C#

int x = 1000;
        int y = 1000;

        if (x == y)
            Console.WriteLine("Value is same");
        else
            Console.WriteLine("Value is not same");

        if (x.Equals(y))
            Console.WriteLine("Value is same");
        else
            Console.WriteLine("Value is not same");

        if (object.ReferenceEquals(x,y))
            Console.WriteLine("ref is same");
        else
            Console.WriteLine("ref is not same");


        string s1 = "Hello";
        string s2 = "Hello";

        if (s1 == s2)
            Console.WriteLine("Value is same");
        else
            Console.WriteLine("Value is not same");

        if (s1.Equals(s2))
            Console.WriteLine("Value is same");
        else
            Console.WriteLine("Value is not same");

        if (object.ReferenceEquals(s1, s2))
            Console.WriteLine("ref is same");
        else
            Console.WriteLine("ref is not same");

if (object.ReferenceEquals(x,y))
    Console.WriteLine("ref is same");
else
    Console.WriteLine("ref is not same");

if (object.ReferenceEquals(s1, s2))
        Console.WriteLine("ref is same");
    else
        Console.WriteLine("ref is not same");

Below is a program that selects the coefficients and corresponds to the result. After that sorting is performed for the statement.
Initially the program calculated the coefficient from 10%.
I tried to change the accuracy by 2%. The result turned out to be bad - the time for selecting the coefficients was greatly increased.
The question is:
Can other methods be used to speed up the finding of the result. And how fast can the program work?
Maybe someone already faced a similar problem?
Below is the code of the program

using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace Flerov.PortfolioOptimizer
{
    class Program
    {
        [STAThread]
        static void Main(string[] args)
        {
            var  dlg = new OpenFileDialog();

            if (dlg.ShowDialog() != DialogResult.OK)
                return;

            var input = File.ReadAllLines(dlg.FileName).Skip(2).Select(line =>
                {
                    var res = line.Split(';');
                    var date = DateTime.ParseExact(res[0], "dd.MM.yyyy", (IFormatProvider)CultureInfo.InvariantCulture);
                    //var date = DateTime.ParseExact(res[0] + " " + res[1], "dd.MM.yyyy 00:00", (IFormatProvider)CultureInfo.InvariantCulture);
                    //  "dd.MM.yyyy", (IFormatProvider)CultureInfo.InvariantCulture)
                    var data = res.Skip(1).Select(decimal.Parse).ToArray();
                    return new Tuple<DateTime, decimal[]>(date, data);
                }).ToArray();

            var count = input.First().Item2.Length;

            var allKkoefs = new List<decimal>();
 //           for (decimal i = 0; i <= 1; i+=0.1m) 
            for (decimal i = 0; i <= 1; i += 0.02m)
                {
                    allKkoefs.Add(i);
            }

            var listResult = new List<Tuple<decimal[], decimal>>();

            var permutation = allKkoefs.Permutations(count).Select(p => p.ToArray()).Where(p => p.Sum() == 1).ToArray();

            foreach (var k in permutation)
            {
                var koefs = k.ToArray();

                var sum = input.Select(p => p.Item2.Zip(koefs, (arg1, arg2) => arg1*arg2).Sum()).ToArray();
                var avg = sum.Average();
                var std = sum.StandardDeviation(avg);
                if (std == 0) std = 1;

                var res = (decimal) (avg/std);

                listResult.Add(new Tuple<decimal[], decimal>(koefs, res));
            }

            var best = listResult.OrderByDescending(p => p.Item2).Take(30).ToArray();

            var header = "value;";
            for (int i = 1; i <= count; i++)
            {
                header += "koef" + i + ";";
            }

