[2040] | 1 | /* -*- C++ -*- |
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| 2 | * |
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| 3 | * This file is a part of LEMON, a generic C++ optimization library |
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| 4 | * |
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| 5 | * Copyright (C) 2003-2006 |
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| 6 | * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
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| 7 | * (Egervary Research Group on Combinatorial Optimization, EGRES). |
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| 8 | * |
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| 9 | * Permission to use, modify and distribute this software is granted |
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| 10 | * provided that this copyright notice appears in all copies. For |
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| 11 | * precise terms see the accompanying LICENSE file. |
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| 12 | * |
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| 13 | * This software is provided "AS IS" with no warranty of any kind, |
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| 14 | * express or implied, and with no claim as to its suitability for any |
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| 15 | * purpose. |
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| 16 | * |
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| 17 | */ |
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| 18 | |
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| 19 | #ifndef LEMON_BIPARTITE_MATCHING |
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| 20 | #define LEMON_BIPARTITE_MATCHING |
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| 21 | |
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[2051] | 22 | #include <functional> |
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| 23 | |
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| 24 | #include <lemon/bin_heap.h> |
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| 25 | #include <lemon/maps.h> |
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[2040] | 26 | |
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| 27 | #include <iostream> |
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| 28 | |
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| 29 | ///\ingroup matching |
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| 30 | ///\file |
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| 31 | ///\brief Maximum matching algorithms in bipartite graphs. |
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| 32 | |
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| 33 | namespace lemon { |
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| 34 | |
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| 35 | /// \ingroup matching |
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| 36 | /// |
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| 37 | /// \brief Bipartite Max Cardinality Matching algorithm |
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| 38 | /// |
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| 39 | /// Bipartite Max Cardinality Matching algorithm. This class implements |
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[2051] | 40 | /// the Hopcroft-Karp algorithm which has \f$ O(e\sqrt{n}) \f$ time |
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[2040] | 41 | /// complexity. |
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| 42 | template <typename BpUGraph> |
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| 43 | class MaxBipartiteMatching { |
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| 44 | protected: |
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| 45 | |
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| 46 | typedef BpUGraph Graph; |
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| 47 | |
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| 48 | typedef typename Graph::Node Node; |
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| 49 | typedef typename Graph::ANodeIt ANodeIt; |
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| 50 | typedef typename Graph::BNodeIt BNodeIt; |
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| 51 | typedef typename Graph::UEdge UEdge; |
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| 52 | typedef typename Graph::UEdgeIt UEdgeIt; |
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| 53 | typedef typename Graph::IncEdgeIt IncEdgeIt; |
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| 54 | |
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| 55 | typedef typename BpUGraph::template ANodeMap<UEdge> ANodeMatchingMap; |
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| 56 | typedef typename BpUGraph::template BNodeMap<UEdge> BNodeMatchingMap; |
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| 57 | |
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| 58 | |
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| 59 | public: |
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| 60 | |
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| 61 | /// \brief Constructor. |
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| 62 | /// |
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| 63 | /// Constructor of the algorithm. |
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| 64 | MaxBipartiteMatching(const BpUGraph& _graph) |
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| 65 | : anode_matching(_graph), bnode_matching(_graph), graph(&_graph) {} |
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| 66 | |
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| 67 | /// \name Execution control |
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| 68 | /// The simplest way to execute the algorithm is to use |
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| 69 | /// one of the member functions called \c run(). |
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| 70 | /// \n |
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| 71 | /// If you need more control on the execution, |
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| 72 | /// first you must call \ref init() or one alternative for it. |
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| 73 | /// Finally \ref start() will perform the matching computation or |
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| 74 | /// with step-by-step execution you can augment the solution. |
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| 75 | |
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| 76 | /// @{ |
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| 77 | |
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| 78 | /// \brief Initalize the data structures. |
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| 79 | /// |
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| 80 | /// It initalizes the data structures and creates an empty matching. |
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| 81 | void init() { |
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| 82 | for (ANodeIt it(*graph); it != INVALID; ++it) { |
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| 83 | anode_matching[it] = INVALID; |
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| 84 | } |
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| 85 | for (BNodeIt it(*graph); it != INVALID; ++it) { |
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| 86 | bnode_matching[it] = INVALID; |
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| 87 | } |
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[2051] | 88 | matching_size = 0; |
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[2040] | 89 | } |
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| 90 | |
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| 91 | /// \brief Initalize the data structures. |
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| 92 | /// |
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| 93 | /// It initalizes the data structures and creates a greedy |
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| 94 | /// matching. From this matching sometimes it is faster to get |
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| 95 | /// the matching than from the initial empty matching. |
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| 96 | void greedyInit() { |
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[2051] | 97 | matching_size = 0; |
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[2040] | 98 | for (BNodeIt it(*graph); it != INVALID; ++it) { |
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| 99 | bnode_matching[it] = INVALID; |
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| 100 | } |
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| 101 | for (ANodeIt it(*graph); it != INVALID; ++it) { |
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| 102 | anode_matching[it] = INVALID; |
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| 103 | for (IncEdgeIt jt(*graph, it); jt != INVALID; ++jt) { |
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| 104 | if (bnode_matching[graph->bNode(jt)] == INVALID) { |
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| 105 | anode_matching[it] = jt; |
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| 106 | bnode_matching[graph->bNode(jt)] = jt; |
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[2051] | 107 | ++matching_size; |
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[2040] | 108 | break; |
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| 109 | } |
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| 110 | } |
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| 111 | } |
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| 112 | } |
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| 113 | |
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| 114 | /// \brief Initalize the data structures with an initial matching. |
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| 115 | /// |
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| 116 | /// It initalizes the data structures with an initial matching. |
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| 117 | template <typename MatchingMap> |
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| 118 | void matchingInit(const MatchingMap& matching) { |
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| 119 | for (ANodeIt it(*graph); it != INVALID; ++it) { |
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| 120 | anode_matching[it] = INVALID; |
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| 121 | } |
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| 122 | for (BNodeIt it(*graph); it != INVALID; ++it) { |
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| 123 | bnode_matching[it] = INVALID; |
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| 124 | } |
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[2051] | 125 | matching_size = 0; |
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[2040] | 126 | for (UEdgeIt it(*graph); it != INVALID; ++it) { |
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| 127 | if (matching[it]) { |
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[2051] | 128 | ++matching_size; |
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[2040] | 129 | anode_matching[graph->aNode(it)] = it; |
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| 130 | bnode_matching[graph->bNode(it)] = it; |
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| 131 | } |
