Cod sursa(job #393046)

Utilizator PavelRazvanPavel Razvan PavelRazvan Data 8 februarie 2010 19:56:45
Problema Algoritmul Bellman-Ford Scor 15
Compilator cpp Status done
Runda Arhiva educationala Marime 1.39 kb
#include<algorithm>
using namespace std;
#include<vector>

#define DIM 50005
#define DIM2 250010

vector <pair <int,int> > lst[DIM];
vector <pair<int,pair<int,int> > > muc;
vector <int> c;

int n,a[DIM],m;
void read ()
{
    int i,x,y,c;
    scanf("%d%d",&n,&m);
    for(i=2;i<=n;++i)
        a[i]=1<<18;
    for(i=1;i<=m;++i)
    {
        scanf("%d%d%d",&x,&y,&c);
        muc.push_back (make_pair(x,make_pair(y,c)));
        lst[x].push_back (make_pair (y,c));
    }
}
int solve ()
{
    int i,aux;
    long long pas=1;
    c.push_back (1);
    while(!c.empty ())
    {
        aux=c.back ();
        for(i=0;i<lst[aux].size ();++i)
            if(a[aux]+lst[aux][i].second<a[lst[aux][i].first])
            {
                a[lst[aux][i].first]=a[aux]+lst[aux][i].second;
                c.push_back (lst[aux][i].first);
            }
        c.pop_back ();
        if(++pas>(long long)n*m)
            return 1;
    }
    for(i=0;i<muc.size ();++i)
        if(a[muc[i].first]+muc[i].second.second<a[muc[i].second.first])
            return 1;
    return 0;
}
void show ()
{
    int i,k=0;
    for(i=2;i<=n;++i)
        printf("%d ",a[i]);
}
int main ()
{
    freopen ("bellmanford.in","r",stdin);
    freopen ("bellmanford.out","w",stdout);
    read ();
    if(solve ())
        printf("Ciclu negativ!\n");
    else
        show ();
    return 0;
}