Bulls and Cows Game - Optimized

/*
 * Created by SharpDevelop.
 * User: Admin
 * Date: 12.1.2022 г.
 * Time: 11:18
 *
 * To change this template use Tools | Options | Coding | Edit Standard Headers.
 */
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Windows.Forms;

namespace bulls_cows
{
    /// <summary>
    /// Description of MainForm.
    /// </summary>
    public partial class MainForm : Form
    {
        public int pcNumber = 0;
        public List<int> pcDigits = new List<int>();
        public int tries = 10;

        public MainForm()
        {
            //
            // The InitializeComponent() call is required for Windows Forms designer support.
            //
            InitializeComponent();

            //
            // TODO: Add constructor code after the InitializeComponent() call.
            //
        }
        void LinkLabel1LinkClicked(object sender, LinkLabelLinkClickedEventArgs e)
        {
            Info info = new Info();
            info.Show();
        }


        void ButtonNewGameClick(object sender, EventArgs e)
        {
            tries = 10;

            labelPcNumber.Text = "";
            textBoxUserNumber.Text = "";
            labelTries.Text = "";
            listBoxResult.Items.Clear();

            buttonCheck.Enabled = true;
            textBoxUserNumber.Enabled = true;

            Random r = new Random();

            while (true)
            {
                pcNumber = r.Next(1000, 10000);

                if (Different(pcNumber, true)) break;
            }


        }


        void ButtonCheckClick(object sender, EventArgs e)
        {
            int userNumber = 0;

            try
            {
                userNumber = int.Parse(textBoxUserNumber.Text);
            }
            catch
            {
                MessageBox.Show("Въведи 4-цифрено число");
                textBoxUserNumber.Text = "";
                textBoxUserNumber.Select();
                return;
            }

            textBoxUserNumber.Text = "";
            textBoxUserNumber.Select();

            //if (textBoxUserNumber.Text.Length != 4)
            if (userNumber < 1000 || userNumber > 9999)
            {
                MessageBox.Show("Числото трябва да е 4-цифрено");
                return;
            }


            if (!Different(userNumber, false))
            {
                MessageBox.Show("Цифрите трябва да са различни");
                return;
            }

            int bulls = 0;
            int cows = 0;
            tries--;

            int a = userNumber / 1000;
            int b = userNumber % 1000 / 100;
            int c = userNumber % 100 / 10;
            int d = userNumber % 10;

            if (pcDigits[0] == a) bulls++;
            else if (pcDigits.Contains(a)) cows++;

            if (pcDigits[1] == b) bulls++;
            else if (pcDigits.Contains(b)) cows++;

            if (pcDigits[2] == c) bulls++;
            else if (pcDigits.Contains(c)) cows++;

            if (pcDigits[3] == d) bulls++;
            else if (pcDigits.Contains(d)) cows++;

            labelTries.Text = "Остават " + tries + " опита";
            if (tries == 1)
            {
                labelTries.Text = "Остава 1 опит";
            }


            if (bulls == 4)
            {
                labelTries.Text = "ПЕЧЕЛИШ !!!";
                labelPcNumber.Text = pcNumber.ToString();
                labelPcNumber.ForeColor = Color.Green;
                buttonCheck.Enabled = false;
                textBoxUserNumber.Enabled = false;
            }

            string bullsWord = bulls == 1 ? "бик" : "бика";
            string cowsWord = cows == 1 ? "крава" : "крави";

            if (tries > 0)
            {
                string result = string.Format("{0}: {1} {2}, {3} {4}",
                    userNumber, bulls, bullsWord, cows, cowsWord);
                listBoxResult.Items.Add(result);
            }
            else
            {
                if (bulls != 4)
                {
                    labelTries.Text = "ГУБИШ !!!";
                    labelPcNumber.Text = pcNumber.ToString();
                    labelPcNumber.ForeColor = Color.Red;
                    buttonCheck.Enabled = false;
                    textBoxUserNumber.Enabled = false;
                }

            }

        }


        public bool Different(int number, bool pc)
        {
            int a = number / 1000;
            int b = number % 1000 / 100;
            int c = number % 100 / 10;
            int d = number % 10;

            List<int> digits = new List<int>();

            if (!digits.Contains(a)) digits.Add(a);
            if (!digits.Contains(b)) digits.Add(b);
            if (!digits.Contains(c)) digits.Add(c);
            if (!digits.Contains(d)) digits.Add(d);

            if (pc) pcDigits = digits;

            return digits.Count == 4;
        }


    }
}