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| 132 | } |
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| 133 | } |
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| 134 | |
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| 135 | /// \brief Initalize the data structures with an initial matching. |
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| 136 | /// |
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| 137 | /// It initalizes the data structures with an initial matching. |
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| 138 | /// \return %True when the given map contains really a matching. |
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| 139 | template <typename MatchingMap> |
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| 140 | void checkedMatchingInit(const MatchingMap& matching) { |
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| 141 | for (ANodeIt it(*graph); it != INVALID; ++it) { |
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| 142 | anode_matching[it] = INVALID; |
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| 143 | } |
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| 144 | for (BNodeIt it(*graph); it != INVALID; ++it) { |
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| 145 | bnode_matching[it] = INVALID; |
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| 146 | } |
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[2051] | 147 | matching_size = 0; |
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[2040] | 148 | for (UEdgeIt it(*graph); it != INVALID; ++it) { |
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| 149 | if (matching[it]) { |
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[2051] | 150 | ++matching_size; |
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[2040] | 151 | if (anode_matching[graph->aNode(it)] != INVALID) { |
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| 152 | return false; |
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| 153 | } |
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| 154 | anode_matching[graph->aNode(it)] = it; |
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| 155 | if (bnode_matching[graph->aNode(it)] != INVALID) { |
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| 156 | return false; |
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| 157 | } |
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| 158 | bnode_matching[graph->bNode(it)] = it; |
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| 159 | } |
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| 160 | } |
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| 161 | return false; |
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| 162 | } |
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| 163 | |
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| 164 | /// \brief An augmenting phase of the Hopcroft-Karp algorithm |
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| 165 | /// |
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| 166 | /// It runs an augmenting phase of the Hopcroft-Karp |
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| 167 | /// algorithm. The phase finds maximum count of edge disjoint |
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| 168 | /// augmenting paths and augments on these paths. The algorithm |
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| 169 | /// consists at most of \f$ O(\sqrt{n}) \f$ phase and one phase is |
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| 170 | /// \f$ O(e) \f$ long. |
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| 171 | bool augment() { |
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| 172 | |
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| 173 | typename Graph::template ANodeMap<bool> areached(*graph, false); |
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| 174 | typename Graph::template BNodeMap<bool> breached(*graph, false); |
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| 175 | |
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| 176 | typename Graph::template BNodeMap<UEdge> bpred(*graph, INVALID); |
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| 177 | |
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| 178 | std::vector<Node> queue, bqueue; |
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| 179 | for (ANodeIt it(*graph); it != INVALID; ++it) { |
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| 180 | if (anode_matching[it] == INVALID) { |
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| 181 | queue.push_back(it); |
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| 182 | areached[it] = true; |
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| 183 | } |
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| 184 | } |
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| 185 | |
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| 186 | bool success = false; |
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| 187 | |
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| 188 | while (!success && !queue.empty()) { |
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| 189 | std::vector<Node> newqueue; |
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| 190 | for (int i = 0; i < (int)queue.size(); ++i) { |
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| 191 | Node anode = queue[i]; |
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| 192 | for (IncEdgeIt jt(*graph, anode); jt != INVALID; ++jt) { |
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| 193 | Node bnode = graph->bNode(jt); |
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| 194 | if (breached[bnode]) continue; |
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| 195 | breached[bnode] = true; |
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| 196 | bpred[bnode] = jt; |
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| 197 | if (bnode_matching[bnode] == INVALID) { |
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| 198 | bqueue.push_back(bnode); |
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| 199 | success = true; |
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| 200 | } else { |
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| 201 | Node newanode = graph->aNode(bnode_matching[bnode]); |
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| 202 | if (!areached[newanode]) { |
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| 203 | areached[newanode] = true; |
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| 204 | newqueue.push_back(newanode); |
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| 205 | } |
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| 206 | } |
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| 207 | } |
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| 208 | } |
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| 209 | queue.swap(newqueue); |
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| 210 | } |
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| 211 | |
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| 212 | if (success) { |
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| 213 | |
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| 214 | typename Graph::template ANodeMap<bool> aused(*graph, false); |
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| 215 | |
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| 216 | for (int i = 0; i < (int)bqueue.size(); ++i) { |
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| 217 | Node bnode = bqueue[i]; |
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| 218 | |
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| 219 | bool used = false; |
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| 220 | |
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| 221 | while (bnode != INVALID) { |
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| 222 | UEdge uedge = bpred[bnode]; |
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| 223 | Node anode = graph->aNode(uedge); |
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| 224 | |
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| 225 | if (aused[anode]) { |
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| 226 | used = true; |
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| 227 | break; |
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| 228 | } |
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| 229 | |
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| 230 | bnode = anode_matching[anode] != INVALID ? |
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| 231 | graph->bNode(anode_matching[anode]) : INVALID; |
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| 232 | |
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| 233 | } |
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| 234 | |
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| 235 | if (used) continue; |
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| 236 | |
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| 237 | bnode = bqueue[i]; |
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| 238 | while (bnode != INVALID) { |
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| 239 | UEdge uedge = bpred[bnode]; |
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| 240 | Node anode = graph->aNode(uedge); |
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| 241 | |
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| 242 | bnode_matching[bnode] = uedge; |
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| 243 | |
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| 244 | bnode = anode_matching[anode] != INVALID ? |
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| 245 | graph->bNode(anode_matching[anode]) : INVALID; |
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| 246 | |
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| 247 | anode_matching[anode] = uedge; |
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| 248 | |
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| 249 | aused[anode] = true; |
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| 250 | } |
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[2051] | 251 | ++matching_size; |
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[2040] | 252 | |
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| 253 | } |
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| 254 | } |
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| 255 | return success; |
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| 256 | } |
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| 257 | |
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| 258 | /// \brief An augmenting phase of the Ford-Fulkerson algorithm |
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| 259 | /// |
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| 260 | /// It runs an augmenting phase of the Ford-Fulkerson |
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| 261 | /// algorithm. The phase finds only one augmenting path and |
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| 262 | /// augments only on this paths. The algorithm consists at most |
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| 263 | /// of \f$ O(n) \f$ simple phase and one phase is at most |
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| 264 | /// \f$ O(e) \f$ long. |
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| 265 | bool simpleAugment() { |
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| 266 | |
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| 267 | typename Graph::template ANodeMap<bool> areached(*graph, false); |
