966: Vowel-Spellchecker
Medium

table of contents

This question is just an implementation question. The main gist of this question is you have to check in this exact order if:

  1. check if the exact query string is present in the wordList
    • return it
  2. check if the case-insensitive query string is present in the wordList
    • return the first instance of it
  3. check if the vowel-error query string is present in the wordList
    • return the first instance of it
  4. else, return an empty string

Then, you can simply create iterate through wordlist and create an unordered_set/unordered_map to check for the first three cases:

unordered_set<string> wordSet;
unordered_map<string, string> caseMatch;
unordered_map<string, string> vowelMatch;

string lowerCase, noVowels;
for (string& word : wordlist) {
    wordSet.insert(word);

    lowerCase = toLowerCase(word);
    // only create mapping if `lowerCase` doesn't exist
    if (!caseMatch.count(lowerCase)) {
        caseMatch[lowerCase] = word;
    }

    noVowels = removeVowels(lowerCase);
    // only create mapping if `noVowels` doesn't exist
    if (!vowelMatch.count(noVowels)) {
        vowelMatch[noVowels] = word;
    }
}

Finally, you can simply run through the four steps, using the unordered_set/unordered_map to check if any of the conditions are fulfilled for each query:

vector<string> ans;
for (string& query : queries) {
    if (wordSet.count(query)) {
        ans.push_back(query);
    } else {
        lowerCase = toLowerCase(query);
        noVowels = removeVowels(lowerCase);
        if (caseMatch.count(lowerCase)) {
            ans.push_back(caseMatch[lowerCase]);
        } else if (vowelMatch.count(noVowels)) {
            ans.push_back(vowelMatch[noVowels]);
        } else {
            ans.push_back("");
        }
    }
}
return ans;

code

class Solution {
public:
    vector<string> spellchecker(vector<string>& wordlist, vector<string>& queries) {
        unordered_set<string> wordSet;
        unordered_map<string, string> caseMatch;
        unordered_map<string, string> vowelMatch;

        string lowerCase, noVowels;
        for (string& word : wordlist) {
            wordSet.insert(word);

            lowerCase = toLowerCase(word);
            if (!caseMatch.count(lowerCase)) {
                caseMatch[lowerCase] = word;
            }

            noVowels = removeVowels(lowerCase);
            if (!vowelMatch.count(noVowels)) {
                vowelMatch[noVowels] = word;
            }
        }
        
        vector<string> ans;
        for (string& query : queries) {
            if (wordSet.count(query)) {
                ans.push_back(query);
            } else {
                lowerCase = toLowerCase(query);
                noVowels = removeVowels(lowerCase);
                if (caseMatch.count(lowerCase)) {
                    ans.push_back(caseMatch[lowerCase]);
                } else if (vowelMatch.count(noVowels)) {
                    ans.push_back(vowelMatch[noVowels]);
                } else {
                    ans.push_back("");
                }
            }
        }
        return ans;
    }
private:
    string toLowerCase (string word) {
        for (char& c : word) {
            c = tolower(c);
        }
        return word;
    }

    string removeVowels (string word) {
        string noVowels = "";
        for (char& c : word) {
            if (c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u') {
                noVowels += "*";
            } else {
                noVowels += c;
            }
        }
        return noVowels;
    }
};

complexity

time taken