题解 | #字符串反转#

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        String str = in.nextLine();
        int len = str.length();
        StringBuilder reverse = new StringBuilder(len);

        for (int i = len-1; i>=0;i--) {
            reverse.append(str.charAt(i));
        }

        System.out.println(reverse);

    }
}