boost/graph/dijkstra_shortest_paths.hpp
//=======================================================================
// Copyright 1997, 1998, 1999, 2000 University of Notre Dame.
// Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek
//
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//=======================================================================
//
//
// Revision History:
// 04 April 2001: Added named parameter variant. (Jeremy Siek)
// 01 April 2001: Modified to use new <boost/limits.hpp> header. (JMaddock)
//
#ifndef BOOST_GRAPH_DIJKSTRA_HPP
#define BOOST_GRAPH_DIJKSTRA_HPP
#include <functional>
#include <boost/limits.hpp>
#include <boost/graph/named_function_params.hpp>
#include <boost/graph/breadth_first_search.hpp>
#include <boost/graph/relax.hpp>
#include <boost/pending/indirect_cmp.hpp>
#include <boost/graph/exception.hpp>
#include <boost/pending/relaxed_heap.hpp>
#include <boost/graph/overloading.hpp>
#include <boost/smart_ptr.hpp>
#include <boost/graph/detail/d_ary_heap.hpp>
#include <boost/graph/two_bit_color_map.hpp>
#include <boost/property_map/property_map.hpp>
#include <boost/property_map/vector_property_map.hpp>
#include <boost/type_traits.hpp>
#include <boost/concept/assert.hpp>
#ifdef BOOST_GRAPH_DIJKSTRA_TESTING
# include <boost/pending/mutable_queue.hpp>
#endif // BOOST_GRAPH_DIJKSTRA_TESTING
namespace boost {
/**
* @brief Updates a particular value in a queue used by Dijkstra's
* algorithm.
*
* This routine is called by Dijkstra's algorithm after it has
* decreased the distance from the source vertex to the given @p
* vertex. By default, this routine will just call @c
* Q.update(vertex). However, other queues may provide more
* specialized versions of this routine.
*
* @param Q the queue that will be updated.
* @param vertex the vertex whose distance has been updated
* @param old_distance the previous distance to @p vertex
*/
template<typename Buffer, typename Vertex, typename DistanceType>
inline void
dijkstra_queue_update(Buffer& Q, Vertex vertex, DistanceType old_distance)
{
(void)old_distance;
Q.update(vertex);
}
#ifdef BOOST_GRAPH_DIJKSTRA_TESTING
// This is a misnomer now: it now just refers to the "default heap", which is
// currently d-ary (d=4) but can be changed by a #define.
static bool dijkstra_relaxed_heap = true;
#endif
template <class Visitor, class Graph>
struct DijkstraVisitorConcept {
void constraints() {
BOOST_CONCEPT_ASSERT(( CopyConstructibleConcept<Visitor> ));
vis.initialize_vertex(u, g);
vis.discover_vertex(u, g);
vis.examine_vertex(u, g);
vis.examine_edge(e, g);
vis.edge_relaxed(e, g);
vis.edge_not_relaxed(e, g);
vis.finish_vertex(u, g);
}
Visitor vis;
Graph g;
typename graph_traits<Graph>::vertex_descriptor u;
typename graph_traits<Graph>::edge_descriptor e;
};
template <class Visitors = null_visitor>
class dijkstra_visitor : public bfs_visitor<Visitors> {
public:
dijkstra_visitor() { }
dijkstra_visitor(Visitors vis)
: bfs_visitor<Visitors>(vis) { }
template <class Edge, class Graph>
void edge_relaxed(Edge e, Graph& g) {
invoke_visitors(this->m_vis, e, g, on_edge_relaxed());
}
template <class Edge, class Graph>
void edge_not_relaxed(Edge e, Graph& g) {
invoke_visitors(this->m_vis, e, g, on_edge_not_relaxed());
}
private:
template <class Edge, class Graph>
void tree_edge(Edge u, Graph& g) { }
};
template <class Visitors>
dijkstra_visitor<Visitors>
make_dijkstra_visitor(Visitors vis) {
return dijkstra_visitor<Visitors>(vis);
}
typedef dijkstra_visitor<> default_dijkstra_visitor;
namespace detail {
template <class UniformCostVisitor, class UpdatableQueue,
class WeightMap, class PredecessorMap, class DistanceMap,
class BinaryFunction, class BinaryPredicate>
struct dijkstra_bfs_visitor
{
typedef typename property_traits<DistanceMap>::value_type D;
dijkstra_bfs_visitor(UniformCostVisitor vis, UpdatableQueue& Q,
WeightMap w, PredecessorMap p, DistanceMap d,
BinaryFunction combine, BinaryPredicate compare,
D zero)
: m_vis(vis), m_Q(Q), m_weight(w), m_predecessor(p), m_distance(d),
m_combine(combine), m_compare(compare), m_zero(zero) { }
template <class Edge, class Graph>
void tree_edge(Edge e, Graph& g) {
