What is the purpose of a set in C++?

In C++, a set is an associative container used to store a collection of unique and sorted elements. It is implemented using a red-black tree and has the following characteristics:

1. Uniqueness: The elements in the set are unique, any duplicate elements will be automatically ignored.
2. Sorting: The elements in a set are ordered according to a specific sorting rule, by default in ascending order.
3. Dynamism: sets are dynamic and allow for the insertion and deletion of elements at any time.

The main applications of set include:

1. Deduplication: Since the elements in a set are unique, it can be used to remove duplicate elements and simplify the data processing process.
2. Arrangement: The elements in a set are sorted according to a specific order, making it easy to search, iterate, and output.
3. Search: The set provides a fast search function, which can determine whether an element exists in the collection and perform search operations in O(logN) time complexity.
4. Set supports various set operations such as finding the intersection, union, and difference between two sets.

In conclusion, a set is a powerful container that can efficiently store and manipulate a collection of unique and ordered elements.