Java collections - performance (Time Complexity)
A set is a collection that contains no duplicate elements.
Add Next Contains Data Structure
HashSet O(1) O(h/n) O(1) Hash Table
EnumSet O(1) O(1) O(1) Bit Vector
LinkedHashSet O(1) O(1) O(1) Hash Table+Linked List
TreeSet O(log n) O(log n) O(log n) Red-black tree
ConcurrentSkipList O(log n) O(1) O(log n) Skip List
CopyonWriteArraySet O(n) O(1) O(n) Array
