Cod sursa(job #1819401)

Utilizator Tiberiu02Tiberiu Musat Tiberiu02 Data 30 noiembrie 2016 16:23:22
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.02 kb
# include <fstream>
# include <queue>
# include <vector>

using namespace std;

struct path
{
    int dist, dest;

    path( int _dest, int _dist )
    {
        dest = _dest;
        dist = _dist;
    }
};

# define MAX_N 100000
int dist[1 + MAX_N];
queue<path> bfs;
vector<int> v[1 + MAX_N];

# define undefined -1

int main()
{
    ifstream fin( "bfs.in" );
    ofstream fout( "bfs.out" );

    ios::sync_with_stdio( false );

    int n, m, s, i, a, b;

    fin >> n >> m >> s;

    for ( i = 0; i < m; i ++ ) {
        fin >> a >> b;
        v[a].push_back( b );
    }

    for ( i = 1; i <= n; i ++ )
        dist[i] = undefined;

    bfs.push( path( s, 0 ) );

    while ( bfs.size() ) {
        path t = bfs.front();
        bfs.pop();

        if ( dist[t.dest] == undefined ) {
            dist[t.dest] = t.dist;

            for ( int i : v[t.dest] )
                bfs.push( path( i, t.dist + 1 ) );
        }
    }

    for ( i = 1; i <= n; i ++ )
        fout << dist[i] << ' ';

    fin.close();
    fout.close();

    return 0;
}