using System;
using System.Text;

public class Example
{
    public static void Main()
    {
        Console.WriteLine("Please input your sentence you want to encode");
        string stringA = Console.ReadLine();
        string[] strings = { stringA };
        Encoding asciiEncoding = Encoding.ASCII;

        // Create array of adequate size.
        byte[] bytes = new byte[49];
        // Create index for current position of array.
        int index = 0;

        Console.WriteLine("Strings to encode:");
        foreach (var stringValue in strings)
        {
            Console.WriteLine("   {0}", stringValue);

            int count = asciiEncoding.GetByteCount(stringValue);
            if (count + index >= bytes.Length)
                Array.Resize(ref bytes, bytes.Length + 50);

            int written = asciiEncoding.GetBytes(stringValue, 0,
                                                 stringValue.Length,
                                                 bytes, index);

            index = index + written;
        }
        Console.WriteLine("\nASCII values of your sentence:");
        Console.WriteLine("{0}", ShowByteValues(bytes, index));
        Console.WriteLine();


        Console.WriteLine("What is your cipher key?");
        var cipherKey = Console.ReadLine();
        Console.WriteLine("Your cipher key is " + cipherKey);

        // Decode Unicode byte array to a string.
        string newString = asciiEncoding.GetString(bytes, 0, index);
        Console.WriteLine("Your sentence is {0}", newString);
        Console.WriteLine("The cipher key is " + cipherKey);
        Console.ReadLine();
    }


    private static string ShowByteValues(byte[] bytes, int last)
    {
        string returnString = "   ";
        for (int ctr = 0; ctr <= last - 1; ctr++)
        {
            if (ctr % 20 == 0)
                returnString += "\n   ";
            returnString += String.Format("{0:X2} ", bytes[ctr]);
        }
        return returnString;
    }
}