[906] | 1 | /* -*- C++ -*- |
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| 2 | * |
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[1956] | 3 | * This file is a part of LEMON, a generic C++ optimization library |
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| 4 | * |
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[2391] | 5 | * Copyright (C) 2003-2007 |
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[1956] | 6 | * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
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[1359] | 7 | * (Egervary Research Group on Combinatorial Optimization, EGRES). |
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[906] | 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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[921] | 19 | #ifndef LEMON_BFS_H |
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| 20 | #define LEMON_BFS_H |
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[774] | 21 | |
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[2376] | 22 | ///\ingroup search |
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[774] | 23 | ///\file |
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| 24 | ///\brief Bfs algorithm. |
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| 25 | |
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[1218] | 26 | #include <lemon/list_graph.h> |
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| 27 | #include <lemon/graph_utils.h> |
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[2335] | 28 | #include <lemon/bits/path_dump.h> |
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[1993] | 29 | #include <lemon/bits/invalid.h> |
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[1218] | 30 | #include <lemon/error.h> |
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| 31 | #include <lemon/maps.h> |
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[774] | 32 | |
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[921] | 33 | namespace lemon { |
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[774] | 34 | |
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| 35 | |
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[1218] | 36 | |
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| 37 | ///Default traits class of Bfs class. |
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| 38 | |
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| 39 | ///Default traits class of Bfs class. |
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| 40 | ///\param GR Graph type. |
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| 41 | template<class GR> |
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| 42 | struct BfsDefaultTraits |
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| 43 | { |
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| 44 | ///The graph type the algorithm runs on. |
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| 45 | typedef GR Graph; |
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| 46 | ///\brief The type of the map that stores the last |
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| 47 | ///edges of the shortest paths. |
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| 48 | /// |
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| 49 | ///The type of the map that stores the last |
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| 50 | ///edges of the shortest paths. |
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[2260] | 51 | ///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
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[1218] | 52 | /// |
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| 53 | typedef typename Graph::template NodeMap<typename GR::Edge> PredMap; |
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| 54 | ///Instantiates a PredMap. |
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| 55 | |
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| 56 | ///This function instantiates a \ref PredMap. |
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| 57 | ///\param G is the graph, to which we would like to define the PredMap. |
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| 58 | ///\todo The graph alone may be insufficient to initialize |
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| 59 | static PredMap *createPredMap(const GR &G) |
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| 60 | { |
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| 61 | return new PredMap(G); |
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| 62 | } |
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| 63 | ///The type of the map that indicates which nodes are processed. |
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| 64 | |
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| 65 | ///The type of the map that indicates which nodes are processed. |
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[2260] | 66 | ///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
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[1218] | 67 | ///\todo named parameter to set this type, function to read and write. |
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| 68 | typedef NullMap<typename Graph::Node,bool> ProcessedMap; |
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| 69 | ///Instantiates a ProcessedMap. |
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| 70 | |
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| 71 | ///This function instantiates a \ref ProcessedMap. |
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[1536] | 72 | ///\param g is the graph, to which |
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[1218] | 73 | ///we would like to define the \ref ProcessedMap |
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[1536] | 74 | #ifdef DOXYGEN |
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| 75 | static ProcessedMap *createProcessedMap(const GR &g) |
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| 76 | #else |
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[1367] | 77 | static ProcessedMap *createProcessedMap(const GR &) |
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[1536] | 78 | #endif |
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[1218] | 79 | { |
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| 80 | return new ProcessedMap(); |
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| 81 | } |
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| 82 | ///The type of the map that indicates which nodes are reached. |
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| 83 | |
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| 84 | ///The type of the map that indicates which nodes are reached. |
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[2260] | 85 | ///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
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[1218] | 86 | ///\todo named parameter to set this type, function to read and write. |
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| 87 | typedef typename Graph::template NodeMap<bool> ReachedMap; |
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| 88 | ///Instantiates a ReachedMap. |
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| 89 | |
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| 90 | ///This function instantiates a \ref ReachedMap. |
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| 91 | ///\param G is the graph, to which |
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| 92 | ///we would like to define the \ref ReachedMap. |
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| 93 | static ReachedMap *createReachedMap(const GR &G) |
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| 94 | { |
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| 95 | return new ReachedMap(G); |
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| 96 | } |
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| 97 | ///The type of the map that stores the dists of the nodes. |
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| 98 | |
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| 99 | ///The type of the map that stores the dists of the nodes. |
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[2260] | 100 | ///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
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[1218] | 101 | /// |
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| 102 | typedef typename Graph::template NodeMap<int> DistMap; |
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| 103 | ///Instantiates a DistMap. |
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| 104 | |
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| 105 | ///This function instantiates a \ref DistMap. |
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| 106 | ///\param G is the graph, to which we would like to define the \ref DistMap |
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| 107 | static DistMap *createDistMap(const GR &G) |
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| 108 | { |
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| 109 | return new DistMap(G); |
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| 110 | } |
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| 111 | }; |
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| 112 | |
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[781] | 113 | ///%BFS algorithm class. |
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[1218] | 114 | |
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[2376] | 115 | ///\ingroup search |
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[1218] | 116 | ///This class provides an efficient implementation of the %BFS algorithm. |
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[774] | 117 | /// |
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[1218] | 118 | ///\param GR The graph type the algorithm runs on. The default value is |
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| 119 | ///\ref ListGraph. The value of GR is not used directly by Bfs, it |
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| 120 | ///is only passed to \ref BfsDefaultTraits. |
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| 121 | ///\param TR Traits class to set various data types used by the algorithm. |
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| 122 | ///The default traits class is |
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| 123 | ///\ref BfsDefaultTraits "BfsDefaultTraits<GR>". |
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| 124 | ///See \ref BfsDefaultTraits for the documentation of |
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| 125 | ///a Bfs traits class. |
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| 126 | /// |
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[1270] | 127 | ///\author Alpar Juttner |
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[774] | 128 | |
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| 129 | #ifdef DOXYGEN |
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[1218] | 130 | template <typename GR, |
