//======================================================================= // 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) //======================================================================= // #ifndef BOOST_GRAPH_MST_PRIM_HPP #define BOOST_GRAPH_MST_PRIM_HPP #include <functional> #include <boost/graph/graph_traits.hpp> #include <boost/graph/dijkstra_shortest_paths.hpp> namespace boost { namespace detail { // this should be somewhere else in boost... template <class U, class V> struct _project2nd { V operator()(U, V v) const { return v; } }; } namespace detail { // This is Prim's algorithm to calculate the Minimum Spanning Tree // for an undirected graph with weighted edges. template <class Graph, class P, class T, class R, class Weight> inline void prim_mst_impl(const Graph& G, typename graph_traits<Graph>::vertex_descriptor s, const bgl_named_params<P,T,R>& params, Weight) { typedef typename property_traits<Weight>::value_type W; std::less<W> compare; detail::_project2nd<W,W> combine; dijkstra_shortest_paths(G, s, params.distance_compare(compare). distance_combine(combine)); } } // namespace detail template <class VertexListGraph, class DijkstraVisitor, class PredecessorMap, class DistanceMap, class WeightMap, class IndexMap> inline void prim_minimum_spanning_tree (const VertexListGraph& g, typename graph_traits<VertexListGraph>::vertex_descriptor s, PredecessorMap predecessor, DistanceMap distance, WeightMap weight, IndexMap index_map, DijkstraVisitor vis) { typedef typename property_traits<WeightMap>::value_type W; std::less<W> compare; detail::_project2nd<W,W> combine; dijkstra_shortest_paths(g, s, predecessor, distance, weight, index_map, compare, combine, (std::numeric_limits<W>::max)(), 0, vis); } template <class VertexListGraph, class PredecessorMap, class P, class T, class R> inline void prim_minimum_spanning_tree (const VertexListGraph& g, PredecessorMap p_map, const bgl_named_params<P,T,R>& params) { detail::prim_mst_impl (g, choose_param(get_param(params, root_vertex_t()), *vertices(g).first), params.predecessor_map(p_map), choose_const_pmap(get_param(params, edge_weight), g, edge_weight)); } template <class VertexListGraph, class PredecessorMap> inline void prim_minimum_spanning_tree (const VertexListGraph& g, PredecessorMap p_map) { detail::prim_mst_impl (g, *vertices(g).first, predecessor_map(p_map). weight_map(get(edge_weight, g)), get(edge_weight, g)); } } // namespace boost #endif // BOOST_GRAPH_MST_PRIM_HPP