Cod sursa(job #1358947)

Utilizator rogoz.bogdanRogoz Bogdan rogoz.bogdan Data 24 februarie 2015 20:41:39
Problema Algoritmul Bellman-Ford Scor 65
Compilator cpp Status done
Runda Arhiva educationala Marime 1.38 kb
#include <fstream>
#include <vector>
#define NX 50001
#define MX 250001
using namespace std;

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

struct muchie
{
    int i,j,c;
};
vector<muchie> v;
int n,m;
int d[NX];
bool demodif[NX];

void citire()
{
    int i;
    muchie e;
    fin>>n>>m;

    for(i=1; i<=m; i++)
    {
        fin>>e.i>>e.j>>e.c;
        v.push_back(e);
    }
}

int main()
{
    int i;
    bool ok=1;
    bool modif1=1;
    muchie u;
    vector<muchie>::iterator it;
    citire();

    for(i=2; i<=n; i++) d[i] = (1<<30);

    demodif[1] = 1;

    for(i=1; i<n && modif1; i++)
    {
        modif1 = 0;
        for(it=v.begin(); it!=v.end(); it++)
        {
            u = *it;
            if(!demodif[u.i]) continue;

            if(d[u.i] + u.c < d[u.j])
            {
                d[u.j] = d[u.i] + u.c;
                demodif[u.j] = 1;
                modif1 = 1;
            }
        }
    }

    for(it=v.begin(); it!=v.end(); it++)
    {
        u = *it;
        if(d[u.i] + u.c < d[u.j])
        {
            ok = 0;
            break;
        }
    }

    if(!ok)
    {
        fout<<"Ciclu negativ!\n";
    }
    else
    {
        for(i=2; i<=n; i++)
        {
            fout<<d[i]<<' ';
        }
    }

    //v.clear();

    fin.close(); fout.close();
    return 0;
}