734

class Solution {
public:
    bool areSentencesSimilar(vector<string>& words1, vector<string>& words2, vector<vector<string>> pairs) {
        if (words1.size() != words2.size()) return false;
        unordered_map<string, unordered_set<string>> map;
        for(auto p : pairs)
            map[p[0]].insert(p[1]);

        for(int i = 0; i < words1.size(); i++)
            if(words1[i] != words2[i] && !map[words1[i]].count(words2[i]) && !map[words2[i]].count(words1[i]))
                return false;
        return true;
    }
};