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| 131 | typename TR> |
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[774] | 132 | #else |
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[1218] | 133 | template <typename GR=ListGraph, |
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| 134 | typename TR=BfsDefaultTraits<GR> > |
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[774] | 135 | #endif |
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[1218] | 136 | class Bfs { |
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[774] | 137 | public: |
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[1218] | 138 | /** |
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| 139 | * \brief \ref Exception for uninitialized parameters. |
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| 140 | * |
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| 141 | * This error represents problems in the initialization |
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| 142 | * of the parameters of the algorithms. |
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| 143 | */ |
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| 144 | class UninitializedParameter : public lemon::UninitializedParameter { |
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| 145 | public: |
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[2151] | 146 | virtual const char* what() const throw() { |
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[1218] | 147 | return "lemon::Bfs::UninitializedParameter"; |
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| 148 | } |
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| 149 | }; |
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| 150 | |
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| 151 | typedef TR Traits; |
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[774] | 152 | ///The type of the underlying graph. |
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[1218] | 153 | typedef typename TR::Graph Graph; |
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[911] | 154 | ///\e |
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[774] | 155 | typedef typename Graph::Node Node; |
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[911] | 156 | ///\e |
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[774] | 157 | typedef typename Graph::NodeIt NodeIt; |
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[911] | 158 | ///\e |
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[774] | 159 | typedef typename Graph::Edge Edge; |
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[911] | 160 | ///\e |
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[774] | 161 | typedef typename Graph::OutEdgeIt OutEdgeIt; |
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| 162 | |
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| 163 | ///\brief The type of the map that stores the last |
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| 164 | ///edges of the shortest paths. |
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[1218] | 165 | typedef typename TR::PredMap PredMap; |
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| 166 | ///The type of the map indicating which nodes are reached. |
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| 167 | typedef typename TR::ReachedMap ReachedMap; |
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| 168 | ///The type of the map indicating which nodes are processed. |
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| 169 | typedef typename TR::ProcessedMap ProcessedMap; |
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[774] | 170 | ///The type of the map that stores the dists of the nodes. |
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[1218] | 171 | typedef typename TR::DistMap DistMap; |
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[774] | 172 | private: |
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[802] | 173 | /// Pointer to the underlying graph. |
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[774] | 174 | const Graph *G; |
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[802] | 175 | ///Pointer to the map of predecessors edges. |
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[1218] | 176 | PredMap *_pred; |
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| 177 | ///Indicates if \ref _pred is locally allocated (\c true) or not. |
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| 178 | bool local_pred; |
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[802] | 179 | ///Pointer to the map of distances. |
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[1218] | 180 | DistMap *_dist; |
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| 181 | ///Indicates if \ref _dist is locally allocated (\c true) or not. |
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| 182 | bool local_dist; |
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| 183 | ///Pointer to the map of reached status of the nodes. |
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| 184 | ReachedMap *_reached; |
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| 185 | ///Indicates if \ref _reached is locally allocated (\c true) or not. |
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| 186 | bool local_reached; |
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| 187 | ///Pointer to the map of processed status of the nodes. |
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| 188 | ProcessedMap *_processed; |
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| 189 | ///Indicates if \ref _processed is locally allocated (\c true) or not. |
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| 190 | bool local_processed; |
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[774] | 191 | |
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[1218] | 192 | std::vector<typename Graph::Node> _queue; |
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| 193 | int _queue_head,_queue_tail,_queue_next_dist; |
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| 194 | int _curr_dist; |
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[774] | 195 | |
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[1218] | 196 | ///Creates the maps if necessary. |
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| 197 | |
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| 198 | ///\todo Better memory allocation (instead of new). |
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| 199 | void create_maps() |
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[774] | 200 | { |
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[1218] | 201 | if(!_pred) { |
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| 202 | local_pred = true; |
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| 203 | _pred = Traits::createPredMap(*G); |
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[774] | 204 | } |
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[1218] | 205 | if(!_dist) { |
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| 206 | local_dist = true; |
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| 207 | _dist = Traits::createDistMap(*G); |
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[774] | 208 | } |
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[1218] | 209 | if(!_reached) { |
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| 210 | local_reached = true; |
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| 211 | _reached = Traits::createReachedMap(*G); |
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| 212 | } |
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| 213 | if(!_processed) { |
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| 214 | local_processed = true; |
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| 215 | _processed = Traits::createProcessedMap(*G); |
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[774] | 216 | } |
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| 217 | } |
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[1710] | 218 | |
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| 219 | protected: |
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[774] | 220 | |
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[1710] | 221 | Bfs() {} |
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| 222 | |
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| 223 | public: |
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[1218] | 224 | |
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[1710] | 225 | typedef Bfs Create; |
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| 226 | |
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[1218] | 227 | ///\name Named template parameters |
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| 228 | |
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| 229 | ///@{ |
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| 230 | |
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| 231 | template <class T> |
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| 232 | struct DefPredMapTraits : public Traits { |
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| 233 | typedef T PredMap; |
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[1799] | 234 | static PredMap *createPredMap(const Graph &) |
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[1218] | 235 | { |
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| 236 | throw UninitializedParameter(); |
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| 237 | } |
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| 238 | }; |
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| 239 | ///\ref named-templ-param "Named parameter" for setting PredMap type |
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| 240 | |
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| 241 | ///\ref named-templ-param "Named parameter" for setting PredMap type |
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| 242 | /// |
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| 243 | template <class T> |
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[1709] | 244 | struct DefPredMap : public Bfs< Graph, DefPredMapTraits<T> > { |
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| 245 | typedef Bfs< Graph, DefPredMapTraits<T> > Create; |
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| 246 | }; |
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[1218] | 247 | |
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| 248 | template <class T> |
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| 249 | struct DefDistMapTraits : public Traits { |
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| 250 | typedef T DistMap; |
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[1799] | 251 | static DistMap *createDistMap(const Graph &) |
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[1218] | 252 | { |
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| 253 | throw UninitializedParameter(); |
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| 254 | } |
