MazeRunner

Maze.cs

using System;
using System.Drawing;

namespace MazeRunner
{
    class Maze
    {
        public int Width { get; }
        public int Height { get; }

        private readonly uint[] _bits;

        private bool IsSet(int index)
        {
            int arrayIndex = index / 32;
            int bitIndex = index - arrayIndex * 32;
            uint mask = (uint)1 << bitIndex;
            return (_bits[arrayIndex] & mask) != 0;
        }

        private void Set(int index)
        {
            int arrayIndex = index / 32;
            int bitIndex = index - arrayIndex * 32;
            uint mask = (uint)1 << bitIndex;
            _bits[arrayIndex] |= mask;
        }

        public Maze(int width, int height)
        {
            Width = width;
            Height = height;

            int bitCount = width * height * 2;
            int wordCount = (bitCount + 31) / 32;
            _bits = new uint[wordCount];
        }

        public void RandomFill(Random random)
        {
            for (int i = 0; i < _bits.Length; ++i)
            {
                uint hi = (uint)(random.Next() & 0xffff);
                uint lo = (uint)(random.Next() & 0xffff);
                _bits[i] = (hi << 16) | lo;
            }
        }

        public Bitmap CreateBitmap(int edge = 1)
        {
            int cellEdge = edge + 1;
            var black = Color.FromKnownColor(KnownColor.Black);
            var white = Color.FromKnownColor(KnownColor.White);
            var result = new Bitmap(cellEdge * Width + 1, cellEdge * Height + 1);
            for (int y = 0; y < Height; ++y)
            for (int x = 0; x < Width; ++x)
            {
                int top = y * cellEdge;
                int left = x * cellEdge;
                result.SetPixel(left, top, black);

                int index = (y * Width + x) * 2;
                var topColor = y == 0 || IsSet(index + 1) ? black : white;

                for (int i = 1; i < cellEdge; ++i)
                    result.SetPixel(left + i, top, topColor);

                var leftColor = x == 0 || IsSet(index) ? black : white;

                for (int i = 1; i < cellEdge; ++i)
                {
                    result.SetPixel(left, top + i, leftColor);

                    for (int j = 1; j < cellEdge; ++j)
                        result.SetPixel(left + j, top + i, white);
                }
            }

            int lastColumn = result.Width - 1;
            for (int i = 0; i < result.Height; ++i)
                result.SetPixel(lastColumn, i, black);
            
            int lastRow = result.Height - 1;
            for (int i = 0; i < result.Width; ++i)
                result.SetPixel(i, lastRow, black);

            return result;
        }
    }
}

Program.cs

using System;
using System.Drawing;
using System.Drawing.Imaging;

namespace MazeRunner
{
    class Program
    {
        static void Main(string[] args)
        {
            var maze = new Maze(64, 64);
            maze.RandomFill(new Random());
            maze.CreateBitmap().Save("maze_1.bmp", ImageFormat.Bmp);
            maze.CreateBitmap(4).Save("maze_4.bmp", ImageFormat.Bmp);
            maze.CreateBitmap(16).Save("maze_16.bmp", ImageFormat.Bmp);
        }
    }
}