Last active
December 2, 2024 16:13
-
-
Save psayre23/c30a821239f4818b0709 to your computer and use it in GitHub Desktop.
Runtime Complexity of Java Collections
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Below are the Big O performance of common functions of different Java Collections. | |
List | Add | Remove | Get | Contains | Next | Data Structure | |
---------------------|------|--------|------|----------|------|--------------- | |
ArrayList | O(1) | O(n) | O(1) | O(n) | O(1) | Array | |
LinkedList | O(1) | O(1) | O(n) | O(n) | O(1) | Linked List | |
CopyOnWriteArrayList | O(n) | O(n) | O(1) | O(n) | O(1) | Array | |
Set | Add | Remove | Contains | Next | Size | Data Structure | |
----------------------|----------|----------|----------|----------|------|------------------------- | |
HashSet | O(1) | O(1) | O(1) | O(h/n) | O(1) | Hash Table | |
LinkedHashSet | O(1) | O(1) | O(1) | O(1) | O(1) | Hash Table + Linked List | |
EnumSet | O(1) | O(1) | O(1) | O(1) | O(1) | Bit Vector | |
TreeSet | O(log n) | O(log n) | O(log n) | O(log n) | O(1) | Red-black tree | |
CopyOnWriteArraySet | O(n) | O(n) | O(n) | O(1) | O(1) | Array | |
ConcurrentSkipListSet | O(log n) | O(log n) | O(log n) | O(1) | O(n) | Skip List | |
Queue | Offer | Peak | Poll | Remove | Size | Data Structure | |
------------------------|----------|------|----------|--------|------|--------------- | |
PriorityQueue | O(log n) | O(1) | O(log n) | O(n) | O(1) | Priority Heap | |
LinkedList | O(1) | O(1) | O(1) | O(1) | O(1) | Array | |
ArrayDequeue | O(1) | O(1) | O(1) | O(n) | O(1) | Linked List | |
ConcurrentLinkedQueue | O(1) | O(1) | O(1) | O(n) | O(n) | Linked List | |
ArrayBlockingQueue | O(1) | O(1) | O(1) | O(n) | O(1) | Array | |
PriorirityBlockingQueue | O(log n) | O(1) | O(log n) | O(n) | O(1) | Priority Heap | |
SynchronousQueue | O(1) | O(1) | O(1) | O(n) | O(1) | None! | |
DelayQueue | O(log n) | O(1) | O(log n) | O(n) | O(1) | Priority Heap | |
LinkedBlockingQueue | O(1) | O(1) | O(1) | O(n) | O(1) | Linked List | |
Map | Get | ContainsKey | Next | Data Structure | |
----------------------|----------|-------------|----------|------------------------- | |
HashMap | O(1) | O(1) | O(h / n) | Hash Table | |
LinkedHashMap | O(1) | O(1) | O(1) | Hash Table + Linked List | |
IdentityHashMap | O(1) | O(1) | O(h / n) | Array | |
WeakHashMap | O(1) | O(1) | O(h / n) | Hash Table | |
EnumMap | O(1) | O(1) | O(1) | Array | |
TreeMap | O(log n) | O(log n) | O(log n) | Red-black tree | |
ConcurrentHashMap | O(1) | O(1) | O(h / n) | Hash Tables | |
ConcurrentSkipListMap | O(log n) | O(log n) | O(1) | Skip List |
Thanks for this. One correction ..... For Queue, I am pretty sure it is "peek" and not "peak". Cheers.
PriorityQueue remove() without arguments, it calls poll() which is same as o(log n), and remove(Object) internally calls its private methods which uses comparator so it is also O(log n)
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
very help full thanks