def test_inf_queue(self):
queue = LinkedListQueue()
queue.enqueue(1)
queue.enqueue(2)
assert queue.is_empty() == False
assert queue.is_full() == False
assert queue.capacity == float('inf')
assert queue.__repr__() == 'LinkedListQueue: front [1,2] tail'
assert len(queue) == 2
assert queue.front() == 1
assert queue.dequeue() == 1
assert queue.is_empty() == False
assert queue.is_full() == False
assert queue.capacity == float('inf')
assert queue.__repr__() == 'LinkedListQueue: front [2] tail'
assert len(queue) == 1
assert queue.front() == 2
assert queue.dequeue() == 2
assert queue.is_empty() == True
assert queue.is_full() == False
assert queue.capacity == float('inf')
assert queue.__repr__() == 'LinkedListQueue: front [] tail'
assert len(queue) == 0
with pytest.raises(EmptyError):
queue.front()
with pytest.raises(EmptyError):
queue.dequeue()
def test_fix_len_queue(self):
queue = LinkedListQueue(3)
queue.enqueue(1)
queue.enqueue(2)
assert queue.is_empty() == False
assert queue.is_full() == False
assert queue.capacity == 3
assert queue.__repr__() == 'LinkedListQueue: front [1,2] tail'
assert len(queue) == 2
assert queue.front() == 1
queue.enqueue(3)
assert queue.is_empty() == False
assert queue.is_full() == True
assert queue.capacity == 3
assert queue.__repr__() == 'LinkedListQueue: front [1,2,3] tail'
assert len(queue) == 3
assert queue.front() == 1
with pytest.raises(FullError):
queue.enqueue(4)
assert queue.dequeue() == 1
assert queue.is_empty() == False
assert queue.is_full() == False
assert queue.capacity == 3
assert queue.__repr__() == 'LinkedListQueue: front [2,3] tail'
assert len(queue) == 2
assert queue.front() == 2
def breadthfirst(self):
if not self.is_empty():
q = LinkedListQueue()
q.enqueue(self.root())
while not q.is_empty():
p = q.dequeue()
yield p
for c in self.children(p):
q.enqueue(c)
def main():
print("Creating a new queue...")
q = LinkedListQueue()
print("length of the queue:", len(q))
print("The queue is empty:", q.is_empty())
print()
print("Adding 10 to the queue...")
q.enqueue(10)
print("The front element is", q.first())
print("length of the queue:", len(q))
print("The queue is empty:", q.is_empty())
print()
print("Adding 20 30 40 50 in this order...")
q.enqueue(20)
q.enqueue(30)
q.enqueue(40)
q.enqueue(50)
print("The front element is", q.first())
print("length of the queue:", len(q))
print("The queue is empty:", q.is_empty())
print()
print("Dequeue 3 times...")
for i in range(3):
q.dequeue()
print("The front element is", q.first())
print("length of the queue:", len(q))
print("The queue is empty:", q.is_empty())
print()
print("Adding 10 elements...")
for i in range(10):
q.enqueue(i)
print("The front element is", q.first())
print("length of the queue:", len(q))
print("The queue is empty:", q.is_empty())
print()
def test_fix_len_empty_queue(self):
queue = LinkedListQueue(0)
assert queue.is_empty() == True
assert queue.is_full() == True
assert queue.capacity == 0
assert queue.__repr__() == 'LinkedListQueue: front [] tail'
assert len(queue) == 0
with pytest.raises(EmptyError):
queue.front()
with pytest.raises(EmptyError):
queue.dequeue()
with pytest.raises(FullError):
queue.enqueue(1)
queue = LinkedListQueue(3)
assert queue.is_empty() == True
assert queue.is_full() == False
assert queue.capacity == 3
assert queue.__repr__() == 'LinkedListQueue: front [] tail'
assert len(queue) == 0
with pytest.raises(EmptyError):
queue.front()
with pytest.raises(EmptyError):
queue.dequeue()
class EarliestUsageCache(object):
def __init__(self, capacity=1000):
self.capacity = capacity
self.size = 0
self.keyQueue = LinkedListQueue()
self.cache = dict()
def add(self, key, value):
if (not self.contains(key)):
if (self.isFull()):
self.__evict()
self.keyQueue.enqueue(key)
self.size += 1
self.cache[key] = value
def get(self, key):
if (not self.contains(key)):
raise ValueError("%s is not a key in this cache" % key)
return self.cache[key]
def contains(self, key):
return key in self.cache
def isFull(self):
return self.size == self.capacity
def clear(self):
self.size = 0
self.keyQueue = LinkedListQueue()
self.cache = dict()
def __evict(self):
key = self.keyQueue.dequeue()
self.cache.pop(key)
self.size -= 1
#back of queue at tail '''ll_queue = LinkedList() #enqueue ll_queue.append(40) ll_queue.append(49) ll_queue.append(50) #ll_queue.print_list() #front #print(ll_queue.head.data) #dequeue ll_queue.delete_from_head() print(ll_queue.head.data)''' ll_queue = LinkedListQueue() ll_queue.enqueue(6) ll_queue.enqueue(20) ll_queue.enqueue(16) ll_queue.enqueue(5) ll_queue.dequeue() print(ll_queue.front())