What are the differences between queue and deque in C++ STL?

What are the differences between queue and deque in C++ STL?

In C++ STL, a queue is a FIFO (First In First Out) data structure, while a deque (double-ended queue) allows insertion and deletion from both ends.

Can you give me examples of when to use each?

Use a queue when you need to process items in the order they arrive, like in task scheduling. Use a deque when you need more flexibility, such as adding or removing elements from both ends.

Are there performance differences between them?

Yes, both have similar performance for basic operations, but a deque may have slightly more overhead due to its flexibility.

Which one is more memory efficient?

Generally, a queue can be more memory efficient since it has a simpler structure, but it depends on the specific use case and implementation.