# 1. define node class

class Node:

def __init__(self, position, parent=None):

# 2. Define heuristic functions

def heuristic(node, goal):

# 3. Get a neighbor node

def get_neighbors(node, grid, goal, mode):

# 4. Define a two-way A* search

def a_star_bidirectional(start, goal, grid, connectivity = 8):

# 5. Check if the paths meet and merge the paths

def meet_in_the_middle():

# 6. Read map data from an Excel file

def read_data_from_excel(file_path):

# 7. Optimize the path

def optimize_path(path, grid, goal):

# 8. Draw maps and routes

def plot_grid(grid, search_start, search_goal, path1, path2, start, goal):

# Main process

file_path = ‘map_model.xlsx’

grid, start, goal = read_data_from_excel(file_path)

path1, path2, search_path_start, search_path_goal = a_star_bidirectional(start, goal, grid)

optimized_path = optimize_path(path1 + path2, grid, goal)

plot_grid(grid, search_path_start, search_path_goal, optimized_path, [], start, goal)