def uniform_cost_search(problem):
root = Node(problem.initial)
frontier = PriorityQueue()
frontier.append(root)
explored = set()
while True:
if len(frontier) == 0:
return "fail"
node = frontier.pop()
if problem.goal_test(node.state):
return node
explored.add(node)
for action in problem.actions(node.state):
child = node.child_node(problem, action)
if child.state not in explored:
print(child.state + " > ")
frontier.append(child)
elif child in frontier:
item = frontier.__getitem__(child)
if child.path_cost < item.path_cost:
pass