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| 255 | }; |
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| 256 | ///\ref named-templ-param "Named parameter" for setting DistMap type |
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| 257 | |
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| 258 | ///\ref named-templ-param "Named parameter" for setting DistMap type |
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| 259 | /// |
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| 260 | template <class T> |
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[1709] | 261 | struct DefDistMap : public Bfs< Graph, DefDistMapTraits<T> > { |
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| 262 | typedef Bfs< Graph, DefDistMapTraits<T> > Create; |
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| 263 | }; |
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[1218] | 264 | |
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| 265 | template <class T> |
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| 266 | struct DefReachedMapTraits : public Traits { |
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| 267 | typedef T ReachedMap; |
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[1799] | 268 | static ReachedMap *createReachedMap(const Graph &) |
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[1218] | 269 | { |
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| 270 | throw UninitializedParameter(); |
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| 271 | } |
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| 272 | }; |
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| 273 | ///\ref named-templ-param "Named parameter" for setting ReachedMap type |
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| 274 | |
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| 275 | ///\ref named-templ-param "Named parameter" for setting ReachedMap type |
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| 276 | /// |
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| 277 | template <class T> |
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[1709] | 278 | struct DefReachedMap : public Bfs< Graph, DefReachedMapTraits<T> > { |
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| 279 | typedef Bfs< Graph, DefReachedMapTraits<T> > Create; |
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| 280 | }; |
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[1218] | 281 | |
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| 282 | template <class T> |
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| 283 | struct DefProcessedMapTraits : public Traits { |
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| 284 | typedef T ProcessedMap; |
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[2033] | 285 | static ProcessedMap *createProcessedMap(const Graph &) |
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[1218] | 286 | { |
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| 287 | throw UninitializedParameter(); |
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| 288 | } |
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| 289 | }; |
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| 290 | ///\ref named-templ-param "Named parameter" for setting ProcessedMap type |
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| 291 | |
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| 292 | ///\ref named-templ-param "Named parameter" for setting ProcessedMap type |
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| 293 | /// |
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| 294 | template <class T> |
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[1709] | 295 | struct DefProcessedMap : public Bfs< Graph, DefProcessedMapTraits<T> > { |
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| 296 | typedef Bfs< Graph, DefProcessedMapTraits<T> > Create; |
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| 297 | }; |
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[1218] | 298 | |
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| 299 | struct DefGraphProcessedMapTraits : public Traits { |
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| 300 | typedef typename Graph::template NodeMap<bool> ProcessedMap; |
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| 301 | static ProcessedMap *createProcessedMap(const Graph &G) |
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| 302 | { |
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| 303 | return new ProcessedMap(G); |
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| 304 | } |
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| 305 | }; |
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| 306 | ///\brief \ref named-templ-param "Named parameter" |
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| 307 | ///for setting the ProcessedMap type to be Graph::NodeMap<bool>. |
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| 308 | /// |
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| 309 | ///\ref named-templ-param "Named parameter" |
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| 310 | ///for setting the ProcessedMap type to be Graph::NodeMap<bool>. |
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[1270] | 311 | ///If you don't set it explicitly, it will be automatically allocated. |
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[1218] | 312 | template <class T> |
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[1709] | 313 | struct DefProcessedMapToBeDefaultMap : |
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| 314 | public Bfs< Graph, DefGraphProcessedMapTraits> { |
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| 315 | typedef Bfs< Graph, DefGraphProcessedMapTraits> Create; |
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| 316 | }; |
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[1218] | 317 | |
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| 318 | ///@} |
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| 319 | |
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| 320 | public: |
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| 321 | |
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[802] | 322 | ///Constructor. |
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| 323 | |
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| 324 | ///\param _G the graph the algorithm will run on. |
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[911] | 325 | /// |
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[774] | 326 | Bfs(const Graph& _G) : |
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| 327 | G(&_G), |
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[1218] | 328 | _pred(NULL), local_pred(false), |
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| 329 | _dist(NULL), local_dist(false), |
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| 330 | _reached(NULL), local_reached(false), |
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| 331 | _processed(NULL), local_processed(false) |
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[774] | 332 | { } |
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| 333 | |
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[802] | 334 | ///Destructor. |
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[774] | 335 | ~Bfs() |
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| 336 | { |
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[1218] | 337 | if(local_pred) delete _pred; |
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| 338 | if(local_dist) delete _dist; |
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| 339 | if(local_reached) delete _reached; |
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| 340 | if(local_processed) delete _processed; |
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[774] | 341 | } |
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| 342 | |
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| 343 | ///Sets the map storing the predecessor edges. |
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| 344 | |
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| 345 | ///Sets the map storing the predecessor edges. |
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| 346 | ///If you don't use this function before calling \ref run(), |
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[1270] | 347 | ///it will allocate one. The destructor deallocates this |
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[774] | 348 | ///automatically allocated map, of course. |
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| 349 | ///\return <tt> (*this) </tt> |
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[1218] | 350 | Bfs &predMap(PredMap &m) |
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[774] | 351 | { |
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[1218] | 352 | if(local_pred) { |
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| 353 | delete _pred; |
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| 354 | local_pred=false; |
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[774] | 355 | } |
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[1218] | 356 | _pred = &m; |
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[774] | 357 | return *this; |
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| 358 | } |
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| 359 | |
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[1218] | 360 | ///Sets the map indicating the reached nodes. |
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[774] | 361 | |
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[1218] | 362 | ///Sets the map indicating the reached nodes. |
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[774] | 363 | ///If you don't use this function before calling \ref run(), |
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[1270] | 364 | ///it will allocate one. The destructor deallocates this |
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[774] | 365 | ///automatically allocated map, of course. |
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| 366 | ///\return <tt> (*this) </tt> |
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[1218] | 367 | Bfs &reachedMap(ReachedMap &m) |
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[774] | 368 | { |
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[1218] | 369 | if(local_reached) { |
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| 370 | delete _reached; |
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| 371 | local_reached=false; |
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[774] | 372 | } |
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[1218] | 373 | _reached = &m; |
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[774] | 374 | return *this; |
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| 375 | } |
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| 376 | |
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[1218] | 377 | ///Sets the map indicating the processed nodes. |
