农夫过河问题Python代码
时间: 2024-05-13 22:12:00 浏览: 10
农夫过河问题是一个经典的智力游戏,题目描述如下:
农夫要带着一只狼、一只羊和一棵白菜过河。但是,河边只有一条小船,而且这条小船最多只能载两个物品(包括农夫),而且狼会吃羊,羊会吃白菜。请问,农夫应该如何安排,才能安全地把这三个物品都运到对岸?
下面是一个可能的Python代码实现:
```python
def farmer_cross_river(start, end):
# 定义初始状态和目标状态
initial_state = {'farmer': start, 'wolf': start, 'sheep': start, 'cabbage': start}
goal_state = {'farmer': end, 'wolf': end, 'sheep': end, 'cabbage': end}
# 定义安全状态
safe_states = [
{'farmer': start, 'wolf': start, 'sheep': start, 'cabbage': end},
{'farmer': start, 'wolf': start, 'sheep': end, 'cabbage': start},
{'farmer': end, 'wolf': end, 'sheep': start, 'cabbage': start},
{'farmer': end, 'wolf': end, 'sheep': end, 'cabbage': end},
{'farmer': end, 'wolf': start, 'sheep': end, 'cabbage': end}
]
# 定义当前状态和已经走过的状态
current_state = initial_state.copy()
walked_states = [current_state]
while current_state != goal_state:
# 判断当前状态可以到达哪些状态
next_states = []
for item1 in current_state:
if current_state[item1] == current_state['farmer']:
for item2 in current_state:
if current_state[item2] == current_state[item1]:
next_state = current_state.copy()
next_state['farmer'] = end if current_state['farmer'] == start else start
next_state[item1] = end if current_state['farmer'] == start else start
next_state[item2] = end if current_state['farmer'] == start else start
if next_state in safe_states and next_state not in walked_states:
next_states.append(next_state)
# 随机选择下一个状态
if len(next_states) > 0:
current_state = random.choice(next_states)
walked_states.append(current_state)
else:
# 如果没有下一个状态可以到达,则回溯到上一个状态
walked_states.pop()
current_state = walked_states[-1]
return walked_states
```
使用这个函数可以得到从起点到终点的所有可能状态的列表。