Word Search Puzzle - Position finder

word-search-puzzle-position-finder.js

//* Function to solve a word search puzzle
function wordSearch(board, words) {
  board = board.map((row) => row.split(''));

  //* Define the possible directions to move on the board
  const directions = [
    [-1, 0, '↑'], // up
    [1, 0, '↓'], // down
    [0, -1, '←'], // left
    [0, 1, '→'], // right
  ];

  const results = {};

  //* Define a helper function to search for a word starting at a specific position
  function search(x, y, word, index) {
    //* If we have reached the end of the word, return true
    if (index === word.length) return true;
    //* If the current position is out of bounds or the character does not match, return false
    if (x < 0 || y < 0 || x >= board.length || y >= board[0].length || board[x][y].toLowerCase() !== word[index])
      return false;

    //* Mark the current position as visited
    board[x][y] = '*';

    //* Try each direction from the current position
    for (let [dx, dy, direction] of directions) {
      //* If we find the word in this direction, return the direction and the current position
      if (search(x + dx, y + dy, word, index + 1)) {
        return { direction, x, y };
      }
    }

    //* If we didn't find the word, backtrack by resetting the current position and return false
    board[x][y] = word[index];
    return false;
  }

  //* For each word in the list
  words.forEach((word) => {
    //* Convert the word to lower case to make a case insensitive search
    word = word.toLowerCase();
    //* Try to find the word starting at each position on the board
    const result = board.some((row, i) =>
      row.some((_, j) => {
        //* If we find the word, store the result and return true
        const found = search(i, j, word, 0);
        if (found) results[word] = found;
        return found;
      })
    );
    //* If we didn't find the word, store false in the results
    if (!result) results[word] = false;
  });

  return results;
}

const board = [
  'ROFENTEEDSREMELSLRVRGTMNAV',
  'DBVCSHTSOXRHOTWNELITRMOTYB',
  'RESDRIVINGLICENCEMGTMNAVIL',
  'TDPTDODDSLRCOSLSNCQWAHEAOT',
  'UREVERSEHORNBOVERLOADINGFF',
  'VEERECXVIHAHAITLOPVCSHDNER',
  'AFDOXRTIAITZEDSRSQGOSLOWND',
  'SPLSTUSEATBELTQDAHEAFENLTB',
  'PEISALQWMELBTYGEDSRSVIOIEV',
  'OAMGLSPMOTORVEHICLEACHTTEC',
  'ROITAVIIIHAAEEDSREMFSATRDS',
  'OSTMNCHREAFCQCRUSHHELMETSH',
  'ATBEESARWNERVCSHTDODFEXIRT',
  'DEVICHHOMGTOIHAHAITIELTSED',
  'NECHHTARHITSEAFEKSOSKIASMO',
  'ADSAAADICROSSWITHCAUTIONEED',
  'USHHNOTLQHNIRNAVNAFANEDILC',
  'ERTAGDLSKUFNBOFEOHENADDHSS',
  'FEDIEYDUINEGLTFRAAKCUSRALO',
  'PMOTKQTTRAFFICRULESEERIHRN',
  'EEDLIRIUPORONRVGCAHAFEVAVI',
  'UBFQULTREAOSDIEROADSAFETYL',
  'URBSHUVNELSLSVRBHTFRDBVCSH',
  'WOVERTAKINGFPKSOOTISSEIHAH',
  'EDSREMELSLREOITRLECEPLEAFE',
  'CSHTDODCSONTTNAVGXRHOTWNEL',
];

console.log(wordSearch(board, ['OVER', 'LANE', 'REVO', 'ATSR', 'OLTI', 'SEAT', 'UNKNOWN', 'DRIVING']));

Output:

{
  over: { direction: '→', x: 4, y: 13 },
  lane: { direction: '↓', x: 9, y: 4 },
  revo: { direction: '←', x: 23, y: 4 },
  atsr: { direction: '↑', x: 13, y: 16 },
  olti: { direction: '←', x: 5, y: 16 },
  seat: { direction: '→', x: 7, y: 6 },
  unknown: false,
  driving: { direction: '→', x: 2, y: 3 }
}