word-tree.js

/*
 * Time for a little data structure and algorithm exercise.
 * 
 * Websites commonly make use of a "search suggestion" feature.
 * As you type, options are suggested to you based on what others
 * have searched for in the past. For example, if I type 'Le',
 * I will be presented with other things for which people have searched--
 * other terms that begin with 'Le', such as "Levi", "Lego", and "Level".
 * One way to accomplish this is by using a tree structure, breaking each previous
 * search term into characters and then storing them in a tree, like so:
 *
 * *
 * |
 * -- L
 *    |
 *    -- e
 *       |
 *       -- v
 *       |  |
 *       |  -- e   
 *       |  |  |
 *       |  |  -- l
 *       |  |
 *       |  -- i
 *       |
 *       -- g
 *          |
 *          -- o
 *
 * In this exercise, we want you to build such a tree structure.
 * It will have a method called 'search', which will always return an array
 * of any letters that could follow the provided search term, based on what's been
 * searched in the past.
 *
 * tree.search('Levi'); // []
 * tree.search('Lego'); // []
 * tree.search('Le'); // ['g', 'v']
 * tree.search('Leg'); // ['o']
 *
 * Use the provided Node and WordTree objects, then build the
 * search method so that it passes the provided tests.
 */

const expect = require('chai').expect


class Node {
    constructor(data) {
      this.data = data
      this.parent = null
      this.children = []
    }
}

class WordTree {
  constructor() {
    this.root = new Node({})
  }
  
  search(word, nodes) {
    // your code goes here-- good luck!
  }
}

let tree = new WordTree()

expect(tree.search('Levi')).to.deep.equal([])
expect(tree.search('Level')).to.deep.equal([])
expect(tree.search('Lego')).to.deep.equal([])
expect(tree.search('Le')).to.deep.equal(['v', 'g'])
expect(tree.search('Leg')).to.deep.equal(['o'])