Disjoint-Set-Union-On-Tree (graph/tree/disjoint-set-union-on-tree.hpp)

• View this file on GitHub
• Last update: 2024-05-01 23:44:47+09:00
• Include: #include "graph/tree/disjoint-set-union-on-tree.hpp"

Depends on

• Graph Template(グラフテンプレート) (graph/graph-template.hpp)

Code

#pragma once

#include "../graph-template.hpp"

/**
 * @brief Disjoint-Set-Union-On-Tree
 */
template <typename T>
struct DisjointSetUnionOnTree : Graph<T> {
  using F = function<void(int)>;
  using Graph<T>::g;
  vector<int> heavy, sz, in, out, ord;
  const F expand, shrink, query;

  explicit DisjointSetUnionOnTree(int n, F expand, F shrink, F query)
      : Graph<T>(n),
        expand(move(expand)),
        shrink(move(shrink)),
        query(move(query)) {}

 private:
  queue<int> que;

  int build_subtree(int idx) {
    in[idx] = ord.size();
    ord.emplace_back(idx);
    for (auto &to : g[idx]) {
      int sub = build_subtree(to);
      sz[idx] += sub;
      if (heavy[idx] == -1 || sz[heavy[idx]] < sub) {
        heavy[idx] = to;
      }
    }
    out[idx] = ord.size();
    return sz[idx];
  }

  void dfs(int idx, bool keep) {
    for (auto &to : g[idx]) {
      if (heavy[idx] == to) continue;
      dfs(to, false);
    }
    if (heavy[idx] != -1) {
      dfs(heavy[idx], true);
    }
    for (auto &to : g[idx]) {
      if (heavy[idx] == to) continue;
      for (int p = in[to]; p < out[to]; p++) {
        expand(ord[p]);
      }
    }
    expand(idx);
    query(idx);
    if (!keep) {
      for (int p = in[idx]; p < out[idx]; p++) shrink(ord[p]);
    }
  }

 public:
  void build(int root = 0) {
    g = convert_rooted_tree(*this, root).g;
    sz.assign(g.size(), 1);
    heavy.assign(g.size(), -1);
    in.resize(g.size());
    out.resize(g.size());
    build_subtree(root);
    dfs(root, false);
  }
};

#line 2 "graph/tree/disjoint-set-union-on-tree.hpp"

#line 2 "graph/graph-template.hpp"

/**
 * @brief Graph Template(グラフテンプレート)
 */
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) {
    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);
    }
  }

  inline vector<Edge<T> > &operator[](const int &k) { return g[k]; }

  inline const vector<Edge<T> > &operator[](const int &k) const { return g[k]; }
};

template <typename T = int>
using Edges = vector<Edge<T> >;
#line 4 "graph/tree/disjoint-set-union-on-tree.hpp"

/**
 * @brief Disjoint-Set-Union-On-Tree
 */
template <typename T>
struct DisjointSetUnionOnTree : Graph<T> {
  using F = function<void(int)>;
  using Graph<T>::g;
  vector<int> heavy, sz, in, out, ord;
  const F expand, shrink, query;

  explicit DisjointSetUnionOnTree(int n, F expand, F shrink, F query)
      : Graph<T>(n),
        expand(move(expand)),
        shrink(move(shrink)),
        query(move(query)) {}

 private:
  queue<int> que;

  int build_subtree(int idx) {
    in[idx] = ord.size();
    ord.emplace_back(idx);
    for (auto &to : g[idx]) {
      int sub = build_subtree(to);
      sz[idx] += sub;
      if (heavy[idx] == -1 || sz[heavy[idx]] < sub) {
        heavy[idx] = to;
      }
    }
    out[idx] = ord.size();
    return sz[idx];
  }

  void dfs(int idx, bool keep) {
    for (auto &to : g[idx]) {
      if (heavy[idx] == to) continue;
      dfs(to, false);
    }
    if (heavy[idx] != -1) {
      dfs(heavy[idx], true);
    }
    for (auto &to : g[idx]) {
      if (heavy[idx] == to) continue;
      for (int p = in[to]; p < out[to]; p++) {
        expand(ord[p]);
      }
    }
    expand(idx);
    query(idx);
    if (!keep) {
      for (int p = in[idx]; p < out[idx]; p++) shrink(ord[p]);
    }
  }

 public:
  void build(int root = 0) {
    g = convert_rooted_tree(*this, root).g;
    sz.assign(g.size(), 1);
    heavy.assign(g.size(), -1);
    in.resize(g.size());
    out.resize(g.size());
    build_subtree(root);
    dfs(root, false);
  }
};

Back to top page