CCF 201312-2 ISBN号码 Java

就是把-去掉，然后验证，只需要改最后一位。

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String str = sc.next();//原字符串
        String substr = str.replaceAll("-", "");//去掉-
        int sum = 0;
        int len = substr.length();
        int last;
        for(int i = 0;i<len-1;i++) {
            sum += (i+1) * Integer.parseInt(substr.substring(i, i+1));
        }
        if(substr.substring(len-1, len).equals("X")) {
            last = 10;
        }else {
            last = Integer.parseInt(substr.substring(len-1, len));
        }
        if(sum % 11 == last) {
            System.out.println("Right");
        }else {
            if(sum % 11 == 10) {
                System.out.println(str.substring(0,str.length()-1) + "X");
            }else {
                System.out.println(str.substring(0, str.length()-1) + sum%11);
            }
        }
        sc.close();
    }

}