Key
| Good | Fair | Poor |
Data Structures
| Data Structure | Time Complexity | Space Complexity | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Average | Worst | Worst | |||||||
| Indexing | Search | Insertion | Deletion | Indexing | Search | Insertion | Deletion | ||
| Basic Array (Array) | O(1) | O(n) | - | - | O(1) | O(n) | - | - | O(n) |
| Dynamic Array (List<T> and ArrayList) | O(1) | O(n) | O(n) | O(n) | O(1) | O(n) | O(n) | O(n) | O(n) |
| Singly-Linked List | O(n) | O(n) | O(1) | O(1) | O(n) | O(n) | O(1) | O(1) | O(n) |
| Doubly-Linked List (LinkedList<T>) | O(n) | O(n) | O(1) | O(1) | O(n) | O(n) | O(1) | O(1) | O(n) |
| Skip List | O(log(n)) | O(log(n)) | O(log(n)) | O(log(n)) | O(n) | O(n) | O(n) | O(n) | O(n log(n)) |
| Hash Table (HashSet<T> Dictionary<TKey, TValue> and Hashtable) | - | O(1) | O(1) | O(1) | - | O(n) | O(n) | O(n) | O(n) |
| Binary Search Tree (SortedDictionary<TKey, TValue>) | O(log(n)) | O(log(n)) | O(log(n)) | O(log(n)) | O(n) | O(n) | O(n) | O(n) | O(n) |
| Sorted Array using Binary Search (SortedList<TKey, TValue>) | O(log(n)) | O(?) | O(1) | O(1) | O(log(n)) | O(?) | O(n) | O(n) | O(?) |
| Cartesian Tree | - | O(log(n)) | O(log(n)) | O(log(n)) | - | O(n) | O(n) | O(n) | O(n) |
| Splay Tree | - | O(log(n)) | O(log(n)) | O(log(n)) | - | O(log(n)) | O(log(n)) | O(log(n)) | O(n) |
| Red-Black Tree (SortedSet<T> No Duplicates) | O(log(n)) | O(log(n)) | O(log(n)) | O(log(n)) | O(log(n)) | O(log(n)) | O(log(n)) | O(log(n)) | O(n) |
| AVL Tree | O(log(n)) | O(log(n)) | O(log(n)) | O(log(n)) | O(log(n)) | O(log(n)) | O(log(n)) | O(log(n)) | O(n) |
| B-Tree | O(log(n)) | O(log(n)) | O(log(n)) | O(log(n)) | O(log(n)) | O(log(n)) | O(log(n)) | O(log(n)) | O(n) |
Searching
| Algorithm | Data Structure | Time Complexity | Space Complexity | |||
|---|---|---|---|---|---|---|
| Average | Worst | Worst | ||||
| Depth First Search (DFS) | Graph of |V| vertices and |E| edges | - | O(|E| + |V|) | O(|V|) | ||
| Breadth First Search (BFS) | Graph of |V| vertices and |E| edges | - | O(|E| + |V|) | O(|V|) | ||
| Binary search (Array.BinarySearch or List<T>.BinarySearch) | Sorted array of n elements | O(log(n)) | O(log(n)) | O(1) | ||
| Linear (Brute Force) | Array | O(n) | O(n) | O(1) | ||
| Shortest path by Dijkstra, using a Min-heap as priority queue |
Graph with |V| vertices and |E| edges | O((|V| + |E|) log |V|) | O((|V| + |E|) log |V|) | O(|V|) | ||
| Shortest path by Dijkstra, using an unsorted array as priority queue |
Graph with |V| vertices and |E| edges | O(|V|^2) | O(|V|^2) | O(|V|) | ||
| Shortest path by Bellman-Ford | Graph with |V| vertices and |E| edges | O(|V||E|) | O(|V||E|) | O(|V|) | ||
Sorting
| Algorithm | Data Structure | Time Complexity | Worst Case Auxiliary Space Complexity | ||||
|---|---|---|---|---|---|---|---|
| Best | Average | Worst | Worst | ||||
| Quicksort (Array.Sort and List<T>.Sort and Enumerable.OrderBy<TSource, TKey>) | Array | O(n log(n)) | O(n log(n)) | O(n^2) | O(n) | ||
| Mergesort | Array | O(n log(n)) | O(n log(n)) | O(n log(n)) | O(n) | ||
| Heapsort | Array | O(n log(n)) | O(n log(n)) | O(n log(n)) | O(1) | ||
| Bubble Sort | Array | O(n) | O(n^2) | O(n^2) | O(1) | ||
| Insertion Sort | Array | O(n) | O(n^2) | O(n^2) | O(1) | ||
| Select Sort | Array | O(n^2) | O(n^2) | O(n^2) | O(1) | ||
| Bucket Sort | Array | O(n+k) | O(n+k) | O(n^2) | O(nk) | ||
| Radix Sort | Array | O(nk) | O(nk) | O(nk) | O(n+k) | ||
Heaps
| Heaps | Time Complexity | |||||||
|---|---|---|---|---|---|---|---|---|
| Heapify | Find Max | Extract Max | Increase Key | Insert | Delete | Merge | ||
| Linked List (sorted) | - | O(1) | O(1) | O(n) | O(n) | O(1) | O(m+n) | |
| Linked List (unsorted) | - | O(n) | O(n) | O(1) | O(1) | O(1) | O(1) | |
| Binary Heap | O(n) | O(1) | O(log(n)) | O(log(n)) | O(log(n)) | O(log(n)) | O(m+n) | |
| Binomial Heap | - | O(log(n)) | O(log(n)) | O(log(n)) | O(log(n)) | O(log(n)) | O(log(n)) | |
| Fibonacci Heap | - | O(1) | O(log(n))* | O(1)* | O(1) | O(log(n))* | O(1) | |
Graphs
| Node / Edge Management | Storage | Add Vertex | Add Edge | Remove Vertex | Remove Edge | Query |
|---|---|---|---|---|---|---|
| Adjacency list | O(|V|+|E|) | O(1) | O(1) | O(|V| + |E|) | O(|E|) | O(|V|) |
| Incidence list | O(|V|+|E|) | O(1) | O(1) | O(|E|) | O(|E|) | O(|E|) |
| Adjacency matrix | O(|V|^2) | O(|V|^2) | O(1) | O(|V|^2) | O(1) | O(1) |
| Incidence matrix | O(|V| ⋅ |E|) | O(|V| ⋅ |E|) | O(|V| ⋅ |E|) | O(|V| ⋅ |E|) | O(|V| ⋅ |E|) | O(|E|) |
Big-O Complexity Chart
