Cod sursa(job #523218)

Utilizator BitOneSAlexandru BitOne Data 17 ianuarie 2011 14:56:27
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.96 kb
/* 
 * File:   main.cpp
 * Author: salexandru
 *
 * Created on January 17, 2011, 2:47 PM
 */
#include <queue>
#include <vector>
#include <fstream>
#include <cstdlib>
#include <iterator>
#include <algorithm>
#define N_MAX 100011

using namespace std;

/*
 * 
 */
int d[N_MAX];
queue< int > Q;
vector< int > G[N_MAX];
vector< int >::const_iterator it, iend;
int main(int argc, char** argv)
{
    int N, M, start, x, y;
    ifstream in( "bfs.in" );
    for( in>>N>>M>>start; M; --M )
    {
        in>>x>>y;
        G[x].push_back(y);
    }
    for( x=1; x <= N; ++x )
        d[x]=-1;
    d[start]=0;
    for( Q.push(start); !Q.empty(); )
    {
        x=Q.front(); Q.pop();
        for( it=G[x].begin(), iend=G[x].end(); it < iend; ++it )
            if( -1 == d[*it] )
            {
                d[*it]=d[x]+1;
                Q.push(*it);
            }
    }
    ofstream out( "bfs.out" );
    copy( d+1, d+N+1, ostream_iterator<int>( out, " ") );
    out<<'\n';
    return 0;
}