            File.WriteAllLines(dlg.FileName + ".result.csv", new[]{header});
            File.AppendAllLines(dlg.FileName + ".result.csv", best.Select(i => string.Format("{0};{1}", i.Item2,
                i.Item1.Aggregate("", (s, arg2) => s+arg2+";"))));
        }
    }

    static class Helper
    {
        public static decimal StandardDeviation(this ICollection<decimal> num, decimal? avg)
        {
            if (num.Count == 1)
                return num.First();

            if (avg == null)
                avg = num.Average();

            var sumOfSqrs = num.Sum(t => Math.Pow((double)(t - avg.Value), 2));

            var n = num.Count;
            return (decimal)Math.Sqrt(sumOfSqrs / (n - 1));
        }

        public static IEnumerable<IEnumerable<T>> Permutations<T>(this IEnumerable<T> pool, int selectionSize)
        {
            var idxs = new int[selectionSize];
            var pl = pool.ToArray();
            var length = pl.Length;

            do
            {
                yield return GetItems(pl, idxs, selectionSize);
                GetNextPermutation(idxs, selectionSize, length);
            } while (idxs[0] < length);
        }

        private static void GetNextPermutation(IList<int> idxs, int selectionSize, int poolSize)
        {
            var position = selectionSize - 1;

            idxs[position]++;
            while (idxs[position] == poolSize && position > 0)
            {
                idxs[position - 1]++;
                for (var i = position; i < selectionSize; i++)
                    idxs[i] = 0;
                position--;
            }
        }

        private static IEnumerable<T> GetItems<T>(IList<T> items, IList<int> idxs, int length)
        {
            for (var i = 0; i < length; i++)
                yield return items[idxs[i]];
        }
    }
}

using System;
    using System;
    using System.Windows.Forms;
    using System.Threading;
    using System.Net.Sockets;
    using System.IO;

    namespace question_game_client
    {
      public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private NetworkStream output; // stream for receiving data           
        private BinaryWriter writer; // facilitates writing to the stream    
        private BinaryReader reader; // facilitates reading from the stream  
        private Thread readThread; // Thread for processing incoming messages
        private string message = "";

        private void Form1_Load(object sender, EventArgs e)
        {
            readThread = new Thread(new ThreadStart(RunClient));
            readThread.Start();   
        }

        // close all threads associated with this application
        private void Form1_FormClosing(object sender,
           FormClosingEventArgs e)
        {
            //System.Environment.Exit(System.Environment.ExitCode);
        } // end method ChatClientForm_FormClosing

        // delegate that allows method DisplayMessage to be called
        // in the thread that creates and maintains the GUI       
        private delegate void DisplayDelegate(string message);

        // method DisplayMessage sets displayTextBox's Text property
        // in a thread-safe manner
        private void DisplayMessage(string message)
        {
            // if modifying displayTextBox is not thread safe
            if (displayTextBox.InvokeRequired)
            {
                // use inherited method Invoke to execute DisplayMessage
                // via a delegate                                       
                Invoke(new DisplayDelegate(DisplayMessage),
                   new object[] { message });
            } // end if
            else // OK to modify displayTextBox in current thread
                displayTextBox.Text += message;
        } // end method DisplayMessage

        // delegate that allows method DisableInput to be called 
        // in the thread that creates and maintains the GUI
        private delegate void DisableInputDelegate(bool value);

        // sends text the user typed to server
        private void inputTextBox_KeyDown(object sender, KeyEventArgs e)
        {
            try
            {
                  // create objects for writing and reading across stream
               
                if (e.KeyCode == Keys.Enter && inputTextBox.ReadOnly == false)

                {
                    writer.Write(inputTextBox.Text);
                   
                    inputTextBox.Clear();
                   

                } // end if
            } // end try
            catch (SocketException)
            {
                displayTextBox.Text += "\nError writing object";
            } // end catch
        } // end method inputTextBox_KeyDown

        // connect to server and display server-generated text
        public void RunClient()
        {
            TcpClient client;

            // instantiate TcpClient for sending data to server
            try
            {
       
                // Step 1: create TcpClient and connect to server
                client = new TcpClient();
                client.Connect("127.0.0.1", 8190);

                // Step 2: get NetworkStream associated with TcpClient
                output = client.GetStream();

                // create objects for writing and reading across stream
                writer = new BinaryWriter(output);
                reader = new BinaryReader(output);

                // loop until server signals termination
                do
                {
                    // Step 3: processing phase
                    try
                    {
                        
                        DisplayMessage("\r\n" + message);
                        // read message from server        
                        message = reader.ReadString();
                    } // end try
                    catch (Exception e)
                    {
                        // handle exception if error in reading server data
                        //System.Environment.Exit(System.Environment.ExitCode);

