Use c++ to write code cor the functions.

size_t CountGroups () const: Return the number of connected components in the graph (i.e. the number of groups who are connected by ANY activity).

size_t CountGroups(const std::string& relationship) const: Return the number of connected components in the graph after edges in the graph are filtered: only consider edges relationship.

size_t CountGroups(const std::vector& relationships) const: Return the number of connected components in the graph after edges in the graph are filtered: only consider edges in relationships.

Exist code:

class Graph {

public:

Constractor(const std::string &people_fpath, const std::string &relations_fpath);

size_t CountGroups () const;

size_t CountGroups(const std::string& relationship) const;

size_t CountGroups(const std::vector& relationships) const

void AddVertex(const std::string& vertex);

void AddEdge(const std::string& v1, const std::string& v2);

private:

bool VertexInGraph(const std::string vertex);

std::vector relation;

std::map> graph_;

};

bool Graph::VertexInGraph(const std::string vertex) {

return static_cast(graph_.count(vertex));

}

void Graph::AddEdge(const std::string& v1, const std::string& v2) {

if (!VertexInGraph(v1) || !VertexInGraph(v2)) {

throw std::runtime_error("invalid argument");

}

graph_.at(v1).push_back(v2);

graph_.at(v2).push_back(v1);

}

void Graph::AddVertex(const std::string& vertex) {

if (VertexInGraph(vertex))

throw std::runtime_error("vertex already in graph.");

graph_.insert({vertex, std::list()});

}

Graph::Constractor(const std::string &people_fpath, const std::string &relations_fpath) {

std::ifstream ifs{people_fpath};

for (std::string line; std::getline(ifs, line); line = "") {

AddVertex(line);

}

std::ifstream ifp{relations_fpath};

for (std::string line; std::getline(ifp, line); line = "") {

std::vector one;

one = utilities::Split(line, ',');

AddEdge(one[0], one[1]);

relation.push_back(one[2]);

}

}