题解 | 字符逆序

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);
        
        String line = in.nextLine();
        
        StringBuilder sb = new StringBuilder();
        for(int i = line.length() - 1; i >= 0; i--) sb.append(line.charAt(i));
        System.out.println(sb.toString());
    }
}