Leetcode•Nov 13, 2026

Vowel Spellchecker

Hazrat Ali

Leetcode

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 capitalization, 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].

 

Example 1:

Input: wordlist = ["KiTe","kite","hare","Hare"], queries = ["kite","Kite","KiTe","Hare","HARE","Hear","hear","keti","keet","keto"]
Output: ["kite","KiTe","KiTe","Hare","hare","","","KiTe","","KiTe"]

Example 2:

Input: wordlist = ["yellow"], queries = ["YellOw"]
Output: ["yellow"]

Solution
var spellchecker = function(wordlist, queries) {
    const exact = new Set(wordlist);
    const caseInsensitive = new Map();
    const vowelInsensitive = new Map();

    for (const word of wordlist) {
        const lower = word.toLowerCase();
        const devoweled = lower.replace(/[aeiou]/g, '#');

        if (!caseInsensitive.has(lower)) {
            caseInsensitive.set(lower, word);
        }

        if (!vowelInsensitive.has(devoweled)) {
            vowelInsensitive.set(devoweled, word);
        }
    }

    const result = [];

    for (const query of queries) {
        const lower = query.toLowerCase();
        const devoweled = lower.replace(/[aeiou]/g, '#');

        if (exact.has(query)) {
            result.push(query);
        } else if (caseInsensitive.has(lower)) {
            result.push(caseInsensitive.get(lower));
        } else if (vowelInsensitive.has(devoweled)) {
            result.push(vowelInsensitive.get(devoweled));
        } else {
            result.push("");
        }
    }

    return result;
};



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