GFG PTOD | 30 Dec | Union of Arrays with Duplicates

int findUnion(vector<int>& a, vector<int>& b) {
        // code here
        unordered_set<int> s(a.begin(), a.end());
        for(int i=0; i<b.size(); i++) {
            s.insert(b[i]);
        }
        return s.size();
    }