利用校验位检查学生输入的学号是否正确

package checkTheID;

import java.util.Scanner;

public class CheckTheID {

    //学号6位数字,校验位第7位。也可以修改。
    //用户输入学号及校验位,程序检测用户输入的学号是否正确。
    //校验位=(1*(第1位数字)+2*(第2位数字)+3*(第3位数字)
    //+4*(第4位数字)+5*(第5位数字)+6*(第6位数字))%10
    public static final int IDLENGTH = 7;
    public static void main(String[] args) {
        
        Scanner console = new Scanner(System.in); 
        System.out.print("input your id (" + IDLENGTH + " bit): ");
        int id = console.nextInt();
        
        int[] s = new int[IDLENGTH];
        s = computeEverBit(id);
        int checkbit;
        checkbit = getCheckBit(s);
        
        if(checkbit != s[IDLENGTH - 1])
            System.out.println("input the wrong id!Please input again:");
        else 
            System.out.println("there is 90% possibility that you input the right id!");
    }
    
//输入:学号(整数值),输出:返回数组,每个元素即为学号的每个数字
    public static int[] computeEverBit(int id)
    {
       int[] s = new int[IDLENGTH];
       for(int i = 0;i < IDLENGTH;i++)
       {
          s[i] = id / (int)Math.pow(10,IDLENGTH-1-i);
          id = id % (int)Math.pow(10,IDLENGTH-1-i);
       }
       return s;
    }
    
//输入:数组,输出:返回根据前六个元素得到校验位
    public static int getCheckBit(int[] s)
    {
      int checkbit,sum = 0;
      for(int i = 1;i<= IDLENGTH - 1;i++)
         sum += s[i-1]*i;
      checkbit =sum % 10;
      return checkbit;
    }
}
原文地址:https://www.cnblogs.com/diligentcalf/p/3601975.html