# Include <deque>

Deque

The \ (deque \) header file mainly includes a dual-end queue container. It is a linear storage space that can be inserted at both ends to delete, similar to vector and queue. Compared with \ (vector \), \ (deque \) can insert elements at the beginning of \ (O (1. Compared with \ (queue \), \ (deque \) can be randomly accessed as an array.

Declaration Method

Deque <int> q; deque <int>: iterator it;

Q. Size ()

Returns the size of the double-ended queue.

Q. Empty ()

Whether the double-end queue is empty.

Q. Clear ()

Clear the container.

[]

Random Access like \ (vector.

Q. Begin ()/Q. End ()

Returns the first iterator or the last iterator.

Q. Front ()/Q. Back ()

Returns the header/tail element.

Q. push_front (X)/Q. push_back ()

Insert element \ (x \) at the head/end of the team \).

Q. pop_front ()/Q. pop_back ()

Show team Header/team end Elements

# Include <deque>