本文整理汇总了Python中queue.PriorityQueue.popleft方法的典型用法代码示例。如果您正苦于以下问题：Python PriorityQueue.popleft方法的具体用法？Python PriorityQueue.popleft怎么用？Python PriorityQueue.popleft使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类queue.PriorityQueue的用法示例。
在下文中一共展示了PriorityQueue.popleft方法的1个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的Python代码示例。
示例1: heap
# 需要导入模块: from queue import PriorityQueue [as 别名]
# 或者: from queue.PriorityQueue import popleft [as 别名]
class NPuzzleSolver:
"""
Uses the BFS/DFS/A* algos to solve a given n-puzzle board
"""
initial_state = None
algo = ""
# The frontier in BFS/DFS is a queue/stack and for A*, its a heap (PriorityQueue)
# Frontier set made to test membership in O(1)
frontier = None
frontier_set = set()
# All of the fully explored states in this set
explored = set()
def __init__(self, algo, initial_state=None):
self.initial_state = initial_state
if algo == "bfs" or algo == "dfs":
self.frontier = dq()
self.frontier.append(initial_state)
else:
self.frontier = PriorityQueue()
self.frontier.put(initial_state)
self.frontier_set.add(initial_state)
self.algo = algo
def solve(self):
"""
Attempts to solve an n-puzzle and returns a stats
dict, or None if no solution exists
"""
start_time = time.time()
maxdepth = 0
break_cond = False
while(not break_cond):
if self.algo == "bfs":
# Pop the leftmost element if doing a bfs (Queue)
current_state = self.frontier.popleft()
elif self.algo == "dfs":
# Pop the rightmost element if doing a dfs (Stack)
current_state = self.frontier.pop()
else:
# Get element with highest priority if doing A* (Heap)
current_state = self.frontier.get()
self.frontier_set.remove(current_state)
if (self.isFinalState(current_state)):
soln = self.get_solution_moves(current_state)
end_time = time.time()
stats = {}
stats["nodes_expanded"] = len(self.explored)
stats["search_depth"] = current_state.depth
stats["max_search_depth"] = maxdepth
stats["cost_of_path"] = len(soln)
stats["time"] = end_time - start_time
stats["path"] = soln
return stats
neighbors = current_state.generate_possible_states()
if self.algo == "dfs":
neighbors.reverse()
for neighbor in neighbors:
if neighbor not in self.explored and neighbor not in self.frontier_set:
if self.algo == "bfs" or self.algo == "dfs":
self.frontier.append(neighbor)
else:
self.frontier.put(neighbor)
self.frontier_set.add(neighbor)
if neighbor.depth > maxdepth:
maxdepth = neighbor.depth
self.explored.add(current_state)
if self.algo == "bfs" or self.algo == "dfs":
frontier_sz = len(self.frontier)
else:
frontier_sz = self.frontier.qsize()
logging.debug("Frontier size = " +
str(frontier_sz) +
"; Explored size = " +
str(len(self.explored)))
if self.algo == "bfs" or self.algo == "dfs":
break_cond = len(self.frontier) == 0
else:
break_cond = self.frontier.empty()
logging.error("This is an unsolvable board!")
return None
def get_solution_moves(self, final_state):
"""
Gets the sequence of moves from parent to this state
"""
moves = dq()
current_state = final_state
while current_state is not None:
if current_state.parent_move is not None:
moves.appendleft(current_state.parent_move)
current_state = current_state.parent
res = []
[res.append(move) for move in moves]
return res
#.........这里部分代码省略.........