std::unordered_set

This container is akin to std::set but with a twist: it does not maintain the elements in any particular order. Instead, it employs a hashing mechanism to access its elements quickly. This hash-based approach can offer constant time average complexity for most operations, given a good hash function.

Purpose and suitability

std::unordered_set is a hash-based container in the C++ Standard Template Library (STL) that stores unique elements in no particular order. Its core strengths include the following:

• Providing average constant-time operations for insertions, deletions, and searches
• Handling non-trivial data types effectively

You should choose std::unordered_set in the following scenarios:

• When you need rapid checks for the existence of elements
• When the order of elements is not a concern
• When frequent insertions and deletions are expected

However, if the ordering of elements is crucial, std::set might be a better alternative...