leetcode每日一题：290. 单词规律

print(s.wordPattern("abba", "dog cat cat fish"))
print(s.wordPattern("abba", "dog dog dog dog"))

class Solution:
    def wordPattern(self, pattern: str, s: str) -> bool:
        if not pattern:
            return not s
        if not s:
            return not pattern
        i = 0
        s = s.split(" ")
        if len(s) != len(pattern):
            return False
        mapping = {}
        rev = set()
        while i < len(pattern):
            if pattern[i] not in mapping:
                if s[i] not in rev:
                    mapping[pattern[i]] = s[i]
                    rev.add(s[i])
                else:
                    return False
            else:
                if mapping[pattern[i]] != s[i]:
                    return False
            i += 1
        return True

class Solution:
    def wordPattern(self, pattern: str, s: str) -> bool:
        word2ch = dict()
        ch2word = dict()
        words = s.split()
        if len(pattern) != len(words):
            return False

        for ch, word in zip(pattern, words):
            # 更简洁
            if (word in word2ch and word2ch[word] != ch) or (ch in ch2word and ch2word[ch] != word):
                return False
            word2ch[word] = ch
            ch2word[ch] = word

        return True

# 作者：LeetCode-Solution
# 链接：https://leetcode-cn.com/problems/word-pattern/solution/dan-ci-gui-lu-by-leetcode-solution-6vqv/
# 来源：力扣（LeetCode）
# 著作权归作者所有。商业转载请联系作者获得授权，非商业转载请注明出处。