Stack/QueueStack & Queue

Deque (Double-Ended Queue)

A queue that supports O(1) insertion and removal at both the front and the back.

Commands — Comma separated: pushfront N, pushback N, popfront, popback

1/13A deque supports O(1) insertion and removal at both ends, so it can act as a stack, a queue, or both at once.

Just pushedBeing poppedFrontBack

1push_front(x): items.insert(0, x)
2push_back(x): items.append(x)
3pop_front(): return items.pop_front()
4pop_back(): return items.pop()

Variables

size0

Complexity

access O(1)

search O(n)

insert O(1)

delete O(1)

Speed