LeetcodeWordPattern.cpp

class Solution {
public:
   bool wordPattern(string pattern, string str) {
        vector<string> words = split(str, ' ');
        map<char, string> strMap;
        map<string, string> checkWord;
        
        if (pattern.length() == 0 || str.length() == 0)
            return false;
        if (words.size() != pattern.length())
            return false;
        
        // pattern mapping str
        for(int i=0; i < pattern.size(); i++)
        {
            if(strMap.find(pattern[i]) != strMap.end())
            {
                if(strMap[pattern[i]] != words[i])
                    return false;
            }
            else
            {
                if (checkWord.find(words[i]) == checkWord.end())
                {
                    strMap[pattern[i]] = words[i];
                    checkWord[words[i]] = "";
                }
                else
                    return false;
            }
        }
        
        return true;
    }
   
private:
    vector<string> split(const string &s, char delim) {
        stringstream ss(s);
        string item;
        vector<string> tokens;
        while (getline(ss, item, delim)) {
            tokens.push_back(item);
        }
        return tokens;
    }
};