Big O notation
Big-O Complexity Chart
Horrible |
Bad |
Fair |
Good |
Excellent |
Common Data Structure Operations
| Data Structure | Time Complexity | Space Complexity | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Average | Worst | Worst | |||||||
| Access | Search | Insertion | Deletion | Access | Search | Insertion | Deletion | ||
| Array | Θ(1) |
Θ(n) |
Θ(n) |
Θ(n) |
O(1) |
O(n) |
O(n) |
O(n) |
O(n) |
| Stack | Θ(n) |
Θ(n) |
Θ(1) |
Θ(1) |
O(n) |
O(n) |
O(1) |
O(1) |
O(n) |
| Queue | Θ(n) |
Θ(n) |
Θ(1) |
Θ(1) |
O(n) |
O(n) |
O(1) |
O(1) |
O(n) |
| Singly-Linked List | Θ(n) |
Θ(n) |
Θ(1) |
Θ(1) |
O(n) |
O(n) |
O(1) |
O(1) |
O(n) |
| Doubly-Linked List | Θ(n) |
Θ(n) |
Θ(1) |
Θ(1) |
O(n) |
O(n) |
O(1) |
O(1) |
O(n) |
| Skip List | Θ(log(n)) |
Θ(log(n)) |
Θ(log(n)) |
Θ(log(n)) |
O(n) |
O(n) |
O(n) |
O(n) |
O(n log(n)) |
| Hash Table | N/A |
Θ(1) |
Θ(1) |
Θ(1) |
N/A |
O(n) |
O(n) |
O(n) |
O(n) |
| Binary Search Tree | Θ(log(n)) |
Θ(log(n)) |
Θ(log(n)) |
Θ(log(n)) |
O(n) |
O(n) |
O(n) |
O(n) |
O(n) |
| Cartesian Tree | N/A |
Θ(log(n)) |
Θ(log(n)) |
Θ(log(n)) |
N/A |
O(n) |
O(n) |
O(n) |
O(n) |
| B-Tree | Θ(log(n)) |
Θ(log(n)) |
Θ(log(n)) |
Θ(log(n)) |
O(log(n)) |
O(log(n)) |
O(log(n)) |
O(log(n)) |
O(n) |
| Red-Black Tree | Θ(log(n)) |
Θ(log(n)) |
Θ(log(n)) |
Θ(log(n)) |
O(log(n)) |
O(log(n)) |
O(log(n)) |
O(log(n)) |
O(n) |
| Splay Tree | N/A |
Θ(log(n)) |
Θ(log(n)) |
Θ(log(n)) |
N/A |
O(log(n)) |
O(log(n)) |
O(log(n)) |
O(n) |
| AVL Tree | Θ(log(n)) |
Θ(log(n)) |
Θ(log(n)) |
Θ(log(n)) |
O(log(n)) |
O(log(n)) |
O(log(n)) |
O(log(n)) |
O(n) |
| KD Tree | Θ(log(n)) |
Θ(log(n)) |
Θ(log(n)) |
Θ(log(n)) |
O(n) |
O(n) |
O(n) |
O(n) |
O(n) |
Array Sorting Algorithms
| Algorithm | Time Complexity | Space Complexity | ||
|---|---|---|---|---|
| Best | Average | Worst | Worst | |
| Quicksort | Ω(n log(n)) |
Θ(n log(n)) |
O(n^2) |
O(log(n)) |
| Mergesort | Ω(n log(n)) |
Θ(n log(n)) |
O(n log(n)) |
O(n) |
| Timsort | Ω(n) |
Θ(n log(n)) |
O(n log(n)) |
O(n) |
| Heapsort | Ω(n log(n)) |
Θ(n log(n)) |
O(n log(n)) |
O(1) |
| Bubble Sort | Ω(n) |
Θ(n^2) |
O(n^2) |
O(1) |
| Insertion Sort | Ω(n) |
Θ(n^2) |
O(n^2) |
O(1) |
| Selection Sort | Ω(n^2) |
Θ(n^2) |
O(n^2) |
O(1) |
| Tree Sort | Ω(n log(n)) |
Θ(n log(n)) |
O(n^2) |
O(n) |
| Shell Sort | Ω(n log(n)) |
Θ(n(log(n))^2) |
O(n(log(n))^2) |
O(1) |
| Bucket Sort | Ω(n+k) |
Θ(n+k) |
O(n^2) |
O(n) |
| Radix Sort | Ω(nk) |
Θ(nk) |
O(nk) |
O(n+k) |
| Counting Sort | Ω(n+k) |
Θ(n+k) |
O(n+k) |
O(k) |
| Cubesort | Ω(n) |
Θ(n log(n)) |
O(n log(n)) |
O(n) |
