Cod sursa(job #2268436)

Utilizator Ioana_AndreeaCristescu Ioana Ioana_Andreea Data 24 octombrie 2018 20:09:26
Problema Algoritmul Bellman-Ford Scor 35
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.07 kb
#include <fstream>
#include <vector>
#include <queue>
using namespace std;

ifstream fin("bellmanford.in");
ofstream fout("bellmanford.out");

const int NMax = 50000;
const int oo = 1000000000;
int N,M,D[NMax+5];
vector < pair <int, int> > G[NMax+5];
queue <int> Q;

void Read()
{
  fin>>N>>M;
  for(int i = 1; i <= M ; ++i)
    {
      int x,y,c;
      fin>>x>>y>>c;
      G[x].push_back(make_pair(y,c));
    }
}

int BellmanFord()
{
    for(int i = 2; i <= N; ++i)
        D[i] = oo;
    Q.push(1);
    while(!Q.empty())
    {
        int Nod = Q.front(); Q.pop();
        for(auto i : G[Nod])
        {
            int Vecin = i.first, Cost = i.second;
            if(D[Vecin] > D[Nod] + Cost)
            {
                D[Vecin] = D[Nod] + Cost;
                Q.push(Vecin);
            }
        }
    }
    return 0;
}

void Print()
{
  for(int i = 2; i <= N ; ++i)
    fout<<D[i]<<" ";
  fout<<"\n";
}

int main()
{
    Read();
    if(BellmanFord()==-1)
      fout<<"Ciclu negativ!\n";
    else
      Print();
    return 0;
}