test/verify/aoj-grl-2-a-3.test.cpp

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• Last update: 2026-08-10 10:49:23+00:00
• Problem: http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=GRL_2_A

Depends on

• Boruvka (最小全域木) (graph/mst/boruvka.hpp)
• Union Find (structure/union-find/union-find.hpp)

Code

// clang-format off
// competitive-verifier: PROBLEM http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=GRL_2_A
// clang-format on

#include <algorithm>
#include <iostream>
#include <utility>
#include <vector>

#include "../../graph/mst/boruvka.hpp"

using namespace std;

int main() {
  int V, E;
  cin >> V >> E;
  vector<int> X(E), Y(E), Z(E);
  for (int i = 0; i < E; i++) {
    cin >> X[i] >> Y[i] >> Z[i];
  }
  Boruvka<int> mst(V);
  auto f = [&](vector<pair<int, int>>& ret) {
    for (int i = 0; i < E; i++) {
      X[i] = mst.find(X[i]);
      Y[i] = mst.find(Y[i]);
      if (X[i] == Y[i]) continue;
      ret[X[i]] = min(ret[X[i]], make_pair(Z[i], Y[i]));
      ret[Y[i]] = min(ret[Y[i]], make_pair(Z[i], X[i]));
    }
    return ret;
  };
  cout << mst.build(f) << endl;
}

#line 1 "test/verify/aoj-grl-2-a-3.test.cpp"
// clang-format off
// competitive-verifier: PROBLEM http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=GRL_2_A
// clang-format on

#include <algorithm>
#include <iostream>
#include <utility>
#include <vector>

#line 2 "graph/mst/boruvka.hpp"

#line 4 "graph/mst/boruvka.hpp"
#include <cstddef>
#include <limits>
#line 8 "graph/mst/boruvka.hpp"

#line 2 "structure/union-find/union-find.hpp"

#line 7 "structure/union-find/union-find.hpp"

struct UnionFind {
  std::vector<int> data;

  UnionFind() = default;

  explicit UnionFind(std::size_t sz) : data(sz, -1) {}

  bool unite(int x, int y) {
    x = find(x), y = find(y);
    if (x == y) return false;
    if (data[x] > data[y]) std::swap(x, y);
    data[x] += data[y];
    data[y] = x;
    return true;
  }

  int find(int k) {
    if (data[k] < 0) return (k);
    return data[k] = find(data[k]);
  }

  int size(int k) { return -data[find(k)]; }

  bool same(int x, int y) { return find(x) == find(y); }

  std::vector<std::vector<int>> groups() {
    int n = (int)data.size();
    std::vector<std::vector<int>> ret(n);
    for (int i = 0; i < n; i++) {
      ret[find(i)].emplace_back(i);
    }
    ret.erase(
        std::remove_if(ret.begin(), ret.end(),
                       [&](const std::vector<int>& v) { return v.empty(); }),
        ret.end());
    return ret;
  }
};
#line 10 "graph/mst/boruvka.hpp"

/**
 * @brief Boruvka(最小全域木)
 *
 */
template <typename T>
struct Boruvka {
 private:
  std::size_t V;
  UnionFind uf;
  const T INF;

 public:
  explicit Boruvka(std::size_t V, T INF = std::numeric_limits<T>::max())
      : V(V), uf(V), INF(INF) {}

  inline int find(int k) { return uf.find(k); }

  template <typename F>
  T build(const F& update) {
    T ret = T();
    while (uf.size(0) < (int)V) {
      std::vector<std::pair<T, int> > v(V, std::make_pair(INF, -1));
      update(v);
      bool con = false;
      for (int i = 0; i < (int)V; i++) {
        if (v[i].second >= 0 && uf.unite(i, v[i].second)) {
          ret += v[i].first;
          con = true;
        }
      }
      if (!con) return INF;
    }
    return ret;
  }
};
#line 11 "test/verify/aoj-grl-2-a-3.test.cpp"

using namespace std;

int main() {
  int V, E;
  cin >> V >> E;
  vector<int> X(E), Y(E), Z(E);
  for (int i = 0; i < E; i++) {
    cin >> X[i] >> Y[i] >> Z[i];
  }
  Boruvka<int> mst(V);
  auto f = [&](vector<pair<int, int>>& ret) {
    for (int i = 0; i < E; i++) {
      X[i] = mst.find(X[i]);
      Y[i] = mst.find(Y[i]);
      if (X[i] == Y[i]) continue;
      ret[X[i]] = min(ret[X[i]], make_pair(Z[i], Y[i]));
      ret[Y[i]] = min(ret[Y[i]], make_pair(Z[i], X[i]));
    }
    return ret;
  };
  cout << mst.build(f) << endl;
}

Test cases

Env	Name	Status	Elapsed	Memory
g++	00_sample1	AC	2 ms	4 MB
g++	00_sample2	AC	2 ms	3 MB
g++	critical1	AC	2 ms	4 MB
g++	critical2	AC	7 ms	4 MB
g++	critical3	AC	48 ms	4 MB
g++	out1	AC	2 ms	4 MB
g++	out10	AC	57 ms	5 MB
g++	out11	AC	18 ms	4 MB
g++	out12	AC	29 ms	4 MB
g++	out13	AC	23 ms	4 MB
g++	out14	AC	28 ms	4 MB
g++	out15	AC	20 ms	4 MB
g++	out2	AC	2 ms	4 MB
g++	out3	AC	2 ms	4 MB
g++	out4	AC	2 ms	4 MB
g++	out5	AC	2 ms	3 MB
g++	out6	AC	56 ms	5 MB
g++	out7	AC	58 ms	5 MB
g++	out8	AC	58 ms	5 MB
g++	out9	AC	56 ms	5 MB
clang++	00_sample1	AC	2 ms	4 MB
clang++	00_sample2	AC	2 ms	4 MB
clang++	critical1	AC	2 ms	4 MB
clang++	critical2	AC	7 ms	4 MB
clang++	critical3	AC	48 ms	4 MB
clang++	out1	AC	2 ms	4 MB
clang++	out10	AC	59 ms	4 MB
clang++	out11	AC	18 ms	4 MB
clang++	out12	AC	30 ms	4 MB
clang++	out13	AC	24 ms	4 MB
clang++	out14	AC	29 ms	4 MB
clang++	out15	AC	21 ms	4 MB
clang++	out2	AC	2 ms	4 MB
clang++	out3	AC	2 ms	4 MB
clang++	out4	AC	2 ms	4 MB
clang++	out5	AC	2 ms	4 MB
clang++	out6	AC	57 ms	5 MB
clang++	out7	AC	59 ms	4 MB
clang++	out8	AC	59 ms	5 MB
clang++	out9	AC	57 ms	5 MB

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