グラフテンプレート(Graph-template)

説明

グラフを扱う際のテンプレート。

コード

template <typename T = int>
struct Edge
{
  int from, to;
  T cost;
  int idx;

  Edge() = default;

  Edge(int from, int to, T cost = 1, int idx = -1) : from(from), to(to), cost(cost), idx(idx) {}

  operator int() const { return to; }
};

template <typename T = int>
struct Graph
{
  vector<vector<Edge<T>>> g;
  int es;

  Graph() = default;

  explicit Graph(int n) : g(n), es(0) {}

  size_t size() const
  {
    return g.size();
  }

  void add_directed_edge(int from, int to, T cost = 1)
  {
    g[from].emplace_back(from, to, cost, es++);
  }

  void add_edge(int from, int to, T cost = 1)
  {
    g[from].emplace_back(from, to, cost, es);
    g[to].emplace_back(to, from, cost, es++);
  }

  void read(int M, int padding = -1, bool weighted = false, bool directed = false) //読み込み
  {
    for (int i = 0; i < M; i++)
    {
      int a, b;
      cin >> a >> b;
      a += padding;
      b += padding;
      T c = T(1);
      if (weighted)
        cin >> c;
      if (directed)
        add_directed_edge(a, b, c);
      else
        add_edge(a, b, c);
    }
  }
};

template <typename T = int>
using Edges = vector<Edge<T>>;

出典

ei1333.github.io