def __bounded_search(self, prob, strategy, max_depth):
"""
Method required to do the bounded search. It uses a border, a queue of Nodes that
have to be checked.
:param prob: Problem Object, used to know if a Node is solution, and get successors.
:param strategy: String, Strategy to follow, to get a solution
:param max_depth: Integer, Maximum depth that the search tree must reach.
:return: The solution, a list of successors to get the objective Node. If the algorithm
doesn't find a solution, it returns None.
"""
border = Border()
closed_list = {} # List needed to prune the tree
initial_node = Node(prob.initial_state(), 0, None, 0, None, 0)
border.InsertNode(initial_node)
#closed_list[initial_node.get_state().__str__()] = initial_node.get_value()
sol = False
while not sol and not border.IsEmpty():
actual_node = border.Delete()
if strategy == 'BFS' or strategy == 'DFS':
closed_list[actual_node.get_state().__str__()] = actual_node.get_cost()
else:
closed_list[actual_node.get_state().get_unique_representation()] = actual_node.get_value()
if prob.goal_state(actual_node.get_state()):
actual_node.get_state().print_terrain()
sol = True
else:
if actual_node.get_depth() < max_depth:
successors_list = prob.successors(actual_node.get_state())
for successor in successors_list:
new_node = actual_node.create_node(successor, actual_node, strategy, max_depth,prob)
# Prune the tree
if strategy == 'BFS' or strategy == 'DFS':
if new_node.get_state().get_unique_representation() not in closed_list:
border.InsertNode(new_node)
closed_list[new_node.get_state().get_unique_representation()] = new_node.get_cost()
else:
if closed_list[new_node.get_state().get_unique_representation()] > new_node.get_cost():
closed_list[new_node.get_state().get_unique_representation()] = new_node.get_cost()
border.InsertNode(new_node)
else:
if new_node.get_state().get_unique_representation() not in closed_list:
border.InsertNode(new_node)
closed_list[new_node.get_state().get_unique_representation] = new_node.get_value()
else:
if closed_list[new_node.get_state().get_unique_representation()] > new_node.get_value():
closed_list[new_node.get_state().get_unique_representation()] = new_node.get_value()
border.InsertNode(new_node)
if sol:
print('El costo de la solución es: '+ str(actual_node.get_cost()))
print('La profundidad es: ' + str(actual_node.get_depth()))
return self.__create_solution(actual_node)
else:
return None
