Esempio n. 1
0
void GraphAL::eraseEdge( size_t n1, size_t n2 ) {
    DAI_ASSERT( n1 < nrNodes() );
    DAI_ASSERT( n2 < nrNodes() );
    size_t iter;
    // Search for edge among neighbors of n1
    for( iter = 0; iter < nb(n1).size(); iter++ )
        if( nb(n1, iter).node == n2 ) {
            // Remove it
            nb(n1).erase( nb(n1).begin() + iter );
            break;
        }
    // Change the iter and dual values of the subsequent neighbors
    for( ; iter < nb(n1).size(); iter++ ) {
        Neighbor &m = nb( n1, iter );
        m.iter = iter;
        nb( m.node, m.dual ).dual = iter;
    }
    // Search for edge among neighbors of n2
    for( iter = 0; iter < nb(n2).size(); iter++ )
        if( nb(n2, iter).node == n1 ) {
            // Remove it
            nb(n2).erase( nb(n2).begin() + iter );
            break;
        }
    // Change the iter and node values of the subsequent neighbors
    for( ; iter < nb(n2).size(); iter++ ) {
        Neighbor &m = nb( n2, iter );
        m.iter = iter;
        nb( m.node, m.dual ).dual = iter;
    }
}
Esempio n. 2
0
void GraphAL::printDot( std::ostream& os ) const {
    os << "graph GraphAL {" << endl;
    os << "node[shape=circle,width=0.4,fixedsize=true];" << endl;
    for( size_t n = 0; n < nrNodes(); n++ )
        os << "\tx" << n << ";" << endl;
    for( size_t n1 = 0; n1 < nrNodes(); n1++ )
        foreach( const Neighbor &n2, nb(n1) )
            if( n1 < n2 )
                os << "\tx" << n1 << " -- x" << n2 << ";" << endl;
    os << "}" << endl;
}
Esempio n. 3
0
bool GraphAL::isConnected() const {
    if( nrNodes() == 0 ) {
        return true;
    } else {
        std::vector<bool> incomponent( nrNodes(), false );

        incomponent[0] = true;
        bool found_new_nodes;
        do {
            found_new_nodes = false;

            // For all nodes, check if they are connected with the (growing) component
            for( size_t n1 = 0; n1 < nrNodes(); n1++ )
                if( !incomponent[n1] ) {
                    foreach( const Neighbor &n2, nb(n1) ) {
                        if( incomponent[n2] ) {
                            found_new_nodes = true;
                            incomponent[n1] = true;
                            break;
                        }
                    }
                }
        } while( found_new_nodes );

        // Check if there are remaining nodes (not in the component)
        bool all_connected = true;
        for( size_t n1 = 0; (n1 < nrNodes()) && all_connected; n1++ )
            if( !incomponent[n1] )
                all_connected = false;

        return all_connected;

        // BGL implementation is slower...
    /*  using namespace boost;
        typedef adjacency_list< vecS, vecS, undirectedS, property<vertex_distance_t, int> > boostGraphAL;
        typedef pair<size_t, size_t> E;

        // Copy graph structure into boostGraphAL object
        vector<E> edges;
        edges.reserve( nrEdges() );
        for( size_t n1 = 0; n1 < nrNodes(); n1++ )
            foreach( const Neighbor &n2, nb(n1) )
                if( n1 < n2 )
                    edges.push_back( E( n1, n2 ) );
        boostGraphAL g( edges.begin(), edges.end(), nrNodes() );

        // Construct connected components using Boost GraphAL Library
        std::vector<int> component( num_vertices( g ) );
        int num_comp = connected_components( g, make_iterator_property_map(component.begin(), get(vertex_index, g)) );

        return (num_comp == 1);
    */
    }
}
Esempio n. 4
0
bool GraphAL::isTree() const {
    typedef vector<Edge> levelType; // first is node, second is its parent
    vector<levelType> levels;

    if( nrNodes() == 0 )
        return true;
    else {
        // start with root node 0
        levels.push_back( levelType( 1, Edge( 0, 0 ) ) );
        size_t treeSize = 1;
        bool foundCycle = false;
        do {
            levels.push_back( levelType() );
            const levelType &prevLevel = levels[levels.size() - 2];
            // build new level: add all neighbors of nodes in the previous level
            // (without backtracking), aborting if a cycle is detected
            for( size_t e = 0; e < prevLevel.size(); e++ ) {
                size_t n2 = prevLevel[e].first; // for all nodes n2 in the previous level
                foreach( const Neighbor &n1, nb(n2) ) { // for all neighbors n1 of n2
                    if( n1 != prevLevel[e].second ) { // no backtracking allowed
                        for( size_t l = 0; l < levels.size() && !foundCycle; l++ )
                            for( size_t f = 0; f < levels[l].size() && !foundCycle; f++ )
                                if( levels[l][f].first == n1 )
                                    // n1 has been visited before -> found a cycle
                                    foundCycle = true;
                        if( !foundCycle )
                            // add n1 (and its parent n2) to current level
                            levels.back().push_back( Edge( n1, n2 ) ); 
                    }
                    if( foundCycle )
                        break;
                }
                if( foundCycle )
                    break;
            }
            treeSize += levels.back().size();
        } while( (levels.back().size() != 0) && !foundCycle );
        if( treeSize == nrNodes() && !foundCycle )
            return true;
        else
            return false;
    }
}
Esempio n. 5
0
void GraphAL::eraseNode( size_t n ) {
    DAI_ASSERT( n < nrNodes() );
    // Erase neighbor entry of node n
    _nb.erase( _nb.begin() + n );
    // Adjust neighbor entries of nodes
    for( size_t n2 = 0; n2 < nrNodes(); n2++ ) {
        for( size_t iter = 0; iter < nb(n2).size(); ) {
            Neighbor &m = nb(n2, iter);
            if( m.node == n ) {
                // delete this entry, because it points to the deleted node
                nb(n2).erase( nb(n2).begin() + iter );
            } else {
                // update this entry and the corresponding dual of the neighboring node
                if( m.node > n ) 
                    m.node--;
                nb( m.node, m.dual ).dual = iter;
                m.iter = iter++;
            }
        }
    }
}
Esempio n. 6
0
void GraphAL::checkConsistency() const {
    size_t N = nrNodes();
    for( size_t n1 = 0; n1 < N; n1++ ) {
        size_t iter = 0;
        foreach( const Neighbor &n2, nb(n1) ) {
            DAI_ASSERT( n2.iter == iter );
            DAI_ASSERT( n2.node < N );
            DAI_ASSERT( n2.dual < nb(n2).size() );
            DAI_ASSERT( nb(n2, n2.dual) == n1 );
            iter++;
        }
    }
Esempio n. 7
0
unsigned
ConstraintTree::nrNodes (const CTNode* n) const
{
  unsigned nr = 0;
  if (n->isLeaf() == false) {
    for (CTChilds::const_iterator chIt = n->childs().begin();
         chIt != n->childs().end(); ++ chIt) {
      nr += nrNodes (*chIt);
    }
  }
  return nr;
}