test/verify/aoj-grl-5-c.test.cpp

• View this file on GitHub
• Last update: 2026-08-10 10:52:01+00:00
• Problem: http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=GRL_5_C

Depends on

• Graph Template (グラフテンプレート) (graph/graph-template.hpp)
• Doubling Lowest Common Ancestor (最小共通祖先) (graph/tree/doubling-lowest-common-ancestor.hpp)

Code

// clang-format off
// competitive-verifier: PROBLEM http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=GRL_5_C
// clang-format on

#include <iostream>

#include "../../graph/tree/doubling-lowest-common-ancestor.hpp"

using namespace std;

int main() {
  int N, Q;
  cin >> N;
  DoublingLowestCommonAncestor<int> dlca(N);
  for (int i = 0; i < N; i++) {
    int k;
    cin >> k;
    for (int j = 0; j < k; j++) {
      int c;
      cin >> c;
      dlca.add_edge(i, c);
    }
  }
  dlca.build();
  cin >> Q;
  for (int i = 0; i < Q; i++) {
    int u, v;
    cin >> u >> v;
    cout << dlca.lca(u, v) << "\n";
  }
}

#line 1 "test/verify/aoj-grl-5-c.test.cpp"
// clang-format off
// competitive-verifier: PROBLEM http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=GRL_5_C
// clang-format on

#include <iostream>

#line 2 "graph/tree/doubling-lowest-common-ancestor.hpp"

#include <utility>
#include <vector>

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

#include <cstddef>
#line 6 "graph/graph-template.hpp"

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 {
  std::vector<std::vector<Edge<T> > > g;
  int es;

  Graph() = default;

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

  std::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;
      std::cin >> a >> b;
      a += padding;
      b += padding;
      T c = T(1);
      if (weighted) std::cin >> c;
      if (directed)
        add_directed_edge(a, b, c);
      else
        add_edge(a, b, c);
    }
  }

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

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

template <typename T = int>
using Edges = std::vector<Edge<T> >;
#line 7 "graph/tree/doubling-lowest-common-ancestor.hpp"

/**
 * @brief Doubling-Lowest-Common-Ancestor(最小共通祖先)
 *
 */
template <typename T>
struct DoublingLowestCommonAncestor : Graph<T> {
 public:
  using Graph<T>::g;
  std::vector<int> dep;
  std::vector<T> sum;
  std::vector<std::vector<int> > table;
  const int LOG;

  explicit DoublingLowestCommonAncestor(int n)
      : Graph<T>(n), LOG(32 - __builtin_clz(g.size())) {}

  explicit DoublingLowestCommonAncestor(const Graph<T>& g)
      : LOG(32 - __builtin_clz(g.size())), Graph<T>(g) {}

  void build(int root = 0) {
    dep.assign(g.size(), 0);
    sum.assign(g.size(), 0);
    table.assign(LOG, std::vector<int>(g.size(), -1));
    dfs(root, -1, 0);
    for (int k = 0; k + 1 < LOG; k++) {
      for (int i = 0; i < (int)table[k].size(); i++) {
        if (table[k][i] == -1)
          table[k + 1][i] = -1;
        else
          table[k + 1][i] = table[k][table[k][i]];
      }
    }
  }

  int lca(int u, int v) {
    if (dep[u] > dep[v]) std::swap(u, v);
    v = climb(v, dep[v] - dep[u]);
    if (u == v) return u;
    for (int i = LOG - 1; i >= 0; i--) {
      if (table[i][u] != table[i][v]) {
        u = table[i][u];
        v = table[i][v];
      }
    }
    return table[0][u];
  }

  int climb(int u, int k) {
    if (dep[u] < k) return -1;
    for (int i = LOG - 1; i >= 0; i--) {
      if ((k >> i) & 1) u = table[i][u];
    }
    return u;
  }

  T dist(int u, int v) { return sum[u] + sum[v] - 2 * sum[lca(u, v)]; }

 private:
  void dfs(int idx, int par, int d) {
    table[0][idx] = par;
    dep[idx] = d;
    for (auto& to : g[idx]) {
      if (to != par) {
        sum[to] = sum[idx] + to.cost;
        dfs(to, idx, d + 1);
      }
    }
  }
};
#line 8 "test/verify/aoj-grl-5-c.test.cpp"

using namespace std;

int main() {
  int N, Q;
  cin >> N;
  DoublingLowestCommonAncestor<int> dlca(N);
  for (int i = 0; i < N; i++) {
    int k;
    cin >> k;
    for (int j = 0; j < k; j++) {
      int c;
      cin >> c;
      dlca.add_edge(i, c);
    }
  }
  dlca.build();
  cin >> Q;
  for (int i = 0; i < Q; i++) {
    int u, v;
    cin >> u >> v;
    cout << dlca.lca(u, v) << "\n";
  }
}