bool decreased = relax(e, g, m_weight, m_predecessor, m_distance,
m_combine, m_compare);
if (decreased)
m_vis.edge_relaxed(e, g);
else
m_vis.edge_not_relaxed(e, g);
}
template <class Edge, class Graph>
void gray_target(Edge e, Graph& g) {
D old_distance = get(m_distance, target(e, g));
bool decreased = relax(e, g, m_weight, m_predecessor, m_distance,
m_combine, m_compare);
if (decreased) {
dijkstra_queue_update(m_Q, target(e, g), old_distance);
m_vis.edge_relaxed(e, g);
} else
m_vis.edge_not_relaxed(e, g);
}
template <class Vertex, class Graph>
void initialize_vertex(Vertex u, Graph& g)
{ m_vis.initialize_vertex(u, g); }
template <class Edge, class Graph>
void non_tree_edge(Edge, Graph&) { }
template <class Vertex, class Graph>
void discover_vertex(Vertex u, Graph& g) { m_vis.discover_vertex(u, g); }
template <class Vertex, class Graph>
void examine_vertex(Vertex u, Graph& g) { m_vis.examine_vertex(u, g); }
template <class Edge, class Graph>
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);
}
template <class Edge, class Graph>
void black_target(Edge, Graph&) { }
template <class Vertex, class Graph>
void finish_vertex(Vertex u, Graph& g) { m_vis.finish_vertex(u, g); }
UniformCostVisitor m_vis;
UpdatableQueue& m_Q;
WeightMap m_weight;
PredecessorMap m_predecessor;
DistanceMap m_distance;
BinaryFunction m_combine;
BinaryPredicate m_compare;
D m_zero;
};
} // namespace detail
namespace detail {
template <class Graph, class IndexMap, class Value, bool KnownNumVertices>
struct vertex_property_map_generator_helper {};
template <class Graph, class IndexMap, class Value>
struct vertex_property_map_generator_helper<Graph, IndexMap, Value, true> {
typedef boost::iterator_property_map<Value*, IndexMap> type;
static type build(const Graph& g, const IndexMap& index, boost::scoped_array<Value>& array_holder) {
array_holder.reset(new Value[num_vertices(g)]);
std::fill(array_holder.get(), array_holder.get() + num_vertices(g), Value());
return make_iterator_property_map(array_holder.get(), index);
}
};
template <class Graph, class IndexMap, class Value>
struct vertex_property_map_generator_helper<Graph, IndexMap, Value, false> {
typedef boost::vector_property_map<Value, IndexMap> type;
static type build(const Graph& g, const IndexMap& index, boost::scoped_array<Value>& array_holder) {
return boost::make_vector_property_map<Value>(index);
}
};
template <class Graph, class IndexMap, class Value>
struct vertex_property_map_generator {
typedef boost::is_base_and_derived<
boost::vertex_list_graph_tag,
typename boost::graph_traits<Graph>::traversal_category>
known_num_vertices;
typedef vertex_property_map_generator_helper<Graph, IndexMap, Value, known_num_vertices::value> helper;
typedef typename helper::type type;
static type build(const Graph& g, const IndexMap& index, boost::scoped_array<Value>& array_holder) {
return helper::build(g, index, array_holder);
}
};
}
namespace detail {
template <class Graph, class IndexMap, bool KnownNumVertices>
struct default_color_map_generator_helper {};
template <class Graph, class IndexMap>
struct default_color_map_generator_helper<Graph, IndexMap, true> {
typedef boost::two_bit_color_map<IndexMap> type;
static type build(const Graph& g, const IndexMap& index) {
size_t nv = num_vertices(g);
return boost::two_bit_color_map<IndexMap>(nv, index);
}
};
template <class Graph, class IndexMap>
struct default_color_map_generator_helper<Graph, IndexMap, false> {
typedef boost::vector_property_map<boost::two_bit_color_type, IndexMap> type;
static type build(const Graph& g, const IndexMap& index) {
return boost::make_vector_property_map<boost::two_bit_color_type>(index);
}
};
template <class Graph, class IndexMap>
struct default_color_map_generator {
typedef boost::is_base_and_derived<
boost::vertex_list_graph_tag,
typename boost::graph_traits<Graph>::traversal_category>
known_num_vertices;
typedef default_color_map_generator_helper<Graph, IndexMap, known_num_vertices::value> helper;
typedef typename helper::type type;
static type build(const Graph& g, const IndexMap& index) {
return helper::build(g, index);
}
};
}
// Call breadth first search with default color map.
