C++ STL Container Comparison

What are the main differences between std::vector and std::list in C++?

std::vector is a dynamic array that provides fast random access, while std::list is a doubly linked list that allows for efficient insertions and deletions.

When should I use std::deque instead of std::vector?

Use std::deque when you need fast insertions and deletions at both ends, as it allows for efficient operations at both the front and back.

Can you explain the performance implications of using std::map versus std::unordered_map?

std::map is implemented as a balanced tree, providing O(log n) complexity for insertions and lookups, while std::unordered_map uses a hash table, offering average O(1) complexity but can degrade to O(n) in worst cases.

What about std::set? How does it differ from std::unordered_set?

std::set is ordered and implemented as a balanced tree, while std::unordered_set is not ordered and uses a hash table, making it faster for certain operations.