Vowel Spellchecker — LeetCode 966 Python Solution

The problem

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

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"]

Python solution

class Solution:
    def spellchecker(self, wordlist: List[str], queries: List[str]) -> List[str]:
        def f(w):
            t = []
            for c in w:
                t.append("*" if c in "aeiou" else c)
            return "".join(t)

        s = set(wordlist)
        low, pat = {}, {}
        for w in wordlist:
            t = w.lower()
            low.setdefault(t, w)
            pat.setdefault(f(t), w)

        ans = []
        for q in queries:
            if q in s:
                ans.append(q)
                continue
            q = q.lower()
            if q in low:
                ans.append(low[q])
                continue
            q = f(q)
            if q in pat:
                ans.append(pat[q])
                continue
            ans.append("")
        return ans

Complexity

Pattern: Hash Map

Trade memory for time: remember what you have seen so the second pass never happens. LeetCode 966. Vowel Spellchecker is filed here on both counts: the reference solution below belongs to the algorithm family this hub collects, and LeetCode tags it Hash Table.

The hash map guide has the Python template for the pattern and the 709 LeetCode problems that use it.

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