test/verify/aoj-grl-1-b.test.cpp

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• Last update: 2026-08-10 10:48:01+00:00
• Problem: http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=GRL_1_B

Depends on

• Graph Template (グラフテンプレート) (graph/graph-template.hpp)
• Bellman Ford (単一始点最短路) (graph/shortest-path/bellman-ford.hpp)

Code

// clang-format off
// competitive-verifier: PROBLEM http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=GRL_1_B
// clang-format on

#include <iostream>
#include <limits>

#include "../../graph/shortest-path/bellman-ford.hpp"

using namespace std;

int main() {
  int V, E, R;
  cin >> V >> E >> R;
  Edges<> es;
  for (int i = 0; i < E; i++) {
    int a, b, c;
    cin >> a >> b >> c;
    es.emplace_back(a, b, c);
  }
  auto dists = bellman_ford(es, V, R);
  for (auto& dist : dists) {
    if (dist == numeric_limits<int>::min()) {
      cout << "NEGATIVE CYCLE\n";
      return 0;
    }
  }
  for (auto& dist : dists) {
    if (dist == numeric_limits<int>::max())
      cout << "INF\n";
    else
      cout << dist << "\n";
  }
}

#line 1 "test/verify/aoj-grl-1-b.test.cpp"
// clang-format off
// competitive-verifier: PROBLEM http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=GRL_1_B
// clang-format on

#include <iostream>
#include <limits>

#line 2 "graph/shortest-path/bellman-ford.hpp"

#include <algorithm>
#line 5 "graph/shortest-path/bellman-ford.hpp"
#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 8 "graph/shortest-path/bellman-ford.hpp"

template <typename T>
std::vector<T> bellman_ford(const Edges<T>& edges, int n, int s) {
  const auto INF = std::numeric_limits<T>::max();
  const auto M_INF = std::numeric_limits<T>::min();
  std::vector<T> dist(n, INF);
  dist[s] = 0;
  for (int i = 0; i < n - 1; i++) {
    for (auto& e : edges) {
      if (dist[e.from] == INF) continue;
      dist[e.to] = std::min(dist[e.to], dist[e.from] + e.cost);
    }
  }
  std::vector<bool> negative(n);
  for (int i = 0; i < n; i++) {
    for (auto& e : edges) {
      if (dist[e.from] == INF) continue;
      if (dist[e.from] + e.cost < dist[e.to]) {
        dist[e.to] = dist[e.from] + e.cost;
        negative[e.to] = true;
      }
      if (negative[e.from]) {
        negative[e.to] = true;
      }
    }
  }
  for (int i = 0; i < n; i++) {
    if (negative[i]) dist[i] = M_INF;
  }
  return dist;
}
#line 9 "test/verify/aoj-grl-1-b.test.cpp"

using namespace std;

int main() {
  int V, E, R;
  cin >> V >> E >> R;
  Edges<> es;
  for (int i = 0; i < E; i++) {
    int a, b, c;
    cin >> a >> b >> c;
    es.emplace_back(a, b, c);
  }
  auto dists = bellman_ford(es, V, R);
  for (auto& dist : dists) {
    if (dist == numeric_limits<int>::min()) {
      cout << "NEGATIVE CYCLE\n";
      return 0;
    }
  }
  for (auto& dist : dists) {
    if (dist == numeric_limits<int>::max())
      cout << "INF\n";
    else
      cout << dist << "\n";
  }
}

Test cases

Env	Name	Status	Elapsed	Memory
g++	00_sample_00	AC	2 ms	4 MB
g++	00_sample_01	AC	2 ms	4 MB
g++	00_sample_02	AC	2 ms	4 MB
g++	01_small_00	AC	2 ms	4 MB
g++	01_small_01	AC	2 ms	4 MB
g++	02_corner_00	AC	2 ms	4 MB
g++	02_corner_01	AC	2 ms	4 MB
g++	02_corner_02	AC	2 ms	4 MB
g++	02_corner_03	AC	2 ms	4 MB
g++	02_corner_04	AC	2 ms	4 MB
g++	02_corner_05	AC	2 ms	4 MB
g++	02_corner_06	AC	2 ms	3 MB
g++	03_medium_00	AC	2 ms	4 MB
g++	03_medium_01	AC	2 ms	3 MB
g++	03_medium_02	AC	2 ms	4 MB
g++	03_medium_03	AC	2 ms	4 MB
g++	04_rand_00	AC	2 ms	3 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	3 ms	4 MB
g++	05_dag_00	AC	2 ms	3 MB
g++	05_dag_01	AC	2 ms	3 MB
g++	05_dag_02	AC	2 ms	4 MB
g++	05_dag_03	AC	2 ms	4 MB
g++	06_ring_00	AC	2 ms	4 MB
g++	06_ring_01	AC	2 ms	4 MB
g++	06_ring_02	AC	2 ms	3 MB
g++	06_ring_03	AC	2 ms	4 MB
g++	07_large_00	AC	2 ms	4 MB
g++	07_large_01	AC	3 ms	3 MB
g++	07_large_02	AC	2 ms	4 MB
g++	07_large_03	AC	2 ms	4 MB
g++	08_maximum_00	AC	4 ms	4 MB
g++	08_maximum_01	AC	9 ms	4 MB
g++	08_maximum_02	AC	7 ms	4 MB
g++	08_maximum_03	AC	10 ms	4 MB
clang++	00_sample_00	AC	2 ms	4 MB
clang++	00_sample_01	AC	2 ms	4 MB
clang++	00_sample_02	AC	2 ms	4 MB
clang++	01_small_00	AC	2 ms	4 MB
clang++	01_small_01	AC	2 ms	4 MB
clang++	02_corner_00	AC	2 ms	4 MB
clang++	02_corner_01	AC	2 ms	4 MB
clang++	02_corner_02	AC	2 ms	4 MB
clang++	02_corner_03	AC	2 ms	4 MB
clang++	02_corner_04	AC	2 ms	4 MB
clang++	02_corner_05	AC	2 ms	4 MB
clang++	02_corner_06	AC	2 ms	4 MB
clang++	03_medium_00	AC	2 ms	4 MB
clang++	03_medium_01	AC	2 ms	4 MB
clang++	03_medium_02	AC	2 ms	4 MB
clang++	03_medium_03	AC	2 ms	4 MB
clang++	04_rand_00	AC	2 ms	4 MB
clang++	04_rand_01	AC	2 ms	4 MB
clang++	04_rand_02	AC	2 ms	4 MB
clang++	04_rand_03	AC	2 ms	4 MB
clang++	04_rand_04	AC	2 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	3 ms	4 MB
clang++	05_dag_00	AC	2 ms	4 MB
clang++	05_dag_01	AC	2 ms	4 MB
clang++	05_dag_02	AC	2 ms	4 MB
clang++	05_dag_03	AC	2 ms	4 MB
clang++	06_ring_00	AC	2 ms	4 MB
clang++	06_ring_01	AC	2 ms	4 MB
clang++	06_ring_02	AC	2 ms	4 MB
clang++	06_ring_03	AC	2 ms	4 MB
clang++	07_large_00	AC	2 ms	4 MB
clang++	07_large_01	AC	3 ms	4 MB
clang++	07_large_02	AC	2 ms	4 MB
clang++	07_large_03	AC	2 ms	4 MB
clang++	08_maximum_00	AC	4 ms	4 MB
clang++	08_maximum_01	AC	9 ms	4 MB
clang++	08_maximum_02	AC	7 ms	4 MB
clang++	08_maximum_03	AC	10 ms	4 MB

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