85 lines
2.9 KiB
C++
85 lines
2.9 KiB
C++
//=======================================================================
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// Copyright 1997, 1998, 1999, 2000 University of Notre Dame.
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// Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek
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//
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// Distributed under the Boost Software License, Version 1.0. (See
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// accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt)
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//=======================================================================
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//
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#ifndef BOOST_GRAPH_MST_PRIM_HPP
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#define BOOST_GRAPH_MST_PRIM_HPP
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#include <functional>
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#include <boost/graph/graph_traits.hpp>
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#include <boost/graph/dijkstra_shortest_paths.hpp>
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namespace boost
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{
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namespace detail
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{
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// this should be somewhere else in boost...
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template < class U, class V > struct _project2nd
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{
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V operator()(U, V v) const { return v; }
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};
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}
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namespace detail
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{
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// This is Prim's algorithm to calculate the Minimum Spanning Tree
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// for an undirected graph with weighted edges.
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template < class Graph, class P, class T, class R, class Weight >
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inline void prim_mst_impl(const Graph& G,
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typename graph_traits< Graph >::vertex_descriptor s,
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const bgl_named_params< P, T, R >& params, Weight)
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{
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typedef typename property_traits< Weight >::value_type W;
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std::less< W > compare;
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detail::_project2nd< W, W > combine;
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dijkstra_shortest_paths(
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G, s, params.distance_compare(compare).distance_combine(combine));
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}
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} // namespace detail
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template < class VertexListGraph, class DijkstraVisitor, class PredecessorMap,
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class DistanceMap, class WeightMap, class IndexMap >
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inline void prim_minimum_spanning_tree(const VertexListGraph& g,
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typename graph_traits< VertexListGraph >::vertex_descriptor s,
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PredecessorMap predecessor, DistanceMap distance, WeightMap weight,
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IndexMap index_map, DijkstraVisitor vis)
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{
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typedef typename property_traits< WeightMap >::value_type W;
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std::less< W > compare;
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detail::_project2nd< W, W > combine;
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dijkstra_shortest_paths(g, s, predecessor, distance, weight, index_map,
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compare, combine, (std::numeric_limits< W >::max)(), 0, vis);
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}
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template < class VertexListGraph, class PredecessorMap, class P, class T,
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class R >
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inline void prim_minimum_spanning_tree(const VertexListGraph& g,
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PredecessorMap p_map, const bgl_named_params< P, T, R >& params)
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{
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detail::prim_mst_impl(g,
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choose_param(get_param(params, root_vertex_t()), *vertices(g).first),
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params.predecessor_map(p_map),
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choose_const_pmap(get_param(params, edge_weight), g, edge_weight));
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}
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template < class VertexListGraph, class PredecessorMap >
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inline void prim_minimum_spanning_tree(
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const VertexListGraph& g, PredecessorMap p_map)
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{
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detail::prim_mst_impl(g, *vertices(g).first,
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predecessor_map(p_map).weight_map(get(edge_weight, g)),
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get(edge_weight, g));
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}
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} // namespace boost
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#endif // BOOST_GRAPH_MST_PRIM_HPP
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