));
				}
			}
			System.out.println(P);
		}
	}
}