What are the differences between C++ STL containers?

Can you explain the differences between vector, list, and deque in C++ STL?

Sure! A vector is a dynamic array that allows random access and is efficient for adding/removing elements at the end. A list is a doubly linked list, which is efficient for insertions and deletions at any position but does not allow random access. A deque (double-ended queue) allows fast insertions and deletions at both ends and supports random access.

When should I use a list instead of a vector?

You should use a list when you need frequent insertions and deletions in the middle of the container, as lists are more efficient for those operations compared to vectors.

What about performance differences in terms of memory usage?

Vectors generally use less memory overhead compared to lists because lists require additional memory for pointers to the next and previous elements. However, vectors may require reallocation when they grow, which can be costly.

Can you give me an example of when to use a deque?

A deque is ideal when you need to add or remove elements from both ends frequently, such as in a queue or a sliding window algorithm.