template <class V>
Graph<V>::Graph(bool directional)
  :_directional(directional){};

template <class V>
void Graph<V>::add_vertex(const V& name){
  if(!has_vertex(name)){
    _short_names.insert({name, _edges.size()});
    _long_names.push_back(name);
    _edges.emplace_back();
  }
}

template <class V>
void Graph<V>::add_edge(const V& name1, const V& name2, double lenght){
  add_vertex(name1);
  add_vertex(name2);
  _add_edge(name1, name2, lenght);
  if(!_directional)
    _add_edge(name2, name1, lenght);
}

template <class V>
bool Graph<V>::has_vertex(const V& name) const{
  return _short_names.find(name) != _short_names.end();
}

template <class V>
bool Graph<V>::has_edge(const V& name1, const V& name2) const{
  if(!has_vertex(name1) || !has_vertex(name2))
    return false;
  auto s_name1 = (*_short_names.find(name1)).second;
  auto s_name2 = (*_short_names.find(name2)).second;
  for(const auto& item:_edges[s_name1]){
    if(item.first == s_name2)
      return true;
  }
  return false;
}

template <class V>
void Graph<V>::print() const{
  int i = 0;
  for(auto it = _edges.begin(); it != _edges.end(); ++it, ++i){
    std::cout<<_long_names[i]<<" -> ";
    for(const auto &item:*it){
      std::cout<<"("<<_long_names[item.first]<<" , "<<item.second<<") ";
    }
    std::cout<<std::endl;
  }
}

template <class V>
void Graph<V>::_add_edge(const V& name1, const V& name2, double lenght){
  _edges[_short_names[name1]].push_back({_short_names[name2], lenght});
}