Cod sursa(job #1251460)

Utilizator OctaDuiu Octavian Octa Data 29 octombrie 2014 15:43:50
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.78 kb
# include <fstream>
# include <vector>
# include <queue>
using namespace std;
ifstream f("bfs.in");
ofstream g("bfs.out");
vector <int> v[100005];
queue <int> q;
int i,n,m,S,k,x,y;
int NR[100010];
void BFS ()
{
    int i;
    for (i=1; i<=n; ++i)
        NR[i]=-1;
    NR[S]=0;
    q.push(S);
    while (! q.empty())
    {
        k=q.front(); q.pop ();
        for (i=0; i<v[k].size(); ++i)
        {
            if (NR[v[k][i]]==-1)
            {
                NR[v[k][i]]=NR[k]+1;
                q.push(v[k][i]);
            }
        }
    }
}
int main ()
{
    f>>n>>m>>S;
    for (i=2; i<=m; ++i)
    {
        f>>x>>y;
        v[x].push_back(y);
    }
    BFS ();
    for (i=1; i<=n; ++i)
        g<<NR[i]<<" ";
    g<<"\n";
    return 0;
}