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| 378 | |
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| 379 | ///Sets the map indicating the processed nodes. |
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| 380 | ///If you don't use this function before calling \ref run(), |
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[1270] | 381 | ///it will allocate one. The destructor deallocates this |
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[1218] | 382 | ///automatically allocated map, of course. |
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| 383 | ///\return <tt> (*this) </tt> |
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| 384 | Bfs &processedMap(ProcessedMap &m) |
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| 385 | { |
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| 386 | if(local_processed) { |
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| 387 | delete _processed; |
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| 388 | local_processed=false; |
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| 389 | } |
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| 390 | _processed = &m; |
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| 391 | return *this; |
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| 392 | } |
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| 393 | |
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[774] | 394 | ///Sets the map storing the distances calculated by the algorithm. |
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| 395 | |
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| 396 | ///Sets the map storing the distances calculated by the algorithm. |
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| 397 | ///If you don't use this function before calling \ref run(), |
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[1270] | 398 | ///it will allocate one. The destructor deallocates this |
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[774] | 399 | ///automatically allocated map, of course. |
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| 400 | ///\return <tt> (*this) </tt> |
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[1218] | 401 | Bfs &distMap(DistMap &m) |
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[774] | 402 | { |
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[1218] | 403 | if(local_dist) { |
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| 404 | delete _dist; |
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| 405 | local_dist=false; |
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[774] | 406 | } |
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[1218] | 407 | _dist = &m; |
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[774] | 408 | return *this; |
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| 409 | } |
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| 410 | |
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[1218] | 411 | public: |
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| 412 | ///\name Execution control |
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| 413 | ///The simplest way to execute the algorithm is to use |
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| 414 | ///one of the member functions called \c run(...). |
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| 415 | ///\n |
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| 416 | ///If you need more control on the execution, |
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| 417 | ///first you must call \ref init(), then you can add several source nodes |
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| 418 | ///with \ref addSource(). |
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| 419 | ///Finally \ref start() will perform the actual path |
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| 420 | ///computation. |
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| 421 | |
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| 422 | ///@{ |
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| 423 | |
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| 424 | ///Initializes the internal data structures. |
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| 425 | |
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| 426 | ///Initializes the internal data structures. |
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| 427 | /// |
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| 428 | void init() |
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| 429 | { |
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| 430 | create_maps(); |
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| 431 | _queue.resize(countNodes(*G)); |
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| 432 | _queue_head=_queue_tail=0; |
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| 433 | _curr_dist=1; |
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[774] | 434 | for ( NodeIt u(*G) ; u!=INVALID ; ++u ) { |
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[1218] | 435 | _pred->set(u,INVALID); |
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| 436 | _reached->set(u,false); |
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| 437 | _processed->set(u,false); |
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[774] | 438 | } |
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| 439 | } |
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| 440 | |
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[1218] | 441 | ///Adds a new source node. |
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[774] | 442 | |
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[1218] | 443 | ///Adds a new source node to the set of nodes to be processed. |
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| 444 | /// |
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| 445 | void addSource(Node s) |
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| 446 | { |
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| 447 | if(!(*_reached)[s]) |
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| 448 | { |
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| 449 | _reached->set(s,true); |
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| 450 | _pred->set(s,INVALID); |
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| 451 | _dist->set(s,0); |
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| 452 | _queue[_queue_head++]=s; |
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| 453 | _queue_next_dist=_queue_head; |
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| 454 | } |
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| 455 | } |
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| 456 | |
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| 457 | ///Processes the next node. |
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| 458 | |
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| 459 | ///Processes the next node. |
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| 460 | /// |
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[1516] | 461 | ///\return The processed node. |
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| 462 | /// |
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[1218] | 463 | ///\warning The queue must not be empty! |
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[1516] | 464 | Node processNextNode() |
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[1218] | 465 | { |
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| 466 | if(_queue_tail==_queue_next_dist) { |
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| 467 | _curr_dist++; |
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| 468 | _queue_next_dist=_queue_head; |
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| 469 | } |
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| 470 | Node n=_queue[_queue_tail++]; |
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| 471 | _processed->set(n,true); |
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| 472 | Node m; |
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| 473 | for(OutEdgeIt e(*G,n);e!=INVALID;++e) |
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| 474 | if(!(*_reached)[m=G->target(e)]) { |
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| 475 | _queue[_queue_head++]=m; |
---|
| 476 | _reached->set(m,true); |
---|
| 477 | _pred->set(m,e); |
---|
| 478 | _dist->set(m,_curr_dist); |
---|
| 479 | } |
---|
[1516] | 480 | return n; |
---|
[1218] | 481 | } |
---|
[2300] | 482 | |
---|
| 483 | ///Processes the next node. |
---|
| 484 | |
---|
| 485 | ///Processes the next node. And checks that the given target node |
---|
| 486 | ///is reached. If the target node is reachable from the processed |
---|
| 487 | ///node then the reached parameter will be set true. The reached |
---|
| 488 | ///parameter should be initially false. |
---|
| 489 | /// |
---|
| 490 | ///\param target The target node. |
---|
[2386] | 491 | ///\retval reach Indicates that the target node is reached. |
---|
[2300] | 492 | ///\return The processed node. |
---|
| 493 | /// |
---|
| 494 | ///\warning The queue must not be empty! |
---|
[2386] | 495 | Node processNextNode(Node target, bool& reach) |
---|
[2300] | 496 | { |
---|
| 497 | if(_queue_tail==_queue_next_dist) { |
---|
| 498 | _curr_dist++; |
---|
| 499 | _queue_next_dist=_queue_head; |
---|
| 500 | } |
---|
| 501 | Node n=_queue[_queue_tail++]; |
---|
| 502 | _processed->set(n,true); |
---|
| 503 | Node m; |
---|
| 504 | for(OutEdgeIt e(*G,n);e!=INVALID;++e) |
---|
| 505 | if(!(*_reached)[m=G->target(e)]) { |
---|
| 506 | _queue[_queue_head++]=m; |
---|
| 507 | _reached->set(m,true); |
---|
| 508 | _pred->set(m,e); |
---|
| 509 | _dist->set(m,_curr_dist); |
---|
[2386] | 510 | reach = reach || (target == m); |
---|
[2300] | 511 | } |
---|
| 512 | return n; |
---|
| 513 | } |
---|
| 514 | |
---|
| 515 | ///Processes the next node. |
---|
| 516 | |
---|
| 517 | ///Processes the next node. And checks that at least one of |
---|
| 518 | ///reached node has true value in the \c nm nodemap. If one node |
---|
| 519 | ///with true value is reachable from the processed node then the |
---|
| 520 | ///reached parameter will be set true. The reached parameter |
---|
| 521 | ///should be initially false. |
---|
| 522 | /// |
---|
[2350] | 523 | ///\param nm The nodemaps of possible targets. |
---|
[2386] | 524 | ///\retval reach Indicates that one of the target nodes is reached. |
---|
[2300] | 525 | ///\return The processed node. |
---|
| 526 | /// |
---|
| 527 | ///\warning The queue must not be empty! |
---|
| 528 | template<class NM> |
---|
[2386] | 529 | Node processNextNode(const NM& nm, bool& reach) |
---|
[2300] | 530 | { |
---|
| 531 | if(_queue_tail==_queue_next_dist) { |
---|
| 532 | _curr_dist++; |
---|
| 533 | _queue_next_dist=_queue_head; |
---|
| 534 | } |
---|
| 535 | Node n=_queue[_queue_tail++]; |
---|
| 536 | _processed->set(n,true); |
---|
| 537 | Node m; |
---|
| 538 | for(OutEdgeIt e(*G,n);e!=INVALID;++e) |
---|
| 539 | if(!(*_reached)[m=G->target(e)]) { |
---|
