using System;

using System.Linq;

using System.Text;

​

public static class Program

{

    public static void Main(string[] args)

    {

        var encodings = Encoding.GetEncodings().Select(e => e.GetEncoding()).ToList();

        var asciiCompatible = encodings.Where(e => IsAsciiCompatible(e)).ToList();

        var nonAsciiCompatbile = encodings.Except(asciiCompatible).ToList();

​

        Console.WriteLine("ASCII compatible: ");

        foreach (var encodingName in asciiCompatible.Select(e => e.EncodingName).OrderBy(n => n))

            Console.WriteLine("* " + encodingName);

        Console.WriteLine();

        Console.WriteLine("Non-ASCII compatible: ");

        foreach (var encodingName in nonAsciiCompatbile.Select(e => e.EncodingName).OrderBy(n => n))

            Console.WriteLine("* " + encodingName);

    }

​

    private static readonly byte[] asciiValues = Enumerable.Range(0, 128).Select(b => (byte)b).ToArray();

    private static readonly string asciiChars = new string(asciiValues.Select(b => (char)b).ToArray());

    public static bool IsAsciiCompatible(Encoding encoding)

    {

        return encoding.GetString(asciiValues).Equals(asciiChars, StringComparison.Ordinal)

            && encoding.GetBytes(asciiChars).SequenceEqual(asciiValues);

    }    

}