using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Circles
{
    class Program
    {
        /// <summary>
        /// Структура круга
        /// </summary>
        struct t_circle { 
            public int x, y, d;
            public t_circle(int x, int y, int d)
            {
                this.x = x;
                this.y = y;
                this.d = d;
            }
        }
        static List<t_circle> l_circles = new List<t_circle>();

        /// <summary>
        /// Рекурсивно добавляет структуры кругов в массив, пока n>0
        /// </summary>
        static void add_circle( int x, int y, int dia, int n)
        {
            if (n>0)
            {
                //Console.WriteLine($"{x}, {y}, {dia}, {n}");
                t_circle t = new t_circle(x, y, dia);
                l_circles.Add(t);

                add_circle(x - dia / 2, y, dia / 2, n - 1);
                add_circle(x + dia / 2, y, dia / 2, n - 1);
                add_circle(x, y - dia / 2, dia / 2, n - 1);
                add_circle(x, y + dia / 2, dia / 2, n - 1);
            }
        }

        static void Main(string[] args)
        {
            Console.Write("Enter depth of circles [1..6] : ");
            string val = Console.ReadLine();
            try
            {
                int n = Convert.ToInt32(val);

                if (n<1 || n>6)
                {
                    Console.WriteLine("invalid input!");
                } else
                {
                    int dia = Convert.ToInt32(20 * Math.Pow(2, n));
                    int w = dia * 2;
                    
                    add_circle(w/2, w/2, dia, n);
                    
                    Bitmap bmp = new Bitmap(w, w);
                    using (Graphics graph = Graphics.FromImage(bmp))
                    {
                        Rectangle ImageSize = new Rectangle(0, 0, w, w);
                        graph.FillRectangle(Brushes.White, ImageSize);

                        Pen pen = new Pen(Color.Black, 1);
                        foreach (var t in l_circles)
                            graph.DrawEllipse(pen, t.x - t.d / 2, t.y - t.d / 2, t.d, t.d);
                    }
                    string filePath = AppDomain.CurrentDomain.BaseDirectory + $"out_{n}.bmp";
                    bmp.Save(filePath);
                    Console.WriteLine($"Image saved to \"{filePath}\"");
                }
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
                throw;
            }
            
        }
    }
}