                        MessageBox.Show(e.ToString());
                    } // end catch
                } while (message != "SERVER>>> TERMINATE");

                // Step 4: close connection
                writer.Close();
                reader.Close();
                output.Close();
                client.Close();

                //Application.Exit();
            } // end try
            catch (Exception error)
            {
                // handle exception if error in establishing connection
                MessageBox.Show(error.ToString(), "Connection Error",
                   MessageBoxButtons.OK, MessageBoxIcon.Error);
                  // Environment.Exit(Environment.ExitCode);
            } // end catch
        } // end method RunClient

        private void inputTextBox_TextChanged(object sender, EventArgs e)
        {

        }
    }


    }

using System;
    using System.Threading;
    using System.Net;
    using System.Net.Sockets;
    using System.Collections.Generic;
    using System.IO;

    namespace question_game_server
    {
    

    class Program
    {
        private Socket connection; // Socket for accepting a connection
        private int port = 8190;
        private Random rand = new Random();
        string message = null;
        string answer = null;

        static void Main(string[] args)
        {
            new Program().Run();
        }

        void Run()
        {
            new Thread(RunServer).Start();
            getquestions();
        }

        public void RunServer()
        {

            Thread readThread; // Thread for processing incoming messages
            bool done = false;

            TcpListener listener;
            try
            {

                // Step 1: create TcpListener
                //IPAddress local = IPAddress.Parse("127.0.0.1");
                listener = new TcpListener(IPAddress.Any, port);
                listener.Start();
                Console.WriteLine("Waiting for connection ...");

                while (!done)
                {
                    // This is where the server sits and waits for clients
                    connection = listener.AcceptSocket();
                   
        
                    // Start a new thread for a client
                    readThread = new Thread(GetMessages);
                    readThread.Start();
                }
            }
            catch (Exception)
            {
                Console.WriteLine("Port " + port + " may be busy. Try another.");
            }
        }
       
        //Reads the file with the questions and splits the question and the answer into two arrays.
        //Each question ends with ; and there is a : between each question and answer.
        public string getquestions()
        {
            int countquestions;
            int random_question_val;
           

            try
            {   // Open the text file using a stream reader.
                using (StreamReader sr = new StreamReader("questions_and_answers.txt"))
                {
                    // Read the stream to a string, and write the string to the console.
                    String line = sr.ReadToEnd();

                    string[] questions_and_answers = line.Split(';');

                    //Counts the questions
                    countquestions = questions_and_answers.Length-1;

                    random_question_val = rand.Next(0, (countquestions));

                    Console.WriteLine(random_question_val);

                    //Splits the answer ans the question
                    string[] question_and_answer = questions_and_answers[random_question_val].Split(':');

  
                    //The Answer

                    Console.WriteLine("Answer:"+question_and_answer[1]);

                    answer = question_and_answer[1];
              
                   
                    sr.Close();

                    //The question
                    return question_and_answer[0];

                   
                }
            }
            catch (Exception e)
            {
                Console.WriteLine("The file could not be read:");
                Console.WriteLine(e.Message);
                return null;
            }

        }

       

        public void GetMessages()
        {
            Socket socket = connection;
            NetworkStream socketStream = null;
            BinaryWriter writer = null;
            BinaryReader reader = null;

            try
            {
                // establish the communication streams
                socketStream = new NetworkStream(socket);
                reader = new BinaryReader(socketStream);
                writer = new BinaryWriter(socketStream);
          
                Console.WriteLine("Connection successful.\n");
               
                writer.Write(getquestions());
                  
                message = reader.ReadString();

                Console.WriteLine(message);

                if (answer == message)

                {
                    writer.Write("Correct Answer!");
                    Console.WriteLine(message);
                }

                if (answer != message && message != null)
                {
                    Console.WriteLine(message);
                    writer.Write("Wrong Answer!");
                }

            }


            catch (Exception error)
            {
                Console.WriteLine(error.ToString());
            }

            finally
            {
                reader.Close();
                writer.Close();
                socketStream.Close();
                socket.Close();
            }
              Console.ReadKey();
        }

          


        }
    }

selling point