What are the differences between std::set and std::unordered_set in C++?

What are the differences between std::set and std::unordered_set in C++?

The main difference is that std::set is ordered while std::unordered_set is not. std::set maintains elements in a specific order, using a binary search tree, while std::unordered_set uses a hash table for storage.

Which one is faster for searching elements?

std::unordered_set is generally faster for search operations because it uses hashing, providing average constant time complexity. std::set, on the other hand, has logarithmic time complexity due to its ordered nature.

Are there any memory usage differences between them?

Yes, std::unordered_set typically uses more memory due to the overhead of the hash table and potential collisions. std::set may use less memory since it only needs to store the elements in a tree structure.

When should I use one over the other?

Use std::set when you need ordered elements or require range queries. Use std::unordered_set when you prioritize faster access and don't need order.