Cod sursa(job #2196100)

Utilizator MikeStrikeAgache Mihai MikeStrike Data 18 aprilie 2018 14:06:22
Problema Algoritmul Bellman-Ford Scor 35
Compilator cpp Status done
Runda Arhiva educationala Marime 1.37 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#define INF 0x3f3f3f3f
using namespace std;
ifstream in("bellmanford.in");
ofstream out("bellmanford.out");
int n,m;
vector< pair<int, int> >graf[50005];
vector <int> v;
queue <int> coada;
int d[50005];
int viz[50005];
int esteincoada[50005];
bool bellmanford(int nodS)
{
    for(int i=1;i<=n;i++)
    {
        viz[i]=0;
        esteincoada[i]=0;
        d[i]=INF;
    }
    d[nodS]=0;
    coada.push(nodS);
    esteincoada[nodS]=1;
    while(!coada.empty())
    {
        int nod=coada.front();
        viz[nod]++;
        if(viz[nod]>=n) return false;
        coada.pop();
         esteincoada[nod] = 0;
       for(vector<pair<int,int> >::iterator ii = graf[nod].begin();ii!=graf[nod].end();ii++)
         {
              int vecin=ii->first;
            int cost=ii->second;
            if(d[nod]+cost<d[vecin])
            {
                d[vecin]=d[nod]+cost;
                if(!esteincoada[vecin])
                    coada.push(vecin);
            }
         }
    }
    return true;
}
int main()
{in>>n>>m;
for(int i=1;i<=m;i++)
{
    int x,y,c;
    in>>x>>y>>c;
    graf[x].push_back(make_pair(y,c));
}
  if(bellmanford(1))
    {
        for(int i=2;i<=n;i++)
            out<<d[i]<<" ";
    }
    else
      out<<"Ciclu negativ";



    return 0;
}