C++ Skip List vs Hash Table

What are the main differences between a skip list and a hash table in C++?

Skip lists are probabilistic data structures that allow for fast search, insertion, and deletion, while hash tables use a hash function to map keys to values for quick access. Skip lists maintain a sorted order, whereas hash tables do not.

When should I use a skip list instead of a hash table?

You should consider using a skip list when you need ordered data and efficient range queries. Hash tables are better for quick lookups when order is not important.

Can you explain how the performance of both structures compares?

Skip lists have an average time complexity of O(log n) for search, insert, and delete operations, while hash tables offer O(1) average time complexity for these operations. However, hash tables can degrade to O(n) in the worst case due to collisions.

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

Yes, if you need to maintain a sorted list or perform range queries, skip lists are preferred. For fast lookups without the need for order, hash tables are ideal.