template <class Graph, class DijkstraVisitor,
class PredecessorMap, class DistanceMap,
class WeightMap, class IndexMap, class Compare, class Combine,
class DistZero>
inline void
dijkstra_shortest_paths_no_init
(const Graph& g,
typename graph_traits<Graph>::vertex_descriptor s,
PredecessorMap predecessor, DistanceMap distance, WeightMap weight,
IndexMap index_map,
Compare compare, Combine combine, DistZero zero,
DijkstraVisitor vis)
{
typedef
detail::default_color_map_generator<Graph, IndexMap>
ColorMapHelper;
typedef typename ColorMapHelper::type ColorMap;
ColorMap color =
ColorMapHelper::build(g, index_map);
dijkstra_shortest_paths_no_init( g, s, predecessor, distance, weight,
index_map, compare, combine, zero, vis,
color);
}
// Call breadth first search
template <class Graph, class DijkstraVisitor,
class PredecessorMap, class DistanceMap,
class WeightMap, class IndexMap, class Compare, class Combine,
class DistZero, class ColorMap>
inline void
dijkstra_shortest_paths_no_init
(const Graph& g,
typename graph_traits<Graph>::vertex_descriptor s,
PredecessorMap predecessor, DistanceMap distance, WeightMap weight,
IndexMap index_map,
Compare compare, Combine combine, DistZero zero,
DijkstraVisitor vis, ColorMap color)
{
typedef indirect_cmp<DistanceMap, Compare> IndirectCmp;
IndirectCmp icmp(distance, compare);
typedef typename graph_traits<Graph>::vertex_descriptor Vertex;
#ifdef BOOST_GRAPH_DIJKSTRA_TESTING
if (!dijkstra_relaxed_heap) {
typedef mutable_queue<Vertex, std::vector<Vertex>, IndirectCmp, IndexMap>
MutableQueue;
MutableQueue Q(num_vertices(g), icmp, index_map);
detail::dijkstra_bfs_visitor<DijkstraVisitor, MutableQueue, WeightMap,
PredecessorMap, DistanceMap, Combine, Compare>
bfs_vis(vis, Q, weight, predecessor, distance, combine, compare, zero);
breadth_first_visit(g, s, Q, bfs_vis, color);
return;
}
#endif // BOOST_GRAPH_DIJKSTRA_TESTING
#ifdef BOOST_GRAPH_DIJKSTRA_USE_RELAXED_HEAP
typedef relaxed_heap<Vertex, IndirectCmp, IndexMap> MutableQueue;
MutableQueue Q(num_vertices(g), icmp, index_map);
#else // Now the default: use a d-ary heap
boost::scoped_array<std::size_t> index_in_heap_map_holder;
typedef
detail::vertex_property_map_generator<Graph, IndexMap, std::size_t>
IndexInHeapMapHelper;
typedef typename IndexInHeapMapHelper::type IndexInHeapMap;
IndexInHeapMap index_in_heap =
IndexInHeapMapHelper::build(g, index_map, index_in_heap_map_holder);
typedef d_ary_heap_indirect<Vertex, 4, IndexInHeapMap, DistanceMap, Compare>
MutableQueue;
MutableQueue Q(distance, index_in_heap, compare);
#endif // Relaxed heap
detail::dijkstra_bfs_visitor<DijkstraVisitor, MutableQueue, WeightMap,
PredecessorMap, DistanceMap, Combine, Compare>
bfs_vis(vis, Q, weight, predecessor, distance, combine, compare, zero);
breadth_first_visit(g, s, Q, bfs_vis, color);
}
// Initialize distances and call breadth first search with default color map
template <class VertexListGraph, class DijkstraVisitor,
class PredecessorMap, class DistanceMap,
class WeightMap, class IndexMap, class Compare, class Combine,
class DistInf, class DistZero, typename T, typename Tag,
typename Base>
inline void
dijkstra_shortest_paths
(const VertexListGraph& g,
typename graph_traits<VertexListGraph>::vertex_descriptor s,
PredecessorMap predecessor, DistanceMap distance, WeightMap weight,
IndexMap index_map,
Compare compare, Combine combine, DistInf inf, DistZero zero,
DijkstraVisitor vis,
const bgl_named_params<T, Tag, Base>&
BOOST_GRAPH_ENABLE_IF_MODELS_PARM(VertexListGraph,vertex_list_graph_tag))
{
boost::two_bit_color_map<IndexMap> color(num_vertices(g), index_map);
dijkstra_shortest_paths(g, s, predecessor, distance, weight, index_map,
compare, combine, inf, zero, vis,
color);
}
// Initialize distances and call breadth first search
template <class VertexListGraph, class DijkstraVisitor,
class PredecessorMap, class DistanceMap,
class WeightMap, class IndexMap, class Compare, class Combine,
class DistInf, class DistZero, class ColorMap>
inline void
