Question

对于大学的一个项目，我想编程一个探路者，该探路者使用a星级来找到从终点到目标的最佳方法。对于几乎直线，该算法运行良好。当创建障碍物并且必须转弯时，算法会遇到问题，程序将无法找到路径。我想尝试使该场景工作在左侧显示，但是到目前为止，我还没有找到令人满意的解决方案。

对于算法和GUI，您还可以转到https://github.com/NiklasB1337/PathFinder1.1

左侧显示了发生问题的位置： https://i.gyazo.com/4488e22ad5610c81061e682514524ed2.png

# Astar
def astar(self, maze, start, end):

    """Returns a list of tuples as a path from the given start to the given end in the given maze"""

    # Create start and end node
    start_node = Node(None, start)
    start_node.g = start_node.h = start_node.f = 0
    end_node = Node(None, end)
    end_node.g = end_node.h = end_node.f = 0

    # Initialize open and closed list
    open_list = []
    closed_list = []

    # Add the start node
    open_list.append(start_node)

    # Loop until the end is found
    while len(open_list) > 0:

        # get the current node
        current_node = open_list[0]
        current_index = 0
        for index, item in enumerate(open_list):
            if item.f < current_node.f:
                current_node = item
                current_index = index

        # pop current off open list, add to closed list
        open_list.pop(current_index)
        closed_list.append(current_node)

        # finding the goal
        if current_node == end_node:
            path = []
            current = current_node
            while current is not None:
                path.append(current.position)
                current = current.parent
            return path[::-1]  # Return reversed path

        # generate children
        children = []
        for new_position in [(0, -1), (0, 1), (-1, 0), (1, 0)]:  # Adjacent squares

            # get node position
            node_position = (current_node.position[0] + new_position[0], current_node.position[1] + new_position[1])

            # make sure the node is within range
            if node_position[0] > (len(maze) - 1) or node_position[0] < 0 or node_position[1] > (
                    len(maze[len(maze) - 1]) - 1) or node_position[1] < 0:
                continue

            # make sure the terrain is walkable
            if maze[node_position[0]][node_position[1]] != 0:
                continue

            # create new node
            new_node = Node(current_node, node_position)

            # Append
            children.append(new_node)

        # loop through children
        for child in children:

            # child is on the closed list
            for closed_child in closed_list:
                if child == closed_child:
                    continue

            #cCreate the f, g, and h values
            child.g = current_node.g + 1
            child.h = ((child.position[0] - end_node.position[0]) ** 2) + (
                        (child.position[1] - end_node.position[1]) ** 2)
            child.f = child.g + child.h

            # child is already in the open list
            for open_node in open_list:
                if child == open_node and child.g > open_node.g:
                    continue

            # add the child to the open list
            open_list.append(child)

Answer 1

仅查看图像，似乎开始或结束处在障碍物上，无法到达。如果它是左上角的起始块，则对邻居的第一次扫描将不会返回任何内容。？

寻路算法无法正常工作

1 个答案: