题解 | #多组_带空格的字符串_T组形式#

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        
        int num = in.nextInt();

        String[] strs = new String[num];
        for(int i = 0;i < num;i++){
            int len = in.nextInt();
            //消耗掉换行符
            in.nextLine();
            //此时才能正确读取一行的字符串内容
            strs[i] = in.nextLine();
        }

        for(String str : strs){
            for(int j = str.length() - 1;j >= 0;j--){
                char c = str.charAt(j);
                if(c != ' '){
                    System.out.print(c);
                }
            }
            System.out.println();
        }
    }
}