diff -r 666f914201fb -r 2fe1408b6811 epoc32/include/stdapis/boost/graph/dag_shortest_paths.hpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/epoc32/include/stdapis/boost/graph/dag_shortest_paths.hpp Tue Mar 16 16:12:26 2010 +0000 @@ -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 +#include + +// single-source shortest paths for a Directed Acyclic Graph (DAG) + +namespace boost { + + // Initalize distances and call depth first search + template + inline void + dag_shortest_paths + (const VertexListGraph& g, + typename graph_traits::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::vertex_descriptor Vertex; + std::vector 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 > > + topo_visitor(std::back_inserter(rev_topo_order)); + depth_first_visit(g, s, topo_visitor, color); + + typename graph_traits::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::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::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 + inline void + dag_sp_dispatch2 + (const VertexListGraph& g, + typename graph_traits::vertex_descriptor s, + DistanceMap distance, WeightMap weight, ColorMap color, IndexMap id, + DijkstraVisitor vis, const Params& params) + { + typedef typename property_traits::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()), + choose_param(get_param(params, distance_combine_t()), closed_plus()), + choose_param(get_param(params, distance_inf_t()), + (std::numeric_limits::max)()), + choose_param(get_param(params, distance_zero_t()), + D())); + } + + // Handle DistanceMap and ColorMap defaults + template + inline void + dag_sp_dispatch1 + (const VertexListGraph& g, + typename graph_traits::vertex_descriptor s, + DistanceMap distance, WeightMap weight, ColorMap color, IndexMap id, + DijkstraVisitor vis, const Params& params) + { + typedef typename property_traits::value_type T; + typename std::vector::size_type n; + n = is_default_param(distance) ? num_vertices(g) : 1; + std::vector distance_map(n); + n = is_default_param(color) ? num_vertices(g) : 1; + std::vector 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 + inline void + dag_shortest_paths + (const VertexListGraph& g, + typename graph_traits::vertex_descriptor s, + const bgl_named_params& 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