leetcode_python_150/290_Word_Pattern.py at main · Ishazaka/leetcode_python_150 · GitHub

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// Two hash map

class Solution:
    def wordPattern(self, pattern: str, s: str) -> bool:
        words = s.split(" ")
        if len(pattern) != len(words):
            return False

        charToWord = {}
        wordToChar = {}

        for c, w in zip(pattern, words):
            if c in charToWord and charToWord[c] != w:
                return False
            if w in wordToChar and wordToChar[w] != c:
                return False
            charToWord[c] = w
            wordToChar[w] = c
        return True


// 2nd way


class Solution:
    def wordPattern(self, pattern: str, s: str) -> bool:
        charToWord = {}
        wordToChar = {}
        words = s.split()

        if len(pattern) != len(words):
            return False

        for i, (c, word) in enumerate(zip(pattern, words)):
            if charToWord.get(c, 0) != wordToChar.get(word, 0):
                return False
            charToWord[c] = i + 1
            wordToChar[word] = i + 1

        return True


// hash set

class Solution:
    def wordPattern(self, pattern: str, s: str) -> bool:
        words = s.split()
        if len(pattern) != len(words):
            return False

        charToWord = {}
        store = set()

        for i, (c, w) in enumerate(zip(pattern, words)):
            if c in charToWord:
                if words[charToWord[c]] != w:
                    return False
            else:
                if w in store:
                    return False
                charToWord[c] = i
                store.add(w)

        return True


// Single Hash Map


class Solution:
    def wordPattern(self, pattern: str, s: str) -> bool:
        words = s.split()
        if len(pattern) != len(words):
            return False

        charToWord = {}

        for i, (c, w) in enumerate(zip(pattern, words)):
            if c in charToWord:
                if words[charToWord[c]] != w:
                    return False
            else:
                # iterates atmost 26 times (a - z)
                for k in charToWord:
                    if words[charToWord[k]] == w:
                        return False
                charToWord[c] = i

        return True