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| 268 | typename Graph::template BNodeMap<bool> breached(*graph, false); |
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| 269 | |
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| 270 | typename Graph::template BNodeMap<UEdge> bpred(*graph, INVALID); |
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| 271 | |
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| 272 | std::vector<Node> queue; |
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| 273 | for (ANodeIt it(*graph); it != INVALID; ++it) { |
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| 274 | if (anode_matching[it] == INVALID) { |
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| 275 | queue.push_back(it); |
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| 276 | areached[it] = true; |
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| 277 | } |
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| 278 | } |
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| 279 | |
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| 280 | while (!queue.empty()) { |
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| 281 | std::vector<Node> newqueue; |
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| 282 | for (int i = 0; i < (int)queue.size(); ++i) { |
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| 283 | Node anode = queue[i]; |
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| 284 | for (IncEdgeIt jt(*graph, anode); jt != INVALID; ++jt) { |
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| 285 | Node bnode = graph->bNode(jt); |
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| 286 | if (breached[bnode]) continue; |
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| 287 | breached[bnode] = true; |
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| 288 | bpred[bnode] = jt; |
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| 289 | if (bnode_matching[bnode] == INVALID) { |
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| 290 | while (bnode != INVALID) { |
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| 291 | UEdge uedge = bpred[bnode]; |
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| 292 | anode = graph->aNode(uedge); |
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| 293 | |
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| 294 | bnode_matching[bnode] = uedge; |
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| 295 | |
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| 296 | bnode = anode_matching[anode] != INVALID ? |
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| 297 | graph->bNode(anode_matching[anode]) : INVALID; |
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| 298 | |
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| 299 | anode_matching[anode] = uedge; |
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| 300 | |
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| 301 | } |
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[2051] | 302 | ++matching_size; |
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[2040] | 303 | return true; |
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| 304 | } else { |
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| 305 | Node newanode = graph->aNode(bnode_matching[bnode]); |
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| 306 | if (!areached[newanode]) { |
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| 307 | areached[newanode] = true; |
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| 308 | newqueue.push_back(newanode); |
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| 309 | } |
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| 310 | } |
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| 311 | } |
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| 312 | } |
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| 313 | queue.swap(newqueue); |
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| 314 | } |
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| 315 | |
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| 316 | return false; |
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| 317 | } |
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| 318 | |
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| 319 | /// \brief Starts the algorithm. |
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| 320 | /// |
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| 321 | /// Starts the algorithm. It runs augmenting phases until the optimal |
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| 322 | /// solution reached. |
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| 323 | void start() { |
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| 324 | while (augment()) {} |
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| 325 | } |
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| 326 | |
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| 327 | /// \brief Runs the algorithm. |
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| 328 | /// |
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| 329 | /// It just initalize the algorithm and then start it. |
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| 330 | void run() { |
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[2058] | 331 | greedyInit(); |
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[2040] | 332 | start(); |
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| 333 | } |
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| 334 | |
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| 335 | /// @} |
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| 336 | |
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| 337 | /// \name Query Functions |
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| 338 | /// The result of the %Matching algorithm can be obtained using these |
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| 339 | /// functions.\n |
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| 340 | /// Before the use of these functions, |
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| 341 | /// either run() or start() must be called. |
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| 342 | |
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| 343 | ///@{ |
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| 344 | |
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| 345 | /// \brief Returns an minimum covering of the nodes. |
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| 346 | /// |
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| 347 | /// The minimum covering set problem is the dual solution of the |
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| 348 | /// maximum bipartite matching. It provides an solution for this |
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| 349 | /// problem what is proof of the optimality of the matching. |
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| 350 | /// \return The size of the cover set. |
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| 351 | template <typename CoverMap> |
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[2058] | 352 | int coverSet(CoverMap& covering) const { |
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[2040] | 353 | |
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| 354 | typename Graph::template ANodeMap<bool> areached(*graph, false); |
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| 355 | typename Graph::template BNodeMap<bool> breached(*graph, false); |
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| 356 | |
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| 357 | std::vector<Node> queue; |
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| 358 | for (ANodeIt it(*graph); it != INVALID; ++it) { |
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| 359 | if (anode_matching[it] == INVALID) { |
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| 360 | queue.push_back(it); |
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| 361 | } |
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| 362 | } |
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| 363 | |
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| 364 | while (!queue.empty()) { |
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| 365 | std::vector<Node> newqueue; |
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| 366 | for (int i = 0; i < (int)queue.size(); ++i) { |
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| 367 | Node anode = queue[i]; |
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| 368 | for (IncEdgeIt jt(*graph, anode); jt != INVALID; ++jt) { |
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| 369 | Node bnode = graph->bNode(jt); |
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| 370 | if (breached[bnode]) continue; |
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| 371 | breached[bnode] = true; |
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| 372 | if (bnode_matching[bnode] != INVALID) { |
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| 373 | Node newanode = graph->aNode(bnode_matching[bnode]); |
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| 374 | if (!areached[newanode]) { |
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| 375 | areached[newanode] = true; |
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| 376 | newqueue.push_back(newanode); |
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| 377 | } |
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| 378 | } |
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| 379 | } |
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| 380 | } |
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| 381 | queue.swap(newqueue); |
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| 382 | } |
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| 383 | |
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| 384 | int size = 0; |
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| 385 | for (ANodeIt it(*graph); it != INVALID; ++it) { |
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| 386 | covering[it] = !areached[it] && anode_matching[it] != INVALID; |
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| 387 | if (!areached[it] && anode_matching[it] != INVALID) { |
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| 388 | ++size; |
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| 389 | } |
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| 390 | } |
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| 391 | for (BNodeIt it(*graph); it != INVALID; ++it) { |
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| 392 | covering[it] = breached[it]; |
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| 393 | if (breached[it]) { |
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| 394 | ++size; |
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| 395 | } |
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| 396 | } |
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| 397 | return size; |
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| 398 | } |
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| 399 | |
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| 400 | /// \brief Set true all matching uedge in the map. |
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| 401 | /// |
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| 402 | /// Set true all matching uedge in the map. It does not change the |
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| 403 | /// value mapped to the other uedges. |
