What are the best practices for using map and unordered_map in C++?

What are the best practices for using map and unordered_map in C++?

When using map, prefer it for ordered data and when you need to maintain the order of elements. Use unordered_map for faster access when order doesn't matter.

Can you explain the time complexity differences between them?

Sure! map has a time complexity of O(log n) for insertions and lookups, while unordered_map has an average time complexity of O(1) due to its hash table implementation.

Are there any specific scenarios where one is preferred over the other?

Yes, if you need sorted keys or range queries, use map. For high-performance scenarios with large datasets where order is irrelevant, unordered_map is better.

What about memory usage? Is there a significant difference?

Yes, unordered_map generally uses more memory due to its hash table structure, which requires additional space for buckets and handling collisions.