Added boost header

test/external/boost/graph/dag_shortest_paths.hpp

@@ -0,0 +1,159 @@
+//=======================================================================
+// 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 (boost::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 (boost::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;
+      D inf =
+        choose_param(get_param(params, distance_inf_t()), 
+                     (std::numeric_limits<D>::max)());
+      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>(inf)),
+         inf,
+         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