Pr11NumberWords

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

// Write a program that converts a number in the range [0…999] to words,
// corresponding to the English pronunciation.
class Pr11NumberWords
{
    static void Main(string[] args)
    {
        Console.Write("Enter how many tests you would like to run: ");
        int tests = int.Parse(Console.ReadLine());
        for (int t = 0; t < tests; t++)
        {
            // Res
            string[] ones = { "zero", "one", "two", "three", "four", "five","six", "seven",
                              "eight", "nine", "ten", "eleven", "twelve", "thirteen", "fourteen",
                              "fifteen", "sixteen", "seventeen", "eighteen", "nineteen" };

            string[] tens = { "twenty", "thirty", "forty", "fifty", "sixty",
                              "seventy", "eighty", "ninety" };

            // Input
            string input = Console.ReadLine();
            StringBuilder result = new StringBuilder();
            short number = short.Parse(input);
            short digit1s = (short) (number % 10);
            short digitTeens = (short) (number % 100);
            short digit10s = (short) (digitTeens / 10);
            short digit100s = (short) (number / 100);

            // Zero
            if (number == 0)
            {
                result.Append(ones[0]);
            }

            // Hundreds
            if (digit100s != 0)
            {
                result.Append(ones[digit100s]);
            }

            // Post hundreds
            if (digit100s != 0)
            {
                result.Append(" hundred");
                if (digitTeens != 0)
                {
                    result.Append(" and ");
                }
            }

            // Teens
            if (digitTeens > 9 && digitTeens < 20)
            {
                result.Append(ones[digitTeens]);
            }

            // Non-teens
            else
            {
                // Tens
                if (digit10s > 1)
                {
                    result.Append(tens[digit10s - 2]);
                }

                // Post tens
                if (digit10s != 0 && digit1s != 0)
                {
                    result.Append(" ");
                }

                // Ones
                if (digit1s != 0)
                {
                    result.Append(ones[digit1s]);
                }
            }

            // Capitalize first letter
            result[0] = (char) (result[0] - 32);
            string output = result.ToString();

            // Output
            Console.WriteLine(output);
        }
    }
}