def ucs(state):
# initialize the frontier
frontier = PriorityQueue()
node0 = Node(state, None)
frontier.push(node0)
# record the visited node
visited = []
visited.append(node0.state)
while True:
solution = []
if frontier.isempty():
print("Failure. There is no solution!")
return None
leafnode = frontier.pop()
if leafnode.state == goal_state:
print("GOAL!")
solution.append(leafnode.state)
while leafnode.parent is not None:
leafnode = leafnode.parent
solution.append(leafnode.state)
return solution
# add child and traverse the children of leafnode
for i in range(2, len(leafnode.state)):
childstate = leafnode.flip(i)
childnode = Node(childstate, leafnode)
leafnode.add_child(childnode)
childnode.calculate_priority()
childnode.priority = childnode.backCost
if not frontier.find(childnode):
if not childnode.state in visited:
frontier.push(childnode)
visited.append(childnode.state)
else:
node_in_queue = frontier.get_node(childnode)
if node_in_queue.priority > childnode.priority:
frontier.delete(node_in_queue)
frontier.push(childnode)
def getActions(self, start, final):
print(
"*****************************************************************************************************"
)
print("Cel: " + str(final))
actions = []
explored = []
currentState = start
currentState.priority = 99
fringe = PriorityQueue()
fringe.insert(currentState)
while not self.testGoal(currentState, final):
currentState = fringe.delete(currentState, self.mapElements)
print("Zmieniamy obecny stan")
print(str(currentState.position), str(currentState.rotation))
explored.append(currentState)
if self.testGoal(currentState, final):
ns = currentState
while ns.parent is not None:
actions = [ns.action] + actions
ns = ns.parent
return actions
#explored.append(currentState)
for j in self.getSuccessors(currentState):
print("Sprawdzam dany następnik:")
x = copy.deepcopy(j[1])
x.action = j[0]
x.parent = copy.deepcopy(currentState)
x.priority = self.getPriority(x, final)
print(str(x.position), str(x.rotation), "priorytet: ",
str(x.priority))
if not self.stateValueExists(
x, explored) and not self.stateValueExists(
x, fringe.queue):
fringe.insert(x)
print(
"Dodano następnik, nie było go ani we fringe ani w explored"
)
elif self.stateValueExists(x, fringe.queue):
print("Następnik był we fringe")
for i in fringe.queue:
if x.position == i.position and x.rotation == i.rotation and x.priority < i.priority:
i = x #copy.deepcopy(x)
print(
"~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~"
)
class UCS(Algorithm):
def __init__(self, initial_vertex):
super().__init__(Graph(initial_vertex))
self.inistial_vertex = initial_vertex
self.frontier = PriorityQueue()
self.frontier.insert(initial_vertex)
self.explored = []
def execute(self):
while True:
if self.frontier.is_empty():
return False
lowest_cost_rubik = self.frontier.delete()
if self.goal_test(lowest_cost_rubik):
return True
self.explored.append(lowest_cost_rubik)
children = lowest_cost_rubik.children_nodes()
self.update_number_of_nodes_info_after_expanding(len(children))
for child_rubik in children:
child_rubik.path_cost = lowest_cost_rubik.path_cost + 1
if not self.visited(child_rubik):
print(child_rubik.path_cost)
self.frontier.insert(child_rubik)
else:
self.nodes_in_memory -= 1
for rubik_in_queue in self.frontier.queue:
if rubik_in_queue.equal(child_rubik):
if rubik_in_queue.path_cost > child_rubik.path_cost:
self.frontier.queue.remove(rubik_in_queue)
self.frontier.insert(child_rubik)
else:
break
def visited(self, rubik):
if self.inside_queue(self.frontier.queue, rubik):
return True
if self.inside_queue(self.explored, rubik):
return True
return False
