写一个python a*算法
时间: 2023-05-16 09:04:37 浏览: 67
好的,以下是一个简单的 Python A* 算法实现:
```python
import heapq
def astar(start, goal, neighbors_fn, heuristic_fn):
frontier = [(0, start)]
came_from = {}
cost_so_far = {start: 0}
while frontier:
_, current = heapq.heappop(frontier)
if current == goal:
break
for neighbor in neighbors_fn(current):
new_cost = cost_so_far[current] + 1
if neighbor not in cost_so_far or new_cost < cost_so_far[neighbor]:
cost_so_far[neighbor] = new_cost
priority = new_cost + heuristic_fn(goal, neighbor)
heapq.heappush(frontier, (priority, neighbor))
came_from[neighbor] = current
path = [goal]
while path[-1] != start:
path.append(came_from[path[-1]])
path.reverse()
return path
```
这个算法实现了 A* 算法,用于寻找从起点到终点的最短路径。它需要以下参数:
- `start`:起点
- `goal`:终点
- `neighbors_fn`:一个函数,接受一个节点,返回与该节点相邻的节点列表
- `heuristic_fn`:一个函数,接受两个节点,返回从第一个节点到第二个节点的估计距离
它返回一个节点列表,表示从起点到终点的最短路径。