#ifndef GRAPH_H_
#define GRAPH_H_

#include <map>
#include <set>
#include <utility>
#include <vector>
#include <iostream>

namespace graph {

template<typename T>
class Graph {
public:
  Graph() = default;

  // Add vertex v
  void insert(const T& v);

  // Add edge between v and u
  void insert(const T& v, const T& u);

  // Delete vertex v
  void erase(T& v);
  
  // Delete edge between v and u
  void erase(T& v, T& u);

  // Adjacency matrix representation
  std::set<T> vertices;
  std::map<T, std::vector<T>> adjMatrix;
};

template<typename T>
inline void Graph<T>::insert(const T& v) {
  vertices.insert(v);
}

template<typename T>
inline void Graph<T>::insert(const T& v, const T& u) {
  vertices.insert(v);
  vertices.insert(u);
  adjMatrix[v].push_back(u);
}

template<typename T>
inline void Graph<T>::erase(T& v) {
  //
}

template<typename T>
inline void Graph<T>::erase(T& v, T& u) {
  //
}

} // namespace graph

#endif