| 540 | _queue[_queue_head++]=m; |
---|
| 541 | _reached->set(m,true); |
---|
| 542 | _pred->set(m,e); |
---|
| 543 | _dist->set(m,_curr_dist); |
---|
[2386] | 544 | reached = reach || nm[m]; |
---|
[2300] | 545 | } |
---|
| 546 | return n; |
---|
| 547 | } |
---|
[1218] | 548 | |
---|
[1665] | 549 | ///Next node to be processed. |
---|
| 550 | |
---|
| 551 | ///Next node to be processed. |
---|
| 552 | /// |
---|
| 553 | ///\return The next node to be processed or INVALID if the queue is |
---|
| 554 | /// empty. |
---|
[1694] | 555 | Node nextNode() |
---|
[1665] | 556 | { |
---|
| 557 | return _queue_tail<_queue_head?_queue[_queue_tail]:INVALID; |
---|
| 558 | } |
---|
| 559 | |
---|
[1218] | 560 | ///\brief Returns \c false if there are nodes |
---|
| 561 | ///to be processed in the queue |
---|
| 562 | /// |
---|
| 563 | ///Returns \c false if there are nodes |
---|
| 564 | ///to be processed in the queue |
---|
| 565 | bool emptyQueue() { return _queue_tail==_queue_head; } |
---|
| 566 | ///Returns the number of the nodes to be processed. |
---|
| 567 | |
---|
| 568 | ///Returns the number of the nodes to be processed in the queue. |
---|
| 569 | /// |
---|
| 570 | int queueSize() { return _queue_head-_queue_tail; } |
---|
| 571 | |
---|
| 572 | ///Executes the algorithm. |
---|
| 573 | |
---|
| 574 | ///Executes the algorithm. |
---|
| 575 | /// |
---|
| 576 | ///\pre init() must be called and at least one node should be added |
---|
| 577 | ///with addSource() before using this function. |
---|
| 578 | /// |
---|
| 579 | ///This method runs the %BFS algorithm from the root node(s) |
---|
| 580 | ///in order to |
---|
| 581 | ///compute the |
---|
| 582 | ///shortest path to each node. The algorithm computes |
---|
| 583 | ///- The shortest path tree. |
---|
| 584 | ///- The distance of each node from the root(s). |
---|
| 585 | /// |
---|
| 586 | void start() |
---|
| 587 | { |
---|
| 588 | while ( !emptyQueue() ) processNextNode(); |
---|
| 589 | } |
---|
| 590 | |
---|
[2307] | 591 | ///Executes the algorithm until \c dest is reached. |
---|
[1218] | 592 | |
---|
[2307] | 593 | ///Executes the algorithm until \c dest is reached. |
---|
[1218] | 594 | /// |
---|
| 595 | ///\pre init() must be called and at least one node should be added |
---|
| 596 | ///with addSource() before using this function. |
---|
| 597 | /// |
---|
| 598 | ///This method runs the %BFS algorithm from the root node(s) |
---|
| 599 | ///in order to |
---|
| 600 | ///compute the |
---|
| 601 | ///shortest path to \c dest. The algorithm computes |
---|
| 602 | ///- The shortest path to \c dest. |
---|
| 603 | ///- The distance of \c dest from the root(s). |
---|
| 604 | /// |
---|
| 605 | void start(Node dest) |
---|
| 606 | { |
---|
[2386] | 607 | bool reach = false; |
---|
| 608 | while ( !emptyQueue() && !reach) processNextNode(dest, reach); |
---|
[1218] | 609 | } |
---|
| 610 | |
---|
| 611 | ///Executes the algorithm until a condition is met. |
---|
| 612 | |
---|
| 613 | ///Executes the algorithm until a condition is met. |
---|
| 614 | /// |
---|
| 615 | ///\pre init() must be called and at least one node should be added |
---|
| 616 | ///with addSource() before using this function. |
---|
| 617 | /// |
---|
[2306] | 618 | ///\param nm must be a bool (or convertible) node map. The |
---|
[2307] | 619 | ///algorithm will stop when it reached a node \c v with |
---|
[2350] | 620 | /// <tt>nm[v]</tt> true. |
---|
[2300] | 621 | ///\todo query the reached target |
---|
[1218] | 622 | template<class NM> |
---|
[1755] | 623 | void start(const NM &nm) |
---|
| 624 | { |
---|
[2386] | 625 | bool reach = false; |
---|
| 626 | while ( !emptyQueue() && !reach) processNextNode(nm, reach); |
---|
[1755] | 627 | } |
---|
[1218] | 628 | |
---|
| 629 | ///Runs %BFS algorithm from node \c s. |
---|
| 630 | |
---|
| 631 | ///This method runs the %BFS algorithm from a root node \c s |
---|
| 632 | ///in order to |
---|
| 633 | ///compute the |
---|
| 634 | ///shortest path to each node. The algorithm computes |
---|
| 635 | ///- The shortest path tree. |
---|
| 636 | ///- The distance of each node from the root. |
---|
| 637 | /// |
---|
[2306] | 638 | ///\note b.run(s) is just a shortcut of the following code. |
---|
[1218] | 639 | ///\code |
---|
[2306] | 640 | /// b.init(); |
---|
| 641 | /// b.addSource(s); |
---|
| 642 | /// b.start(); |
---|
[1218] | 643 | ///\endcode |
---|
| 644 | void run(Node s) { |
---|
| 645 | init(); |
---|
| 646 | addSource(s); |
---|
| 647 | start(); |
---|
| 648 | } |
---|
| 649 | |
---|
| 650 | ///Finds the shortest path between \c s and \c t. |
---|
| 651 | |
---|
| 652 | ///Finds the shortest path between \c s and \c t. |
---|
| 653 | /// |
---|
| 654 | ///\return The length of the shortest s---t path if there exists one, |
---|
| 655 | ///0 otherwise. |
---|
[2306] | 656 | ///\note Apart from the return value, b.run(s) is |
---|
[1218] | 657 | ///just a shortcut of the following code. |
---|
| 658 | ///\code |
---|
[2306] | 659 | /// b.init(); |
---|
| 660 | /// b.addSource(s); |
---|
| 661 | /// b.start(t); |
---|
[1218] | 662 | ///\endcode |
---|
| 663 | int run(Node s,Node t) { |
---|
| 664 | init(); |
---|
| 665 | addSource(s); |
---|
| 666 | start(t); |
---|
[2300] | 667 | return reached(t)? _curr_dist : 0; |
---|
[1218] | 668 | } |
---|
| 669 | |
---|
| 670 | ///@} |
---|
| 671 | |
---|
| 672 | ///\name Query Functions |
---|
| 673 | ///The result of the %BFS algorithm can be obtained using these |
---|
| 674 | ///functions.\n |
---|
| 675 | ///Before the use of these functions, |
---|
[2306] | 676 | ///either run() or start() must be calleb. |
---|
[1218] | 677 | |
---|
| 678 | ///@{ |
---|
| 679 | |
---|
[2335] | 680 | typedef PredMapPath<Graph, PredMap> Path; |
---|
| 681 | |
---|
| 682 | ///Gives back the shortest path. |
---|
[1283] | 683 | |
---|
[2335] | 684 | ///Gives back the shortest path. |
---|
| 685 | ///\pre The \c t should be reachable from the source. |
---|
| 686 | Path path(Node t) |
---|
[1283] | 687 | { |
---|
[2335] | 688 | return Path(*G, *_pred, t); |
---|
[1283] | 689 | } |
---|
| 690 | |
---|
[1218] | 691 | ///The distance of a node from the root(s). |
---|
| 692 | |
---|
| 693 | ///Returns the distance of a node from the root(s). |
---|
[774] | 694 | ///\pre \ref run() must be called before using this function. |
---|
[1218] | 695 | ///\warning If node \c v in unreachable from the root(s) the return value |
---|
[1270] | 696 | ///of this function is undefined. |
---|
[1218] | 697 | int dist(Node v) const { return (*_dist)[v]; } |
---|
[774] | 698 | |
---|
[1218] | 699 | ///Returns the 'previous edge' of the shortest path tree. |
---|
[774] | 700 | |
---|
[1218] | 701 | ///For a node \c v it returns the 'previous edge' |
---|
| 702 | ///of the shortest path tree, |
---|
| 703 | ///i.e. it returns the last edge of a shortest path from the root(s) to \c |
---|
[774] | 704 | ///v. It is \ref INVALID |
---|
[1218] | 705 | ///if \c v is unreachable from the root(s) or \c v is a root. The |
---|
| 706 | ///shortest path tree used here is equal to the shortest path tree used in |
---|
[1631] | 707 | ///\ref predNode(). |
---|
[1218] | 708 | ///\pre Either \ref run() or \ref start() must be called before using |
---|
[774] | 709 | ///this function. |
---|
[1763] | 710 | Edge predEdge(Node v) const { return (*_pred)[v];} |
---|
[774] | 711 | |
---|
[1218] | 712 | ///Returns the 'previous node' of the shortest path tree. |
---|
[774] | 713 | |
---|
[1218] | 714 | ///For a node \c v it returns the 'previous node' |
---|
| 715 | ///of the shortest path tree, |
---|
[774] | 716 | ///i.e. it returns the last but one node from a shortest path from the |
---|
[1218] | 717 | ///root(a) to \c /v. |
---|
| 718 | ///It is INVALID if \c v is unreachable from the root(s) or |
---|
| 719 | ///if \c v itself a root. |
---|
| 720 | ///The shortest path tree used here is equal to the shortest path |
---|
[1763] | 721 | ///tree used in \ref predEdge(). |
---|
[1218] | 722 | ///\pre Either \ref run() or \ref start() must be called before |
---|
[774] | 723 | ///using this function. |
---|
[1218] | 724 | Node predNode(Node v) const { return (*_pred)[v]==INVALID ? INVALID: |
---|
| 725 | G->source((*_pred)[v]); } |
---|
[774] | 726 | |
---|
| 727 | ///Returns a reference to the NodeMap of distances. |
---|
[1218] | 728 | |
---|
| 729 | ///Returns a reference to the NodeMap of distances. |
---|
| 730 | ///\pre Either \ref run() or \ref init() must |
---|
[774] | 731 | ///be called before using this function. |
---|
[1218] | 732 | const DistMap &distMap() const { return *_dist;} |
---|
[774] | 733 | |
---|
[1218] | 734 | ///Returns a reference to the shortest path tree map. |
---|
[774] | 735 | |
---|
| 736 | ///Returns a reference to the NodeMap of the edges of the |
---|
[1218] | 737 | ///shortest path tree. |
---|
| 738 | ///\pre Either \ref run() or \ref init() |
---|
| 739 | ///must be called before using this function. |
---|
| 740 | const PredMap &predMap() const { return *_pred;} |
---|
[774] | 741 | |
---|
| 742 | ///Checks if a node is reachable from the root. |
---|
| 743 | |
---|
| 744 | ///Returns \c true if \c v is reachable from the root. |
---|
[1270] | 745 | ///\warning The source nodes are indicated as unreached. |
---|
[1218] | 746 | ///\pre Either \ref run() or \ref start() |
---|
| 747 | ///must be called before using this function. |
---|
[774] | 748 | /// |
---|
[1218] | 749 | bool reached(Node v) { return (*_reached)[v]; } |
---|
| 750 | |
---|
| 751 | ///@} |
---|
| 752 | }; |
---|
| 753 | |
---|
| 754 | ///Default traits class of Bfs function. |
---|
| 755 | |
---|
| 756 | ///Default traits class of Bfs function. |
---|
| 757 | ///\param GR Graph type. |
---|
| 758 | template<class GR> |
---|
| 759 | struct BfsWizardDefaultTraits |
---|
| 760 | { |
---|
| 761 | ///The graph type the algorithm runs on. |
---|
| 762 | typedef GR Graph; |
---|
| 763 | ///\brief The type of the map that stores the last |
---|
| 764 | ///edges of the shortest paths. |
---|
| 765 | /// |
---|
| 766 | ///The type of the map that stores the last |
---|
| 767 | ///edges of the shortest paths. |
---|
[2260] | 768 | ///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
---|
[774] | 769 | /// |
---|
[1218] | 770 | typedef NullMap<typename Graph::Node,typename GR::Edge> PredMap; |
---|
| 771 | ///Instantiates a PredMap. |
---|
| 772 | |
---|
| 773 | ///This function instantiates a \ref PredMap. |
---|
[1536] | 774 | ///\param g is the graph, to which we would like to define the PredMap. |
---|
[1218] | 775 | ///\todo The graph alone may be insufficient to initialize |
---|
[1536] | 776 | #ifdef DOXYGEN |
---|
| 777 | static PredMap *createPredMap(const GR &g) |
---|
| 778 | #else |
---|
[1367] | 779 | static PredMap *createPredMap(const GR &) |
---|
[1536] | 780 | #endif |
---|
[1218] | 781 | { |
---|
| 782 | return new PredMap(); |
---|
| 783 | } |
---|
| 784 | |
---|
| 785 | ///The type of the map that indicates which nodes are processed. |
---|
| 786 | |
---|
| 787 | ///The type of the map that indicates which nodes are processed. |
---|
[2260] | 788 | ///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
---|
