Cod sursa(job #2427559)

Utilizator PrekzursilAndrei Visalon Prekzursil Data 31 mai 2019 23:29:17
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.4 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 s)
{
    for(int i=1;i<=n;i++)
    {
        viz[i]=0;
        esteincoada[i]=0;
        d[i]=INF;
    }
    d[s] = 0;
    coada.push(s);
    esteincoada[s] = 1;
    while(!coada.empty())
    {
        int nodcurent = coada.front();
        viz[nodcurent]++;
        if(viz[nodcurent] >= n)
            return false;
        coada.pop();
        esteincoada[nodcurent] = 0;
        for(size_t i=0;i<graf[nodcurent].size();i++)
        {
            int vecin = graf[nodcurent][i].first;
            int cost = graf[nodcurent][i].second;
            if(d[nodcurent]+cost < d[vecin])
            {
                d[vecin] = d[nodcurent]+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;
}