5.11ConditionalStatements_NumberAsWords_v.2

using System;

class NumberAsWordsV2
{
    static void PrintNumbersFrom1UpTo9 (int number)
    {
        switch (number)
        {
            case 1:
                Console.Write("one ");
                break;
            case 2:
                Console.Write("two ");
                break;
            case 3:
                Console.Write("three ");
                break;
            case 4:
                Console.Write("four ");
                break;
            case 5:
                Console.Write("five ");
                break;
            case 6:
                Console.Write("six ");
                break;
            case 7:
                Console.Write("seven ");
                break;
            case 8:
                Console.Write("eight ");
                break;
            case 9:
                Console.Write("nine ");
                break;
            default:
                Console.WriteLine("Unexpected Error !!!");
                break;
        }
    }

    static void PrintNumbersFrom10UpTo19 (int number)
    {
        switch (number)
        {
            case 0:
                Console.Write("ten ");
                break;
            case 1:
                Console.Write("eleven ");
                break;
            case 2:
                Console.Write("twelve ");
                break;
            case 3:
                Console.Write("thirteen ");
                break;
            case 4:
                Console.Write("fourteen ");
                break;
            case 5:
                Console.Write("fifteen ");
                break;
            case 6:
                Console.Write("sixteen ");
                break;
            case 7:
                Console.Write("seventeen ");
                break;
            case 8:
                Console.Write("eighteen ");
                break;
            case 9:
                Console.Write("nineteen ");
                break;
            default:
                Console.WriteLine("Unexpected Error !!!");
                break;
        }
    }

    static void PrintNumbersFrom20UpTo90 (int number)
    {
        switch (number)
        {
            case 2:
                Console.Write("twenty ");
                break;
            case 3:
                Console.Write("thirty ");
                break;
            case 4:
                Console.Write("forty ");
                break;
            case 5:
                Console.Write("fifty ");
                break;
            case 6:
                Console.Write("sixty ");
                break;
            case 7:
                Console.Write("seventy ");
                break;
            case 8:
                Console.Write("eighty ");
                break;
            case 9:
                Console.Write("ninety ");
                break;
            default:
                Console.WriteLine("Unexpected Error !!!");
                break;
        }
    }

    static void Main ()
    {
        Console.Write("Please, enter a whole number in the range [0 ... 999], N = ");
        string numberStr = Console.ReadLine();
        int numberN = int.Parse(numberStr);

        if (numberN < 0 || numberN > 999)
        {
            Console.WriteLine("Error - The Number is out of range !!!");
            Console.ReadLine();
            return;
        }

        Console.Write("YOUR NUMBER: ");
        if (numberN > 0)
        {
            int hundred = numberN / 100;
            switch (hundred)
            {
                case 0:
                    break;
                case 1:
                    Console.Write("One hundred ");
                    break;
                case 2:
                    Console.Write("Two hundred ");
                    break;
                case 3:
                    Console.Write("Three hundred ");
                    break;
                case 4:
                    Console.Write("Four hundred ");
                    break;
                case 5:
                    Console.Write("Five hundred ");
                    break;
                case 6:
                    Console.Write("Six hundred ");
                    break;
                case 7:
                    Console.Write("Seven hundred ");
                    break;
                case 8:
                    Console.Write("Eight hundred ");
                    break;
                case 9:
                    Console.Write("Nine hundred ");
                    break;
                default:
                    Console.WriteLine("Unexpected Error !!!");
                    break;
            }
            if ((numberN % 100) > 0)
            {
                if (numberN >= 100)
                {
                    Console.Write("and ");
                }
                int tenth = (numberN % 100) / 10;
                if (tenth == 1)
                {
                    PrintNumbersFrom10UpTo19((numberN % 100) % 10);
                    Console.WriteLine("!");
                    Console.ReadLine();
                    return;
                }
                else if (tenth > 1)
                {
                    PrintNumbersFrom20UpTo90(tenth);
                }
                int remainder = (numberN % 100) % 10;
                if (remainder > 0)
                {
                    PrintNumbersFrom1UpTo9(remainder);
                }
            }
        }
        else if (numberN == 0)
        {
            Console.Write("Zero ");
        }
        Console.WriteLine("!");
        Console.ReadLine();
    }
}