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| 404 | /// \return The number of the matching edges. |
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| 405 | template <typename MatchingMap> |
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[2058] | 406 | int quickMatching(MatchingMap& matching) const { |
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[2040] | 407 | for (ANodeIt it(*graph); it != INVALID; ++it) { |
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| 408 | if (anode_matching[it] != INVALID) { |
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| 409 | matching[anode_matching[it]] = true; |
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| 410 | } |
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| 411 | } |
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[2051] | 412 | return matching_size; |
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[2040] | 413 | } |
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| 414 | |
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| 415 | /// \brief Set true all matching uedge in the map and the others to false. |
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| 416 | /// |
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| 417 | /// Set true all matching uedge in the map and the others to false. |
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| 418 | /// \return The number of the matching edges. |
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| 419 | template <typename MatchingMap> |
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[2058] | 420 | int matching(MatchingMap& matching) const { |
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[2040] | 421 | for (UEdgeIt it(*graph); it != INVALID; ++it) { |
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| 422 | matching[it] = it == anode_matching[graph->aNode(it)]; |
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| 423 | } |
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[2051] | 424 | return matching_size; |
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[2040] | 425 | } |
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| 426 | |
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| 427 | |
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| 428 | /// \brief Return true if the given uedge is in the matching. |
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| 429 | /// |
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| 430 | /// It returns true if the given uedge is in the matching. |
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[2058] | 431 | bool matchingEdge(const UEdge& edge) const { |
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[2040] | 432 | return anode_matching[graph->aNode(edge)] == edge; |
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| 433 | } |
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| 434 | |
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| 435 | /// \brief Returns the matching edge from the node. |
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| 436 | /// |
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| 437 | /// Returns the matching edge from the node. If there is not such |
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| 438 | /// edge it gives back \c INVALID. |
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[2058] | 439 | UEdge matchingEdge(const Node& node) const { |
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[2040] | 440 | if (graph->aNode(node)) { |
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| 441 | return anode_matching[node]; |
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| 442 | } else { |
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| 443 | return bnode_matching[node]; |
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| 444 | } |
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| 445 | } |
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| 446 | |
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| 447 | /// \brief Gives back the number of the matching edges. |
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| 448 | /// |
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| 449 | /// Gives back the number of the matching edges. |
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[2051] | 450 | int matchingSize() const { |
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| 451 | return matching_size; |
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[2040] | 452 | } |
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| 453 | |
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| 454 | /// @} |
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| 455 | |
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| 456 | private: |
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| 457 | |
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| 458 | ANodeMatchingMap anode_matching; |
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| 459 | BNodeMatchingMap bnode_matching; |
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| 460 | const Graph *graph; |
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| 461 | |
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[2051] | 462 | int matching_size; |
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| 463 | |
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| 464 | }; |
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| 465 | |
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[2058] | 466 | /// \ingroup matching |
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| 467 | /// |
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| 468 | /// \brief Maximum cardinality bipartite matching |
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| 469 | /// |
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| 470 | /// This function calculates the maximum cardinality matching |
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| 471 | /// in a bipartite graph. It gives back the matching in an undirected |
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| 472 | /// edge map. |
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| 473 | /// |
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| 474 | /// \param graph The bipartite graph. |
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| 475 | /// \retval matching The undirected edge map which will be set to |
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| 476 | /// the matching. |
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| 477 | /// \return The size of the matching. |
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| 478 | template <typename BpUGraph, typename MatchingMap> |
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| 479 | int maxBipartiteMatching(const BpUGraph& graph, MatchingMap& matching) { |
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| 480 | MaxBipartiteMatching<BpUGraph> bpmatching(graph); |
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| 481 | bpmatching.run(); |
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| 482 | bpmatching.matching(matching); |
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| 483 | return bpmatching.matchingSize(); |
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| 484 | } |
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| 485 | |
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[2051] | 486 | /// \brief Default traits class for weighted bipartite matching algoritms. |
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| 487 | /// |
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| 488 | /// Default traits class for weighted bipartite matching algoritms. |
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| 489 | /// \param _BpUGraph The bipartite undirected graph type. |
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| 490 | /// \param _WeightMap Type of weight map. |
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| 491 | template <typename _BpUGraph, typename _WeightMap> |
---|
| 492 | struct WeightedBipartiteMatchingDefaultTraits { |
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| 493 | /// \brief The type of the weight of the undirected edges. |
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| 494 | typedef typename _WeightMap::Value Value; |
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| 495 | |
---|
| 496 | /// The undirected bipartite graph type the algorithm runs on. |
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| 497 | typedef _BpUGraph BpUGraph; |
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| 498 | |
---|
| 499 | /// The map of the edges weights |
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| 500 | typedef _WeightMap WeightMap; |
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| 501 | |
---|
| 502 | /// \brief The cross reference type used by heap. |
---|
| 503 | /// |
---|
| 504 | /// The cross reference type used by heap. |
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| 505 | /// Usually it is \c Graph::NodeMap<int>. |
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| 506 | typedef typename BpUGraph::template NodeMap<int> HeapCrossRef; |
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| 507 | |
---|
| 508 | /// \brief Instantiates a HeapCrossRef. |
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| 509 | /// |
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| 510 | /// This function instantiates a \ref HeapCrossRef. |
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| 511 | /// \param graph is the graph, to which we would like to define the |
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| 512 | /// HeapCrossRef. |
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| 513 | static HeapCrossRef *createHeapCrossRef(const BpUGraph &graph) { |
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| 514 | return new HeapCrossRef(graph); |
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| 515 | } |
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| 516 | |
---|
| 517 | /// \brief The heap type used by weighted matching algorithms. |
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| 518 | /// |
---|
| 519 | /// The heap type used by weighted matching algorithms. It should |
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| 520 | /// minimize the priorities and the heap's key type is the graph's |
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| 521 | /// anode graph's node. |
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| 522 | /// |
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| 523 | /// \sa BinHeap |
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| 524 | typedef BinHeap<typename BpUGraph::Node, Value, HeapCrossRef> Heap; |
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| 525 | |
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| 526 | /// \brief Instantiates a Heap. |
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| 527 | /// |
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| 528 | /// This function instantiates a \ref Heap. |
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| 529 | /// \param crossref The cross reference of the heap. |
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| 530 | static Heap *createHeap(HeapCrossRef& crossref) { |
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| 531 | return new Heap(crossref); |
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| 532 | } |
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| 533 | |
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| 534 | }; |
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| 535 | |
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| 536 | |
---|
| 537 | /// \ingroup matching |
