word-pattern.cpp

class Solution {
    
public:
    bool wordPattern(string pattern, string str) {
        unordered_map<char, string> char_map;
        unordered_map<string, char> word_map;
        
        stringstream s(str);
        string word;
        int n = pattern.size(), i = 0;
        
        while(s >> word){
            if(i == n) 
                return false;
            char c = pattern[i];
            
            if(char_map.count(c) != word_map.count(word)) 
                return false;
            if(char_map.count(c)){
                if( (word_map[word] != c) || (char_map[c] != word)) 
                    return false;
            } else {
                char_map.insert({c, word});
                word_map.insert({word, c});
            }
            i++;
        }
        return i == n;
    }
};