Common Mistakes with unordered_map in C++

What are some common mistakes people make when using unordered_map in C++?

Some common mistakes include not initializing the unordered_map, using the wrong key type, and not handling collisions properly.

Can you explain how to handle collisions in unordered_map?

In unordered_map, collisions are handled using chaining or open addressing. Chaining uses linked lists to store multiple elements at the same index.

What happens if I use a non-hashable type as a key?

If you use a non-hashable type as a key, you'll encounter a compilation error since unordered_map requires a hash function for the key type.

How can I improve the performance of unordered_map?

You can improve performance by choosing an appropriate load factor, reserving space in advance, and using efficient hash functions.