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| 538 | /// |
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| 539 | /// \brief Bipartite Max Weighted Matching algorithm |
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| 540 | /// |
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| 541 | /// This class implements the bipartite Max Weighted Matching |
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| 542 | /// algorithm. It uses the successive shortest path algorithm to |
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| 543 | /// calculate the maximum weighted matching in the bipartite |
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| 544 | /// graph. The algorithm can be used also to calculate the maximum |
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| 545 | /// cardinality maximum weighted matching. The time complexity |
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| 546 | /// of the algorithm is \f$ O(ne\log(n)) \f$ with the default binary |
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| 547 | /// heap implementation but this can be improved to |
---|
| 548 | /// \f$ O(n^2\log(n)+ne) \f$ if we use fibonacci heaps. |
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| 549 | /// |
---|
| 550 | /// The algorithm also provides a potential function on the nodes |
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| 551 | /// which a dual solution of the matching algorithm and it can be |
---|
| 552 | /// used to proof the optimality of the given pimal solution. |
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| 553 | #ifdef DOXYGEN |
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| 554 | template <typename _BpUGraph, typename _WeightMap, typename _Traits> |
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| 555 | #else |
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| 556 | template <typename _BpUGraph, |
---|
| 557 | typename _WeightMap = typename _BpUGraph::template UEdgeMap<int>, |
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| 558 | typename _Traits = WeightedBipartiteMatchingDefaultTraits<_BpUGraph, _WeightMap> > |
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| 559 | #endif |
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| 560 | class MaxWeightedBipartiteMatching { |
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| 561 | public: |
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| 562 | |
---|
| 563 | typedef _Traits Traits; |
---|
| 564 | typedef typename Traits::BpUGraph BpUGraph; |
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| 565 | typedef typename Traits::WeightMap WeightMap; |
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| 566 | typedef typename Traits::Value Value; |
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| 567 | |
---|
| 568 | protected: |
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| 569 | |
---|
| 570 | typedef typename Traits::HeapCrossRef HeapCrossRef; |
---|
| 571 | typedef typename Traits::Heap Heap; |
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| 572 | |
---|
| 573 | |
---|
| 574 | typedef typename BpUGraph::Node Node; |
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| 575 | typedef typename BpUGraph::ANodeIt ANodeIt; |
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| 576 | typedef typename BpUGraph::BNodeIt BNodeIt; |
---|
| 577 | typedef typename BpUGraph::UEdge UEdge; |
---|
| 578 | typedef typename BpUGraph::UEdgeIt UEdgeIt; |
---|
| 579 | typedef typename BpUGraph::IncEdgeIt IncEdgeIt; |
---|
| 580 | |
---|
| 581 | typedef typename BpUGraph::template ANodeMap<UEdge> ANodeMatchingMap; |
---|
| 582 | typedef typename BpUGraph::template BNodeMap<UEdge> BNodeMatchingMap; |
---|
| 583 | |
---|
| 584 | typedef typename BpUGraph::template ANodeMap<Value> ANodePotentialMap; |
---|
| 585 | typedef typename BpUGraph::template BNodeMap<Value> BNodePotentialMap; |
---|
| 586 | |
---|
| 587 | |
---|
| 588 | public: |
---|
| 589 | |
---|
| 590 | /// \brief \ref Exception for uninitialized parameters. |
---|
| 591 | /// |
---|
| 592 | /// This error represents problems in the initialization |
---|
| 593 | /// of the parameters of the algorithms. |
---|
| 594 | class UninitializedParameter : public lemon::UninitializedParameter { |
---|
| 595 | public: |
---|
[2151] | 596 | virtual const char* what() const throw() { |
---|
[2051] | 597 | return "lemon::MaxWeightedBipartiteMatching::UninitializedParameter"; |
---|
| 598 | } |
---|
| 599 | }; |
---|
| 600 | |
---|
| 601 | ///\name Named template parameters |
---|
| 602 | |
---|
| 603 | ///@{ |
---|
| 604 | |
---|
| 605 | template <class H, class CR> |
---|
| 606 | struct DefHeapTraits : public Traits { |
---|
| 607 | typedef CR HeapCrossRef; |
---|
| 608 | typedef H Heap; |
---|
| 609 | static HeapCrossRef *createHeapCrossRef(const BpUGraph &) { |
---|
| 610 | throw UninitializedParameter(); |
---|
| 611 | } |
---|
| 612 | static Heap *createHeap(HeapCrossRef &) { |
---|
| 613 | throw UninitializedParameter(); |
---|
| 614 | } |
---|
| 615 | }; |
---|
| 616 | |
---|
| 617 | /// \brief \ref named-templ-param "Named parameter" for setting heap |
---|
| 618 | /// and cross reference type |
---|
| 619 | /// |
---|
| 620 | /// \ref named-templ-param "Named parameter" for setting heap and cross |
---|
| 621 | /// reference type |
---|
| 622 | template <class H, class CR = typename BpUGraph::template NodeMap<int> > |
---|
| 623 | struct DefHeap |
---|
| 624 | : public MaxWeightedBipartiteMatching<BpUGraph, WeightMap, |
---|
| 625 | DefHeapTraits<H, CR> > { |
---|
| 626 | typedef MaxWeightedBipartiteMatching<BpUGraph, WeightMap, |
---|
| 627 | DefHeapTraits<H, CR> > Create; |
---|
| 628 | }; |
---|
| 629 | |
---|
| 630 | template <class H, class CR> |
---|
| 631 | struct DefStandardHeapTraits : public Traits { |
---|
| 632 | typedef CR HeapCrossRef; |
---|
| 633 | typedef H Heap; |
---|
| 634 | static HeapCrossRef *createHeapCrossRef(const BpUGraph &graph) { |
---|
| 635 | return new HeapCrossRef(graph); |
---|
| 636 | } |
---|
| 637 | static Heap *createHeap(HeapCrossRef &crossref) { |
---|
| 638 | return new Heap(crossref); |
---|
| 639 | } |
---|
| 640 | }; |
---|
| 641 | |
---|
| 642 | /// \brief \ref named-templ-param "Named parameter" for setting heap and |
---|
| 643 | /// cross reference type with automatic allocation |
---|
| 644 | /// |
---|
| 645 | /// \ref named-templ-param "Named parameter" for setting heap and cross |
---|
| 646 | /// reference type. It can allocate the heap and the cross reference |
---|
| 647 | /// object if the cross reference's constructor waits for the graph as |
---|
| 648 | /// parameter and the heap's constructor waits for the cross reference. |
---|
| 649 | template <class H, class CR = typename BpUGraph::template NodeMap<int> > |
---|
| 650 | struct DefStandardHeap |
---|
| 651 | : public MaxWeightedBipartiteMatching<BpUGraph, WeightMap, |
---|
| 652 | DefStandardHeapTraits<H, CR> > { |
---|
| 653 | typedef MaxWeightedBipartiteMatching<BpUGraph, WeightMap, |
---|
| 654 | DefStandardHeapTraits<H, CR> > |
---|
| 655 | Create; |
---|
| 656 | }; |
---|
| 657 | |
---|
| 658 | ///@} |
---|
| 659 | |
---|
| 660 | |
---|
| 661 | /// \brief Constructor. |
---|
| 662 | /// |
---|
| 663 | /// Constructor of the algorithm. |
---|
| 664 | MaxWeightedBipartiteMatching(const BpUGraph& _graph, |
---|
| 665 | const WeightMap& _weight) |
---|
| 666 | : graph(&_graph), weight(&_weight), |
---|
| 667 | anode_matching(_graph), bnode_matching(_graph), |
---|
| 668 | anode_potential(_graph), bnode_potential(_graph), |
---|
| 669 | _heap_cross_ref(0), local_heap_cross_ref(false), |
---|
| 670 | _heap(0), local_heap(0) {} |
---|
| 671 | |
---|
| 672 | /// \brief Destructor. |
---|
| 673 | /// |
---|
| 674 | /// Destructor of the algorithm. |
---|
| 675 | ~MaxWeightedBipartiteMatching() { |
---|
| 676 | destroyStructures(); |
---|
| 677 | } |
---|
| 678 | |
---|
| 679 | /// \brief Sets the heap and the cross reference used by algorithm. |
---|
| 680 | /// |
---|
| 681 | /// Sets the heap and the cross reference used by algorithm. |
---|
| 682 | /// If you don't use this function before calling \ref run(), |
---|
| 683 | /// it will allocate one. The destuctor deallocates this |
---|
| 684 | /// automatically allocated map, of course. |
---|
| 685 | /// \return \c (*this) |
---|
| 686 | MaxWeightedBipartiteMatching& heap(Heap& heap, HeapCrossRef &crossRef) { |
---|
| 687 | if(local_heap_cross_ref) { |
---|
| 688 | delete _heap_cross_ref; |
---|
| 689 | local_heap_cross_ref = false; |
---|
| 690 | } |
---|
| 691 | _heap_cross_ref = &crossRef; |
---|
| 692 | if(local_heap) { |
---|
| 693 | delete _heap; |
---|
| 694 | local_heap = false; |
---|
| 695 | } |
---|
| 696 | _heap = &heap; |
---|
| 697 | return *this; |
---|
| 698 | } |
---|
| 699 | |
---|
| 700 | /// \name Execution control |
---|
| 701 | /// The simplest way to execute the algorithm is to use |
---|
| 702 | /// one of the member functions called \c run(). |
---|
| 703 | /// \n |
---|
| 704 | /// If you need more control on the execution, |
---|
| 705 | /// first you must call \ref init() or one alternative for it. |
---|
| 706 | /// Finally \ref start() will perform the matching computation or |
---|
| 707 | /// with step-by-step execution you can augment the solution. |
---|
| 708 | |
---|
| 709 | /// @{ |
---|
| 710 | |
---|
| 711 | /// \brief Initalize the data structures. |
---|
| 712 | /// |
---|
| 713 | /// It initalizes the data structures and creates an empty matching. |
---|
| 714 | void init() { |
---|
| 715 | initStructures(); |
---|
| 716 | for (ANodeIt it(*graph); it != INVALID; ++it) { |
---|
| 717 | anode_matching[it] = INVALID; |
---|
| 718 | anode_potential[it] = 0; |
---|
| 719 | } |
---|
| 720 | for (BNodeIt it(*graph); it != INVALID; ++it) { |
---|
| 721 | bnode_matching[it] = INVALID; |
---|
| 722 | bnode_potential[it] = 0; |
---|
| 723 | for (IncEdgeIt jt(*graph, it); jt != INVALID; ++jt) { |
---|
[2058] | 724 | if ((*weight)[jt] > bnode_potential[it]) { |
---|
| 725 | bnode_potential[it] = (*weight)[jt]; |
---|
[2051] | 726 | } |
---|
| 727 | } |
---|
| 728 | } |
---|
| 729 | matching_value = 0; |
---|
| 730 | matching_size = 0; |
---|
| 731 | } |
---|
| 732 | |
---|
| 733 | |
---|
| 734 | /// \brief An augmenting phase of the weighted matching algorithm |
---|
| 735 | /// |
---|
| 736 | /// It runs an augmenting phase of the weighted matching |
---|
| 737 | /// algorithm. The phase finds the best augmenting path and |
---|
| 738 | /// augments only on this paths. |
---|
| 739 | /// |
---|
| 740 | /// The algorithm consists at most |
---|
| 741 | /// of \f$ O(n) \f$ phase and one phase is \f$ O(n\log(n)+e) \f$ |
---|
| 742 | /// long with Fibonacci heap or \f$ O((n+e)\log(n)) \f$ long |
---|
| 743 | /// with binary heap. |
---|
| 744 | /// \param decrease If the given parameter true the matching value |
---|
| 745 | /// can be decreased in the augmenting phase. If we would like |
---|
| 746 | /// to calculate the maximum cardinality maximum weighted matching |
---|
| 747 | /// then we should let the algorithm to decrease the matching |
---|
| 748 | /// value in order to increase the number of the matching edges. |
---|
| 749 | bool augment(bool decrease = false) { |
---|
| 750 | |
---|
| 751 | typename BpUGraph::template BNodeMap<Value> bdist(*graph); |
---|
| 752 | typename BpUGraph::template BNodeMap<UEdge> bpred(*graph, INVALID); |
---|
| 753 | |
---|
| 754 | Node bestNode = INVALID; |
---|
| 755 | Value bestValue = 0; |
---|
| 756 | |
---|
| 757 | _heap->clear(); |
---|
| 758 | for (ANodeIt it(*graph); it != INVALID; ++it) { |
---|
| 759 | (*_heap_cross_ref)[it] = Heap::PRE_HEAP; |
---|
| 760 | } |
---|
| 761 | |
---|
| 762 | for (ANodeIt it(*graph); it != INVALID; ++it) { |
---|