dijkstra_shortest_paths
(const VertexListGraph& g,
typename graph_traits<VertexListGraph>::vertex_descriptor s,
PredecessorMap predecessor, DistanceMap distance, WeightMap weight,
IndexMap index_map,
Compare compare, Combine combine, DistInf inf, DistZero zero,
DijkstraVisitor vis, ColorMap color)
{
typedef typename property_traits<ColorMap>::value_type ColorValue;
typedef color_traits<ColorValue> Color;
typename graph_traits<VertexListGraph>::vertex_iterator ui, ui_end;
for (boost::tie(ui, ui_end) = vertices(g); ui != ui_end; ++ui) {
vis.initialize_vertex(*ui, g);
put(distance, *ui, inf);
put(predecessor, *ui, *ui);
put(color, *ui, Color::white());
}
put(distance, s, zero);
dijkstra_shortest_paths_no_init(g, s, predecessor, distance, weight,
index_map, compare, combine, zero, vis, color);
}
// Initialize distances and call breadth first search
template <class VertexListGraph, class DijkstraVisitor,
class PredecessorMap, class DistanceMap,
class WeightMap, class IndexMap, class Compare, class Combine,
class DistInf, class DistZero>
inline void
dijkstra_shortest_paths
(const VertexListGraph& g,
typename graph_traits<VertexListGraph>::vertex_descriptor s,
PredecessorMap predecessor, DistanceMap distance, WeightMap weight,
IndexMap index_map,
Compare compare, Combine combine, DistInf inf, DistZero zero,
DijkstraVisitor vis)
{
dijkstra_shortest_paths(g, s, predecessor, distance, weight, index_map,
compare, combine, inf, zero, vis,
no_named_parameters());
}
namespace detail {
// Handle defaults for PredecessorMap and
// Distance Compare, Combine, Inf and Zero
template <class VertexListGraph, class DistanceMap, class WeightMap,
class IndexMap, class Params>
inline void
dijkstra_dispatch2
(const VertexListGraph& g,
typename graph_traits<VertexListGraph>::vertex_descriptor s,
DistanceMap distance, WeightMap weight, IndexMap index_map,
const Params& params)
{
// Default for predecessor map
dummy_property_map p_map;
typedef typename property_traits<DistanceMap>::value_type D;
D inf = choose_param(get_param(params, distance_inf_t()),
(std::numeric_limits<D>::max)());
dijkstra_shortest_paths
(g, s,
choose_param(get_param(params, vertex_predecessor), p_map),
distance, weight, index_map,
choose_param(get_param(params, distance_compare_t()),
std::less<D>()),
choose_param(get_param(params, distance_combine_t()),
closed_plus<D>(inf)),
inf,
choose_param(get_param(params, distance_zero_t()),
D()),
choose_param(get_param(params, graph_visitor),
make_dijkstra_visitor(null_visitor())),
params);
}
template <class VertexListGraph, class DistanceMap, class WeightMap,
class IndexMap, class Params>
inline void
dijkstra_dispatch1
(const VertexListGraph& g,
typename graph_traits<VertexListGraph>::vertex_descriptor s,
DistanceMap distance, WeightMap weight, IndexMap index_map,
const Params& params)
{
// Default for distance map
typedef typename property_traits<WeightMap>::value_type D;
typename std::vector<D>::size_type
n = is_default_param(distance) ? num_vertices(g) : 1;
std::vector<D> distance_map(n);
detail::dijkstra_dispatch2
(g, s, choose_param(distance, make_iterator_property_map
(distance_map.begin(), index_map,
distance_map[0])),
weight, index_map, params);
}
} // namespace detail
// Named Parameter Variant
template <class VertexListGraph, class Param, class Tag, class Rest>
inline void
dijkstra_shortest_paths
(const VertexListGraph& g,
typename graph_traits<VertexListGraph>::vertex_descriptor s,
const bgl_named_params<Param,Tag,Rest>& params)
{
// Default for edge weight and vertex index map is to ask for them
// from the graph. Default for the visitor is null_visitor.
detail::dijkstra_dispatch1
(g, s,
get_param(params, vertex_distance),
choose_const_pmap(get_param(params, edge_weight), g, edge_weight),
choose_const_pmap(get_param(params, vertex_index), g, vertex_index),
params);
}
} // namespace boost
#ifdef BOOST_GRAPH_USE_MPI
# include <boost/graph/distributed/dijkstra_shortest_paths.hpp>
#endif
#endif // BOOST_GRAPH_DIJKSTRA_HPP