[1218] | 789 | ///\todo named parameter to set this type, function to read and write. |
---|
| 790 | typedef NullMap<typename Graph::Node,bool> ProcessedMap; |
---|
| 791 | ///Instantiates a ProcessedMap. |
---|
| 792 | |
---|
| 793 | ///This function instantiates a \ref ProcessedMap. |
---|
[1536] | 794 | ///\param g is the graph, to which |
---|
[1218] | 795 | ///we would like to define the \ref ProcessedMap |
---|
[1536] | 796 | #ifdef DOXYGEN |
---|
| 797 | static ProcessedMap *createProcessedMap(const GR &g) |
---|
| 798 | #else |
---|
[1367] | 799 | static ProcessedMap *createProcessedMap(const GR &) |
---|
[1536] | 800 | #endif |
---|
[1218] | 801 | { |
---|
| 802 | return new ProcessedMap(); |
---|
| 803 | } |
---|
| 804 | ///The type of the map that indicates which nodes are reached. |
---|
| 805 | |
---|
| 806 | ///The type of the map that indicates which nodes are reached. |
---|
[2260] | 807 | ///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
---|
[1218] | 808 | ///\todo named parameter to set this type, function to read and write. |
---|
| 809 | typedef typename Graph::template NodeMap<bool> ReachedMap; |
---|
| 810 | ///Instantiates a ReachedMap. |
---|
| 811 | |
---|
| 812 | ///This function instantiates a \ref ReachedMap. |
---|
| 813 | ///\param G is the graph, to which |
---|
| 814 | ///we would like to define the \ref ReachedMap. |
---|
| 815 | static ReachedMap *createReachedMap(const GR &G) |
---|
| 816 | { |
---|
| 817 | return new ReachedMap(G); |
---|
| 818 | } |
---|
| 819 | ///The type of the map that stores the dists of the nodes. |
---|
| 820 | |
---|
| 821 | ///The type of the map that stores the dists of the nodes. |
---|
[2260] | 822 | ///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
---|
[1218] | 823 | /// |
---|
| 824 | typedef NullMap<typename Graph::Node,int> DistMap; |
---|
| 825 | ///Instantiates a DistMap. |
---|
| 826 | |
---|
| 827 | ///This function instantiates a \ref DistMap. |
---|
[1536] | 828 | ///\param g is the graph, to which we would like to define the \ref DistMap |
---|
| 829 | #ifdef DOXYGEN |
---|
| 830 | static DistMap *createDistMap(const GR &g) |
---|
| 831 | #else |
---|
[1367] | 832 | static DistMap *createDistMap(const GR &) |
---|
[1536] | 833 | #endif |
---|
[1218] | 834 | { |
---|
| 835 | return new DistMap(); |
---|
| 836 | } |
---|
| 837 | }; |
---|
| 838 | |
---|
| 839 | /// Default traits used by \ref BfsWizard |
---|
| 840 | |
---|
| 841 | /// To make it easier to use Bfs algorithm |
---|
| 842 | ///we have created a wizard class. |
---|
| 843 | /// This \ref BfsWizard class needs default traits, |
---|
| 844 | ///as well as the \ref Bfs class. |
---|
| 845 | /// The \ref BfsWizardBase is a class to be the default traits of the |
---|
| 846 | /// \ref BfsWizard class. |
---|
| 847 | template<class GR> |
---|
| 848 | class BfsWizardBase : public BfsWizardDefaultTraits<GR> |
---|
| 849 | { |
---|
| 850 | |
---|
| 851 | typedef BfsWizardDefaultTraits<GR> Base; |
---|
| 852 | protected: |
---|
| 853 | /// Type of the nodes in the graph. |
---|
| 854 | typedef typename Base::Graph::Node Node; |
---|
| 855 | |
---|
| 856 | /// Pointer to the underlying graph. |
---|
| 857 | void *_g; |
---|
| 858 | ///Pointer to the map of reached nodes. |
---|
| 859 | void *_reached; |
---|
| 860 | ///Pointer to the map of processed nodes. |
---|
| 861 | void *_processed; |
---|
| 862 | ///Pointer to the map of predecessors edges. |
---|
| 863 | void *_pred; |
---|
| 864 | ///Pointer to the map of distances. |
---|
| 865 | void *_dist; |
---|
| 866 | ///Pointer to the source node. |
---|
| 867 | Node _source; |
---|
| 868 | |
---|
| 869 | public: |
---|
| 870 | /// Constructor. |
---|
| 871 | |
---|
| 872 | /// This constructor does not require parameters, therefore it initiates |
---|
| 873 | /// all of the attributes to default values (0, INVALID). |
---|
| 874 | BfsWizardBase() : _g(0), _reached(0), _processed(0), _pred(0), |
---|
| 875 | _dist(0), _source(INVALID) {} |
---|
| 876 | |
---|
| 877 | /// Constructor. |
---|
| 878 | |
---|
| 879 | /// This constructor requires some parameters, |
---|
| 880 | /// listed in the parameters list. |
---|
| 881 | /// Others are initiated to 0. |
---|
| 882 | /// \param g is the initial value of \ref _g |
---|
| 883 | /// \param s is the initial value of \ref _source |
---|
| 884 | BfsWizardBase(const GR &g, Node s=INVALID) : |
---|
[2386] | 885 | _g(reinterpret_cast<void*>(const_cast<GR*>(&g))), |
---|
| 886 | _reached(0), _processed(0), _pred(0), _dist(0), _source(s) {} |
---|
[1218] | 887 | |
---|
| 888 | }; |
---|
| 889 | |
---|
| 890 | /// A class to make the usage of Bfs algorithm easier |
---|
| 891 | |
---|
| 892 | /// This class is created to make it easier to use Bfs algorithm. |
---|
| 893 | /// It uses the functions and features of the plain \ref Bfs, |
---|
| 894 | /// but it is much simpler to use it. |
---|
| 895 | /// |
---|
| 896 | /// Simplicity means that the way to change the types defined |
---|
| 897 | /// in the traits class is based on functions that returns the new class |
---|
| 898 | /// and not on templatable built-in classes. |
---|
| 899 | /// When using the plain \ref Bfs |
---|
| 900 | /// the new class with the modified type comes from |
---|
| 901 | /// the original class by using the :: |
---|
| 902 | /// operator. In the case of \ref BfsWizard only |
---|
| 903 | /// a function have to be called and it will |
---|
| 904 | /// return the needed class. |
---|
| 905 | /// |
---|
| 906 | /// It does not have own \ref run method. When its \ref run method is called |
---|
| 907 | /// it initiates a plain \ref Bfs class, and calls the \ref Bfs::run |
---|
| 908 | /// method of it. |
---|
| 909 | template<class TR> |
---|
| 910 | class BfsWizard : public TR |
---|
| 911 | { |
---|
| 912 | typedef TR Base; |
---|
| 913 | |
---|
| 914 | ///The type of the underlying graph. |
---|
| 915 | typedef typename TR::Graph Graph; |
---|
| 916 | //\e |
---|
| 917 | typedef typename Graph::Node Node; |
---|
| 918 | //\e |
---|
| 919 | typedef typename Graph::NodeIt NodeIt; |
---|
| 920 | //\e |
---|
| 921 | typedef typename Graph::Edge Edge; |
---|
| 922 | //\e |
---|
| 923 | typedef typename Graph::OutEdgeIt OutEdgeIt; |
---|
| 924 | |
---|
| 925 | ///\brief The type of the map that stores |
---|
| 926 | ///the reached nodes |
---|
| 927 | typedef typename TR::ReachedMap ReachedMap; |
---|
| 928 | ///\brief The type of the map that stores |
---|
| 929 | ///the processed nodes |
---|
| 930 | typedef typename TR::ProcessedMap ProcessedMap; |
---|
| 931 | ///\brief The type of the map that stores the last |
---|
| 932 | ///edges of the shortest paths. |
---|
| 933 | typedef typename TR::PredMap PredMap; |
---|
| 934 | ///The type of the map that stores the dists of the nodes. |
---|
| 935 | typedef typename TR::DistMap DistMap; |
---|
| 936 | |
---|
[2306] | 937 | public: |
---|
[1218] | 938 | /// Constructor. |
---|
| 939 | BfsWizard() : TR() {} |
---|
| 940 | |
---|
| 941 | /// Constructor that requires parameters. |
---|
| 942 | |
---|
| 943 | /// Constructor that requires parameters. |
---|
| 944 | /// These parameters will be the default values for the traits class. |
---|
| 945 | BfsWizard(const Graph &g, Node s=INVALID) : |
---|
| 946 | TR(g,s) {} |
---|
| 947 | |
---|
| 948 | ///Copy constructor |
---|
| 949 | BfsWizard(const TR &b) : TR(b) {} |
---|
| 950 | |
---|
| 951 | ~BfsWizard() {} |
---|
| 952 | |
---|
| 953 | ///Runs Bfs algorithm from a given node. |
---|
| 954 | |
---|
| 955 | ///Runs Bfs algorithm from a given node. |
---|
| 956 | ///The node can be given by the \ref source function. |
---|
| 957 | void run() |
---|
| 958 | { |
---|
| 959 | if(Base::_source==INVALID) throw UninitializedParameter(); |
---|
[2386] | 960 | Bfs<Graph,TR> alg(*reinterpret_cast<const Graph*>(Base::_g)); |
---|
[1218] | 961 | if(Base::_reached) |
---|
[2386] | 962 | alg.reachedMap(*reinterpret_cast<ReachedMap*>(Base::_reached)); |
---|
| 963 | if(Base::_processed) |
---|
| 964 | alg.processedMap(*reinterpret_cast<ProcessedMap*>(Base::_processed)); |
---|
| 965 | if(Base::_pred) |
---|
| 966 | alg.predMap(*reinterpret_cast<PredMap*>(Base::_pred)); |
---|
| 967 | if(Base::_dist) |
---|
| 968 | alg.distMap(*reinterpret_cast<DistMap*>(Base::_dist)); |
---|
[1218] | 969 | alg.run(Base::_source); |
---|
| 970 | } |
---|
| 971 | |
---|
| 972 | ///Runs Bfs algorithm from the given node. |
---|
| 973 | |
---|
| 974 | ///Runs Bfs algorithm from the given node. |
---|
| 975 | ///\param s is the given source. |
---|
| 976 | void run(Node s) |
---|
| 977 | { |
---|
| 978 | Base::_source=s; |
---|
| 979 | run(); |
---|
| 980 | } |
---|
| 981 | |
---|
| 982 | template<class T> |
---|
| 983 | struct DefPredMapBase : public Base { |
---|
| 984 | typedef T PredMap; |
---|
[1367] | 985 | static PredMap *createPredMap(const Graph &) { return 0; }; |
---|
[1236] | 986 | DefPredMapBase(const TR &b) : TR(b) {} |
---|
[1218] | 987 | }; |
---|
| 988 | |
---|
| 989 | ///\brief \ref named-templ-param "Named parameter" |
---|
| 990 | ///function for setting PredMap |
---|
| 991 | /// |
---|
| 992 | /// \ref named-templ-param "Named parameter" |
---|
| 993 | ///function for setting PredMap |
---|
| 994 | /// |
---|
| 995 | template<class T> |
---|
| 996 | BfsWizard<DefPredMapBase<T> > predMap(const T &t) |
---|
| 997 | { |
---|
[2386] | 998 | Base::_pred=reinterpret_cast<void*>(const_cast<T*>(&t)); |
---|
[1218] | 999 | return BfsWizard<DefPredMapBase<T> >(*this); |
---|
| 1000 | } |
---|
| 1001 | |
---|
| 1002 | |
---|
| 1003 | template<class T> |
---|
| 1004 | struct DefReachedMapBase : public Base { |
---|
| 1005 | typedef T ReachedMap; |
---|
[1367] | 1006 | static ReachedMap *createReachedMap(const Graph &) { return 0; }; |
---|
[1236] | 1007 | DefReachedMapBase(const TR &b) : TR(b) {} |
---|
[1218] | 1008 | }; |
---|
| 1009 | |
---|
| 1010 | ///\brief \ref named-templ-param "Named parameter" |
---|
| 1011 | ///function for setting ReachedMap |
---|
| 1012 | /// |
---|
| 1013 | /// \ref named-templ-param "Named parameter" |
---|
| 1014 | ///function for setting ReachedMap |
---|
| 1015 | /// |
---|
| 1016 | template<class T> |
---|
| 1017 | BfsWizard<DefReachedMapBase<T> > reachedMap(const T &t) |
---|
| 1018 | { |
---|
[2386] | 1019 | Base::_pred=reinterpret_cast<void*>(const_cast<T*>(&t)); |
---|
[1218] | 1020 | return BfsWizard<DefReachedMapBase<T> >(*this); |
---|
| 1021 | } |
---|
| 1022 | |
---|
| 1023 | |
---|
| 1024 | template<class T> |
---|
| 1025 | struct DefProcessedMapBase : public Base { |
---|
| 1026 | typedef T ProcessedMap; |
---|
[1367] | 1027 | static ProcessedMap *createProcessedMap(const Graph &) { return 0; }; |
---|
[1236] | 1028 | DefProcessedMapBase(const TR &b) : TR(b) {} |
---|
[1218] | 1029 | }; |
---|
| 1030 | |
---|
| 1031 | ///\brief \ref named-templ-param "Named parameter" |
---|
| 1032 | ///function for setting ProcessedMap |
---|
| 1033 | /// |
---|
| 1034 | /// \ref named-templ-param "Named parameter" |
---|
| 1035 | ///function for setting ProcessedMap |
---|
| 1036 | /// |
---|
| 1037 | template<class T> |
---|
| 1038 | BfsWizard<DefProcessedMapBase<T> > processedMap(const T &t) |
---|
| 1039 | { |
