C++: Vector vs Deque

What are the main differences between vectors and deques in C++?

Vectors are dynamic arrays that allow fast access and are efficient for adding/removing elements at the end. Deques, or double-ended queues, allow fast insertion and deletion at both ends but have slightly slower access times.

When should I use a deque instead of a vector?

Use a deque when you need to frequently add or remove elements from both ends. For example, if you're implementing a queue or a stack that requires operations at both ends, a deque is more suitable.

Are there any performance considerations I should be aware of?

Yes, vectors have better cache locality and are generally faster for random access. Deques may have overhead due to their structure, so if you only need to add/remove from the end, prefer vectors.

Can you give me an example of when to use each?

Sure! Use a vector for a list of items where you mostly add or access elements, like a dynamic array. Use a deque for a task manager where you need to add and remove tasks from both ends.