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单词规律 II⚓︎

Leetcode题目链接

描述⚓︎

详见中文题目链接。

解答⚓︎

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class Solution {
private:
    bool backtracking(int pIndex, int sIndex, 
    const string& pattern, const string& s, 
    unordered_map<char, string>& patternToWord, 
    unordered_map<string, char>& wordToPattern) {
        if (pIndex == pattern.size() && sIndex == s.size()) return true;
        if (pIndex >= pattern.size() || sIndex >= s.size()) return false;

        char currentChar = pattern[pIndex];

        for (int i = sIndex; i < s.size(); i++) {
            string word = s.substr(sIndex, i - sIndex + 1);
            if ((patternToWord.count(currentChar) && patternToWord[currentChar] == word)
            || (wordToPattern.count(word) && wordToPattern[word] == currentChar)) {
                if (backtracking(pIndex + 1, i + 1, pattern, s, patternToWord, wordToPattern)) 
                    return true;
            } else if (!patternToWord.count(currentChar) && !wordToPattern.count(word)) {
                patternToWord[currentChar] = word;
                wordToPattern[word] = currentChar;
                if (backtracking(pIndex + 1, i + 1, pattern, s, patternToWord, wordToPattern))
                    return true;
                patternToWord.erase(currentChar);
                wordToPattern.erase(word);
            }
        }

        return false;
    }

public:
    bool wordPatternMatch(string pattern, string s) {
        unordered_map<char, string> patternToWord;
        unordered_map<string, char> wordToPattern;
        return backtracking(0, 0, pattern, s, patternToWord, wordToPattern);
    }
};