using System;
using System.IO;

namespace Test
{
    static class Program
    {
        static Stack<string> stack = new Stack<string>();
        static void Main()
        {
            IterateDirectory(@"C:\Test");
        }

        static void IterateDirectory(string directory)
        {
            stack.push(subDirectory);

            while (stack.Count > 0)
            {
                directory = stack.pop();

                foreach (string file in Directory.GetFiles(directory))
                    Console.WriteLine(file);

                foreach (string subDirectory in Directory.EnumerateDirectories(directory))
                    stack.push(subDirectory);
            }
        }
    }
}