0966-vowel-spellchecker.js

/**
 * 966. Vowel Spellchecker
 * https://leetcode.com/problems/vowel-spellchecker/
 * Difficulty: Medium
 *
 * Given a wordlist, we want to implement a spellchecker that converts a query word into a correct word.
 * For a given query word, the spell checker handles two categories of spelling mistakes:
 *
 * - Capitalization: If the query matches a word in the wordlist (case-insensitive), then the query word
 *   is returned with the same case as the case in the wordlist.
 *   Example: wordlist = ["yellow"], query = "YellOw": correct = "yellow"
 *   Example: wordlist = ["Yellow"], query = "yellow": correct = "Yellow"
 *   Example: wordlist = ["yellow"], query = "yellow": correct = "yellow"
 * - Vowel Errors: If after replacing the vowels ('a', 'e', 'i', 'o', 'u') of the query word with any vowel
 *   individually, it matches a word in the wordlist (case-insensitive), then the query word is returned
 *   with the same case as the match in the wordlist.
 *   Example: wordlist = ["YellOw"], query = "yollow": correct = "YellOw"
 *   Example: wordlist = ["YellOw"], query = "yeellow": correct = "" (no match)
 *   Example: wordlist = ["YellOw"], query = "yllw": correct = "" (no match)
 *
 * In addition, the spell checker operates under the following precedence rules:
 * - When the query exactly matches a word in the wordlist (case-sensitive), you should return the same word back.
 * - When the query matches a word up to capitlization, you should return the first such match in the wordlist.
 * - When the query matches a word up to vowel errors, you should return the first such match in the wordlist.
 * - If the query has no matches in the wordlist, you should return the empty string.
 *
 * Given some queries, return a list of words answer, where answer[i] is the correct word for query = queries[i].
 */

/**
 * @param {string[]} words
 * @param {string[]} queries
 * @return {string[]}
 */
var spellchecker = function(words, queries) {
  const set = new Set(words);
  const map = new Map();
  const format = s => s.toLowerCase().replace(/[aeiou]/g, '_');
  words.forEach(word => {
    if (!map.has(word.toLowerCase())) map.set(word.toLowerCase(), word);
    if (!map.has(format(word))) map.set(format(word), word);
  });
  return queries.map(q => set.has(q) ? q : map.get(q.toLowerCase()) || map.get(format(q)) || '');
};