Cod sursa(job #1247456)

Utilizator DanyPrvPirvoaica Daniel DanyPrv Data 22 octombrie 2014 20:55:47
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.18 kb
#include <fstream>
#include <vector>
#include <limits.h>
using namespace std;
ifstream f("bellmanford.in");
ofstream g("bellmanford.out");
vector <pair<int, int> >a[50001];
int m,n,x,y,z,p,u,q[500001],nre[50001],c[50001],i,nrap[50001];
bool viz[50001];
int main()
{
    f>>n>>m;
    for(int i=1;i<=m;i++){
        f>>x>>y>>z;
        a[x].push_back(make_pair(y,z));
        nre[x]++;
    }
    for(i=2;i<=n;i++)
        c[i]=INT_MAX;
    p=u=q[1]=viz[1]=1;

    while(p<=u){
       // viz[q[p]]=1;
        for(i=0;i<nre[q[p]];i++){
                if(a[q[p]][i].second+c[q[p]]<c[a[q[p]][i].first]){
                    nrap[q[p]]++;
                    if(viz[a[q[p]][i].first]==0){
                        viz[a[q[p]][i].first]=1;
                        q[++u]=a[q[p]][i].first;
                    }
                    c[a[q[p]][i].first]=a[q[p]][i].second+c[q[p]];
                }

        }
        if(nrap[q[p]]>=n){
            g<<"Ciclu negativ!";
            return 0;
        }
        viz[q[p]]=0;
        p++;
    }
    for(i=2;i<=n;i++)
        if(c[i]==INT_MAX)
            g<<0<<' ';
        else
            g<<c[i]<<' ';
    return 0;
}