class Solution {

public:

    vector<string> findOcurrences(string text, string first, string second) {

        string bigram = first + ' ' + second + ' ';

        vector<string> res;

        int n = bigram.size();

        auto p = text.find(bigram);

        while(p != string::npos)

        {

            auto p1 = p+n, p2 = p1;

            while(p2<text.size() && text[p2]!=' ') p2++;

            res.push_back(text.substr(p1, p2-p1));//err...

            p = text.find(bigram, p+);

        }

        return res;

    }

};