C++ Visitor::on_enter_loop方法代码示例

void r_c_shortest_paths_dispatch
( const Graph& g, 
  const VertexIndexMap& vertex_index_map, 
  const EdgeIndexMap& /*edge_index_map*/, 
  typename graph_traits<Graph>::vertex_descriptor s, 
  typename graph_traits<Graph>::vertex_descriptor t, 
  // each inner vector corresponds to a pareto-optimal path
  std::vector
    <std::vector
      <typename graph_traits
        <Graph>::edge_descriptor> >& pareto_optimal_solutions, 
  std::vector
    <Resource_Container>& pareto_optimal_resource_containers, 
  bool b_all_pareto_optimal_solutions, 
  // to initialize the first label/resource container 
  // and to carry the type information
  const Resource_Container& rc, 
  Resource_Extension_Function& ref, 
  Dominance_Function& dominance, 
  // to specify the memory management strategy for the labels
  Label_Allocator /*la*/, 
  Visitor vis )
{
  pareto_optimal_resource_containers.clear();
  pareto_optimal_solutions.clear();

  unsigned long i_label_num = 0;
  typedef 
    typename 
      Label_Allocator::template rebind
        <r_c_shortest_paths_label
          <Graph, Resource_Container> >::other LAlloc;
  LAlloc l_alloc;
  typedef 
    ks_smart_pointer
      <r_c_shortest_paths_label<Graph, Resource_Container> > Splabel;
  std::priority_queue<Splabel, std::vector<Splabel>, std::greater<Splabel> > 
    unprocessed_labels;

  bool b_feasible = true;
  r_c_shortest_paths_label<Graph, Resource_Container>* first_label = 
    l_alloc.allocate( 1 );
  l_alloc.construct
    ( first_label, 
      r_c_shortest_paths_label
        <Graph, Resource_Container>( i_label_num++, 
                                     rc, 
                                     0, 
                                     typename graph_traits<Graph>::
                                       edge_descriptor(), 
                                     s ) );

  Splabel splabel_first_label = Splabel( first_label );
  unprocessed_labels.push( splabel_first_label );
  std::vector<std::list<Splabel> > vec_vertex_labels( num_vertices( g ) );
  vec_vertex_labels[vertex_index_map[s]].push_back( splabel_first_label );
  std::vector<typename std::list<Splabel>::iterator> 
    vec_last_valid_positions_for_dominance( num_vertices( g ) );
  for( int i = 0; i < static_cast<int>( num_vertices( g ) ); ++i )
    vec_last_valid_positions_for_dominance[i] = vec_vertex_labels[i].begin();
  std::vector<int> vec_last_valid_index_for_dominance( num_vertices( g ), 0 );
  std::vector<bool> 
    b_vec_vertex_already_checked_for_dominance( num_vertices( g ), false );
  while( !unprocessed_labels.empty()  && vis.on_enter_loop(unprocessed_labels, g) )
  {
    Splabel cur_label = unprocessed_labels.top();
    unprocessed_labels.pop();
    vis.on_label_popped( *cur_label, g );
    // an Splabel object in unprocessed_labels and the respective Splabel 
    // object in the respective list<Splabel> of vec_vertex_labels share their 
    // embedded r_c_shortest_paths_label object
    // to avoid memory leaks, dominated 
    // r_c_shortest_paths_label objects are marked and deleted when popped 
    // from unprocessed_labels, as they can no longer be deleted at the end of 
    // the function; only the Splabel object in unprocessed_labels still 
    // references the r_c_shortest_paths_label object
    // this is also for efficiency, because the else branch is executed only 
    // if there is a chance that extending the 
    // label leads to new undominated labels, which in turn is possible only 
    // if the label to be extended is undominated
    if( !cur_label->b_is_dominated )
    {
      int i_cur_resident_vertex_num = cur_label->resident_vertex;
      std::list<Splabel>& list_labels_cur_vertex = 
        vec_vertex_labels[i_cur_resident_vertex_num];
      if( static_cast<int>( list_labels_cur_vertex.size() ) >= 2 
          && vec_last_valid_index_for_dominance[i_cur_resident_vertex_num] 
               < static_cast<int>( list_labels_cur_vertex.size() ) )
      {
        typename std::list<Splabel>::iterator outer_iter = 
          list_labels_cur_vertex.begin();
        bool b_outer_iter_at_or_beyond_last_valid_pos_for_dominance = false;
        while( outer_iter != list_labels_cur_vertex.end() )
        {
          Splabel cur_outer_splabel = *outer_iter;
          typename std::list<Splabel>::iterator inner_iter = outer_iter;
          if( !b_outer_iter_at_or_beyond_last_valid_pos_for_dominance 
              && outer_iter == 
                   vec_last_valid_positions_for_dominance
                     [i_cur_resident_vertex_num] )
//.........这里部分代码省略.........