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;
}
}