C#INFO2.0

using System;
using System.IO;
using System.Threading;

namespace IMJunior
{
    class Program
    {
        static void Main()
        {

            FilesCheck(new string[] {
                "words.txt",
                "in.txt"
            });

            string[] list = File.ReadAllLines("words.txt");
            string text = File.ReadAllText("in.txt");

            text = Filter(text, list);
            string line = GenerateString(Console.WindowWidth, "-");
            WriteColorLine(line);
            WriteColorLine(text, ConsoleColor.Yellow);
            WriteColorLine(line);

            File.WriteAllText("out.txt", text);
        }

        static void FilesCheck(string[] paths)
        {
            for(int i = 0; i < paths.Length; i++)
            {
                if (!File.Exists(paths[i]))
                {
                    Console.WriteLine("Не найден файл - " + paths[i]);
                    Console.ReadLine();
                    Environment.Exit(1);
                }
            }
        }

        static string Filter(string text, string[] blackList)
        {
            for(int i = 0; i < blackList.Length; i++)
            {
                text = text.Replace(blackList[i],
                                    GenerateString(blackList[i].Length));
            }
            return text;
        }


        static string GenerateString(int length, string fuller = "#")
        {
            if (fuller.Length == 0)
            {
                return "";
            }

            string mask = "";
            for (int j = 0; j < length; j += fuller.Length)
            {
                mask += fuller;
            }

            mask = mask.Substring(0, length);

            return mask;
        }

        static void WriteColorLine(string message, ConsoleColor color = ConsoleColor.Red)
        {
            ConsoleColor old = Console.ForegroundColor;
            Console.ForegroundColor = color;
            Console.WriteLine(message);
            Console.ForegroundColor = old;
        }
    }
}