a*算法求解迷宫寻路p代码

A*（A-star）算法是一种启发式搜索算法，用于寻找从起点到目标点的最短路径，常用于解决迷宫寻路问题。它结合了宽度优先搜索（BFS）的广度优先探索特性以及Dijkstra算法的贪心策略。以下是Python中使用A*算法求解迷宫寻路的一个基本代码示例：

import heapq

# 定义节点类
class Node:
    def __init__(self, x, y, cost=0, parent=None):
        self.x = x
        self.y = y
        self.cost = cost
        self.parent = parent
        self.f_score = cost + heuristic(x, y, goal_x, goal_y)  # f_score = g_score + h_score

def heuristic(a, b, c, d):  # 估价函数，这里假设曼哈顿距离
    return abs(a - c) + abs(b - d)

def a_star_search(maze, start, end):
    open_set = []
    heapq.heappush(open_set, (start.f_score, start))
    came_from = {start: None}
    while open_set:
        current = heapq.heappop(open_set)[1]
        if current == end:
            path = []
            while current is not None:
                path.append((current.x, current.y))
                current = came_from[current]
            return path[::-1]  # 返回路径从终点逆序到起点
        for neighbor in neighbors(maze, current):
            tentative_g_score = current.cost + 1  # 每次移动成本加一
            if neighbor in came_from and tentative_g_score >= came_from[neighbor].cost:
                continue  # 如果已经访问过并有更短路径，则跳过
            if neighbor not in open_set or tentative_g_score < open_set[0][0]:
                open_set.remove(neighbor if neighbor in open_set else None)
                neighbor.g_score = tentative_g_score
                neighbor.f_score = tentative_g_score + heuristic(neighbor.x, neighbor.y, end.x, end.y)
                neighbor.parent = current
                heapq.heappush(open_set, (neighbor.f_score, neighbor))
    return None  # 如果找不到路径，返回None

def neighbors(maze, node):
    possible_neighbors = [(node.x+1, node.y), (node.x-1, node.y),
                         (node.x, node.y+1), (node.x, node.y-1)]
    valid_neighbors = [n for n in possible_neighbors if 0 <= n[0] < maze.shape[0] and 0 <= n[1] < maze.shape[1]]
    return [Node(*n, maze[n[0]][n[1]]) for n in valid_neighbors if maze[n[0]][n[1]] != 1]  # 避免走到墙壁

# 使用方法：
maze = ...  # 迷宫矩阵，值1表示墙，0表示可以通行
start = Node(start_x, start_y)  # 起点坐标
end = Node(end_x, end_y)  # 目标坐标
path = a_star_search(maze, start, end)

在这个代码里，你需要提供一个迷宫矩阵`maze`，定义开始位置`start`和结束位置`end`，然后调用`a_star_search`函数计算路径。注意，这个版本仅适用于二维迷宫，并且采用曼哈顿距离作为启发函数。