Cod sursa(job #2069170)

Utilizator KemyKoTeo Virghi KemyKo Data 18 noiembrie 2017 12:14:50
Problema Algoritmul Bellman-Ford Scor 55
Compilator cpp Status done
Runda Arhiva educationala Marime 1.27 kb
#include <fstream>
#include <vector>
#include <queue>
#include <stdlib.h>
#define NMAX 50001
#define INF 1000000000

using namespace std;

ifstream f("bellmanford.in");
ofstream g("bellmanford.out");

priority_queue< pair<int, int>, vector<pair<int, int> >, greater<pair<int, int> > >h;
vector< pair<int, int> >v[NMAX];
int d[NMAX],fv[NMAX];
int n, m;

int main()
{
    int i, a, b, c; //citire
    f>>n>>m;
    for (i=1; i<=m; i++)
    {
        f>>a>>b>>c;
        v[a].push_back(make_pair(c,b));
    }
    for(i=1; i<=n; i++)d[i]=INF;


    int nod;     //rez
    h.push(make_pair(0, 1));
    d[1]=0;
    while(!h.empty())
    {
        nod = h.top().second;
        h.pop();
        for(i=0; i<v[nod].size(); i++)
        {
            if(d[nod] + v[nod][i].first < d[v[nod][i].second])
            {
                d[v[nod][i].second] = d[nod] + v[nod][i].first;
                h.push(make_pair(d[v[nod][i].second], v[nod][i].second));
                fv[d[v[nod][i].second]]++;
                if(fv[d[v[nod][i].second]]>=n)
                {
                    g<<"Ciclu negativ!";
                    return 0;
                }
            }
        }
    }

    for(int i=2; i<=n; i++) //afis
        g<<d[i]<<' ';

    return 0;
}