Programmers Stack Exchange is a question and answer site for professional programmers interested in conceptual questions about software development. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

In the C++ STL, priority_queue (heap) can be used with any underlying container, such as a deque. How does the implementation stay O(log n) if deques don't swap an item in index a with index b in constant time?

share|improve this question
Deque stands for double-ended-queue. – Brian Jan 14 '13 at 15:35
up vote 10 down vote accepted

You are right that it would not be possible to make an efficient heap implementation on top of a doubly linked list. However, deques aren't doubly linked lists; they are random access containers. deques are able to swap an item in index a with index b in constant time. See the SGI documentation for deques.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.