题解 | #字符串反转#

import java.util.Scanner;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.*;
// 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) throws IOException{
        BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
        String str;
        HashSet<Character> hs = new HashSet<>();
        while ((str = bf.readLine()) != null) {
            StringBuilder sb = new StringBuilder();
            System.out.println(sb.append(str).reverse().toString());
        }
    }
}