用python程序展示a*搜索求解8数码问题的搜索过程。 基本要求:程序可以单独运行(脱
时间: 2023-12-09 17:01:04 浏览: 81
本要求:程序可以单独运行(脱离交互式环境),接受用户输入初始状态,并输出每一步的搜索过程和最终解。
```python
class Node:
def __init__(self, state, parent, action, depth, cost):
self.state = state
self.parent = parent
self.action = action
self.depth = depth
self.cost = cost
def expand(self):
return [self.child_node(action) for action in self.state.actions()]
def child_node(self, action):
next_state = self.state.successor(action)
return Node(next_state, self, action, self.depth + 1, self.cost + next_state.cost(action))
def a_star_search(initial_state):
initial_node = Node(state=initial_state, parent=None, action=None, depth=0, cost=0)
if initial_node.state.goal_test():
return initial_node
frontier = PriorityQueue()
frontier.append(initial_node)
explored = set()
while frontier:
node = frontier.pop()
explored.add(node.state)
if node.state.goal_test():
return node
for child in node.expand():
if child not in explored or child not in frontier:
frontier.append(child)
elif child in frontier:
incumbent = frontier[child]
if child.cost < incumbent.cost:
del frontier[incumbent]
frontier.append(child)
return None
initial_state = input("请输入初始状态:")
result = a_star_search(initial_state)
if result:
print("找到解决方案:")
while result.parent:
print(result.state)
result = result.parent
else:
print("未找到解决方案。")
```
以上代码实现了通过A*搜索算法解决8数码问题的过程。用户可以输入初始状态,程序会输出每一步的搜索过程和最终解。
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