题解 | #字符串反转#

import java.util.Scanner;
import java.io.*;
public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader reader=new BufferedReader(new InputStreamReader(System.in));
        String str;
        while ((str=reader.readLine())!=null){
            char[] arr=str.toCharArray();
            int left=0;
            int right=arr.length-1;
            while (left<right){
                char tmp=arr[left];
                arr[left]=arr[right];
                arr[right]=tmp;
                left++;
                right--;
            }
            System.out.println(arr);
        }
    }
}