What is the difference between unordered_set and unordered_map in C++?

Can you explain the difference between unordered_set and unordered_map in C++?

Sure! An unordered_set is a collection of unique elements, while an unordered_map is a collection of key-value pairs where keys are unique.

What are the use cases for each of them?

You would use unordered_set when you need to store unique items without caring about their order. Use unordered_map when you need to associate values with unique keys.

How do they handle collisions?

Both use hash tables to handle collisions. In unordered_set, collisions are resolved by chaining, while unordered_map uses the same method for its key-value pairs.

Which one is more efficient for lookups?

Generally, unordered_map is more efficient for lookups since it allows you to access values directly via keys, while unordered_set requires searching for the element.