| 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 |
Mar 26, 2020 The first has a time complexity of O(N) and the latter has O(1). Python Regex Cheat Sheet. Writing to an excel sheet using Python. Big-O Cheat Sheet Generated December 10, 2013. Algorithm Data Structure Time Complexity Space Complexity Average Worst Depth First Search (DFS) Graph of jVj. Big-O Algorithm Complexity Cheat Sheet Created Date: 7/10/2016 7:49:20 PM.
commented Feb 7, 2021
You've mixed data structures between LinkedList and ArrayDequeue in the Queue section. |
commented Mar 11, 2021
Do these figures still hold in the new Java versions? If not, then I would suggest adding the Java-version these performances were measured at. I presume by and large the performance does not change dramatically though. |
commented Apr 21, 2021
Big O Complexity Cheat Sheet Pdf
I highly doubt this was measured. It's probably inferred from the implementation. And I doubt the complexity of the implementations changed. Most algorithms have been around for a long time. |
| Sorting Algorithms | Space complexity | Time complexity | ||
|---|---|---|---|---|
| Worst case | Best case | Average case | Worst case | |
| Insertion Sort | O(1) | O(n) | O(n2) | O(n2) |
| Selection Sort | O(1) | O(n2) | O(n2) | O(n2) |
| Smooth Sort | O(1) | O(n) | O(n log n) | O(n log n) |
| Bubble Sort | O(1) | O(n) | O(n2) | O(n2) |
| Shell Sort | O(1) | O(n) | O(n log n2) | O(n log n2) |
| Mergesort | O(n) | O(n log n) | O(n log n) | O(n log n) |
| Quicksort | O(log n) | O(n log n) | O(n log n) | O(n log n) |
| Heapsort | O(1) | O(n log n) | O(n log n) | O(n log n) |
Big O Time Complexity Cheat Sheet
| Data Structures | Average Case | Worst Case | ||||
|---|---|---|---|---|---|---|
| Search | Insert | Delete | Search | Insert | Delete | |
| Array | O(n) | N/A | N/A | O(n) | N/A | N/A |
| Sorted Array | O(log n) | O(n) | O(n) | O(log n) | O(n) | O(n) |
| Linked List | O(n) | O(1) | O(1) | O(n) | O(1) | O(1) |
| Doubly Linked List | O(n) | O(1) | O(1) | O(n) | O(1) | O(1) |
| Stack | O(n) | O(1) | O(1) | O(n) | O(1) | O(1) |
| Hash table | O(1) | O(1) | O(1) | O(n) | O(n) | O(n) |
| Binary Search Tree | O(log n) | O(log n) | O(log n) | O(n) | O(n) | O(n) |
| B-Tree | O(log n) | O(log n) | O(log n) | O(log n) | O(log n) | O(log n) |
| Red-Black tree | O(log n) | O(log n) | O(log n) | O(log n) | O(log n) | O(log n) |
| AVL Tree | O(log n) | O(log n) | O(log n) | O(log n) | O(log n) | O(log n) |
Big O Complexity Cheat Sheet Download
| n f(n) | log n | n | n log n | n2 | 2n | n! |
|---|---|---|---|---|---|---|
| 10 | 0.003ns | 0.01ns | 0.033ns | 0.1ns | 1ns | 3.65ms |
| 20 | 0.004ns | 0.02ns | 0.086ns | 0.4ns | 1ms | 77years |
| 30 | 0.005ns | 0.03ns | 0.147ns | 0.9ns | 1sec | 8.4x1015yrs |
| 40 | 0.005ns | 0.04ns | 0.213ns | 1.6ns | 18.3min | -- |
| 50 | 0.006ns | 0.05ns | 0.282ns | 2.5ns | 13days | -- |
| 100 | 0.07 | 0.1ns | 0.644ns | 0.10ns | 4x1013yrs | -- |
| 1,000 | 0.010ns | 1.00ns | 9.966ns | 1ms | -- | -- |
| 10,000 | 0.013ns | 10ns | 130ns | 100ms | -- | -- |
| 100,000 | 0.017ns | 0.10ms | 1.67ms | 10sec | -- | -- |
| 1'000,000 | 0.020ns | 1ms | 19.93ms | 16.7min | -- | -- |
| 10'000,000 | 0.023ns | 0.01sec | 0.23ms | 1.16days | -- | -- |
| 100'000,000 | 0.027ns | 0.10sec | 2.66sec | 115.7days | -- | -- |
| 1,000'000,000 | 0.030ns | 1sec | 29.90sec | 31.7 years | -- | -- |