使用python实现A*算法，要求可以使用鼠标点击方块选择起点、终点，障碍物是随机生成的

好的，我可以为您提供一个基本的 A*算法的实现，并添加鼠标交互和随机障碍物的功能。在代码中，我将使用 Pygame 库来处理鼠标事件和绘制方块。

首先，需要安装 Pygame 库。可以使用以下命令在终端中安装：

pip install pygame

然后，我们可以开始编写代码。下面是完整的代码:

import pygame
from queue import PriorityQueue
import random

# 设置棋盘大小和方块大小
WIDTH = 800
WIN = pygame.display.set_mode((WIDTH, WIDTH))
pygame.display.set_caption("A* Path Finding Algorithm")
BLOCK_SIZE = 20

# 定义颜色
WHITE = (255, 255, 255)
BLACK = (0, 0, 0)
RED = (255, 0, 0)
GREEN = (0, 255, 0)
BLUE = (0, 0, 255)
YELLOW = (255, 255, 0)

# 定义方块类
class Block:
    def __init__(self, row, col):
        self.row = row
        self.col = col
        self.x = row * BLOCK_SIZE
        self.y = col * BLOCK_SIZE
        self.color = WHITE
        self.neighbors = []
    
    def get_pos(self):
        return self.row, self.col
    
    def is_barrier(self):
        return self.color == BLACK
    
    def reset(self):
        self.color = WHITE
    
    def make_start(self):
        self.color = GREEN
    
    def make_barrier(self):
        self.color = BLACK
    
    def make_end(self):
        self.color = RED
    
    def make_path(self):
        self.color = YELLOW
    
    def draw(self):
        pygame.draw.rect(WIN, self.color, (self.x, self.y, BLOCK_SIZE, BLOCK_SIZE))

    # 添加邻居
    def add_neighbors(self, grid):
        if self.row < len(grid) - 1 and not grid[self.row + 1][self.col].is_barrier():  # 下
            self.neighbors.append(grid[self.row + 1][self.col])
        if self.row > 0 and not grid[self.row - 1][self.col].is_barrier():  # 上
            self.neighbors.append(grid[self.row - 1][self.col])
        if self.col < len(grid[0]) - 1 and not grid[self.row][self.col + 1].is_barrier():  # 右
            self.neighbors.append(grid[self.row][self.col + 1])
        if self.col > 0 and not grid[self.row][self.col - 1].is_barrier():  # 左
            self.neighbors.append(grid[self.row][self.col - 1])

    def __lt__(self, other):
        return False

# 定义启发函数
def h(node1, node2):
    return abs(node1.row - node2.row) + abs(node1.col - node2.col)

# 定义算法函数
def a_star_algorithm(grid, start, end):
    count = 0
    open_set = PriorityQueue()
    open_set.put((0, count, start))
    came_from = {}
    g_score = {block: float("inf") for row in grid for block in row}
    g_score[start] = 0
    f_score = {block: float("inf") for row in grid for block in row}
    f_score[start] = h(start, end)

    open_set_hash = {start}

    while not open_set.empty():
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                pygame.quit()

        current = open_set.get()[2]
        open_set_hash.remove(current)

        if current == end:
            reconstruct_path(came_from, end)
            end.make_end()
            return True

        for neighbor in current.neighbors:
            temp_g_score = g_score[current] + 1

            if temp_g_score < g_score[neighbor]:
                came_from[neighbor] = current
                g_score[neighbor] = temp_g_score
                f_score[neighbor] = temp_g_score + h(neighbor, end)
                if neighbor not in open_set_hash:
                    count += 1
                    open_set.put((f_score[neighbor], count, neighbor))
                    open_set_hash.add(neighbor)
                    neighbor.color = BLUE

        draw_grid(grid)
        if current != start:
            current.color = YELLOW
        end.color = RED
        pygame.display.update()

        if start in open_set_hash:
            start.color = GREEN
        else:
            start.color = BLACK

    return False

# 重构路径
def reconstruct_path(came_from, current):
    while current in came_from:
        current = came_from[current]
        current.make_path()

# 绘制网格
def draw_grid(grid):
    for row in grid:
        for block in row:
            block.draw()

    for i in range(len(grid)):
        pygame.draw.line(WIN, BLACK, (0, i * BLOCK_SIZE), (WIDTH, i * BLOCK_SIZE))
        for j in range(len(grid[0])):
            pygame.draw.line(WIN, BLACK, (j * BLOCK_SIZE, 0), (j * BLOCK_SIZE, WIDTH))

    pygame.display.update()

# 创建随机障碍物
def create_barriers(grid):
    for i in range(len(grid)):
        for j in range(len(grid[0])):
            if random.randint(0, 3) == 0:
                grid[i][j].make_barrier()

# 初始化棋盘
def init_grid():
    grid = []
    for i in range(int(WIDTH / BLOCK_SIZE)):
        row = []
        for j in range(int(WIDTH / BLOCK_SIZE)):
            block = Block(i, j)
            row.append(block)
        grid.append(row)

    for i in range(len(grid)):
        for j in range(len(grid[0])):
            grid[i][j].add_neighbors(grid)

    return grid

# 主函数
def main():
    run = True
    started = False
    grid = init_grid()
    start = None
    end = None

    while run:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                run = False

            if started:
                continue

            if pygame.mouse.get_pressed()[0]:  # 鼠标左键按下
                pos = pygame.mouse.get_pos()
                row = pos[0] // BLOCK_SIZE
                col = pos[1] // BLOCK_SIZE
                block = grid[row][col]
                if not start and block != end:
                    start = block
                    start.make_start()
                elif not end and block != start:
                    end = block
                    end.make_end()
                elif block != start and block != end:
                    block.make_barrier()
            elif pygame.mouse.get_pressed()[2]:  # 鼠标右键按下
                pos = pygame.mouse.get_pos()
                row = pos[0] // BLOCK_SIZE
                col = pos[1] // BLOCK_SIZE
                block = grid[row][col]
                block.reset()
                if block == start:
                    start = None
                elif block == end:
                    end = None

            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_SPACE and not started:
                    for row in grid:
                        for block in row:
                            block.add_neighbors(grid)
                    create_barriers(grid)
                    a_star_algorithm(grid, start, end)

    pygame.quit()

if __name__ == "__main__":
    main()

运行代码后，您将看到一个棋盘，您可以使用鼠标左键选择起点、终点，使用鼠标右键删除方块，然后按下空格键运行 A*算法。障碍物将自动随机分布在棋盘上。当算法运行时，您将看到蓝色方块表示算法正在搜索的路径，黄色方块表示搜索到的路径，红色方块表示终点，绿色方块表示起点。

希望这能帮助您开始实现 A*算法。