Trie Prefix Tree

This is a Trie implementation written in JavaScript, with insert and remove capability. It can be used to search a predefined dictionary for prefixes, check a prefix exists and retrieve a list of anagrams and sub-anagrams based on given letters.

What is a Trie?

A Trie (also known as a prefix-tree) is a data structure for storing strings in a tree. Each branch in the tree represents a single character which allows for fast and efficient depth-first searching. Let's say we have a dictionary with the words: CAR, CAT and CURL. We can visualise the trie like this:

Installation

Pull down dependencies:

npm install

This project uses Jest for unit testing and ESLint for linting.

To run combined linting & unit tests:

npm test

To run linting:

npm run lint

Run tests in watch mode:

npm run test-watch

Get code coverage report:

npm run test-coverage

How to Use

To use the Trie, install and save it to your package dependencies:

npm install trie-prefix-tree --save

To create a new Trie:

var trie = require ( ' trie-prefix-tree ' ) ; import trie from ' trie-prefix-tree ' ;

Instantiate the Trie:

var myTrie = trie ( [ ' cat ' , ' cats ' , ' dogs ' , ' elephant ' , ' tiger ' ] ) ;

Trie functionality:

myTrie . dump ( ) ; myTrie . dump ( 2 ) ;

myTrie . tree ( ) ;

myTrie . addWord ( ' lion ' ) ;

myTrie . removeWord ( ' dogs ' ) ;

Adding and removing words can be chained:

myTrie . addWord ( ' hello ' ) . removeWord ( ' hello ' ) ;

Prefix searching:

myTrie . isPrefix ( ' do ' ) ; myTrie . isPrefix ( ' z ' ) ;

myTrie . countPrefix ( ' c ' ) ;

myTrie . getPrefix ( ' c ' ) ; myTrie . getPrefix ( ' c ' , false ) ;

myTrie . getRandomWordWithPrefix ( ' c ' ) ; myTrie . getRandomWordWithPrefix ( ' c ' ) ;

Other:

myTrie . getWords ( ) ; myTrie . getWords ( false ) ;

myTrie . hasWord ( ' elephant ' ) ; myTrie . hasWord ( ' zoo ' ) ;

myTrie . getAnagrams ( ' act ' ) ;

myTrie . getSubAnagrams ( ' ctalion ' ) ; [ ' cat ' , ' cats ' , ' lion ' ] ;

Credits

Credit goes to Kent C. Dodds for providing the awesome 'How to Create an Open Source JavaScript Library' course, available on egghead.io.

License

This project is referenced under the MIT license and is free to use and distribute.

MIT @ Lyndsey Browning