Can you explain the differences between std::vector and std::deque in C++?

Can you explain the differences between std::vector and std::deque in C++?

Sure! Both std::vector and std::deque are sequence containers in C++, but they have different characteristics. std::vector is a dynamic array that allows fast random access and is efficient for adding/removing elements at the end. std::deque, on the other hand, is a double-ended queue that allows fast insertions and deletions at both the front and back.

What are the performance implications of using one over the other?

Good question! std::vector generally has better cache performance due to its contiguous memory allocation, making it faster for accessing elements. However, std::deque can be more efficient for scenarios where you frequently add or remove elements from both ends.

Can you provide a code example for both?

Absolutely! Here's a simple example:

For std::vector:

#include <vector>
std::vector<int> vec = {1, 2, 3};
vec.push_back(4); // Add to the end

For std::deque:

#include <deque>
std::deque<int> deq = {1, 2, 3};
deq.push_front(0); // Add to the front

Are there any specific use cases where one is preferred over the other?

Yes! Use std::vector when you need fast access and mostly add/remove elements at the end. Use std::deque when you need to frequently add/remove elements from both ends.