使用C#写了一个可以推算火车票身份证号码的小程序

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace Geyunfei.CheckID
{
class Program
{
static int[] a = new int[] { 7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2 };
static char[] b = new char[] { '1', '0', 'X', '9', '8', '7', '6', '5', '4', '3', '2' };
static int index = 0;
static void Main(string[] args)
{
System.Console.WriteLine("输入火车票上的身份证号:");
String a = System.Console.ReadLine();
var year = int.Parse(a.Substring(6, 4));
var beginDate = new DateTime(year, 1, 1);
var chk = a.Substring(14);
int days = 365;
if (DateTime.IsLeapYear(year))
days++;
for(int i =0;i<days; i++)
{
var chkDate = beginDate.AddDays(i).ToString("MMdd");
var id = a.Substring(0, 10) + chkDate + chk;
CheckID(id);
}
}
private static void CheckID(string id)
{
int sum = 0;
for(int i = 0; i < 17; i++)
{
sum += int.Parse(id[i].ToString()) * a[i];
}
var chk = b[sum % 11];
if (chk == id[17])
{
index++;
Console.WriteLine(getAstro(int.Parse(id.Substring(10,2)),int.Parse(id.Substring(12,2)))+ index.ToString() +" "+id);
}
}
private static String getAstro(int month, int day)
{
String[] starArr = {"魔羯座","水瓶座", "双鱼座", "牡羊座",
"金牛座", "双子座", "巨蟹座", "狮子座", "处女座", "天秤座", "天蝎座", "射手座" };
int[] DayArr = { 22, 20, 19, 21, 21, 21, 22, 23, 23, 23, 23, 22 }; // 两个星座分割日
int index = month;
// 所查询日期在分割日之前，索引-1，否则不变
if (day < DayArr[month - 1])
{
index = index - 1;
}
index = index % 12;
// 返回索引指向的星座string
return starArr[index];
}
}
}