| 763 | if (anode_matching[it] == INVALID) { |
---|
| 764 | _heap->push(it, 0); |
---|
| 765 | } |
---|
| 766 | } |
---|
| 767 | |
---|
| 768 | Value bdistMax = 0; |
---|
| 769 | while (!_heap->empty()) { |
---|
| 770 | Node anode = _heap->top(); |
---|
| 771 | Value avalue = _heap->prio(); |
---|
| 772 | _heap->pop(); |
---|
| 773 | for (IncEdgeIt jt(*graph, anode); jt != INVALID; ++jt) { |
---|
| 774 | if (jt == anode_matching[anode]) continue; |
---|
| 775 | Node bnode = graph->bNode(jt); |
---|
[2058] | 776 | Value bvalue = avalue - (*weight)[jt] + |
---|
| 777 | anode_potential[anode] + bnode_potential[bnode]; |
---|
[2051] | 778 | if (bpred[bnode] == INVALID || bvalue < bdist[bnode]) { |
---|
| 779 | bdist[bnode] = bvalue; |
---|
| 780 | bpred[bnode] = jt; |
---|
| 781 | } |
---|
| 782 | if (bvalue > bdistMax) { |
---|
| 783 | bdistMax = bvalue; |
---|
| 784 | } |
---|
| 785 | if (bnode_matching[bnode] != INVALID) { |
---|
| 786 | Node newanode = graph->aNode(bnode_matching[bnode]); |
---|
| 787 | switch (_heap->state(newanode)) { |
---|
| 788 | case Heap::PRE_HEAP: |
---|
| 789 | _heap->push(newanode, bvalue); |
---|
| 790 | break; |
---|
| 791 | case Heap::IN_HEAP: |
---|
| 792 | if (bvalue < (*_heap)[newanode]) { |
---|
| 793 | _heap->decrease(newanode, bvalue); |
---|
| 794 | } |
---|
| 795 | break; |
---|
| 796 | case Heap::POST_HEAP: |
---|
| 797 | break; |
---|
| 798 | } |
---|
| 799 | } else { |
---|
| 800 | if (bestNode == INVALID || |
---|
[2058] | 801 | bnode_potential[bnode] - bvalue > bestValue) { |
---|
| 802 | bestValue = bnode_potential[bnode] - bvalue; |
---|
[2051] | 803 | bestNode = bnode; |
---|
| 804 | } |
---|
| 805 | } |
---|
| 806 | } |
---|
| 807 | } |
---|
| 808 | |
---|
| 809 | if (bestNode == INVALID || (!decrease && bestValue < 0)) { |
---|
| 810 | return false; |
---|
| 811 | } |
---|
| 812 | |
---|
| 813 | matching_value += bestValue; |
---|
| 814 | ++matching_size; |
---|
| 815 | |
---|
| 816 | for (BNodeIt it(*graph); it != INVALID; ++it) { |
---|
| 817 | if (bpred[it] != INVALID) { |
---|
[2058] | 818 | bnode_potential[it] -= bdist[it]; |
---|
[2051] | 819 | } else { |
---|
[2058] | 820 | bnode_potential[it] -= bdistMax; |
---|
[2051] | 821 | } |
---|
| 822 | } |
---|
| 823 | for (ANodeIt it(*graph); it != INVALID; ++it) { |
---|
| 824 | if (anode_matching[it] != INVALID) { |
---|
| 825 | Node bnode = graph->bNode(anode_matching[it]); |
---|
| 826 | if (bpred[bnode] != INVALID) { |
---|
| 827 | anode_potential[it] += bdist[bnode]; |
---|
| 828 | } else { |
---|
| 829 | anode_potential[it] += bdistMax; |
---|
| 830 | } |
---|
| 831 | } |
---|
| 832 | } |
---|
| 833 | |
---|
| 834 | while (bestNode != INVALID) { |
---|
| 835 | UEdge uedge = bpred[bestNode]; |
---|
| 836 | Node anode = graph->aNode(uedge); |
---|
| 837 | |
---|
| 838 | bnode_matching[bestNode] = uedge; |
---|
| 839 | if (anode_matching[anode] != INVALID) { |
---|
| 840 | bestNode = graph->bNode(anode_matching[anode]); |
---|
| 841 | } else { |
---|
| 842 | bestNode = INVALID; |
---|
| 843 | } |
---|
| 844 | anode_matching[anode] = uedge; |
---|
| 845 | } |
---|
| 846 | |
---|
| 847 | |
---|
| 848 | return true; |
---|
| 849 | } |
---|
| 850 | |
---|
| 851 | /// \brief Starts the algorithm. |
---|
| 852 | /// |
---|
| 853 | /// Starts the algorithm. It runs augmenting phases until the |
---|
| 854 | /// optimal solution reached. |
---|
| 855 | /// |
---|
| 856 | /// \param maxCardinality If the given value is true it will |
---|
| 857 | /// calculate the maximum cardinality maximum matching instead of |
---|
| 858 | /// the maximum matching. |
---|
| 859 | void start(bool maxCardinality = false) { |
---|
| 860 | while (augment(maxCardinality)) {} |
---|
| 861 | } |
---|
| 862 | |
---|
| 863 | /// \brief Runs the algorithm. |
---|
| 864 | /// |
---|
| 865 | /// It just initalize the algorithm and then start it. |
---|
| 866 | /// |
---|
| 867 | /// \param maxCardinality If the given value is true it will |
---|
| 868 | /// calculate the maximum cardinality maximum matching instead of |
---|
| 869 | /// the maximum matching. |
---|
| 870 | void run(bool maxCardinality = false) { |
---|
| 871 | init(); |
---|
| 872 | start(maxCardinality); |
---|
| 873 | } |
---|
| 874 | |
---|
| 875 | /// @} |
---|
| 876 | |
---|
| 877 | /// \name Query Functions |
---|
| 878 | /// The result of the %Matching algorithm can be obtained using these |
---|
| 879 | /// functions.\n |
---|
| 880 | /// Before the use of these functions, |
---|
| 881 | /// either run() or start() must be called. |
---|
| 882 | |
---|
| 883 | ///@{ |
---|
| 884 | |
---|
| 885 | /// \brief Gives back the potential in the NodeMap |
---|
| 886 | /// |
---|
[2058] | 887 | /// Gives back the potential in the NodeMap. The matching is optimal |
---|
| 888 | /// with the current number of edges if \f$ \pi(a) + \pi(b) - w(ab) = 0 \f$ |
---|
| 889 | /// for each matching edges and \f$ \pi(a) + \pi(b) - w(ab) \ge 0 \f$ |
---|
| 890 | /// for each edges. |
---|
[2051] | 891 | template <typename PotentialMap> |
---|
[2058] | 892 | void potential(PotentialMap& potential) const { |
---|
[2051] | 893 | for (ANodeIt it(*graph); it != INVALID; ++it) { |
---|
| 894 | potential[it] = anode_potential[it]; |
---|
| 895 | } |
---|
| 896 | for (BNodeIt it(*graph); it != INVALID; ++it) { |
---|
| 897 | potential[it] = bnode_potential[it]; |
---|
| 898 | } |
---|
| 899 | } |
---|
| 900 | |
---|
| 901 | /// \brief Set true all matching uedge in the map. |
---|
| 902 | /// |
---|
| 903 | /// Set true all matching uedge in the map. It does not change the |
---|
| 904 | /// value mapped to the other uedges. |
---|
| 905 | /// \return The number of the matching edges. |
---|
| 906 | template <typename MatchingMap> |
---|
[2058] | 907 | int quickMatching(MatchingMap& matching) const { |
---|
[2051] | 908 | for (ANodeIt it(*graph); it != INVALID; ++it) { |
---|
| 909 | if (anode_matching[it] != INVALID) { |
---|
| 910 | matching[anode_matching[it]] = true; |
---|
| 911 | } |
---|
| 912 | } |
---|
| 913 | return matching_size; |
---|
| 914 | } |
---|
| 915 | |
---|
| 916 | /// \brief Set true all matching uedge in the map and the others to false. |
---|
| 917 | /// |
---|
| 918 | /// Set true all matching uedge in the map and the others to false. |
---|
| 919 | /// \return The number of the matching edges. |
---|
| 920 | template <typename MatchingMap> |
---|
[2058] | 921 | int matching(MatchingMap& matching) const { |
---|
[2051] | 922 | for (UEdgeIt it(*graph); it != INVALID; ++it) { |
---|
| 923 | matching[it] = it == anode_matching[graph->aNode(it)]; |
---|
| 924 | } |
---|
| 925 | return matching_size; |
---|
| 926 | } |
---|
| 927 | |
---|
| 928 | |
---|
| 929 | /// \brief Return true if the given uedge is in the matching. |
---|
| 930 | /// |
---|
| 931 | /// It returns true if the given uedge is in the matching. |
---|
[2058] | 932 | bool matchingEdge(const UEdge& edge) const { |
---|
[2051] | 933 | return anode_matching[graph->aNode(edge)] == edge; |
---|
| 934 | } |
---|
| 935 | |
---|
| 936 | /// \brief Returns the matching edge from the node. |
---|
| 937 | /// |
---|
| 938 | /// Returns the matching edge from the node. If there is not such |
---|
| 939 | /// edge it gives back \c INVALID. |
---|
[2058] | 940 | UEdge matchingEdge(const Node& node) const { |
---|
[2051] | 941 | if (graph->aNode(node)) { |
---|
| 942 | return anode_matching[node]; |
---|
| 943 | } else { |
---|
| 944 | return bnode_matching[node]; |
---|
| 945 | } |
---|
| 946 | } |
---|
| 947 | |
---|
| 948 | /// \brief Gives back the sum of weights of the matching edges. |
---|
| 949 | /// |
---|
| 950 | /// Gives back the sum of weights of the matching edges. |
---|
| 951 | Value matchingValue() const { |
---|
| 952 | return matching_value; |
---|
| 953 | } |
---|
| 954 | |
---|
| 955 | /// \brief Gives back the number of the matching edges. |
---|
| 956 | /// |
---|
| 957 | /// Gives back the number of the matching edges. |
---|
| 958 | int matchingSize() const { |
---|
| 959 | return matching_size; |
---|
| 960 | } |
---|
| 961 | |
---|
| 962 | /// @} |
---|
| 963 | |
---|
| 964 | private: |
---|
| 965 | |
---|
| 966 | void initStructures() { |
---|
| 967 | if (!_heap_cross_ref) { |
---|
| 968 | local_heap_cross_ref = true; |
---|
| 969 | _heap_cross_ref = Traits::createHeapCrossRef(*graph); |
---|
| 970 | } |
---|
| 971 | if (!_heap) { |
---|
| 972 | local_heap = true; |
---|
| 973 | _heap = Traits::createHeap(*_heap_cross_ref); |
---|
| 974 | } |
---|
| 975 | } |
---|
| 976 | |
---|
| 977 | void destroyStructures() { |
---|
| 978 | if (local_heap_cross_ref) delete _heap_cross_ref; |
---|
| 979 | if (local_heap) delete _heap; |
---|
| 980 | } |
---|
| 981 | |
---|
| 982 | |
---|
| 983 | private: |
---|
| 984 | |
---|
| 985 | const BpUGraph *graph; |
---|
| 986 | const WeightMap* weight; |
---|
| 987 | |
---|
| 988 | ANodeMatchingMap anode_matching; |
---|
| 989 | BNodeMatchingMap bnode_matching; |
---|
| 990 | |
---|
| 991 | ANodePotentialMap anode_potential; |
---|
| 992 | BNodePotentialMap bnode_potential; |
---|
| 993 | |
---|
| 994 | Value matching_value; |
---|
| 995 | int matching_size; |
---|
| 996 | |
---|
| 997 | HeapCrossRef *_heap_cross_ref; |
---|
| 998 | bool local_heap_cross_ref; |
---|
| 999 | |
---|
| 1000 | Heap *_heap; |
---|
| 1001 | bool local_heap; |
---|
| 1002 | |
---|
| 1003 | }; |
---|
| 1004 | |
---|
[2058] | 1005 | /// \ingroup matching |
---|
| 1006 | /// |
---|
| 1007 | /// \brief Maximum weighted bipartite matching |
---|
| 1008 | /// |
---|
| 1009 | /// This function calculates the maximum weighted matching |
---|
| 1010 | /// in a bipartite graph. It gives back the matching in an undirected |
---|
| 1011 | /// edge map. |
---|
| 1012 | /// |
---|
| 1013 | /// \param graph The bipartite graph. |
---|
| 1014 | /// \param weight The undirected edge map which contains the weights. |
---|
| 1015 | /// \retval matching The undirected edge map which will be set to |
---|
| 1016 | /// the matching. |
---|
| 1017 | /// \return The value of the matching. |
---|
| 1018 | template <typename BpUGraph, typename WeightMap, typename MatchingMap> |
---|
| 1019 | typename WeightMap::Value |
---|
| 1020 | maxWeightedBipartiteMatching(const BpUGraph& graph, const WeightMap& weight, |
---|
| 1021 | MatchingMap& matching) { |
---|
| 1022 | MaxWeightedBipartiteMatching<BpUGraph, WeightMap> |
---|
| 1023 | bpmatching(graph, weight); |
---|
| 1024 | bpmatching.run(); |
---|
| 1025 | bpmatching.matching(matching); |
---|
| 1026 | return bpmatching.matchingValue(); |
---|
| 1027 | } |
---|
| 1028 | |
---|
| 1029 | /// \ingroup matching |
---|
| 1030 | /// |
---|
| 1031 | /// \brief Maximum weighted maximum cardinality bipartite matching |
---|
| 1032 | /// |
---|
| 1033 | /// This function calculates the maximum weighted of the maximum cardinality |
---|
| 1034 | /// matchings of a bipartite graph. It gives back the matching in an |
---|
| 1035 | /// undirected edge map. |
---|
| 1036 | /// |
---|
| 1037 | /// \param graph The bipartite graph. |
---|
| 1038 | /// \param weight The undirected edge map which contains the weights. |
---|
| 1039 | /// \retval matching The undirected edge map which will be set to |
---|
| 1040 | /// the matching. |
---|
| 1041 | /// \return The value of the matching. |
---|
| 1042 | template <typename BpUGraph, typename WeightMap, typename MatchingMap> |
---|
| 1043 | typename WeightMap::Value |
---|
| 1044 | maxWeightedMaxBipartiteMatching(const BpUGraph& graph, |
---|
| 1045 | const WeightMap& weight, |
---|
| 1046 | MatchingMap& matching) { |
---|
| 1047 | MaxWeightedBipartiteMatching<BpUGraph, WeightMap> |
---|
| 1048 | bpmatching(graph, weight); |
---|
| 1049 | bpmatching.run(true); |
---|
| 1050 | bpmatching.matching(matching); |
---|
