题解 | 多组_字符串_T组形式

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        StringBuilder reversed= new StringBuilder(); 
        int t = in.nextInt();
        for(int i = 0; i < t; i++){
            int n = in.nextInt();
            String s = in.next();
            int m = s.length(); 
            for(int j = m - 1; j >= 0; j--){
                reversed.append(s.charAt(j));
            }
            System.out.println(reversed.toString());
            reversed.setLength(0);
        }

        in.close();
    }
}