Cod sursa(job #886004)

Utilizator ard_procesoareLupicu ard_procesoare Data 22 februarie 2013 16:39:15
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.51 kb
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream fin("bellmanford.in");
ofstream fout("bellmanford.out");
#define NMAX 50005
vector <int> v[NMAX],cost[NMAX];
queue <int> qnod,qval;
int n,m,nr[NMAX],drum[NMAX];
bool viz[NMAX],ever[NMAX];
void read()
{
    int a,b,c;
    fin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        fin>>a>>b>>c;
        v[a].push_back(b);
        cost[a].push_back(c);
    }
}
bool bfs()
{
    int nod,val;
    qnod.push(1);
    while(!qnod.empty())
    {
        nod=qnod.front();
        qnod.pop();
        viz[nod]=false;
        ever[nod]=true;
        for(int i=0;i<v[nod].size();i++)
        {
            if(drum[nod]+cost[nod][i] < drum[v[nod][i]] || ever[v[nod][i]]==false)
            {
                ever[v[nod][i]]=true;
                drum[v[nod][i]] = drum[nod]+cost[nod][i];
                nr[v[nod][i]]++;
                if(nr[v[nod][i]]>n)
                    return 1;
                if(viz[v[nod][i]] == false)
                    qnod.push(v[nod][i]);
                viz[v[nod][i]] = true;
            }
        }
    }
    return 0;
}
void tipar()
{
    for(int i=1;i<=m;i++)
    {
        for(int j=0;j<v[i].size();j++)
        {
            fout<<i<<" "<<v[i][j]<<" "<<cost[i][j]<<endl;
        }
    }
}
int main()
{
    read();
  //  tipar();
    if(bfs()==1)
    {
        fout<<"Ciclu negativ!";
        return 0;
    }
    for(int i=2;i<=n;i++)
        fout<<drum[i]<<" ";

}