Vowel Spellchecker Problem
Description
LeetCode Problem 966.
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].
Example 1:
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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:
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Input: wordlist = ["yellow"], queries = ["YellOw"]
Output: ["yellow"]
Constraints:
- 1 <= wordlist.length, queries.length <= 5000
- 1 <= wordlist[i].length, queries[i].length <= 7
- wordlist[i] and queries[i] consist only of only English letters.
Sample C++ Code
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class Solution {
public:
string removeVowels(string s) {
for (int i = 0; i < s.size(); i++) {
if (s[i] == 'a' || s[i] == 'e' || s[i] == 'o' || s[i] == 'u' || s[i] == 'i')
s[i] = '*';
}
return s;
}
string tolow(string s) {
string c;
for (char x: s)
c += tolower(x);
return c;
}
vector<string> spellchecker(vector<string>& wordlist, vector<string>& queries) {
unordered_map<string, string> c;
unordered_map<string, string> v;
unordered_set<string> s2;
for (string word: wordlist) {
s2.insert(word);
string temp = tolow(word);
if (c.find(temp) == c.end())
c[temp] = word;
if (v.find(removeVowels(temp)) == v.end())
v[removeVowels(temp)] = word;
}
vector<string> ans;
for (string q: queries) {
string lq = tolow(q);
if (s2.find(q) != s2.end())
ans.push_back(q);
else if (c.find(lq) != c.end())
ans.push_back(c[lq]);
else if (v.find(removeVowels(lq)) != v.end())
ans.push_back(v[removeVowels(lq)]);
else
ans.push_back("");
}
return ans;
}
};