Cod sursa(job #1486259)

Utilizator gedicaAlpaca Gedit gedica Data 14 septembrie 2015 14:53:46
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.95 kb
#include <algorithm>
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

const int NMAX= 100000;

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

vector <int> g[NMAX+1];
queue <int> q;
int v[NMAX+1];

void init(int N)
{
    for( int i= 1; i<=N; ++i)
    {
        v[i]= -1;
    }
}

int main(  )
{
    int N, M, S;
    in >> N >> M >> S;
    for( int i= 1; i<=M; ++i )
    {
        int x, y;
        in >> x >> y;
        g[x].push_back(y);
    }
    q.push(S);
    init( N );
    v[S]= 0;
    while( q.empty()==0 )
    {
        int a= q.front();
        q.pop();
        for( int i=0; i<(int)g[a].size(); ++i )
        {
            int b= g[a][i];
            if( v[b]==-1 )
            {
                v[b]= v[a]+1;
                q.push(b);
            }
        }
    }
    for( int i= 1; i<=N; ++i )
    {
        out << v[i] << ' ';
    }
    out << '\n';

    return 0;
}