编写一个A*算法的python程序
时间: 2023-12-04 17:52:27 浏览: 36
好的,下面是一个简单的A*算法的Python程序示例:
```python
from queue import PriorityQueue
def A_star(start, goal, neighbors_fn, heuristic_fn):
frontier = PriorityQueue()
frontier.put(start, 0)
came_from = {}
cost_so_far = {start: 0}
came_from[start] = None
while not frontier.empty():
current = frontier.get()
if current == goal:
break
for next in neighbors_fn(current):
new_cost = cost_so_far[current] + 1
if next not in cost_so_far or new_cost < cost_so_far[next]:
cost_so_far[next] = new_cost
priority = new_cost + heuristic_fn(goal, next)
frontier.put(next, priority)
came_from[next] = current
return came_from, cost_so_far
```
使用该程序,可以在给定起点、终点、邻居函数和启发函数的情况下,计算出最短路径。例如:
```python
def neighbors_fn(node):
# 返回节点的邻居列表
pass
def heuristic_fn(a, b):
# 返回启发函数的估计值
pass
start_node = ...
goal_node = ...
came_from, cost_so_far = A_star(start_node, goal_node, neighbors_fn, heuristic_fn)
# 输出最短路径和路径长度
path = [goal_node]
while path[-1] != start_node:
path.append(came_from[path[-1]])
path.reverse()
print(path)
print(cost_so_far[goal_node])
```
如果您有任何问题,请随时询问!
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