题解 | #数字颠倒#

import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        while (in.hasNextInt()) { // 注意 while 处理多个 case
            String str = in.next();
            System.out.println(myAns(str));
        }
    }
    
    private static String myAns(String num) {
        char [] cs = num.toCharArray();
        StringBuilder sb = new StringBuilder(cs.length);
        for(int i = cs.length-1; i >= 0; i--) {
            sb.append(cs[i]);
        }
        return sb.toString();
    }
    private static String myAns2(String num) {
        StringBuilder sb = new StringBuilder(num.length());
        for(int i = num.length()-1; i >= 0; i--) {
            sb.append(num.charAt(i));
        }
        return sb.toString();
    }
}