基于之前写的迷宫生成器实现了Djkstra算法搜索路径。

https://blog.csdn.net/ChillingKangaroo/article/details/122800431

Djkstra基于广度优先算法，与简单搜索不同的是Djkstra在访问每一个节点的时候会计算到该节点的最短路径以及上一个节点，如果有新的路径比之前的路径更短，储存的上一个路径点则会被替换掉。在完成计算之后只需要取终点的数据然后就可以沿记录找到已搜索范围中最短的路径。
因为我之前迷宫基于深度优先生成，另外因为路径没有权重（走一格的距离都是相同的）所以其实Djkstra不太能发挥出来，实现中没有使用优先级序列，不过算法还是有效的。

实现用了python的链表，动态添加很方便，在没有找到终点的时候循环，每次循环查找列表中节点的四个方向，如果没有访问过则添加到新列表中，循环结尾再把新列表值给查找列表，在查找到终点时就停止。

实现效果如下，绿色表示djkstra查找范围，蓝色表示最短路径，使用40x40矩阵测试

import pygame as pg
import time
import randomclass Tile(): #Tile is for generating mazedef __init__(self,grid_size,screen_size,x,y):self.x,self.y = x,yself.connected = [0,0,0,0] # up,right,down,left 0 for not connectedself.grid_size = grid_sizeself.tile_size = [(screen_size[0]-100)/grid_size[0],(screen_size[1]-100)/grid_size[1]]self.rectangle = (self.x*self.tile_size[0]+50,self.y*self.tile_size[1]+50,self.tile_size[0],self.tile_size[1])self.points = [ [self.x*self.tile_size[0]+50,self.y*self.tile_size[1]+50],    #uppper left[self.x*self.tile_size[0]+50+self.tile_size[0],self.y*self.tile_size[1]+50],    #upper right[self.x*self.tile_size[0]+50+self.tile_size[0],self.y*self.tile_size[1]+50+self.tile_size[1]],    #lower right[self.x*self.tile_size[0]+50,self.y*self.tile_size[1]+50+self.tile_size[1]],    #lower left] self.visited = Falseself.color = (255,253,150)def draw(self,color = None): #x,y represents the tile coordinates  color = self.color if not color else colorpg.draw.rect(screen,color,self.rectangle)for i in range(4):if not self.connected[i]:pg.draw.line(screen,(150,175,255),(self.points[i]),(self.points[((i+1)%4)]),5)class Node():def __init__(self):self.visited = Falseself.last_node = Noneself.steps = Nonedef maze_gen(path):global tile_coveredx,y = path[-1]if x < 0 or x >= grid_size[0] or y < 0 or y >= grid_size[1]:print(f'index out of range at {x,y}')returnif matrix[y][x].visited:print(f'node already visited at {x,y}')returnelif tile_covered <= grid_size[0]*grid_size[1]:tile_covered += 1print(x,y)matrix[y][x].visited = Truepath_choice = [0,1,2,3]random.shuffle(path_choice)for i in path_choice:x_,y_ = x+directions[i][0],y+directions[i][1]path.append([x_,y_])if maze_gen(path):  # tile is not visitedmatrix[y][x].connected[i] = 1 #walls of current nodematrix[y_][x_].connected[(i+2)%4] = 1#reverse the vector directionmatrix[y][x].draw()matrix[y_][x_].draw()pg.display.update()path.pop(-1)return Trueelse:print('all node visited')returndef djkstra():end_point = (grid_size[0]-1,grid_size[1]-1)x,y = start_pointmatrix[y][x].draw((255,0,0))matrix[end_point[0]][end_point[1]].draw((255,0,0))pg.display.update()border = [[0,0]]steps = 0while True:steps += 1new_border = []for x,y in border:if (x,y) == end_point:print('exit found')return end_pointfor i in range(4):if matrix[y][x].connected[i]: #if there is a waynext_x,next_y = directions[i][0]+x,directions[i][1]+yif found_path[next_y][next_x].visited == False:new_border.append([next_x,next_y])matrix[next_y][next_x].draw((0,255,0))pg.display.update()if found_path[next_y][next_x].last_node == None:found_path[next_y][next_x].last_node = (x,y)elif steps < found_path[next_y][next_x].steps:found_path[next_y][next_x].last_node = (x,y)print(f'setting {x,y} to visited')found_path[y][x].visited = Trueborder = new_borderif new_border == []:print('No exit point found')returndef draw_path(end_point):if not end_point:returnelse:x,y = end_pointwhile [x,y] != start_point:print(f'going though node {x,y}')matrix[y][x].draw((0,0,255))print(f'{(x,y)} == {start_point}:')print((x,y) == start_point)x,y = found_path[y][x].last_nodepg.display.update()screen_size = [800,800]
grid_size = [40,40]tile_covered = 0
run = Truescreen = pg.display.set_mode(screen_size)matrix = []
directions = [[0,-1],[1,0],[0,1],[-1,0]] # up,right,down,left 0 for not connected
found_path = [[Node() for x in range(grid_size[0])] for y in range(grid_size[1])]for y in range(grid_size[1]):temp = []for x in range(grid_size[0]):tile = Tile(grid_size,screen_size,x,y)temp.append(tile)matrix.append(temp)pg.init()
path = [[0,0]]
start_point = [0,0]screen.fill((255,255,255))
maze_gen(path)pg.display.update()print('======== Generation Finished ========')end_point = djkstra()
draw_path(end_point)while run:for event in pg.event.get():if event.type == pg.QUIT:run = Falsepg.quit()