def test_peek_from_queue():
queue = Queue()
queue.enqueue(1)
queue.enqueue(2)
assert queue.peek() == 1
assert queue.dequeue() == 1
assert queue.peek() == 2
assert queue.dequeue() == 2
assert queue.peek() == 'Queue is empty'
def test_is_empty():
queue = Queue()
queue.enqueue(1)
queue.enqueue(2)
queue.dequeue()
queue.dequeue()
assert queue.isEmpty() == True
class AnimalShelter():
def __init__(self):
self.dogs = Queue()
self.cats = Queue()
def enqueue(self, animal):
try:
if animal.type == 'cat':
self.cats.enqueue(animal)
elif animal.type == 'dog':
self.dogs.enqueue(animal)
except AttributeError as e:
return 'Add Cat or Dog Only'
def dequeue(self, pref):
try:
if pref == 'cat':
cat = self.cats.dequeue()
return cat.name
elif pref == 'dog':
dog = self.dogs.dequeue()
return dog.name
except AttributeError as e:
return None
def bfs(self, start_node):
nodes = []
visited = set()
breadth = Queue()
breadth.enqueue(start_node)
visited.add(start_node)
while len(breadth)>0:
node = breadth.dequeue()
nodes.append(node)
for n in self.adjacency_list[node]:
if n not in visited:
breadth.enqueue(n)
visited.add(n)
return nodes
def test_peek_on_empty_queue():
nums = Queue()
actual = nums.peek()
expected = 'Queue is empty'
assert actual == expected
def test_init():
queue = Queue()
assert queue.front == None
assert queue.rear == None
def test_queue_peek():
queue = Queue()
queue.enqueue(7)
queue.enqueue(3)
assert queue.peek() == 7
def test_dequeue():
queue = Queue()
queue.enqueue(1)
queue.enqueue(3)
queue.dequeue()
assert queue.front.value == 3
def test_enqueue_multiple():
queue = Queue()
queue.enqueue(1)
queue.enqueue(2)
assert queue.rear.value == 2
assert queue.front.value == 1
def test_enqueue_one():
queue = Queue()
queue.enqueue(6)
assert queue.rear.value == 6
def __init__(self):
self.dogs = Queue()
self.cats = Queue()