---|
[2386] | 1040 | Base::_pred=reinterpret_cast<void*>(const_cast<T*>(&t)); |
---|
[1218] | 1041 | return BfsWizard<DefProcessedMapBase<T> >(*this); |
---|
| 1042 | } |
---|
| 1043 | |
---|
| 1044 | |
---|
| 1045 | template<class T> |
---|
| 1046 | struct DefDistMapBase : public Base { |
---|
| 1047 | typedef T DistMap; |
---|
[1367] | 1048 | static DistMap *createDistMap(const Graph &) { return 0; }; |
---|
[1236] | 1049 | DefDistMapBase(const TR &b) : TR(b) {} |
---|
[1218] | 1050 | }; |
---|
| 1051 | |
---|
| 1052 | ///\brief \ref named-templ-param "Named parameter" |
---|
| 1053 | ///function for setting DistMap type |
---|
| 1054 | /// |
---|
| 1055 | /// \ref named-templ-param "Named parameter" |
---|
| 1056 | ///function for setting DistMap type |
---|
| 1057 | /// |
---|
| 1058 | template<class T> |
---|
| 1059 | BfsWizard<DefDistMapBase<T> > distMap(const T &t) |
---|
| 1060 | { |
---|
[2386] | 1061 | Base::_dist=reinterpret_cast<void*>(const_cast<T*>(&t)); |
---|
[1218] | 1062 | return BfsWizard<DefDistMapBase<T> >(*this); |
---|
| 1063 | } |
---|
| 1064 | |
---|
| 1065 | /// Sets the source node, from which the Bfs algorithm runs. |
---|
| 1066 | |
---|
| 1067 | /// Sets the source node, from which the Bfs algorithm runs. |
---|
| 1068 | /// \param s is the source node. |
---|
| 1069 | BfsWizard<TR> &source(Node s) |
---|
| 1070 | { |
---|
| 1071 | Base::_source=s; |
---|
| 1072 | return *this; |
---|
| 1073 | } |
---|
[774] | 1074 | |
---|
| 1075 | }; |
---|
| 1076 | |
---|
[1218] | 1077 | ///Function type interface for Bfs algorithm. |
---|
| 1078 | |
---|
[2376] | 1079 | /// \ingroup search |
---|
[1218] | 1080 | ///Function type interface for Bfs algorithm. |
---|
| 1081 | /// |
---|
| 1082 | ///This function also has several |
---|
| 1083 | ///\ref named-templ-func-param "named parameters", |
---|
| 1084 | ///they are declared as the members of class \ref BfsWizard. |
---|
| 1085 | ///The following |
---|
| 1086 | ///example shows how to use these parameters. |
---|
| 1087 | ///\code |
---|
| 1088 | /// bfs(g,source).predMap(preds).run(); |
---|
| 1089 | ///\endcode |
---|
| 1090 | ///\warning Don't forget to put the \ref BfsWizard::run() "run()" |
---|
| 1091 | ///to the end of the parameter list. |
---|
| 1092 | ///\sa BfsWizard |
---|
| 1093 | ///\sa Bfs |
---|
| 1094 | template<class GR> |
---|
| 1095 | BfsWizard<BfsWizardBase<GR> > |
---|
| 1096 | bfs(const GR &g,typename GR::Node s=INVALID) |
---|
| 1097 | { |
---|
| 1098 | return BfsWizard<BfsWizardBase<GR> >(g,s); |
---|
| 1099 | } |
---|
| 1100 | |
---|
[2306] | 1101 | #ifdef DOXYGEN |
---|
| 1102 | /// \brief Visitor class for bfs. |
---|
| 1103 | /// |
---|
| 1104 | /// It gives a simple interface for a functional interface for bfs |
---|
| 1105 | /// traversal. The traversal on a linear data structure. |
---|
| 1106 | template <typename _Graph> |
---|
| 1107 | struct BfsVisitor { |
---|
| 1108 | typedef _Graph Graph; |
---|
| 1109 | typedef typename Graph::Edge Edge; |
---|
| 1110 | typedef typename Graph::Node Node; |
---|
| 1111 | /// \brief Called when the edge reach a node. |
---|
| 1112 | /// |
---|
| 1113 | /// It is called when the bfs find an edge which target is not |
---|
| 1114 | /// reached yet. |
---|
| 1115 | void discover(const Edge& edge) {} |
---|
| 1116 | /// \brief Called when the node reached first time. |
---|
| 1117 | /// |
---|
| 1118 | /// It is Called when the node reached first time. |
---|
| 1119 | void reach(const Node& node) {} |
---|
| 1120 | /// \brief Called when the edge examined but target of the edge |
---|
| 1121 | /// already discovered. |
---|
| 1122 | /// |
---|
| 1123 | /// It called when the edge examined but the target of the edge |
---|
| 1124 | /// already discovered. |
---|
| 1125 | void examine(const Edge& edge) {} |
---|
| 1126 | /// \brief Called for the source node of the bfs. |
---|
| 1127 | /// |
---|
| 1128 | /// It is called for the source node of the bfs. |
---|
| 1129 | void start(const Node& node) {} |
---|
| 1130 | /// \brief Called when the node processed. |
---|
| 1131 | /// |
---|
| 1132 | /// It is Called when the node processed. |
---|
| 1133 | void process(const Node& node) {} |
---|
| 1134 | }; |
---|
| 1135 | #else |
---|
| 1136 | template <typename _Graph> |
---|
| 1137 | struct BfsVisitor { |
---|
| 1138 | typedef _Graph Graph; |
---|
| 1139 | typedef typename Graph::Edge Edge; |
---|
| 1140 | typedef typename Graph::Node Node; |
---|
| 1141 | void discover(const Edge&) {} |
---|
| 1142 | void reach(const Node&) {} |
---|
| 1143 | void examine(const Edge&) {} |
---|
| 1144 | void start(const Node&) {} |
---|
| 1145 | void process(const Node&) {} |
---|
| 1146 | |
---|
| 1147 | template <typename _Visitor> |
---|
| 1148 | struct Constraints { |
---|
| 1149 | void constraints() { |
---|
| 1150 | Edge edge; |
---|
| 1151 | Node node; |
---|
| 1152 | visitor.discover(edge); |
---|
| 1153 | visitor.reach(node); |
---|
| 1154 | visitor.examine(edge); |
---|
| 1155 | visitor.start(node); |
---|
| 1156 | visitor.process(node); |
---|
| 1157 | } |
---|
| 1158 | _Visitor& visitor; |
---|
| 1159 | }; |
---|
| 1160 | }; |
---|
| 1161 | #endif |
---|
| 1162 | |
---|
| 1163 | /// \brief Default traits class of BfsVisit class. |
---|
| 1164 | /// |
---|
| 1165 | /// Default traits class of BfsVisit class. |
---|
| 1166 | /// \param _Graph Graph type. |
---|
| 1167 | template<class _Graph> |
---|
| 1168 | struct BfsVisitDefaultTraits { |
---|
| 1169 | |
---|
| 1170 | /// \brief The graph type the algorithm runs on. |
---|
| 1171 | typedef _Graph Graph; |
---|
| 1172 | |
---|
| 1173 | /// \brief The type of the map that indicates which nodes are reached. |
---|
| 1174 | /// |
---|
| 1175 | /// The type of the map that indicates which nodes are reached. |
---|
| 1176 | /// It must meet the \ref concepts::WriteMap "WriteMap" concept. |
---|
| 1177 | /// \todo named parameter to set this type, function to read and write. |
---|
| 1178 | typedef typename Graph::template NodeMap<bool> ReachedMap; |
---|
| 1179 | |
---|
| 1180 | /// \brief Instantiates a ReachedMap. |
---|
| 1181 | /// |
---|
| 1182 | /// This function instantiates a \ref ReachedMap. |
---|
| 1183 | /// \param graph is the graph, to which |
---|
| 1184 | /// we would like to define the \ref ReachedMap. |
---|
| 1185 | static ReachedMap *createReachedMap(const Graph &graph) { |
---|
| 1186 | return new ReachedMap(graph); |
---|
| 1187 | } |
---|
| 1188 | |
---|
| 1189 | }; |
---|
| 1190 | |
---|
| 1191 | /// %BFS Visit algorithm class. |
---|
| 1192 | |
---|
[2376] | 1193 | /// \ingroup search |
---|
[2306] | 1194 | /// This class provides an efficient implementation of the %BFS algorithm |
---|
| 1195 | /// with visitor interface. |
---|
| 1196 | /// |
---|
| 1197 | /// The %BfsVisit class provides an alternative interface to the Bfs |
---|
| 1198 | /// class. It works with callback mechanism, the BfsVisit object calls |
---|
| 1199 | /// on every bfs event the \c Visitor class member functions. |
---|
| 1200 | /// |
---|
| 1201 | /// \param _Graph The graph type the algorithm runs on. The default value is |
---|
| 1202 | /// \ref ListGraph. The value of _Graph is not used directly by Bfs, it |
---|
| 1203 | /// is only passed to \ref BfsDefaultTraits. |
---|
| 1204 | /// \param _Visitor The Visitor object for the algorithm. The |
---|
| 1205 | /// \ref BfsVisitor "BfsVisitor<_Graph>" is an empty Visitor which |
---|
| 1206 | /// does not observe the Bfs events. If you want to observe the bfs |
---|
| 1207 | /// events you should implement your own Visitor class. |
---|
| 1208 | /// \param _Traits Traits class to set various data types used by the |
---|
| 1209 | /// algorithm. The default traits class is |
---|
| 1210 | /// \ref BfsVisitDefaultTraits "BfsVisitDefaultTraits<_Graph>". |
---|
| 1211 | /// See \ref BfsVisitDefaultTraits for the documentation of |
---|
| 1212 | /// a Bfs visit traits class. |
---|
| 1213 | /// |
---|
| 1214 | /// \author Jacint Szabo, Alpar Juttner and Balazs Dezso |
---|
| 1215 | #ifdef DOXYGEN |
---|
| 1216 | template <typename _Graph, typename _Visitor, typename _Traits> |
---|
| 1217 | #else |
---|
| 1218 | template <typename _Graph = ListGraph, |
---|
| 1219 | typename _Visitor = BfsVisitor<_Graph>, |
---|
| 1220 | typename _Traits = BfsDefaultTraits<_Graph> > |
---|
| 1221 | #endif |
---|
| 1222 | class BfsVisit { |
---|
| 1223 | public: |
---|
| 1224 | |
---|
| 1225 | /// \brief \ref Exception for uninitialized parameters. |
---|
| 1226 | /// |
---|
| 1227 | /// This error represents problems in the initialization |
---|
| 1228 | /// of the parameters of the algorithms. |
---|
| 1229 | class UninitializedParameter : public lemon::UninitializedParameter { |
---|
| 1230 | public: |
---|
| 1231 | virtual const char* what() const throw() |
---|
| 1232 | { |
---|
| 1233 | return "lemon::BfsVisit::UninitializedParameter"; |
---|
| 1234 | } |
---|
| 1235 | }; |
---|
| 1236 | |
---|
| 1237 | typedef _Traits Traits; |
---|
| 1238 | |
---|
| 1239 | typedef typename Traits::Graph Graph; |
---|
| 1240 | |
---|
| 1241 | typedef _Visitor Visitor; |
---|
| 1242 | |
---|
| 1243 | ///The type of the map indicating which nodes are reached. |
---|
| 1244 | typedef typename Traits::ReachedMap ReachedMap; |
---|
| 1245 | |
---|
| 1246 | private: |
---|
| 1247 | |
---|
| 1248 | typedef typename Graph::Node Node; |
---|
| 1249 | typedef typename Graph::NodeIt NodeIt; |
---|
| 1250 | typedef typename Graph::Edge Edge; |
---|
| 1251 | typedef typename Graph::OutEdgeIt OutEdgeIt; |
---|
| 1252 | |
---|
| 1253 | /// Pointer to the underlying graph. |
---|
| 1254 | const Graph *_graph; |
---|
| 1255 | /// Pointer to the visitor object. |
---|
| 1256 | Visitor *_visitor; |
---|
| 1257 | ///Pointer to the map of reached status of the nodes. |
---|
| 1258 | ReachedMap *_reached; |
---|
| 1259 | ///Indicates if \ref _reached is locally allocated (\c true) or not. |
---|
| 1260 | bool local_reached; |
---|
| 1261 | |
---|
| 1262 | std::vector<typename Graph::Node> _list; |
---|
| 1263 | int _list_front, _list_back; |
---|
| 1264 | |
---|
| 1265 | /// \brief Creates the maps if necessary. |
---|
| 1266 | /// |
---|
| 1267 | /// Creates the maps if necessary. |
---|
| 1268 | void create_maps() { |
---|
| 1269 | if(!_reached) { |
---|
| 1270 | local_reached = true; |
---|
| 1271 | _reached = Traits::createReachedMap(*_graph); |
---|
| 1272 | } |
---|
| 1273 | } |
---|
| 1274 | |
---|
| 1275 | protected: |
---|
| 1276 | |
---|
| 1277 | BfsVisit() {} |
---|
| 1278 | |
---|
| 1279 | public: |
---|
| 1280 | |
---|
| 1281 | typedef BfsVisit Create; |
---|
| 1282 | |
---|
| 1283 | /// \name Named template parameters |
---|
| 1284 | |
---|
| 1285 | ///@{ |
---|
| 1286 | template <class T> |
---|
| 1287 | struct DefReachedMapTraits : public Traits { |
---|
| 1288 | typedef T ReachedMap; |
---|
| 1289 | static ReachedMap *createReachedMap(const Graph &graph) { |
---|
| 1290 | throw UninitializedParameter(); |
---|
| 1291 | } |
---|
| 1292 | }; |
---|
| 1293 | /// \brief \ref named-templ-param "Named parameter" for setting |
---|
| 1294 | /// ReachedMap type |
---|
| 1295 | /// |
---|
| 1296 | /// \ref named-templ-param "Named parameter" for setting ReachedMap type |
