MgicCarNumbers

//Cars in Sofia have registration numbers in format "CAabcdXY" where a, b, c and d are digits from 0 to 9 and X and Y are letters from the following subset of the Latin alphabet: 'A', 'B', 'C', 'E', 'H', 'K', 'M', 'P', 'T' and 'X'. Examples of car numbers from Sofia are "CA8517TX", "CA2277PC", "CA0710XC", "CA1111AC", while "CC7512FJ" in not valid car number from Sofia. Local people are keen to choose special numbers for their cars, know as magic car numbers. They calculate the weight of a car number as follows: they sum its digits and letters, assuming that letters have the following values: 'A'  10, 'B'  20, 'C'  30, 'E'  50, 'H'  80, 'K'  110, 'M'  130, 'P'  160, 'T'  200, 'X'  240. For example the weight("CA6511BM") = 30 + 10 + 6 + 5 + 1 + 1 + 20 + 130 = 203. A magic car number is a car number that has a special magic weight (e.g. 256 or 512 for developers) and its number is in some of the formats "CAaaaaXY", "CAabbbXY", "CAaaabXY", "CAaabbXY", "CAababXY" and "CAabbaXY", where a and b are two different digits and X and Y are letters from the Latin alphabet subset { 'A', 'B', 'C', 'E', 'H', 'K', 'M', 'P', 'T', 'X' }.
//Your task is to write a program that calculates how many cars can be registered in Sofia for given magic weight.
//Input
//The input data should be read from the console. It will consist of a single value: the magic weight.
//The input data will always be valid and in the format described. There is no need to check it explicitly.
//Output
//The output should be printed on the console. It is a single value: the number of cars matching given magic value.
//Constraints
//•   All input numbers will be integers in the range [1…1000].
//•   Allowed working time for your program: 0.25 seconds.
//•   Allowed memory: 16 MB.


using System;

class MagicCarNumbers
{
    static int count = 0;

    static void Main()
    {
        int weight = int.Parse(Console.ReadLine());

        char[] letters = {'A', 'B', 'C', 'E', 'H', 'K', 'M', 'P', 'T', 'X'};

        for (int letter1 = 0; letter1 < letters.Length; letter1++) // first letters
        {
            for (int letter2 = 0; letter2 < letters.Length; letter2++) // second letter
            {
                for (int a = 0; a <=9; a++)
                {
                    //"CAaaaaXY"
                    CheckCarNumberForMagic("CA" + a + a + a + a + letters[letter1] + letters[letter2], weight);

                    for (int b = 0; b <=9; b++)
                    {
                        if (b != a)
                        {
                            //, "CAaabbXY", "CAababXY" and "CAabbaXY"
                            CheckCarNumberForMagic("CA" + a + b + b + b + letters[letter1] + letters[letter2], weight);
                            CheckCarNumberForMagic("CA" + a + a + a + b + letters[letter1] + letters[letter2], weight);
                            CheckCarNumberForMagic("CA" + a + b + a + b + letters[letter1] + letters[letter2], weight);
                            CheckCarNumberForMagic("CA" + a + b + b + a + letters[letter1] + letters[letter2], weight);
                            CheckCarNumberForMagic("CA" + a + a + b + b + letters[letter1] + letters[letter2], weight);
                        }
                     }
                }
            }

        }
        Console.WriteLine(count);
    }

    private static void CheckCarNumberForMagic(string carNumber, int weight)
    {
        int tempWeight = 0;
        foreach (var ch in carNumber)
        {
            //http://www.ascii-code.com/

            if (ch >= '0' && ch<='9')
            {
                tempWeight += (ch - '0'); //returns the digit form 0 to 9
            }
            else
            {
                tempWeight += (ch - 64) * 10;
            }

        }
        if (tempWeight == weight)
        {
            count++;
        }
    }
}