void examine_edge(Edge e, Graph& g) {
// Comparison needs to be more complicated because distance and weight
// types may not be the same; see bug 8398
// (https://svn.boost.org/trac/boost/ticket/8398)
D source_dist = get(m_distance, source(e, g));
if (m_compare(m_combine(source_dist, get(m_weight, e)), source_dist))
boost::throw_exception(negative_edge());
m_vis.examine_edge(e, g);
}
inline void
astar_search_no_init_tree
(const VertexListGraph &g,
typename graph_traits<VertexListGraph>::vertex_descriptor s,
AStarHeuristic h, AStarVisitor vis,
PredecessorMap predecessor, CostMap cost,
DistanceMap distance, WeightMap weight,
CompareFunction compare, CombineFunction combine,
CostInf /*inf*/, CostZero zero)
{
typedef typename graph_traits<VertexListGraph>::vertex_descriptor
Vertex;
typedef typename property_traits<DistanceMap>::value_type Distance;
typedef d_ary_heap_indirect<
std::pair<Distance, Vertex>,
4,
null_property_map<std::pair<Distance, Vertex>, std::size_t>,
function_property_map<graph_detail::select1st<Distance, Vertex>, std::pair<Distance, Vertex> >,
CompareFunction>
MutableQueue;
MutableQueue Q(
make_function_property_map<std::pair<Distance, Vertex> >(graph_detail::select1st<Distance, Vertex>()),
null_property_map<std::pair<Distance, Vertex>, std::size_t>(),
compare);
vis.discover_vertex(s, g);
Q.push(std::make_pair(get(cost, s), s));
while (!Q.empty()) {
Vertex v;
Distance v_rank;
boost::tie(v_rank, v) = Q.top();
Q.pop();
vis.examine_vertex(v, g);
BGL_FORALL_OUTEDGES_T(v, e, g, VertexListGraph) {
Vertex w = target(e, g);
vis.examine_edge(e, g);
Distance e_weight = get(weight, e);
if (compare(e_weight, zero))
BOOST_THROW_EXCEPTION(negative_edge());
bool decreased =
relax(e, g, weight, predecessor, distance,
combine, compare);
Distance w_d = combine(get(distance, v), e_weight);
if (decreased) {
vis.edge_relaxed(e, g);
Distance w_rank = combine(get(distance, w), h(w));
put(cost, w, w_rank);
vis.discover_vertex(w, g);
Q.push(std::make_pair(w_rank, w));
} else {
vis.edge_not_relaxed(e, g);
}
}
vis.finish_vertex(v, g);
}
void dijkstra_shortest_paths_no_color_map_no_init
(const Graph& graph,
typename graph_traits<Graph>::vertex_descriptor start_vertex,
PredecessorMap predecessor_map,
DistanceMap distance_map,
WeightMap weight_map,
VertexIndexMap index_map,
DistanceCompare distance_compare,
DistanceWeightCombine distance_weight_combine,
DistanceInfinity distance_infinity,
DistanceZero distance_zero,
DijkstraVisitor visitor)
{
typedef typename graph_traits<Graph>::vertex_descriptor Vertex;
typedef typename property_traits<DistanceMap>::value_type Distance;
typedef indirect_cmp<DistanceMap, DistanceCompare> DistanceIndirectCompare;
DistanceIndirectCompare
distance_indirect_compare(distance_map, distance_compare);
// Choose vertex queue type
#if BOOST_GRAPH_DIJKSTRA_USE_RELAXED_HEAP
typedef relaxed_heap<Vertex, DistanceIndirectCompare, VertexIndexMap>
VertexQueue;
VertexQueue vertex_queue(num_vertices(graph),
distance_indirect_compare,
index_map);
#else
// Default - use d-ary heap (d = 4)
typedef
detail::vertex_property_map_generator<Graph, VertexIndexMap, std::size_t>
IndexInHeapMapHelper;
typedef typename IndexInHeapMapHelper::type IndexInHeapMap;
typedef
d_ary_heap_indirect<Vertex, 4, IndexInHeapMap, DistanceMap, DistanceCompare>
VertexQueue;
boost::scoped_array<std::size_t> index_in_heap_map_holder;
IndexInHeapMap index_in_heap =
IndexInHeapMapHelper::build(graph, index_map,
index_in_heap_map_holder);
VertexQueue vertex_queue(distance_map, index_in_heap, distance_compare);
#endif
// Add vertex to the queue
vertex_queue.push(start_vertex);
// Starting vertex will always be the first discovered vertex
visitor.discover_vertex(start_vertex, graph);
while (!vertex_queue.empty()) {
Vertex min_vertex = vertex_queue.top();
vertex_queue.pop();
visitor.examine_vertex(min_vertex, graph);
// Check if any other vertices can be reached
Distance min_vertex_distance = get(distance_map, min_vertex);
if (!distance_compare(min_vertex_distance, distance_infinity)) {
// This is the minimum vertex, so all other vertices are unreachable
return;
}
// Examine neighbors of min_vertex
BGL_FORALL_OUTEDGES_T(min_vertex, current_edge, graph, Graph) {
visitor.examine_edge(current_edge, graph);
// Check if the edge has a negative weight
if (distance_compare(get(weight_map, current_edge), distance_zero)) {
boost::throw_exception(negative_edge());
}
// Extract the neighboring vertex and get its distance
Vertex neighbor_vertex = target(current_edge, graph);
Distance neighbor_vertex_distance = get(distance_map, neighbor_vertex);
bool is_neighbor_undiscovered =
!distance_compare(neighbor_vertex_distance, distance_infinity);
// Attempt to relax the edge
bool was_edge_relaxed = relax(current_edge, graph, weight_map,
predecessor_map, distance_map,
distance_weight_combine, distance_compare);
if (was_edge_relaxed) {
visitor.edge_relaxed(current_edge, graph);
if (is_neighbor_undiscovered) {
visitor.discover_vertex(neighbor_vertex, graph);
vertex_queue.push(neighbor_vertex);
} else {
vertex_queue.update(neighbor_vertex);
}
} else {
visitor.edge_not_relaxed(current_edge, graph);
}
} // end out edge iteration
visitor.finish_vertex(min_vertex, graph);
} // end while queue not empty
void examine_edge(Edge e, Graph& g) {
if (m_compare(get(m_weight, e), m_zero))
throw negative_edge();
m_vis.examine_edge(e, g);
}
void examine_edge(Edge e, const Graph& g) {
if (m_compare(get(m_weight, e), m_zero))
BOOST_THROW_EXCEPTION(negative_edge());
m_vis.examine_edge(e, g);
}
void examine_edge(Edge e, Graph& g) {
if (m_compare(get(m_weight, e), m_zero))
boost::throw_exception(negative_edge());
m_vis.examine_edge(e, g);
}
