解題思路: 先找出前面8碼的總和  以及 檢查碼 再用在公式裡 然後數字一一對照看哪個是可以用再公式裡 再轉成字母  

沒打過的,先打一下真的不會再看

程式碼: 

import java.util.Scanner;

public class a054 {
      public static void main (String[] args){
       Scanner input = new Scanner(System.in);
       while(input.hasNext()){
           String a = input.next();
           check_number(Character.getNumericValue(a.charAt(8)),eight_number(a.substring(0,9).toCharArray()));
           System.out.println("");



       }
      }

      public static void check_number (int a, int b) {
          int[] number = {10,11,12,13,14,15,16,17,34,18,19,20,21,22,35,23,24,25,26,27,28,29,32,30,31,33};
          String[] ABC = {"A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"};
          int x=0;
          if (a==0){a=10;};
          for (int i=0;i<number.length;i++) {
              if (-((number[i] % 10 * 9) + (number[i] / 10) + b) % 10 == a-10) {
                  System.out.print(ABC[i]);
              }
          }
      }
      public static int eight_number (char[] a){
          int result=0;
          int e =8;
          for(int i=0;i<a.length;i++){
              result += Character.getNumericValue(a[i])*e;
              e--;

          }
          return result;
      }
}