What are the differences between hash tables and maps in C++?

What are the differences between hash tables and maps in C++?

In C++, a hash table is typically implemented using unordered_map, while a map is implemented using ordered_map. The main difference is that unordered_map uses a hash function for fast access, while map maintains order using a binary tree.

Which one should I use for my project?

It depends on your needs. If you require fast access and don't care about order, use unordered_map. If you need to maintain order, go with map.

Are there any performance differences?

Yes, unordered_map generally offers average O(1) time complexity for lookups, while map has O(log n) due to its tree structure.

Can you give an example of when to use each?

Use unordered_map for caching data where speed is crucial, and map for scenarios where you need sorted data, like maintaining a leaderboard.