链接：. - 力扣（LeetCode）

题解：

class Solution {
public:
    vector<string> trulyMostPopular(vector<string>& names, vector<string>& synonyms) {
        UnionFind uf;
        for (auto& syn : synonyms) {
            //cout << "syn:" << syn << endl;
            auto syn_name = split_name(syn);
            uf.add(syn_name.first);
            uf.add(syn_name.second);
            // 将这两个节点放入一个group
            uf.merge(syn_name.first, syn_name.second);
        }
        //
        std::unordered_map<std::string, std::set<People>> fathers;
        std::unordered_map<std::string, int> fathers_count;
        // 遍历所有名字
        for (auto& name : names) {
            People people;
            split(name, people);
            std::string father = uf.get_father(people.name);
            // 获得父亲，并且按照字典序列进行排序
            fathers[father].insert(people);
            //cout << "nnnnn: " << people.name << endl;
            // 统计按照group父亲节点，总数量
            fathers_count[father] += people.count;
        }
        std::vector<std::string> result;
        for (auto& father : fathers) {
            // 获得字典序的第一个名字
            std::string str = father.second.begin()->name;
            //cout << "str:" << str << endl;
            // 获得总数量
            str = str + "(" + to_string(fathers_count[father.first]) + ")";
            // 追加结果
            result.push_back(str);
        }
        return result;
    }
private:
struct People {
    People() {
        count = 0;
    }
    std::string name;
    int count = 0;
    // 按照字典序列进行排序
    bool operator < (const People& people) const {
        return name < people.name;
    }
};
    void split(string& str, People& people) {
        auto it = str.find("(");
        people.name = str.substr(0, it);
        people.count = atoi(str.substr(it+1, str.size() - it -1).c_str());
        //cout << "name: " << people.name << " count:" << people.count << endl;
    }
    std::pair<std::string, std::string> split_name(string& str) {
        auto it = str.find(",");
        std::pair<std::string, std::string> result;
        result.first = str.substr(1, it-1);
        result.second = str.substr(it+1, str.size() - it -1);
        result.second.pop_back();
        //cout << "first: " << result.first << " second:" << result.second << endl;
        return result;
    }
class UnionFind {
public: 
    void add(std::string& p) {
        auto ite = _father.find(p);
        if (ite == _father.end()) {
            _father[p] = p;
        }
    }
    void merge(std::string& p, std::string& q) {
        std::string p_father = get_father(p);
        std::string q_father = get_father(q);
        if (p_father != q_father) {
            _father[p_father] = q_father;
        }
    }
    std::string get_father(std::string& _p) {
        add(_p); //如果没有的节点，也要添加个节点
        std::string p = _p;
        while (_father[p] != p) {
            p = _father[p];
        }
        return p;
    }
    std::unordered_map<std::string, std::string> _father;
};
};