Test cases

Env	Name	Status	Elapsed	Memory
g++	00_sample_00	AC	2 ms	4 MB
g++	01_small_00	AC	2 ms	4 MB
g++	02_middle_00	AC	2 ms	4 MB
g++	02_middle_01	AC	2 ms	4 MB
g++	02_middle_02	AC	2 ms	4 MB
g++	02_middle_03	AC	2 ms	4 MB
g++	03_corner_00	AC	2 ms	4 MB
g++	03_corner_01	AC	2 ms	4 MB
g++	04_rand_00	AC	2 ms	4 MB
g++	04_rand_01	AC	2 ms	4 MB
g++	04_rand_02	AC	2 ms	4 MB
g++	04_rand_03	AC	2 ms	4 MB
g++	04_rand_04	AC	2 ms	4 MB
g++	04_rand_05	AC	2 ms	4 MB
g++	04_rand_06	AC	2 ms	4 MB
g++	04_rand_07	AC	2 ms	4 MB
g++	05_complete_00	AC	2 ms	4 MB
g++	05_complete_01	AC	2 ms	4 MB
g++	05_complete_02	AC	2 ms	4 MB
g++	05_complete_03	AC	2 ms	4 MB
g++	05_complete_04	AC	3 ms	4 MB
g++	05_complete_05	AC	4 ms	5 MB
g++	05_complete_06	AC	11 ms	5 MB
g++	05_complete_07	AC	33 ms	11 MB
g++	06_biased_00	AC	89 ms	5 MB
g++	06_biased_01	AC	123 ms	22 MB
g++	06_biased_02	AC	123 ms	18 MB
g++	06_biased_03	AC	117 ms	20 MB
g++	07_large_00	AC	135 ms	19 MB
g++	07_large_01	AC	139 ms	19 MB
g++	07_large_02	AC	141 ms	19 MB
g++	07_large_03	AC	135 ms	19 MB
clang++	00_sample_00	AC	2 ms	4 MB
clang++	01_small_00	AC	1 ms	4 MB
clang++	02_middle_00	AC	1 ms	4 MB
clang++	02_middle_01	AC	1 ms	4 MB
clang++	02_middle_02	AC	1 ms	4 MB
clang++	02_middle_03	AC	1 ms	4 MB
clang++	03_corner_00	AC	1 ms	4 MB
clang++	03_corner_01	AC	1 ms	4 MB
clang++	04_rand_00	AC	1 ms	4 MB
clang++	04_rand_01	AC	1 ms	4 MB
clang++	04_rand_02	AC	1 ms	4 MB
clang++	04_rand_03	AC	1 ms	4 MB
clang++	04_rand_04	AC	1 ms	4 MB
clang++	04_rand_05	AC	2 ms	4 MB
clang++	04_rand_06	AC	2 ms	4 MB
clang++	04_rand_07	AC	2 ms	4 MB
clang++	05_complete_00	AC	1 ms	4 MB
clang++	05_complete_01	AC	1 ms	4 MB
clang++	05_complete_02	AC	2 ms	4 MB
clang++	05_complete_03	AC	2 ms	4 MB
clang++	05_complete_04	AC	3 ms	4 MB
clang++	05_complete_05	AC	4 ms	5 MB
clang++	05_complete_06	AC	10 ms	5 MB
clang++	05_complete_07	AC	31 ms	11 MB
clang++	06_biased_00	AC	86 ms	5 MB
clang++	06_biased_01	AC	126 ms	24 MB
clang++	06_biased_02	AC	205 ms	18 MB
clang++	06_biased_03	AC	118 ms	21 MB
clang++	07_large_00	AC	185 ms	19 MB
clang++	07_large_01	AC	175 ms	19 MB
clang++	07_large_02	AC	216 ms	19 MB
clang++	07_large_03	AC	196 ms	19 MB

Back to top page