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Diffstat (limited to 'extern/quadriflow/3rd/lemon-1.3.1/lemon/kruskal.h')
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diff --git a/extern/quadriflow/3rd/lemon-1.3.1/lemon/kruskal.h b/extern/quadriflow/3rd/lemon-1.3.1/lemon/kruskal.h new file mode 100644 index 00000000000..04c2ddb9384 --- /dev/null +++ b/extern/quadriflow/3rd/lemon-1.3.1/lemon/kruskal.h @@ -0,0 +1,324 @@ +/* -*- mode: C++; indent-tabs-mode: nil; -*- + * + * This file is a part of LEMON, a generic C++ optimization library. + * + * Copyright (C) 2003-2013 + * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport + * (Egervary Research Group on Combinatorial Optimization, EGRES). + * + * Permission to use, modify and distribute this software is granted + * provided that this copyright notice appears in all copies. For + * precise terms see the accompanying LICENSE file. + * + * This software is provided "AS IS" with no warranty of any kind, + * express or implied, and with no claim as to its suitability for any + * purpose. + * + */ + +#ifndef LEMON_KRUSKAL_H +#define LEMON_KRUSKAL_H + +#include <algorithm> +#include <vector> +#include <lemon/unionfind.h> +#include <lemon/maps.h> + +#include <lemon/core.h> +#include <lemon/bits/traits.h> + +///\ingroup spantree +///\file +///\brief Kruskal's algorithm to compute a minimum cost spanning tree + +namespace lemon { + + namespace _kruskal_bits { + + // Kruskal for directed graphs. + + template <typename Digraph, typename In, typename Out> + typename disable_if<lemon::UndirectedTagIndicator<Digraph>, + typename In::value_type::second_type >::type + kruskal(const Digraph& digraph, const In& in, Out& out,dummy<0> = 0) { + typedef typename In::value_type::second_type Value; + typedef typename Digraph::template NodeMap<int> IndexMap; + typedef typename Digraph::Node Node; + + IndexMap index(digraph); + UnionFind<IndexMap> uf(index); + for (typename Digraph::NodeIt it(digraph); it != INVALID; ++it) { + uf.insert(it); + } + + Value tree_value = 0; + for (typename In::const_iterator it = in.begin(); it != in.end(); ++it) { + if (uf.join(digraph.target(it->first),digraph.source(it->first))) { + out.set(it->first, true); + tree_value += it->second; + } + else { + out.set(it->first, false); + } + } + return tree_value; + } + + // Kruskal for undirected graphs. + + template <typename Graph, typename In, typename Out> + typename enable_if<lemon::UndirectedTagIndicator<Graph>, + typename In::value_type::second_type >::type + kruskal(const Graph& graph, const In& in, Out& out,dummy<1> = 1) { + typedef typename In::value_type::second_type Value; + typedef typename Graph::template NodeMap<int> IndexMap; + typedef typename Graph::Node Node; + + IndexMap index(graph); + UnionFind<IndexMap> uf(index); + for (typename Graph::NodeIt it(graph); it != INVALID; ++it) { + uf.insert(it); + } + + Value tree_value = 0; + for (typename In::const_iterator it = in.begin(); it != in.end(); ++it) { + if (uf.join(graph.u(it->first),graph.v(it->first))) { + out.set(it->first, true); + tree_value += it->second; + } + else { + out.set(it->first, false); + } + } + return tree_value; + } + + + template <typename Sequence> + struct PairComp { + typedef typename Sequence::value_type Value; + bool operator()(const Value& left, const Value& right) { + return left.second < right.second; + } + }; + + template <typename In, typename Enable = void> + struct SequenceInputIndicator { + static const bool value = false; + }; + + template <typename In> + struct SequenceInputIndicator<In, + typename exists<typename In::value_type::first_type>::type> { + static const bool value = true; + }; + + template <typename In, typename Enable = void> + struct MapInputIndicator { + static const bool value = false; + }; + + template <typename In> + struct MapInputIndicator<In, + typename exists<typename In::Value>::type> { + static const bool value = true; + }; + + template <typename In, typename Enable = void> + struct SequenceOutputIndicator { + static const bool value = false; + }; + + template <typename Out> + struct SequenceOutputIndicator<Out, + typename exists<typename Out::value_type>::type> { + static const bool value = true; + }; + + template <typename Out, typename Enable = void> + struct MapOutputIndicator { + static const bool value = false; + }; + + template <typename Out> + struct MapOutputIndicator<Out, + typename exists<typename Out::Value>::type> { + static const bool value = true; + }; + + template <typename In, typename InEnable = void> + struct KruskalValueSelector {}; + + template <typename In> + struct KruskalValueSelector<In, + typename enable_if<SequenceInputIndicator<In>, void>::type> + { + typedef typename In::value_type::second_type Value; + }; + + template <typename In> + struct KruskalValueSelector<In, + typename enable_if<MapInputIndicator<In>, void>::type> + { + typedef typename In::Value Value; + }; + + template <typename Graph, typename In, typename Out, + typename InEnable = void> + struct KruskalInputSelector {}; + + template <typename Graph, typename In, typename Out, + typename InEnable = void> + struct KruskalOutputSelector {}; + + template <typename Graph, typename In, typename Out> + struct KruskalInputSelector<Graph, In, Out, + typename enable_if<SequenceInputIndicator<In>, void>::type > + { + typedef typename In::value_type::second_type Value; + + static Value kruskal(const Graph& graph, const In& in, Out& out) { + return KruskalOutputSelector<Graph, In, Out>:: + kruskal(graph, in, out); + } + + }; + + template <typename Graph, typename In, typename Out> + struct KruskalInputSelector<Graph, In, Out, + typename enable_if<MapInputIndicator<In>, void>::type > + { + typedef typename In::Value Value; + static Value kruskal(const Graph& graph, const In& in, Out& out) { + typedef typename In::Key MapArc; + typedef typename In::Value Value; + typedef typename ItemSetTraits<Graph, MapArc>::ItemIt MapArcIt; + typedef std::vector<std::pair<MapArc, Value> > Sequence; + Sequence seq; + + for (MapArcIt it(graph); it != INVALID; ++it) { + seq.push_back(std::make_pair(it, in[it])); + } + + std::sort(seq.begin(), seq.end(), PairComp<Sequence>()); + return KruskalOutputSelector<Graph, Sequence, Out>:: + kruskal(graph, seq, out); + } + }; + + template <typename T> + struct RemoveConst { + typedef T type; + }; + + template <typename T> + struct RemoveConst<const T> { + typedef T type; + }; + + template <typename Graph, typename In, typename Out> + struct KruskalOutputSelector<Graph, In, Out, + typename enable_if<SequenceOutputIndicator<Out>, void>::type > + { + typedef typename In::value_type::second_type Value; + + static Value kruskal(const Graph& graph, const In& in, Out& out) { + typedef LoggerBoolMap<typename RemoveConst<Out>::type> Map; + Map map(out); + return _kruskal_bits::kruskal(graph, in, map); + } + + }; + + template <typename Graph, typename In, typename Out> + struct KruskalOutputSelector<Graph, In, Out, + typename enable_if<MapOutputIndicator<Out>, void>::type > + { + typedef typename In::value_type::second_type Value; + + static Value kruskal(const Graph& graph, const In& in, Out& out) { + return _kruskal_bits::kruskal(graph, in, out); + } + }; + + } + + /// \ingroup spantree + /// + /// \brief Kruskal's algorithm for finding a minimum cost spanning tree of + /// a graph. + /// + /// This function runs Kruskal's algorithm to find a minimum cost + /// spanning tree of a graph. + /// Due to some C++ hacking, it accepts various input and output types. + /// + /// \param g The graph the algorithm runs on. + /// It can be either \ref concepts::Digraph "directed" or + /// \ref concepts::Graph "undirected". + /// If the graph is directed, the algorithm consider it to be + /// undirected by disregarding the direction of the arcs. + /// + /// \param in This object is used to describe the arc/edge costs. + /// It can be one of the following choices. + /// - An STL compatible 'Forward Container' with + /// <tt>std::pair<GR::Arc,C></tt> or + /// <tt>std::pair<GR::Edge,C></tt> as its <tt>value_type</tt>, where + /// \c C is the type of the costs. The pairs indicates the arcs/edges + /// along with the assigned cost. <em>They must be in a + /// cost-ascending order.</em> + /// - Any readable arc/edge map. The values of the map indicate the + /// arc/edge costs. + /// + /// \retval out Here we also have a choice. + /// - It can be a writable arc/edge map with \c bool value type. After + /// running the algorithm it will contain the found minimum cost spanning + /// tree: the value of an arc/edge will be set to \c true if it belongs + /// to the tree, otherwise it will be set to \c false. The value of + /// each arc/edge will be set exactly once. + /// - It can also be an iteraror of an STL Container with + /// <tt>GR::Arc</tt> or <tt>GR::Edge</tt> as its + /// <tt>value_type</tt>. The algorithm copies the elements of the + /// found tree into this sequence. For example, if we know that the + /// spanning tree of the graph \c g has say 53 arcs, then we can + /// put its arcs into an STL vector \c tree with a code like this. + ///\code + /// std::vector<Arc> tree(53); + /// kruskal(g,cost,tree.begin()); + ///\endcode + /// Or if we don't know in advance the size of the tree, we can + /// write this. + ///\code + /// std::vector<Arc> tree; + /// kruskal(g,cost,std::back_inserter(tree)); + ///\endcode + /// + /// \return The total cost of the found spanning tree. + /// + /// \note If the input graph is not (weakly) connected, a spanning + /// forest is calculated instead of a spanning tree. + +#ifdef DOXYGEN + template <typename Graph, typename In, typename Out> + Value kruskal(const Graph& g, const In& in, Out& out) +#else + template <class Graph, class In, class Out> + inline typename _kruskal_bits::KruskalValueSelector<In>::Value + kruskal(const Graph& graph, const In& in, Out& out) +#endif + { + return _kruskal_bits::KruskalInputSelector<Graph, In, Out>:: + kruskal(graph, in, out); + } + + + template <class Graph, class In, class Out> + inline typename _kruskal_bits::KruskalValueSelector<In>::Value + kruskal(const Graph& graph, const In& in, const Out& out) + { + return _kruskal_bits::KruskalInputSelector<Graph, In, const Out>:: + kruskal(graph, in, out); + } + +} //namespace lemon + +#endif //LEMON_KRUSKAL_H |