Program.cs

using System;
using System.Text;
using System.Net.Sockets;
using System.IO;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            const string strFind1 = "Press enter to start the game";
            const string strFind2 = "Make your move. Type the number of the field you want to set! (1-9)\n\nField: ";
            const string strFind3 = "Press enter to start again";
            const string strFind4 = "Congratulations you won!";
            const string strFind5 = "Congratulations you won! 100/100";
            const int gridSize = 144;
            TcpClient tcpClient = new TcpClient();
            tcpClient.Connect("challenges.hackvent.hacking-lab.com", 1037);
            NetworkStream networkStream = tcpClient.GetStream();
            StreamReader clientStreamReader = new StreamReader(networkStream);
            string readstring = "";
            while (true) {
                int readChar = clientStreamReader.Read();
                if (readChar != -1) {
                    readstring += Convert.ToChar(readChar);
                    if (readstring.Length >= strFind1.Length) {
                        if (readstring.Substring(readstring.Length - strFind1.Length) == strFind1) {
                            readstring = "";
                            byte[] bytesToSend = ASCIIEncoding.ASCII.GetBytes("\n");
                            networkStream.Write(bytesToSend, 0, bytesToSend.Length);
                        }
                    }
                    if (readstring.Length >= strFind2.Length) {
                        if (readstring.Substring(readstring.Length - strFind2.Length) == strFind2) {
                            string grid = readstring.Substring(1, readstring.Length - strFind2.Length - 1).Substring(readstring.Substring(1, readstring.Length - strFind2.Length - 1).Length - gridSize);
                            grid = grid.Replace(" ", "");
                            grid = grid.Replace("|", "");
                            grid = grid.Replace("-", "");
                            grid = grid.Replace("\n", "");
                            readstring = "";
                            string send = "";
                            if (grid == "*********") send = "1";
                            if (grid == "X***O****") send = "9";
                            if (grid == "X*O*O***X") send = "7";
                            if (grid == "X*O*O*XOX") send = "4";
                            if (grid == "XOO*O*X*X") send = "8";
                            if (grid == "XO*******") send = "8";
                            if (grid == "XOO****X*") send = "7";
                            if (grid == "XO**O***X") send = "8";
                            if (grid == "XO**O*OXX") send = "3";
                            if (grid == "XO**O**X*") send = "7";
                            if (grid == "XO**O*XXO") send = "4";
                            if (grid == "XOX*OOOXX") send = "4";
                            if (grid == "XOO*O**XX") send = "7";
                            if (grid == "XOO*O*XX*") send = "9";
                            if (grid == "XOXOO*OXX") send = "6";
                            if (grid == "XOO***XXO") send = "4";
                            if (send == "")
                                throw new Exception("not handled combination!");
                            byte[] bytesToSend = ASCIIEncoding.ASCII.GetBytes(send + "\n");
                            networkStream.Write(bytesToSend, 0, bytesToSend.Length);
                        }
                    }
                    if (readstring.Length >= strFind3.Length) {
                        if (readstring.Substring(readstring.Length - strFind3.Length) == strFind3) {
                            int pos1 = readstring.IndexOf(strFind4);
                            if (pos1 >= 0) {
                                int pos2 = readstring.IndexOf("\n", pos1);
                                string found = readstring.Substring(pos1, pos2 - pos1);
                                if (found != strFind5)
                                    Console.WriteLine(found);
                                else {
                                    Console.WriteLine(readstring.Substring(pos1));
                                    break;
                                }
                            }
                            byte[] bytesToSend = ASCIIEncoding.ASCII.GetBytes("\n");
                            networkStream.Write(bytesToSend, 0, bytesToSend.Length);
                            readstring = "";
                        }
                    }
                }
            }
        }
    }
}