Cod sursa(job #1191160)

Utilizator pop_bogdanBogdan Pop pop_bogdan Data 26 mai 2014 18:52:43
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.08 kb

#include <fstream>
#include <vector>
#include <queue>
using namespace std;

ifstream is("bfs.in");
ofstream os("bfs.out");

int N, M, S;
int x, y;
vector <int> V[100001];
queue <int> Q;
bool Vis[100001];
int Res[100001];

int main()
{
    is >> N >> M >> S;
    for ( int i = 1; i <= M; ++i )
    {
        is >> x >> y;
        if ( x != y)
            V[x].push_back(y);
    }

    Q.push(S), Vis[S] = true, Res[S] = 0;
    int Nod, it(0);

    while ( !Q.empty() )
    {
        Nod = Q.front();
        for ( int i = 0; i < V[Nod].size(); ++i )
        {
            if ( Vis[V[Nod][i]] == false )
            {
                Q.push(V[Nod][i]);
                Res[V[Nod][i]] = Res[Nod]+1;
                Vis[V[Nod][i]] = true;
            }
        }
        Q.pop();
    }

    for ( int i = 1; i <= N; ++i )
    {
        if ( Res[i] != 0)
            os << Res[i] << " ";
        if ( i == S )
            os << 0 << " ";
        if ( Res[i] == 0 && i != S )
            os << Res[i]-1 << " ";
    }

    is.close();
    os.close();
}