--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/ossrv_pub/boost_apis/boost/graph/dag_shortest_paths.hpp Tue Feb 02 02:01:42 2010 +0200
@@ -0,0 +1,157 @@
+//=======================================================================
+// Copyright 2002 Indiana University.
+// 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)
+//=======================================================================
+
+#ifndef BOOST_GRAPH_DAG_SHORTEST_PATHS_HPP
+#define BOOST_GRAPH_DAG_SHORTEST_PATHS_HPP
+
+#include <boost/graph/topological_sort.hpp>
+#include <boost/graph/dijkstra_shortest_paths.hpp>
+
+// single-source shortest paths for a Directed Acyclic Graph (DAG)
+
+namespace boost {
+
+ // Initalize distances and call depth first search
+ template <class VertexListGraph, class DijkstraVisitor,
+ class DistanceMap, class WeightMap, class ColorMap,
+ class PredecessorMap,
+ class Compare, class Combine,
+ class DistInf, class DistZero>
+ inline void
+ dag_shortest_paths
+ (const VertexListGraph& g,
+ typename graph_traits<VertexListGraph>::vertex_descriptor s,
+ DistanceMap distance, WeightMap weight, ColorMap color,
+ PredecessorMap pred,
+ DijkstraVisitor vis, Compare compare, Combine combine,
+ DistInf inf, DistZero zero)
+ {
+ typedef typename graph_traits<VertexListGraph>::vertex_descriptor Vertex;
+ std::vector<Vertex> rev_topo_order;
+ rev_topo_order.reserve(num_vertices(g));
+
+ // Call 'depth_first_visit', not 'topological_sort', because we don't
+ // want to traverse the entire graph, only vertices reachable from 's',
+ // and 'topological_sort' will traverse everything. The logic below
+ // is the same as for 'topological_sort', only we call 'depth_first_visit'
+ // and 'topological_sort' calls 'depth_first_search'.
+ topo_sort_visitor<std::back_insert_iterator<std::vector<Vertex> > >
+ topo_visitor(std::back_inserter(rev_topo_order));
+ depth_first_visit(g, s, topo_visitor, color);
+
+ typename graph_traits<VertexListGraph>::vertex_iterator ui, ui_end;
+ for (tie(ui, ui_end) = vertices(g); ui != ui_end; ++ui) {
+ put(distance, *ui, inf);
+ put(pred, *ui, *ui);
+ }
+
+ put(distance, s, zero);
+ vis.discover_vertex(s, g);
+ typename std::vector<Vertex>::reverse_iterator i;
+ for (i = rev_topo_order.rbegin(); i != rev_topo_order.rend(); ++i) {
+ Vertex u = *i;
+ vis.examine_vertex(u, g);
+ typename graph_traits<VertexListGraph>::out_edge_iterator e, e_end;
+ for (tie(e, e_end) = out_edges(u, g); e != e_end; ++e) {
+ vis.discover_vertex(target(*e, g), g);
+ bool decreased = relax(*e, g, weight, pred, distance,
+ combine, compare);
+ if (decreased)
+ vis.edge_relaxed(*e, g);
+ else
+ vis.edge_not_relaxed(*e, g);
+ }
+ vis.finish_vertex(u, g);
+ }
+ }
+
+ namespace detail {
+
+ // Defaults are the same as Dijkstra's algorithm
+
+ // Handle Distance Compare, Combine, Inf and Zero defaults
+ template <class VertexListGraph, class DijkstraVisitor,
+ class DistanceMap, class WeightMap, class ColorMap,
+ class IndexMap, class Params>
+ inline void
+ dag_sp_dispatch2
+ (const VertexListGraph& g,
+ typename graph_traits<VertexListGraph>::vertex_descriptor s,
+ DistanceMap distance, WeightMap weight, ColorMap color, IndexMap id,
+ DijkstraVisitor vis, const Params& params)
+ {
+ typedef typename property_traits<DistanceMap>::value_type D;
+ dummy_property_map p_map;
+ dag_shortest_paths
+ (g, s, distance, weight, color,
+ choose_param(get_param(params, vertex_predecessor), p_map),
+ vis,
+ choose_param(get_param(params, distance_compare_t()), std::less<D>()),
+ choose_param(get_param(params, distance_combine_t()), closed_plus<D>()),
+ choose_param(get_param(params, distance_inf_t()),
+ (std::numeric_limits<D>::max)()),
+ choose_param(get_param(params, distance_zero_t()),
+ D()));
+ }
+
+ // Handle DistanceMap and ColorMap defaults
+ template <class VertexListGraph, class DijkstraVisitor,
+ class DistanceMap, class WeightMap, class ColorMap,
+ class IndexMap, class Params>
+ inline void
+ dag_sp_dispatch1
+ (const VertexListGraph& g,
+ typename graph_traits<VertexListGraph>::vertex_descriptor s,
+ DistanceMap distance, WeightMap weight, ColorMap color, IndexMap id,
+ DijkstraVisitor vis, const Params& params)
+ {
+ typedef typename property_traits<WeightMap>::value_type T;
+ typename std::vector<T>::size_type n;
+ n = is_default_param(distance) ? num_vertices(g) : 1;
+ std::vector<T> distance_map(n);
+ n = is_default_param(color) ? num_vertices(g) : 1;
+ std::vector<default_color_type> color_map(n);
+
+ dag_sp_dispatch2
+ (g, s,
+ choose_param(distance,
+ make_iterator_property_map(distance_map.begin(), id,
+ distance_map[0])),
+ weight,
+ choose_param(color,
+ make_iterator_property_map(color_map.begin(), id,
+ color_map[0])),
+ id, vis, params);
+ }
+
+ } // namespace detail
+
+ template <class VertexListGraph, class Param, class Tag, class Rest>
+ inline void
+ dag_shortest_paths
+ (const VertexListGraph& g,
+ typename graph_traits<VertexListGraph>::vertex_descriptor s,
+ const bgl_named_params<Param,Tag,Rest>& params)
+ {
+ // assert that the graph is directed...
+ null_visitor null_vis;
+ detail::dag_sp_dispatch1
+ (g, s,
+ get_param(params, vertex_distance),
+ choose_const_pmap(get_param(params, edge_weight), g, edge_weight),
+ get_param(params, vertex_color),
+ choose_const_pmap(get_param(params, vertex_index), g, vertex_index),
+ choose_param(get_param(params, graph_visitor),
+ make_dijkstra_visitor(null_vis)),
+ params);
+ }
+
+} // namespace boost
+
+#endif // BOOST_GRAPH_DAG_SHORTEST_PATHS_HPP