题解 | 多组_带空格的字符串_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);
        int t = in.nextInt();

        for (int i = 1; i <= t; ++i) {
            int n = in.nextInt();
            in.nextLine();
            String line = in.nextLine();
            String[] words = line.split("\\s+");
            StringBuilder sb = new StringBuilder();
            for (int j = 0; j < words.length; ++j) {
                sb.append(words[j]);
            }
            sb.reverse();
            System.out.println(sb.toString());
        }   
    }
}