Word Search in JavaScript

Introduction

You have a client that enjoys solving word search problems, but they would like to know if they can beat a computer in it. Your task is to make a program that will solve word searching for any given letter grid and word list.

Problem Statement

The project contains unit tests and your goal is to make sure all the tests are passing by filling in the missing code.

You are given a WordSearch class that has a letterGrid attribute which holds an array of strings that represent your letter grid, e.g.:

word
oocv
rbrk
dtrd

This class also has a find(words) method which should search through the grid for given words. This method has a missing implementation.

Each row of letterGrid is of the same length.

You are expected to:

Initialize the WordSearch object to hold the letterGrid.
Implement the find method that will search a given grid in all directions.
Make sure the Searching Directions include: horizontal and vertical.

Directions

Horizontal: left-to-right

word
____
____
____

Horizontal: right-to-left

drow
____
____
____

Vertical: top-down

w___
o___
r___
d___

Vertical: bottom-up

d___
r___
o___
w___

Output

The find method should return an object, with keys being words that are searched and values being the coordinates specifying where the words begin and end. For example, if we are looking for basic, csharp and haskell words (wordSearch.find(['basic', 'csharp', 'haskell'])), then the output should have the following structure:

{
  "word": <COORDINATES>,
  "another": <COORDINATES>,
}

Each coordinates is an object defining the row and the column, in which the word starts and ends (index counting from 1):

{
  "start": [ROW, COLUMN],
  "end": [ROW, COLUMN],
}

If the word has not been found, set the value of its key to undefined.

Edge Cases

Each word can only be found once (there is also no place for storing multiple occurrences in a single word result). Do not worry, the test examples will not include any case that a word may be found more than once.

Example

For the following letter grid:

[
  "______",
  "_c____",
  "_s____",
  "_h____",
  "basic_",
  "_r____",
  "_p____",
]

and searched words: 'basic', 'csharp', 'haskell', the result is:

{
  "basic": { // horizontal
    "start": [ 5, 1 ],
    "end": [ 5, 5 ]
  },
  "csharp": { // vertical
    "start": [ 2, 2 ],
    "end": [ 7, 2 ]
  },
  "haskell": undefined // not found
}

Setup

Follow these steps if you are using a .zip/.git mode (i.e. not available inside Devskiller in-browser IDE):

npm install – install dependencies.
npm test – run all the tests once (this will be used to evaluate your solutions).
npm run test:watch - run all the tests in the watch mode (optionally, you can use it locally if you prefer).

Hint

Examples in this readme are included as testcases in the examplesFromReadme.spec.js file, take a look at them.

fovehack / Problemillas