class AnimalShelter:
def __init__(self):
self.dog_queue = Queue()
self.cat_queue = Queue()
def enqueue(self, animal):
animal.time_stamp = time.time()
if animal.type == "dog":
self.dog_queue.add(animal)
if animal.type == "cat":
self.cat_queue.add(animal)
def dequeue_any(self):
if self.dog_queue.is_empty():
return self.cat_queue.remove()
if self.cat_queue.is_empty():
return self.dog_queue.remove()
if self.dog_queue.peek().time_stamp < self.cat_queue.peek().time_stamp:
return self.dog_queue.remove()
else:
return self.cat_queue.remove()
def dequeue_dog(self):
return self.dog_queue.remove()
def dequeue_cat(self):
return self.cat_queue.remove()
def _bfs(self, start_node):
result = []
queue = Queue()
queue.add(start_node)
self.visited.add(start_node)
while not queue.is_empty():
output_node = queue.remove()
for child in output_node.children:
if child not in self.visited:
queue.add(child)
self.visited.add(child)
result += [output_node.data]
return result
def bi_directional_search(self, src, dst):
self._add_inverted_children()
self.reset_node_paths()
queue_src = Queue()
queue_dst = Queue()
src_visited = set()
dst_visited = set()
queue_src.add(src)
src_visited.add(src)
queue_dst.add(dst)
dst_visited.add(dst)
collided = False
while not queue_src.is_empty() or not queue_dst.is_empty():
if len(src_visited.intersection(dst_visited)) > 0:
collided = True
break
if not queue_src.is_empty():
src_output = queue_src.remove()
for child in src_output.children:
if child not in src_visited:
child.forward_pre = src_output
queue_src.add(child)
src_visited.add(child)
if len(src_visited.intersection(dst_visited)) > 0:
collided = True
break
if not queue_dst.is_empty():
dst_output = queue_dst.remove()
if dst_output in self.inverted:
for child in self.inverted[dst_output]:
if child not in dst_visited:
child.backward_pre = dst_output
queue_dst.add(child)
dst_visited.add(child)
if collided:
intersect = src_visited.intersection(dst_visited).pop()
forward = []
ref = intersect
while ref is not None:
forward = [ref.data] + forward
ref = ref.forward_pre
ref = intersect
backward = []
while ref is not None:
backward += [ref.data]
ref = ref.backward_pre
return forward[:-1] + backward
else:
return []
class TestQueue(unittest.TestCase):
def setUp(self):
self.queue = Queue()
def queue_add_small(self):
self.queue.add(1)
self.queue.add(2)
self.queue.add(3)
def sanity_check(self, input_data):
self.assertEqual(self.queue.data, input_data)
def test_init(self):
self.sanity_check([])
def test_add(self):
self.queue.add("hi")
self.sanity_check(["hi"])
self.queue.add("hello")
self.sanity_check(["hi", "hello"])
def test_peek(self):
self.queue_add_small()
self.assertEqual(self.queue.peek(), 1)
def test_remove(self):
self.queue_add_small()
output = self.queue.remove()
self.assertEqual(output, 1)
self.sanity_check([2, 3])
output = self.queue.remove()
self.assertEqual(output, 2)
self.sanity_check([3])
output = self.queue.remove()
self.assertEqual(output, 3)
self.sanity_check([])
def test_peek_error(self):
self.assertRaises(Exception, lambda: self.queue.peek())
def test_pop_error(self):
self.assertRaises(Exception, lambda: self.queue.remove())
