Cod sursa(job #1604778)

Utilizator pinteastefanPintea Teodor Stefan pinteastefan Data 18 februarie 2016 16:23:24
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.82 kb
#include <fstream>
#include <vector>

using namespace std;
ifstream f("bfs.in");
ofstream g("bfs.out");
vector <int> L[100001];
vector <int> :: iterator it;
int n,i,x,y,m,T[100001],Lg[100001],Q[100001],p,u,s;
bool sel[100001];
void load()
{
    f>>n>>m>>s;
    for(i=1;i<=m;i++)
    {
        f>>x>>y;
        L[x].push_back(y);
    }
}
void df(int x)
{
    sel[x]=true;
    T[x]=Lg[x]=0;
    Q[1]=x;p=u=1;
    while(p<=u)
    {
        x=Q[p];
            for(it=L[x].begin () ; it!=L[x].end () ; it++)
                if(!sel[*it])
            {
                Q[++u]=*it; sel[*it]=true;
                T[*it]=x; Lg[*it]=Lg[x]+1;
            }
    p++;
    }
}
int main()
{
    load();
    df(s);
    for(i=1;i<=n;i++) if(i!=s && Lg[i]==0) g<<-1<<" ";
    else g<<Lg[i]<<" ";
    return 0;
}