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 sc = new Scanner(System.in); int t = sc.nextInt(); sc.nextLine(); for(int i=0;i<t;i++){ int n = sc.nextInt(); sc.nextLine(); String s = sc.nextLine(); if(n >= s.length()){ String reversed = reverse(s); System.out.println(reversed); } } sc.close(); } // 反转String类型的字符串。去掉空格 private static String reverse(String s){ // 去掉空格 String noSpace = s.replaceAll(" ", ""); StringBuilder sb = new StringBuilder(noSpace); return sb.reverse().toString(); } }