// Maze generator in Java
// Joe Wingbermuehle
// 2015-07-27

class Maze {

   private static final class MazeObj {

      private static final int WALL = 0;
      private static final int SPACE = 1;

      private byte[][] data;
      private int width;
      private int height;
      private java.util.Random rand = new java.util.Random();

      public MazeObj(int width, int height) {
         this.width = width;
         this.height = height;
         data = new byte[width][];
      }

      private void carve(int x, int y) {

         final int[] upx = { 1, -1, 0, 0 };
         final int[] upy = { 0, 0, 1, -1 };

         int dir = rand.nextInt(4);
         int count = 0;
         while(count < 4) {
            final int x1 = x + upx[dir];
            final int y1 = y + upy[dir];
            final int x2 = x1 + upx[dir];
            final int y2 = y1 + upy[dir];
            if(data[x1][y1] == WALL && data[x2][y2] == WALL) {
               data[x1][y1] = SPACE;
               data[x2][y2] = SPACE;
               carve(x2, y2);
            } else {
               dir = (dir + 1) % 4;
               count += 1;
            }
         }
      }

      public void generate() {
         for(int x = 0; x < width; x++) {
            data[x] = new byte[height];
            for(int y = 0; y < height; y++) {
               data[x][y] = WALL;
            }
         }
         for(int x = 0; x < width; x++) {
            data[x][0] = SPACE;
            data[x][height - 1] = SPACE;
         }
         for(int y = 0; y < height; y++) {
            data[0][y] = SPACE;
            data[width - 1][y] = SPACE;
         }

         data[2][2] = SPACE;
         carve(2, 2);

         data[2][1] = SPACE;
         data[width - 3][height - 2] = SPACE;
      }

      public void print() {
         for(int y = 0; y < height; y++) {
            for(int x = 0; x < width; x++) {
               if(data[x][y] == WALL) {
                  System.out.print("[]");
               } else {
                  System.out.print("  ");
               }
            }
            System.out.println();
         }
      }
      

   }

   public static void main(String[] args) {

      MazeObj m = new MazeObj(39, 23);
      m.generate();
      m.print();

   }

}