test/aoj/GRL/GRL_1_B.test.cpp

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Last update: 2023-11-11 17:58:53+09:00
Problem: https://onlinejudge.u-aizu.ac.jp/problems/GRL_1_B

Depends on

Code

#define PROBLEM "https://onlinejudge.u-aizu.ac.jp/problems/GRL_1_B"

#include "../../../template/template.hpp"

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

int main(){
  cin.tie(nullptr);
  ios::sync_with_stdio(false);
  int n,m,r;
  cin >> n >> m >> r;
  graph root(n);
  rep(i, m){
    int a,b,c;
    cin >> a >> b >> c;
    root[a].push_back({ a, b, c });
  }
  BellmanFord<int,min> bf(root);
  bf.solve(r);
  rep(i, n) if(bf.is_cycle(i)){
    cout << "NEGATIVE CYCLE\n";
    return 0;
  }
  rep(i, n){
    if(bf[i] > (int)1e9) cout << "INF\n";
    else cout << bf[i] << "\n";
  }
}

#line 1 "test/aoj/GRL/GRL_1_B.test.cpp"
#define PROBLEM "https://onlinejudge.u-aizu.ac.jp/problems/GRL_1_B"

#line 1 "template/template.hpp"
#include <iostream>
#include <cmath>
#include <string>
#include <vector>
#include <algorithm>
#include <tuple>
#include <cstdint>
#include <cstdio>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <deque>
#include <bitset>
#include <cctype>
#include <climits>
#include <functional>
#include <cassert>
#include <numeric>
#include <cstring>
#define rep(i, n) for(int i = 0; i < (n); i++)
#define per(i, n) for(int i = (n) - 1; i >= 0; i--)
using ll = long long;
#define vi vector<int>
#define vvi vector<vi>
#define vl vector<ll>
#define pii pair<int, int>
#define pll pair<ll, ll>
#define all(a) (a).begin(), (a).end()
#define rall(a) (a).rbegin(), (a).rend()
constexpr int mod = 1000000007;
using namespace std;
template<class T, class U>
bool chmax(T &a, const U &b){ return a < b ? (a = b, 1) : 0; }
template<class T, class U>
bool chmin(T &a, const U &b){ return a > b ? (a = b, 1) : 0; }
#line 4 "test/aoj/GRL/GRL_1_B.test.cpp"

#line 2 "graph/template.hpp"

/**
 * @brief Graph Template
*/
template <class T>
struct Edge {
  int from,to;
  T cost;
  int idx;
  Edge(){};
  Edge(int f, int t, T c=1, int i=-1) : from(f), to(t), cost(c), idx(i){}
  Edge(int t) : to(t), from(-1), cost(1), idx(-1){}
  operator int() const{ return to; }
  bool operator<(const Edge &e){ return cost < e.cost; }
};
template <class T>
struct Graph : vector<vector<Edge<T>>> {
  Graph(){}
  Graph(const int &n) : vector<vector<Edge<T>>>(n){}
  void add_edge(int a, int b, T c=1, int i=-1){
    (*this)[a].push_back({ a, b, c, i });
  }
};
using graph = Graph<int>;
#line 2 "graph/bellman-ford.hpp"

template <class T, const T&(*op)(const T&, const T&)>
struct BellmanFord {
  BellmanFord(const Graph<T> &r): root(r), n(r.size()){
    inf = -op(inf, -inf);
    res.assign(n, inf);
  }
  void solve(const int s){
    assert(0 <= s && s < n);
    res[s] = 0;
    for(int i = 1; i < n; i++) for(int j = 0; j < n; j++){
      if(res[j] != inf) for(const auto &x : root[j]){
        res[x] = op(res[x], res[j] + x.cost);
      }
    }
    vector<int> loop(n);
    for(int i = 0; i < n; i++) for(int j = 0; j < n; j++){
      if(res[j] != inf) for(const auto &x : root[j]){
        if(op(res[x] + op(1,-1), res[j] + x.cost) == res[j] + x.cost){
          res[x] = res[j] + x.cost;
          loop[x] = 1;
        }
        if(loop[j]) loop[x] = 1;
      }
    }
    for(int i = 0; i < n; i++) if(loop[i]) res[i] = -inf;
  }
  const T &operator[](const int i) const{
    assert(0 <= i && i < n);
    return res[i];
  }
  bool is_cycle(const int i) const{
    assert(0 <= i && i < n);
    return res[i] == -inf;
  }
  private:
  const Graph<T> &root;
  vector<T> res;
  int n;
  T inf = numeric_limits<T>::max()-1;
};
#line 7 "test/aoj/GRL/GRL_1_B.test.cpp"

int main(){
  cin.tie(nullptr);
  ios::sync_with_stdio(false);
  int n,m,r;
  cin >> n >> m >> r;
  graph root(n);
  rep(i, m){
    int a,b,c;
    cin >> a >> b >> c;
    root[a].push_back({ a, b, c });
  }
  BellmanFord<int,min> bf(root);
  bf.solve(r);
  rep(i, n) if(bf.is_cycle(i)){
    cout << "NEGATIVE CYCLE\n";
    return 0;
  }
  rep(i, n){
    if(bf[i] > (int)1e9) cout << "INF\n";
    else cout << bf[i] << "\n";
  }
}