| 1051 | return bpmatching.matchingValue(); |
---|
| 1052 | } |
---|
| 1053 | |
---|
[2051] | 1054 | /// \brief Default traits class for minimum cost bipartite matching |
---|
| 1055 | /// algoritms. |
---|
| 1056 | /// |
---|
| 1057 | /// Default traits class for minimum cost bipartite matching |
---|
| 1058 | /// algoritms. |
---|
| 1059 | /// |
---|
| 1060 | /// \param _BpUGraph The bipartite undirected graph |
---|
| 1061 | /// type. |
---|
| 1062 | /// |
---|
| 1063 | /// \param _CostMap Type of cost map. |
---|
| 1064 | template <typename _BpUGraph, typename _CostMap> |
---|
| 1065 | struct MinCostMaxBipartiteMatchingDefaultTraits { |
---|
| 1066 | /// \brief The type of the cost of the undirected edges. |
---|
| 1067 | typedef typename _CostMap::Value Value; |
---|
| 1068 | |
---|
| 1069 | /// The undirected bipartite graph type the algorithm runs on. |
---|
| 1070 | typedef _BpUGraph BpUGraph; |
---|
| 1071 | |
---|
| 1072 | /// The map of the edges costs |
---|
| 1073 | typedef _CostMap CostMap; |
---|
| 1074 | |
---|
| 1075 | /// \brief The cross reference type used by heap. |
---|
| 1076 | /// |
---|
| 1077 | /// The cross reference type used by heap. |
---|
| 1078 | /// Usually it is \c Graph::NodeMap<int>. |
---|
| 1079 | typedef typename BpUGraph::template NodeMap<int> HeapCrossRef; |
---|
| 1080 | |
---|
| 1081 | /// \brief Instantiates a HeapCrossRef. |
---|
| 1082 | /// |
---|
| 1083 | /// This function instantiates a \ref HeapCrossRef. |
---|
| 1084 | /// \param graph is the graph, to which we would like to define the |
---|
| 1085 | /// HeapCrossRef. |
---|
| 1086 | static HeapCrossRef *createHeapCrossRef(const BpUGraph &graph) { |
---|
| 1087 | return new HeapCrossRef(graph); |
---|
| 1088 | } |
---|
| 1089 | |
---|
| 1090 | /// \brief The heap type used by costed matching algorithms. |
---|
| 1091 | /// |
---|
| 1092 | /// The heap type used by costed matching algorithms. It should |
---|
| 1093 | /// minimize the priorities and the heap's key type is the graph's |
---|
| 1094 | /// anode graph's node. |
---|
| 1095 | /// |
---|
| 1096 | /// \sa BinHeap |
---|
| 1097 | typedef BinHeap<typename BpUGraph::Node, Value, HeapCrossRef> Heap; |
---|
| 1098 | |
---|
| 1099 | /// \brief Instantiates a Heap. |
---|
| 1100 | /// |
---|
| 1101 | /// This function instantiates a \ref Heap. |
---|
| 1102 | /// \param crossref The cross reference of the heap. |
---|
| 1103 | static Heap *createHeap(HeapCrossRef& crossref) { |
---|
| 1104 | return new Heap(crossref); |
---|
| 1105 | } |
---|
| 1106 | |
---|
| 1107 | }; |
---|
| 1108 | |
---|
| 1109 | |
---|
| 1110 | /// \ingroup matching |
---|
| 1111 | /// |
---|
| 1112 | /// \brief Bipartite Min Cost Matching algorithm |
---|
| 1113 | /// |
---|
| 1114 | /// This class implements the bipartite Min Cost Matching algorithm. |
---|
| 1115 | /// It uses the successive shortest path algorithm to calculate the |
---|
| 1116 | /// minimum cost maximum matching in the bipartite graph. The time |
---|
| 1117 | /// complexity of the algorithm is \f$ O(ne\log(n)) \f$ with the |
---|
| 1118 | /// default binary heap implementation but this can be improved to |
---|
| 1119 | /// \f$ O(n^2\log(n)+ne) \f$ if we use fibonacci heaps. |
---|
| 1120 | /// |
---|
| 1121 | /// The algorithm also provides a potential function on the nodes |
---|
| 1122 | /// which a dual solution of the matching algorithm and it can be |
---|
| 1123 | /// used to proof the optimality of the given pimal solution. |
---|
| 1124 | #ifdef DOXYGEN |
---|
| 1125 | template <typename _BpUGraph, typename _CostMap, typename _Traits> |
---|
| 1126 | #else |
---|
| 1127 | template <typename _BpUGraph, |
---|
| 1128 | typename _CostMap = typename _BpUGraph::template UEdgeMap<int>, |
---|
| 1129 | typename _Traits = MinCostMaxBipartiteMatchingDefaultTraits<_BpUGraph, _CostMap> > |
---|
| 1130 | #endif |
---|
| 1131 | class MinCostMaxBipartiteMatching { |
---|
| 1132 | public: |
---|
| 1133 | |
---|
| 1134 | typedef _Traits Traits; |
---|
| 1135 | typedef typename Traits::BpUGraph BpUGraph; |
---|
| 1136 | typedef typename Traits::CostMap CostMap; |
---|
| 1137 | typedef typename Traits::Value Value; |
---|
| 1138 | |
---|
| 1139 | protected: |
---|
| 1140 | |
---|
| 1141 | typedef typename Traits::HeapCrossRef HeapCrossRef; |
---|
| 1142 | typedef typename Traits::Heap Heap; |
---|
| 1143 | |
---|
| 1144 | |
---|
| 1145 | typedef typename BpUGraph::Node Node; |
---|
| 1146 | typedef typename BpUGraph::ANodeIt ANodeIt; |
---|
| 1147 | typedef typename BpUGraph::BNodeIt BNodeIt; |
---|
| 1148 | typedef typename BpUGraph::UEdge UEdge; |
---|
| 1149 | typedef typename BpUGraph::UEdgeIt UEdgeIt; |
---|
| 1150 | typedef typename BpUGraph::IncEdgeIt IncEdgeIt; |
---|
| 1151 | |
---|
| 1152 | typedef typename BpUGraph::template ANodeMap<UEdge> ANodeMatchingMap; |
---|
| 1153 | typedef typename BpUGraph::template BNodeMap<UEdge> BNodeMatchingMap; |
---|
| 1154 | |
---|
| 1155 | typedef typename BpUGraph::template ANodeMap<Value> ANodePotentialMap; |
---|
| 1156 | typedef typename BpUGraph::template BNodeMap<Value> BNodePotentialMap; |
---|
| 1157 | |
---|
| 1158 | |
---|
| 1159 | public: |
---|
| 1160 | |
---|
| 1161 | /// \brief \ref Exception for uninitialized parameters. |
---|
| 1162 | /// |
---|
| 1163 | /// This error represents problems in the initialization |
---|
| 1164 | /// of the parameters of the algorithms. |
---|
| 1165 | class UninitializedParameter : public lemon::UninitializedParameter { |
---|
| 1166 | public: |
---|
[2151] | 1167 | virtual const char* what() const throw() { |
---|
[2051] | 1168 | return "lemon::MinCostMaxBipartiteMatching::UninitializedParameter"; |
---|
| 1169 | } |
---|
| 1170 | }; |
---|
| 1171 | |
---|
| 1172 | ///\name Named template parameters |
---|
| 1173 | |
---|
| 1174 | ///@{ |
---|
| 1175 | |
---|
| 1176 | template <class H, class CR> |
---|
| 1177 | struct DefHeapTraits : public Traits { |
---|
| 1178 | typedef CR HeapCrossRef; |
---|
| 1179 | typedef H Heap; |
---|
| 1180 | static HeapCrossRef *createHeapCrossRef(const BpUGraph &) { |
---|
| 1181 | throw UninitializedParameter(); |
---|
| 1182 | } |
---|
| 1183 | static Heap *createHeap(HeapCrossRef &) { |
---|
| 1184 | throw UninitializedParameter(); |
---|
| 1185 | } |
---|
| 1186 | }; |
---|
| 1187 | |
---|
| 1188 | /// \brief \ref named-templ-param "Named parameter" for setting heap |
---|
| 1189 | /// and cross reference type |
---|
| 1190 | /// |
---|
| 1191 | /// \ref named-templ-param "Named parameter" for setting heap and cross |
---|
| 1192 | /// reference type |
---|
| 1193 | template <class H, class CR = typename BpUGraph::template NodeMap<int> > |
---|
| 1194 | struct DefHeap |
---|
| 1195 | : public MinCostMaxBipartiteMatching<BpUGraph, CostMap, |
---|
| 1196 | DefHeapTraits<H, CR> > { |
---|
| 1197 | typedef MinCostMaxBipartiteMatching<BpUGraph, CostMap, |
---|
| 1198 | DefHeapTraits<H, CR> > Create; |
---|
| 1199 | }; |
---|
| 1200 | |
---|
| 1201 | template <class H, class CR> |
---|
| 1202 | struct DefStandardHeapTraits : public Traits { |
---|
| 1203 | typedef CR HeapCrossRef; |
---|
| 1204 | typedef H Heap; |
---|
| 1205 | static HeapCrossRef *createHeapCrossRef(const BpUGraph &graph) { |
---|
| 1206 | return new HeapCrossRef(graph); |
---|
| 1207 | } |
---|
| 1208 | static Heap *createHeap(HeapCrossRef &crossref) { |
---|
| 1209 | return new Heap(crossref); |
---|
| 1210 | } |
---|
| 1211 | }; |
---|
| 1212 | |
---|
| 1213 | /// \brief \ref named-templ-param "Named parameter" for setting heap and |
---|
| 1214 | /// cross reference type with automatic allocation |
---|
| 1215 | /// |
---|
| 1216 | /// \ref named-templ-param "Named parameter" for setting heap and cross |
---|
| 1217 | /// reference type. It can allocate the heap and the cross reference |
---|
| 1218 | /// object if the cross reference's constructor waits for the graph as |
---|
| 1219 | /// parameter and the heap's constructor waits for the cross reference. |
---|
| 1220 | template <class H, class CR = typename BpUGraph::template NodeMap<int> > |
---|
| 1221 | struct DefStandardHeap |
---|
| 1222 | : public MinCostMaxBipartiteMatching<BpUGraph, CostMap, |
---|
| 1223 | DefStandardHeapTraits<H, CR> > { |
---|
| 1224 | typedef MinCostMaxBipartiteMatching<BpUGraph, CostMap, |
---|
| 1225 | DefStandardHeapTraits<H, CR> > |
---|
| 1226 | Create; |
---|
| 1227 | }; |
---|
| 1228 | |
---|
| 1229 | ///@} |
---|
| 1230 | |
---|
| 1231 | |
---|
| 1232 | /// \brief Constructor. |
---|
| 1233 | /// |
---|
| 1234 | /// Constructor of the algorithm. |
---|
| 1235 | MinCostMaxBipartiteMatching(const BpUGraph& _graph, |
---|
| 1236 | const CostMap& _cost) |
---|
| 1237 | : graph(&_graph), cost(&_cost), |
---|
| 1238 | anode_matching(_graph), bnode_matching(_graph), |
---|
| 1239 | anode_potential(_graph), bnode_potential(_graph), |
---|
| 1240 | _heap_cross_ref(0), local_heap_cross_ref(false), |
---|
| 1241 | _heap(0), local_heap(0) {} |
---|
| 1242 | |
---|
| 1243 | /// \brief Destructor. |
---|
| 1244 | /// |
---|
| 1245 | /// Destructor of the algorithm. |
---|
| 1246 | ~MinCostMaxBipartiteMatching() { |
---|
| 1247 | destroyStructures(); |
---|
| 1248 | } |
---|
| 1249 | |
---|
| 1250 | /// \brief Sets the heap and the cross reference used by algorithm. |
---|
| 1251 | /// |
---|
| 1252 | /// Sets the heap and the cross reference used by algorithm. |
---|
| 1253 | /// If you don't use this function before calling \ref run(), |
---|
| 1254 | /// it will allocate one. The destuctor deallocates this |
---|
| 1255 | /// automatically allocated map, of course. |
---|
| 1256 | /// \return \c (*this) |
---|
| 1257 | MinCostMaxBipartiteMatching& heap(Heap& heap, HeapCrossRef &crossRef) { |
---|
| 1258 | if(local_heap_cross_ref) { |
---|
| 1259 | delete _heap_cross_ref; |
---|
| 1260 | local_heap_cross_ref = false; |
---|
| 1261 | } |
---|
| 1262 | _heap_cross_ref = &crossRef; |
---|
| 1263 | if(local_heap) { |
---|
| 1264 | delete _heap; |
---|
| 1265 | local_heap = false; |
---|
| 1266 | } |
---|
| 1267 | _heap = &heap; |
---|
| 1268 | return *this; |
---|
| 1269 | } |
---|
| 1270 | |
---|
| 1271 | /// \name Execution control |
---|
| 1272 | /// The simplest way to execute the algorithm is to use |
---|
| 1273 | /// one of the member functions called \c run(). |
---|
| 1274 | /// \n |
---|
| 1275 | /// If you need more control on the execution, |
---|
| 1276 | /// first you must call \ref init() or one alternative for it. |
---|
| 1277 | /// Finally \ref start() will perform the matching computation or |
---|
| 1278 | /// with step-by-step execution you can augment the solution. |
---|
| 1279 | |
---|
| 1280 | /// @{ |
---|
| 1281 | |
---|
| 1282 | /// \brief Initalize the data structures. |
---|
| 1283 | /// |
---|
| 1284 | /// It initalizes the data structures and creates an empty matching. |
---|
| 1285 | void init() { |
---|
| 1286 | initStructures(); |
---|
| 1287 | for (ANodeIt it(*graph); it != INVALID; ++it) { |
---|
| 1288 | anode_matching[it] = INVALID; |
---|
| 1289 | anode_potential[it] = 0; |
---|
| 1290 | } |
---|
| 1291 | for (BNodeIt it(*graph); it != INVALID; ++it) { |
---|
| 1292 | bnode_matching[it] = INVALID; |
---|
| 1293 | bnode_potential[it] = 0; |
---|
| 1294 | } |
---|
| 1295 | matching_cost = 0; |
---|
| 1296 | matching_size = 0; |
---|
| 1297 | } |
---|
| 1298 | |
---|
| 1299 | |
---|
| 1300 | /// \brief An augmenting phase of the costed matching algorithm |
---|
| 1301 | /// |
---|
| 1302 | /// It runs an augmenting phase of the matching algorithm. The |
---|
| 1303 | /// phase finds the best augmenting path and augments only on this |
---|
| 1304 | /// paths. |
---|
| 1305 | /// |
---|
| 1306 | /// The algorithm consists at most |
---|
| 1307 | /// of \f$ O(n) \f$ phase and one phase is \f$ O(n\log(n)+e) \f$ |
