using System;

​

public class Program

{

    public static void Main()

    {

        //第一行代碼固定，期限0711，聯邦收款

        string firstLine = "100127C31";

        //輸入第二行代碼，可至電子帳單，下載繳款聯取得，16位

        string secondLine = "0098554416570001";     

        //輸入金額，小於20000

        string bill = "976";        

        //第三行前四碼為月份

        string thirdLine = "10012" + bill.PadLeft(9, '0');

        char[] _a1 = firstLine.ToCharArray();

        char[] _b = secondLine.ToCharArray();

        char[] _c = thirdLine.ToCharArray();

        int odd = 0, even = 0;

        int count = 0;

        foreach (char i in _a1)

        {

            int tmp;

            count++;

            if (Char.IsLetter(i))

            {

                tmp = charConverter(i);

                if (count % 2 == 0)

                    even += Convert.ToInt32(tmp.ToString());

                else

                    odd += Convert.ToInt32(tmp.ToString());

            }

            else

            {

                if (count % 2 == 0)

                    even += Convert.ToInt32(i.ToString());

                else

                    odd += Convert.ToInt32(i.ToString());

            }

        }

​

        count = 0;

        foreach (char i in _b)

        {

            int tmp;

            count++;

            if (Char.IsLetter(i))

            {

                tmp = charConverter(i);

                if (count % 2 == 0)

                    even += Convert.ToInt32(tmp.ToString());

                else

                    odd += Convert.ToInt32(tmp.ToString());

            }

            else

            {

                if (count % 2 == 0)

                    even += Convert.ToInt32(i.ToString());

                else

                    odd += Convert.ToInt32(i.ToString());

            }

        }

​

        count = 0;

        foreach (char i in _c)

        {

            int tmp;

            count++;

            if (Char.IsLetter(i))

            {

                tmp = charConverter(i);

                if (count % 2 == 0)

                    even += Convert.ToInt32(tmp.ToString());

                else

                    odd += Convert.ToInt32(tmp.ToString());

            }

            else

            {

                if (count % 2 == 0)

                    even += Convert.ToInt32(i.ToString());

                else

                    odd += Convert.ToInt32(i.ToString());

            }

        }

​

        //Console.WriteLine(odd.ToString());

        //Console.WriteLine(even.ToString());

        Console.WriteLine("第三行代碼為以下，可到https://www.morovia.com/free-online-barcode-generator/ 以Barcode Format: Code 39生成條碼");

        Console.WriteLine(thirdLine.Substring(0, 4) + odd % 11 + even % 11 + thirdLine.Substring(4));

        Console.WriteLine("參考內容https://www.ewdna.com/2019/09/creditcard-barcode.html");

    }

​

    private static int charConverter(char eng)

    {

        return (eng - 65) % 9 + 1;

    }

}