JavaScript Algorithms and Data Structures

Code Examples

Data Structures

1. Linked List
2. Queue
3. Stack
4. Hash Table
5. Heap
6. Priority Queue
7. Trie
8. Tree
   • Binary Search Tree
   • AVL Tree
9. Graph

Algorithms

• Math
  • Fibonacci Number
  • Cartesian Product
  • Power Set
• String
  • String Permutations
• Graph
  • Depth-First Search (DFS)
  • Breadth-First Search (BFS)
• Sorting
  • Bubble Sort
  • Selection Sort
  • Insertion Sort
  • Heap Sort
  • Merge Sort
  • Quick Sort

Running Tests

Run all tests

npm test

Run tests by name

npm test -- -t 'LinkedList'

Playground

You may play with data-structures and algorithms in ./src/playground/playground.js file and write tests for it in ./src/playground/__test__/playground.test.js.

Then just simply run the following command to test if your playground code works as expected:

npm test -- -t 'playground'

Useful links

• Data Structures and Algorithms on YouTube
• Algorithms
  • Dynamic Programming
    • Introduction to Dynamic Programming 1

Useful Information

Big O Notation

Order of growth of algorithms specified in Big O notation.

Source: Big O Cheat Sheet.

Below is the list of some of the most used Big O notations and their performance comparisons against different sizes of the input data.

Big O Notation	Computations for 10 elements	Computations for 100 elements	Computations for 1000 elements
O(1)	1	1	1
O(log N)	3	6	9
O(N)	10	100	1000
O(N log N)	30	60	9000
O(N^2)	100	10000	1000000
O(2^N)	1024	1.26e+29	1.07e+301
O(N!)	3628800	9.3e+157	4.02e+2567

Common Data Structure Operations Complexity

One	Two
Three

Data Structure	Access	Search	Insertion	Deletion
Array	1	n	n	n
Stack	n	n	1	1
Queue	n	n	1	1
Linked List	n	n	1	1
Hash Table		n	n	n
Binary Search Tree	n	n	n	n
B-Tree	log(n)	log(n)	log(n)	log(n)
Red-Black Tree	log(n)	log(n)	log(n)	log(n)
AVL Tree	log(n)	log(n)	log(n)	log(n)

Array Sorting Algorithms Complexity

Name	Best	Average	Worst	Memory	Stable
Bubble sort	n	n^2	n^2	1	Yes
Insertion sort	n	n^2	n^2	1	Yes
Selection sort	n^2	n^2	n^2	1	No
Heap sort	n log(n)	n log(n)	n log(n)	1	No
Merge sort	n log(n)	n log(n)	n log(n)	n	Yes
Quick sort	n log(n)	n log(n)	n^2	log(n)	No