---|
| 1308 | /// long with Fibonacci heap or \f$ O((n+e)\log(n)) \f$ long |
---|
| 1309 | /// with binary heap. |
---|
| 1310 | bool augment() { |
---|
| 1311 | |
---|
| 1312 | typename BpUGraph::template BNodeMap<Value> bdist(*graph); |
---|
| 1313 | typename BpUGraph::template BNodeMap<UEdge> bpred(*graph, INVALID); |
---|
| 1314 | |
---|
| 1315 | Node bestNode = INVALID; |
---|
| 1316 | Value bestValue = 0; |
---|
| 1317 | |
---|
| 1318 | _heap->clear(); |
---|
| 1319 | for (ANodeIt it(*graph); it != INVALID; ++it) { |
---|
| 1320 | (*_heap_cross_ref)[it] = Heap::PRE_HEAP; |
---|
| 1321 | } |
---|
| 1322 | |
---|
| 1323 | for (ANodeIt it(*graph); it != INVALID; ++it) { |
---|
| 1324 | if (anode_matching[it] == INVALID) { |
---|
| 1325 | _heap->push(it, 0); |
---|
| 1326 | } |
---|
| 1327 | } |
---|
[2136] | 1328 | Value bdistMax = 0; |
---|
[2051] | 1329 | |
---|
| 1330 | while (!_heap->empty()) { |
---|
| 1331 | Node anode = _heap->top(); |
---|
| 1332 | Value avalue = _heap->prio(); |
---|
| 1333 | _heap->pop(); |
---|
| 1334 | for (IncEdgeIt jt(*graph, anode); jt != INVALID; ++jt) { |
---|
| 1335 | if (jt == anode_matching[anode]) continue; |
---|
| 1336 | Node bnode = graph->bNode(jt); |
---|
| 1337 | Value bvalue = avalue + (*cost)[jt] + |
---|
| 1338 | anode_potential[anode] - bnode_potential[bnode]; |
---|
| 1339 | if (bpred[bnode] == INVALID || bvalue < bdist[bnode]) { |
---|
| 1340 | bdist[bnode] = bvalue; |
---|
| 1341 | bpred[bnode] = jt; |
---|
| 1342 | } |
---|
[2136] | 1343 | if (bvalue > bdistMax) { |
---|
| 1344 | bdistMax = bvalue; |
---|
| 1345 | } |
---|
[2051] | 1346 | if (bnode_matching[bnode] != INVALID) { |
---|
| 1347 | Node newanode = graph->aNode(bnode_matching[bnode]); |
---|
| 1348 | switch (_heap->state(newanode)) { |
---|
| 1349 | case Heap::PRE_HEAP: |
---|
| 1350 | _heap->push(newanode, bvalue); |
---|
| 1351 | break; |
---|
| 1352 | case Heap::IN_HEAP: |
---|
| 1353 | if (bvalue < (*_heap)[newanode]) { |
---|
| 1354 | _heap->decrease(newanode, bvalue); |
---|
| 1355 | } |
---|
| 1356 | break; |
---|
| 1357 | case Heap::POST_HEAP: |
---|
| 1358 | break; |
---|
| 1359 | } |
---|
| 1360 | } else { |
---|
| 1361 | if (bestNode == INVALID || |
---|
| 1362 | bvalue + bnode_potential[bnode] < bestValue) { |
---|
| 1363 | bestValue = bvalue + bnode_potential[bnode]; |
---|
| 1364 | bestNode = bnode; |
---|
| 1365 | } |
---|
| 1366 | } |
---|
| 1367 | } |
---|
| 1368 | } |
---|
| 1369 | |
---|
| 1370 | if (bestNode == INVALID) { |
---|
| 1371 | return false; |
---|
| 1372 | } |
---|
| 1373 | |
---|
| 1374 | matching_cost += bestValue; |
---|
| 1375 | ++matching_size; |
---|
| 1376 | |
---|
| 1377 | for (BNodeIt it(*graph); it != INVALID; ++it) { |
---|
| 1378 | if (bpred[it] != INVALID) { |
---|
| 1379 | bnode_potential[it] += bdist[it]; |
---|
[2136] | 1380 | } else { |
---|
| 1381 | bnode_potential[it] += bdistMax; |
---|
[2051] | 1382 | } |
---|
| 1383 | } |
---|
| 1384 | for (ANodeIt it(*graph); it != INVALID; ++it) { |
---|
| 1385 | if (anode_matching[it] != INVALID) { |
---|
| 1386 | Node bnode = graph->bNode(anode_matching[it]); |
---|
| 1387 | if (bpred[bnode] != INVALID) { |
---|
| 1388 | anode_potential[it] += bdist[bnode]; |
---|
[2136] | 1389 | } else { |
---|
| 1390 | anode_potential[it] += bdistMax; |
---|
[2051] | 1391 | } |
---|
| 1392 | } |
---|
| 1393 | } |
---|
| 1394 | |
---|
| 1395 | while (bestNode != INVALID) { |
---|
| 1396 | UEdge uedge = bpred[bestNode]; |
---|
| 1397 | Node anode = graph->aNode(uedge); |
---|
| 1398 | |
---|
| 1399 | bnode_matching[bestNode] = uedge; |
---|
| 1400 | if (anode_matching[anode] != INVALID) { |
---|
| 1401 | bestNode = graph->bNode(anode_matching[anode]); |
---|
| 1402 | } else { |
---|
| 1403 | bestNode = INVALID; |
---|
| 1404 | } |
---|
| 1405 | anode_matching[anode] = uedge; |
---|
| 1406 | } |
---|
| 1407 | |
---|
| 1408 | |
---|
| 1409 | return true; |
---|
| 1410 | } |
---|
| 1411 | |
---|
| 1412 | /// \brief Starts the algorithm. |
---|
| 1413 | /// |
---|
| 1414 | /// Starts the algorithm. It runs augmenting phases until the |
---|
| 1415 | /// optimal solution reached. |
---|
| 1416 | void start() { |
---|
| 1417 | while (augment()) {} |
---|
| 1418 | } |
---|
| 1419 | |
---|
| 1420 | /// \brief Runs the algorithm. |
---|
| 1421 | /// |
---|
| 1422 | /// It just initalize the algorithm and then start it. |
---|
| 1423 | void run() { |
---|
| 1424 | init(); |
---|
| 1425 | start(); |
---|
| 1426 | } |
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| 1427 | |
---|
| 1428 | /// @} |
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| 1429 | |
---|
| 1430 | /// \name Query Functions |
---|
| 1431 | /// The result of the %Matching algorithm can be obtained using these |
---|
| 1432 | /// functions.\n |
---|
| 1433 | /// Before the use of these functions, |
---|
| 1434 | /// either run() or start() must be called. |
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| 1435 | |
---|
| 1436 | ///@{ |
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| 1437 | |
---|
| 1438 | /// \brief Gives back the potential in the NodeMap |
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| 1439 | /// |
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[2058] | 1440 | /// Gives back the potential in the NodeMap. The potential is optimal with |
---|
| 1441 | /// the current number of edges if \f$ \pi(a) - \pi(b) + w(ab) = 0 \f$ for |
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[2051] | 1442 | /// each matching edges and \f$ \pi(a) - \pi(b) + w(ab) \ge 0 \f$ |
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| 1443 | /// for each edges. |
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| 1444 | template <typename PotentialMap> |
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[2058] | 1445 | void potential(PotentialMap& potential) const { |
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[2051] | 1446 | for (ANodeIt it(*graph); it != INVALID; ++it) { |
---|
| 1447 | potential[it] = anode_potential[it]; |
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| 1448 | } |
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| 1449 | for (BNodeIt it(*graph); it != INVALID; ++it) { |
---|
| 1450 | potential[it] = bnode_potential[it]; |
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| 1451 | } |
---|
| 1452 | } |
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| 1453 | |
---|
| 1454 | /// \brief Set true all matching uedge in the map. |
---|
| 1455 | /// |
---|
| 1456 | /// Set true all matching uedge in the map. It does not change the |
---|
| 1457 | /// value mapped to the other uedges. |
---|
| 1458 | /// \return The number of the matching edges. |
---|
| 1459 | template <typename MatchingMap> |
---|
[2058] | 1460 | int quickMatching(MatchingMap& matching) const { |
---|
[2051] | 1461 | for (ANodeIt it(*graph); it != INVALID; ++it) { |
---|
| 1462 | if (anode_matching[it] != INVALID) { |
---|
| 1463 | matching[anode_matching[it]] = true; |
---|
| 1464 | } |
---|
| 1465 | } |
---|
| 1466 | return matching_size; |
---|
| 1467 | } |
---|
| 1468 | |
---|
| 1469 | /// \brief Set true all matching uedge in the map and the others to false. |
---|
| 1470 | /// |
---|
| 1471 | /// Set true all matching uedge in the map and the others to false. |
---|
| 1472 | /// \return The number of the matching edges. |
---|
| 1473 | template <typename MatchingMap> |
---|
[2058] | 1474 | int matching(MatchingMap& matching) const { |
---|
[2051] | 1475 | for (UEdgeIt it(*graph); it != INVALID; ++it) { |
---|
| 1476 | matching[it] = it == anode_matching[graph->aNode(it)]; |
---|
| 1477 | } |
---|
| 1478 | return matching_size; |
---|
| 1479 | } |
---|
| 1480 | |
---|
| 1481 | |
---|
| 1482 | /// \brief Return true if the given uedge is in the matching. |
---|
| 1483 | /// |
---|
| 1484 | /// It returns true if the given uedge is in the matching. |
---|
[2058] | 1485 | bool matchingEdge(const UEdge& edge) const { |
---|
[2051] | 1486 | return anode_matching[graph->aNode(edge)] == edge; |
---|
| 1487 | } |
---|
| 1488 | |
---|
| 1489 | /// \brief Returns the matching edge from the node. |
---|
| 1490 | /// |
---|
| 1491 | /// Returns the matching edge from the node. If there is not such |
---|
| 1492 | /// edge it gives back \c INVALID. |
---|
[2058] | 1493 | UEdge matchingEdge(const Node& node) const { |
---|
[2051] | 1494 | if (graph->aNode(node)) { |
---|
| 1495 | return anode_matching[node]; |
---|
| 1496 | } else { |
---|
| 1497 | return bnode_matching[node]; |
---|
| 1498 | } |
---|
| 1499 | } |
---|
| 1500 | |
---|
| 1501 | /// \brief Gives back the sum of costs of the matching edges. |
---|
| 1502 | /// |
---|
| 1503 | /// Gives back the sum of costs of the matching edges. |
---|
| 1504 | Value matchingCost() const { |
---|
| 1505 | return matching_cost; |
---|
| 1506 | } |
---|
| 1507 | |
---|
| 1508 | /// \brief Gives back the number of the matching edges. |
---|
| 1509 | /// |
---|
| 1510 | /// Gives back the number of the matching edges. |
---|
| 1511 | int matchingSize() const { |
---|
| 1512 | return matching_size; |
---|
| 1513 | } |
---|
| 1514 | |
---|
| 1515 | /// @} |
---|
| 1516 | |
---|
| 1517 | private: |
---|
| 1518 | |
---|
| 1519 | void initStructures() { |
---|
| 1520 | if (!_heap_cross_ref) { |
---|
| 1521 | local_heap_cross_ref = true; |
---|
| 1522 | _heap_cross_ref = Traits::createHeapCrossRef(*graph); |
---|
| 1523 | } |
---|
| 1524 | if (!_heap) { |
---|
| 1525 | local_heap = true; |
---|
| 1526 | _heap = Traits::createHeap(*_heap_cross_ref); |
---|
| 1527 | } |
---|
| 1528 | } |
---|
| 1529 | |
---|
| 1530 | void destroyStructures() { |
---|
| 1531 | if (local_heap_cross_ref) delete _heap_cross_ref; |
---|
| 1532 | if (local_heap) delete _heap; |
---|
| 1533 | } |
---|
| 1534 | |
---|
| 1535 | |
---|
| 1536 | private: |
---|
| 1537 | |
---|
| 1538 | const BpUGraph *graph; |
---|
| 1539 | const CostMap* cost; |
---|
| 1540 | |
---|
| 1541 | ANodeMatchingMap anode_matching; |
---|
| 1542 | BNodeMatchingMap bnode_matching; |
---|
| 1543 | |
---|
| 1544 | ANodePotentialMap anode_potential; |
---|
| 1545 | BNodePotentialMap bnode_potential; |
---|
| 1546 | |
---|
| 1547 | Value matching_cost; |
---|
| 1548 | int matching_size; |
---|
| 1549 | |
---|
| 1550 | HeapCrossRef *_heap_cross_ref; |
---|
| 1551 | bool local_heap_cross_ref; |
---|
| 1552 | |
---|
| 1553 | Heap *_heap; |
---|
| 1554 | bool local_heap; |
---|
[2040] | 1555 | |
---|
| 1556 | }; |
---|
| 1557 | |
---|
[2058] | 1558 | /// \ingroup matching |
---|
| 1559 | /// |
---|
| 1560 | /// \brief Minimum cost maximum cardinality bipartite matching |
---|
| 1561 | /// |
---|
| 1562 | /// This function calculates the minimum cost matching of the maximum |
---|
| 1563 | /// cardinality matchings of a bipartite graph. It gives back the matching |
---|
| 1564 | /// in an undirected edge map. |
---|
| 1565 | /// |
---|
| 1566 | /// \param graph The bipartite graph. |
---|
| 1567 | /// \param cost The undirected edge map which contains the costs. |
---|
| 1568 | /// \retval matching The undirected edge map which will be set to |
---|
| 1569 | /// the matching. |
---|
| 1570 | /// \return The cost of the matching. |
---|
| 1571 | template <typename BpUGraph, typename CostMap, typename MatchingMap> |
---|
| 1572 | typename CostMap::Value |
---|
| 1573 | minCostMaxBipartiteMatching(const BpUGraph& graph, |
---|
| 1574 | const CostMap& cost, |
---|
| 1575 | MatchingMap& matching) { |
---|
| 1576 | MinCostMaxBipartiteMatching<BpUGraph, CostMap> |
---|
| 1577 | bpmatching(graph, cost); |
---|
| 1578 | bpmatching.run(); |
---|
| 1579 | bpmatching.matching(matching); |
---|
| 1580 | return bpmatching.matchingCost(); |
---|
| 1581 | } |
---|
| 1582 | |
---|
[2040] | 1583 | } |
---|
| 1584 | |
---|
| 1585 | #endif |
---|