Cod sursa(job #899532)

Utilizator deea101Andreea deea101 Data 28 februarie 2013 15:04:59
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.06 kb
#include <fstream>
#include <vector>
#include <list>
#define INF (1<<30)-1
#define nmax 50001
using namespace std;
ifstream f("bellmanford.in");
ofstream g("bellmanford.out");
vector < pair <int, int> > v[nmax];
list <int> coada;
int n,d[nmax],k,use[nmax],cnt[nmax];
int main()
{
    f>>n;
    int i,j,m,x,y,c,nod;
    f>>m;
    for(i=0;i<m;i++)
    {
        f>>x>>y>>c;
        v[x].push_back(make_pair(y,c));
    }
    for(i=2;i<=n;i++) d[i]=INF;
    coada.push_back(1);
    d[1]=0;
    while(!coada.empty())
    {
        nod=coada.front();
        cnt[nod]++;
        for(i=0;i<v[nod].size();i++)
        {
            x=v[nod][i].first;
            y=v[nod][i].second;
            if(d[x]>d[nod]+y)
            {
                d[x]=d[nod]+y;
                if(!use[x]) {coada.push_back(x); use[x]=1;}
            }
        }
        coada.pop_front();
        use[nod]=0;
        if(cnt[nod]==n) {k=-1; break;}
    }

    if(k==-1) g<<"Ciclu negativ!";
    else
    {
        for(i=2;i<=n;i++)
            g<<d[i]<<' ';
    }
}