I began to notice that I had to change the collection type from
HashSet<T> to improve performance. Well, actually now it seems that I'd rather do HashSets right away, wherever I used to make Lists before. Or are there situations when List is preferable?
List<T> is an ordered collection that can contain duplicates.
HashSet<T> is an unordered collection, no duplicates. One of the inconveniences is that you need to implement
GetHashCode for elements.
It is not always necessary and possible to use a
HashSet . Although in cases where it can be used, there will be a significant performance increase on large collections, since some operations are faster (for example,
Add are performed in