Submission #1280266

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Source Code Expand

#include <bits/stdc++.h>
using namespace std;

using VI = vector<int>;
using VVI = vector<VI>;
using PII = pair<int, int>;
using LL = long long;
using VL = vector<LL>;
using VVL = vector<VL>;
using PLL = pair<LL, LL>;
using VS = vector<string>;

#define ALL(a)  begin((a)),end((a))
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define EB emplace_back
#define MP make_pair
#define SZ(a) int((a).size())
#define SORT(c) sort(ALL((c)))
#define RSORT(c) sort(RALL((c)))
#define UNIQ(c) (c).erase(unique(ALL((c))), end((c)))

#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)

#define FF first
#define SS second
template<class S, class T>
istream& operator>>(istream& is, pair<S,T>& p){
  return is >> p.FF >> p.SS;
}
template<class S, class T>
ostream& operator<<(ostream& os, const pair<S,T>& p){
  return os << p.FF << " " << p.SS;
}
template<class T>
void maxi(T& x, T y){
  if(x < y) x = y;
}
template<class T>
void mini(T& x, T y){
  if(x > y) x = y;
}


const double EPS = 1e-10;
const double PI  = acos(-1.0);
const LL MOD = 1e9+7;
const LL INF = 1e18;

int main(){
  LL N, M;
  cin >> N >> M;
  vector<vector<PLL>> G(N);
  REP(i,M){
	LL a, b, c;
	cin >> a >> b >> c;
	--a;
	--b;
	G[a].EB(b, c);
  }

  VL dist(N, -INF);
  dist[0] = 0;
  REP(i,N+1){
	REP(j,N){
	  for(PLL& e: G[j]){
		maxi(dist[e.FF], dist[j] + e.SS);
	  }
	}
  }

  VL dist2 = dist;
  REP(i,N*2+1){
	REP(j,N){
	  for(PLL& e: G[j]){
		maxi(dist2[e.FF], dist2[j] + e.SS);
	  }
	}
  }
  if(dist[N-1] < dist2[N-1])
	cout << "inf" << endl;
  else
	cout << dist[N-1] << endl;
  
  return 0;
}

Submission Info

Judge Result