Contador de bytes do Desafio 2

Desafio2.cs

using System;
using System.IO;
using System.Linq;

namespace Desafio2
{
    class Program
    {
        private static string[] EXTENSIONS = new string[] { 
            ".exe", ".log", ".pdb", ".js", ".html", ".htm", 
            ".xhtml", ".xsl", ".xslt", ".hta", ".txt", ".css", ".dll", ".obj" 
        };

        private static bool ShouldCountLength(FileInfo fileInfo) 
        {
            return fileInfo != null 
                && (from e in EXTENSIONS where e == fileInfo.Extension select true).FirstOrDefault();
        }

        static void Main(string[] args)
        {
            var directory = @"c:\TMP\tst";

            Console.WriteLine(string.Format("Total Size: '{0}' bytes",
                     Directory.EnumerateFiles(directory, "*.*", SearchOption.AllDirectories)
                       .Select(f => new FileInfo(f))
                       .Where(ShouldCountLength)
                       .Select(fi => fi.Length)
                       .Sum()
                       ));
            
            Console.ReadLine();
        }
    }
}