734. Sentence Similarity

We can represent a sentence as an array of words, for example, the sentence “I am happy with leetcode” can be represented as arr = [“I”,”am”,happy”,”with”,”leetcode”].

Given two sentences sentence1 and sentence2 each represented as a string array and given an array of string pairs similarPairs where similarPairs[i] = [xi, yi] indicates that the two words xi and yi are similar.

Return true if sentence1 and sentence2 are similar, or false if they are not similar.

Two sentences are similar if:

• They have the same length (i.e., the same number of words)
• sentence1[i] and sentence2[i] are similar.

Notice that a word is always similar to itself, also notice that the similarity relation is not transitive. For example, if the words a and b are similar, and the words b and c are similar, a and c are not necessarily similar.

class Solution {
public:
    bool areSentencesSimilar(vector<string>& s1, vector<string>& s2, vector<vector<string>>& similarPairs) {
        if(s1.size() != s2.size()) return false;
        map<string, unordered_set<string>> p;
        for(auto vec : similarPairs) {
            p[vec[0]].insert(vec[1]);
            p[vec[1]].insert(vec[0]);
        }
        for(int i = 0; i < s1.size(); i++) {
            if(s1[i] == s2[i] or p[s1[i]].count(s2[i])) continue;
            return false;
        }
        return true;
    }
};