def test_queue_remove():
queue = Queue()
queue.add(1)
queue.add(2)
queue.add(3)
assert queue.remove() == 1
assert queue.remove() == 2
assert queue.remove() == 3
assert queue.remove() == None
def test_queue_peek():
queue = Queue()
queue.add(1)
queue.add(2)
queue.add(3)
assert queue.peek() == 1
assert queue.first.data == 1
def test_queue_is_empty():
queue = Queue()
assert queue.is_empty()
queue.add(1)
assert not queue.is_empty()
def test_queue_add():
queue = Queue()
queue.add(1)
assert queue.first is not None
assert queue.last is not None
assert queue.first.data == 1
assert queue.first is queue.last
queue.add(2)
assert queue.first.data == 1
assert queue.last.data == 2
def __init__(self):
self.cats = Queue()
self.dogs = Queue()
self.counter = 0
class PetManager:
def __init__(self):
self.cats = Queue()
self.dogs = Queue()
self.counter = 0
def enqueue(self, animal: str):
assert animal == "cat" or animal == "dog"
if animal == "cat":
self.cats.add(("cat", self.counter))
else:
self.dogs.add(("dog", self.counter))
self.counter += 1
def dequeue_cat(self) -> (str, int) or None:
return self.cats.remove()
def dequeue_dog(self) -> (str, int) or None:
return self.dogs.remove()
def dequeue_any(self) -> (str, int) or None:
if self.cats.is_empty():
return self.dogs.remove()
if self.dogs.is_empty():
return self.cats.remove()
_, cat_n = self.cats.peek()
_, dog_n = self.dogs.peek()
if cat_n < dog_n:
return self.cats.remove()
else:
return self.dogs.remove()
def test_queue_init():
queue = Queue()
assert queue.first is None
assert queue.last is None