vector<int> freqQuery(const vector<vector<int>>& queries) {
    std::unordered_map<int, int> db;
    std::unordered_map<int, int> qdb;
    vector<int> ret;
    for (const auto& line : queries)
    {
        const int op = line.front(), const key = line.back();
        int curr_cnt;
        switch (op)
        {
            case 1:
                curr_cnt = db[key];
                if (curr_cnt)
                    qdb[curr_cnt]--;
                db[key]++;
                qdb[curr_cnt+1]++;
                break;
            case 2:
                curr_cnt = db[key];
                if (curr_cnt)
                {
                    qdb[curr_cnt]--;
                    db[key]--;
                    if (curr_cnt > 1)
                        qdb[curr_cnt-1]++;
                }
                break;
            case 3:
                ret.push_back(min(qdb[key], 1));
                break;
        }
    }
    return ret;
}