Java深度优先搜索迷宫生成算法卡住

Question

我有一个使用深度优先搜索的迷宫生成算法。
它首先生成一个原始的迷宫，看起来像这样：http://www.mazeworks.com/mazegen/mazetut/index.html
结果看起来是这样的：

红色像素标志着目标，绿色

然后使用该算法创建的迷宫一开始。
它被困在目标并且来回跳动，直到它认为它完成。
迷宫发电机来源：

public Maze generate(int width, int height) { 
    Maze maze = getRawMaze(width, height); 

    List<Point> cellStack = new LinkedList<Point>(); 
    int totalAirCells = maze.getTotalAirCells(); 
    Point currentCell = maze.getRandomAirCell(ran); 
    maze.setCellTypeAt(currentCell, Maze.CellType.START);  
    int visitedCells = 1; 

    while(visitedCells<totalAirCells) { 
     Point[] unvisitedNeighbors = getUnvisitedNeighbors(maze, currentCell); 
     if(unvisitedNeighbors.length!=0) { 
      System.out.println("Go Foward"); 
      Point newCell = unvisitedNeighbors[ran.nextInt(unvisitedNeighbors.length)]; 
      maze.connect(newCell, currentCell); 
      cellStack.add(currentCell); 
      currentCell = newCell; 
      visitedCells++; 
     }else { 
      System.out.println("Go Back"); 
      Point recentCell = cellStack.get(cellStack.size()-1); 
      cellStack.remove(cellStack.size()-1); 
      currentCell = recentCell; 
     } 
    } 

    maze.setCellTypeAt(currentCell, Maze.CellType.GOAL); 

    return maze; 
} 

public Point[] getUnvisitedNeighbors(Maze maze, Point p) { 
    List<Point> unvisitedNeighbors = new ArrayList<Point>(); 
    Point[] neighbors = maze.getNeighbors(p); 
    for(Point n : neighbors) { 
     if(maze.getSurroundingWalls(n)==4)unvisitedNeighbors.add(n); 
    } 
    return unvisitedNeighbors.toArray(new Point[unvisitedNeighbors.size()]); 
} 

额外来源：

public int getSurroundingWalls(Point p) { 
    if(getCellTypeAt(p)==CellType.AIR) { 
     int walls = 0; 
     if(getCellTypeAt(new Point(p.x+1, p.y))==CellType.WALL)walls++; 
     if(getCellTypeAt(new Point(p.x-1, p.y))==CellType.WALL)walls++; 
     if(getCellTypeAt(new Point(p.x, p.y+1))==CellType.WALL)walls++; 
     if(getCellTypeAt(new Point(p.x+1, p.y-1))==CellType.WALL)walls++; 
     return walls; 
    }else return -1; 
} 

public Point[] getNeighbors(Point p) { 
    Point[] neighbors = new Point[4]; 
    neighbors[0] = new Point(p.x+2, p.y); 
    neighbors[1] = new Point(p.x-2, p.y); 
    neighbors[2] = new Point(p.x, p.y+2); 
    neighbors[3] = new Point(p.x, p.y-2); 
    return neighbors; 
} 

public void connect(Point a, Point b) { 
    if((a.x==b.x-2)&&(a.y==b.y))setCellTypeAt(new Point(a.x+1, a.y), CellType.AIR); 
    else if((a.x==b.x+2)&&(a.y==b.y))setCellTypeAt(new Point(a.x-1, a.y), CellType.AIR); 
    else if((a.x==b.x)&&(a.y==b.y-2))setCellTypeAt(new Point(a.x, a.y+1), CellType.AIR); 
    else if((a.x==b.x)&&(a.y==b.y+2))setCellTypeAt(new Point(a.x, a.y-1), CellType.AIR); 
} 

public Point getRandomAirCell(Random ran) { 
    List<Point> airCells = new LinkedList<Point>(); 
    for(int x = 0; x<getWidth(); x++) { 
     for(int y = 0; y<getHeight(); y++){ 
      Point p = new Point(x, y); 
      if(getCellTypeAt(p)==Maze.CellType.AIR)airCells.add(p); 
     } 
    } 
    return airCells.get(ran.nextInt(airCells.size())); 
} 

public int getTotalAirCells() { 
    int airCells = 0; 
    for(int x = 0; x<getWidth(); x++) { 
     for(int y = 0; y<getHeight(); y++){ 
      if(getCellTypeAt(new Point(x, y))==Maze.CellType.AIR)airCells++; 
     } 
    } 
    return airCells; 
} 

为什么算法没有完成迷宫？

Answer 1

检查getSurroundingWalls()，检查的第四点是p.x+1, p.y-1但我想应该是p.x, p.y-1。