---|
| 1297 | template <class T> |
---|
| 1298 | struct DefReachedMap : public BfsVisit< Graph, Visitor, |
---|
| 1299 | DefReachedMapTraits<T> > { |
---|
| 1300 | typedef BfsVisit< Graph, Visitor, DefReachedMapTraits<T> > Create; |
---|
| 1301 | }; |
---|
| 1302 | ///@} |
---|
| 1303 | |
---|
| 1304 | public: |
---|
| 1305 | |
---|
| 1306 | /// \brief Constructor. |
---|
| 1307 | /// |
---|
| 1308 | /// Constructor. |
---|
| 1309 | /// |
---|
| 1310 | /// \param graph the graph the algorithm will run on. |
---|
| 1311 | /// \param visitor The visitor of the algorithm. |
---|
| 1312 | /// |
---|
| 1313 | BfsVisit(const Graph& graph, Visitor& visitor) |
---|
| 1314 | : _graph(&graph), _visitor(&visitor), |
---|
| 1315 | _reached(0), local_reached(false) {} |
---|
| 1316 | |
---|
| 1317 | /// \brief Destructor. |
---|
| 1318 | /// |
---|
| 1319 | /// Destructor. |
---|
| 1320 | ~BfsVisit() { |
---|
| 1321 | if(local_reached) delete _reached; |
---|
| 1322 | } |
---|
| 1323 | |
---|
| 1324 | /// \brief Sets the map indicating if a node is reached. |
---|
| 1325 | /// |
---|
| 1326 | /// Sets the map indicating if a node is reached. |
---|
| 1327 | /// If you don't use this function before calling \ref run(), |
---|
| 1328 | /// it will allocate one. The destuctor deallocates this |
---|
| 1329 | /// automatically allocated map, of course. |
---|
| 1330 | /// \return <tt> (*this) </tt> |
---|
| 1331 | BfsVisit &reachedMap(ReachedMap &m) { |
---|
| 1332 | if(local_reached) { |
---|
| 1333 | delete _reached; |
---|
| 1334 | local_reached = false; |
---|
| 1335 | } |
---|
| 1336 | _reached = &m; |
---|
| 1337 | return *this; |
---|
| 1338 | } |
---|
| 1339 | |
---|
| 1340 | public: |
---|
| 1341 | /// \name Execution control |
---|
| 1342 | /// The simplest way to execute the algorithm is to use |
---|
| 1343 | /// one of the member functions called \c run(...). |
---|
| 1344 | /// \n |
---|
| 1345 | /// If you need more control on the execution, |
---|
| 1346 | /// first you must call \ref init(), then you can adda source node |
---|
| 1347 | /// with \ref addSource(). |
---|
| 1348 | /// Finally \ref start() will perform the actual path |
---|
| 1349 | /// computation. |
---|
| 1350 | |
---|
| 1351 | /// @{ |
---|
| 1352 | /// \brief Initializes the internal data structures. |
---|
| 1353 | /// |
---|
| 1354 | /// Initializes the internal data structures. |
---|
| 1355 | /// |
---|
| 1356 | void init() { |
---|
| 1357 | create_maps(); |
---|
| 1358 | _list.resize(countNodes(*_graph)); |
---|
| 1359 | _list_front = _list_back = -1; |
---|
| 1360 | for (NodeIt u(*_graph) ; u != INVALID ; ++u) { |
---|
| 1361 | _reached->set(u, false); |
---|
| 1362 | } |
---|
| 1363 | } |
---|
| 1364 | |
---|
| 1365 | /// \brief Adds a new source node. |
---|
| 1366 | /// |
---|
| 1367 | /// Adds a new source node to the set of nodes to be processed. |
---|
| 1368 | void addSource(Node s) { |
---|
| 1369 | if(!(*_reached)[s]) { |
---|
| 1370 | _reached->set(s,true); |
---|
| 1371 | _visitor->start(s); |
---|
| 1372 | _visitor->reach(s); |
---|
| 1373 | _list[++_list_back] = s; |
---|
| 1374 | } |
---|
| 1375 | } |
---|
| 1376 | |
---|
| 1377 | /// \brief Processes the next node. |
---|
| 1378 | /// |
---|
| 1379 | /// Processes the next node. |
---|
| 1380 | /// |
---|
| 1381 | /// \return The processed node. |
---|
| 1382 | /// |
---|
| 1383 | /// \pre The queue must not be empty! |
---|
| 1384 | Node processNextNode() { |
---|
| 1385 | Node n = _list[++_list_front]; |
---|
| 1386 | _visitor->process(n); |
---|
| 1387 | Edge e; |
---|
| 1388 | for (_graph->firstOut(e, n); e != INVALID; _graph->nextOut(e)) { |
---|
| 1389 | Node m = _graph->target(e); |
---|
| 1390 | if (!(*_reached)[m]) { |
---|
| 1391 | _visitor->discover(e); |
---|
| 1392 | _visitor->reach(m); |
---|
| 1393 | _reached->set(m, true); |
---|
| 1394 | _list[++_list_back] = m; |
---|
| 1395 | } else { |
---|
| 1396 | _visitor->examine(e); |
---|
| 1397 | } |
---|
| 1398 | } |
---|
| 1399 | return n; |
---|
| 1400 | } |
---|
| 1401 | |
---|
| 1402 | /// \brief Processes the next node. |
---|
| 1403 | /// |
---|
| 1404 | /// Processes the next node. And checks that the given target node |
---|
| 1405 | /// is reached. If the target node is reachable from the processed |
---|
| 1406 | /// node then the reached parameter will be set true. The reached |
---|
| 1407 | /// parameter should be initially false. |
---|
| 1408 | /// |
---|
| 1409 | /// \param target The target node. |
---|
[2386] | 1410 | /// \retval reach Indicates that the target node is reached. |
---|
[2306] | 1411 | /// \return The processed node. |
---|
| 1412 | /// |
---|
| 1413 | /// \warning The queue must not be empty! |
---|
[2386] | 1414 | Node processNextNode(Node target, bool& reach) { |
---|
[2306] | 1415 | Node n = _list[++_list_front]; |
---|
| 1416 | _visitor->process(n); |
---|
| 1417 | Edge e; |
---|
| 1418 | for (_graph->firstOut(e, n); e != INVALID; _graph->nextOut(e)) { |
---|
| 1419 | Node m = _graph->target(e); |
---|
| 1420 | if (!(*_reached)[m]) { |
---|
| 1421 | _visitor->discover(e); |
---|
| 1422 | _visitor->reach(m); |
---|
| 1423 | _reached->set(m, true); |
---|
| 1424 | _list[++_list_back] = m; |
---|
[2386] | 1425 | reach = reach || (target == m); |
---|
[2306] | 1426 | } else { |
---|
| 1427 | _visitor->examine(e); |
---|
| 1428 | } |
---|
| 1429 | } |
---|
| 1430 | return n; |
---|
| 1431 | } |
---|
| 1432 | |
---|
| 1433 | /// \brief Processes the next node. |
---|
| 1434 | /// |
---|
| 1435 | /// Processes the next node. And checks that at least one of |
---|
| 1436 | /// reached node has true value in the \c nm nodemap. If one node |
---|
| 1437 | /// with true value is reachable from the processed node then the |
---|
| 1438 | /// reached parameter will be set true. The reached parameter |
---|
| 1439 | /// should be initially false. |
---|
| 1440 | /// |
---|
[2350] | 1441 | /// \param nm The nodemaps of possible targets. |
---|
[2306] | 1442 | /// \retval reached Indicates that one of the target nodes is reached. |
---|
| 1443 | /// \return The processed node. |
---|
| 1444 | /// |
---|
| 1445 | /// \warning The queue must not be empty! |
---|
| 1446 | template <typename NM> |
---|
[2386] | 1447 | Node processNextNode(const NM& nm, bool& reach) { |
---|
[2306] | 1448 | Node n = _list[++_list_front]; |
---|
| 1449 | _visitor->process(n); |
---|
| 1450 | Edge e; |
---|
| 1451 | for (_graph->firstOut(e, n); e != INVALID; _graph->nextOut(e)) { |
---|
| 1452 | Node m = _graph->target(e); |
---|
| 1453 | if (!(*_reached)[m]) { |
---|
| 1454 | _visitor->discover(e); |
---|
| 1455 | _visitor->reach(m); |
---|
| 1456 | _reached->set(m, true); |
---|
| 1457 | _list[++_list_back] = m; |
---|
[2386] | 1458 | reach = reach || nm[m]; |
---|
[2306] | 1459 | } else { |
---|
| 1460 | _visitor->examine(e); |
---|
| 1461 | } |
---|
| 1462 | } |
---|
| 1463 | return n; |
---|
| 1464 | } |
---|
| 1465 | |
---|
| 1466 | /// \brief Next node to be processed. |
---|
| 1467 | /// |
---|
| 1468 | /// Next node to be processed. |
---|
| 1469 | /// |
---|
| 1470 | /// \return The next node to be processed or INVALID if the stack is |
---|
| 1471 | /// empty. |
---|
| 1472 | Node nextNode() { |
---|
| 1473 | return _list_front != _list_back ? _list[_list_front + 1] : INVALID; |
---|
| 1474 | } |
---|
| 1475 | |
---|
| 1476 | /// \brief Returns \c false if there are nodes |
---|
| 1477 | /// to be processed in the queue |
---|
| 1478 | /// |
---|
| 1479 | /// Returns \c false if there are nodes |
---|
| 1480 | /// to be processed in the queue |
---|
| 1481 | bool emptyQueue() { return _list_front == _list_back; } |
---|
| 1482 | |
---|
| 1483 | /// \brief Returns the number of the nodes to be processed. |
---|
| 1484 | /// |
---|
| 1485 | /// Returns the number of the nodes to be processed in the queue. |
---|
| 1486 | int queueSize() { return _list_back - _list_front; } |
---|
| 1487 | |
---|
| 1488 | /// \brief Executes the algorithm. |
---|
| 1489 | /// |
---|
| 1490 | /// Executes the algorithm. |
---|
| 1491 | /// |
---|
| 1492 | /// \pre init() must be called and at least one node should be added |
---|
| 1493 | /// with addSource() before using this function. |
---|
| 1494 | void start() { |
---|
| 1495 | while ( !emptyQueue() ) processNextNode(); |
---|
| 1496 | } |
---|
| 1497 | |
---|
[2307] | 1498 | /// \brief Executes the algorithm until \c dest is reached. |
---|
[2306] | 1499 | /// |
---|
[2307] | 1500 | /// Executes the algorithm until \c dest is reached. |
---|
[2306] | 1501 | /// |
---|
| 1502 | /// \pre init() must be called and at least one node should be added |
---|
| 1503 | /// with addSource() before using this function. |
---|
| 1504 | void start(Node dest) { |
---|
[2386] | 1505 | bool reach = false; |
---|
| 1506 | while (!emptyQueue() && !reach) { |
---|
| 1507 | processNextNode(dest, reach); |
---|
[2306] | 1508 | } |
---|
| 1509 | } |
---|
| 1510 | |
---|
| 1511 | /// \brief Executes the algorithm until a condition is met. |
---|
| 1512 | /// |
---|
| 1513 | /// Executes the algorithm until a condition is met. |
---|
| 1514 | /// |
---|
| 1515 | /// \pre init() must be called and at least one node should be added |
---|
| 1516 | /// with addSource() before using this function. |
---|
| 1517 | /// |
---|
| 1518 | ///\param nm must be a bool (or convertible) node map. The |
---|
[2307] | 1519 | ///algorithm will stop when it reached a node \c v with |
---|
[2350] | 1520 | /// <tt>nm[v]</tt> true. |
---|
[2306] | 1521 | template <typename NM> |
---|
| 1522 | void start(const NM &nm) { |
---|
[2386] | 1523 | bool reach = false; |
---|
| 1524 | while (!emptyQueue() && !reach) { |
---|
| 1525 | processNextNode(nm, reach); |
---|
[2306] | 1526 | } |
---|
| 1527 | } |
---|
| 1528 | |
---|
| 1529 | /// \brief Runs %BFSVisit algorithm from node \c s. |
---|
| 1530 | /// |
---|
| 1531 | /// This method runs the %BFS algorithm from a root node \c s. |
---|
| 1532 | /// \note b.run(s) is just a shortcut of the following code. |
---|
| 1533 | ///\code |
---|
| 1534 | /// b.init(); |
---|
| 1535 | /// b.addSource(s); |
---|
| 1536 | /// b.start(); |
---|
| 1537 | ///\endcode |
---|
| 1538 | void run(Node s) { |
---|
| 1539 | init(); |
---|
| 1540 | addSource(s); |
---|
| 1541 | start(); |
---|
| 1542 | } |
---|
| 1543 | |
---|
| 1544 | /// \brief Runs %BFSVisit algorithm to visit all nodes in the graph. |
---|
| 1545 | /// |
---|
| 1546 | /// This method runs the %BFS algorithm in order to |
---|
| 1547 | /// compute the %BFS path to each node. The algorithm computes |
---|
| 1548 | /// - The %BFS tree. |
---|
| 1549 | /// - The distance of each node from the root in the %BFS tree. |
---|
| 1550 | /// |
---|
| 1551 | ///\note b.run() is just a shortcut of the following code. |
---|
| 1552 | ///\code |
---|
| 1553 | /// b.init(); |
---|
| 1554 | /// for (NodeIt it(graph); it != INVALID; ++it) { |
---|
| 1555 | /// if (!b.reached(it)) { |
---|
| 1556 | /// b.addSource(it); |
---|
| 1557 | /// b.start(); |
---|
| 1558 | /// } |
---|
| 1559 | /// } |
---|
| 1560 | ///\endcode |
---|
| 1561 | void run() { |
---|
| 1562 | init(); |
---|
| 1563 | for (NodeIt it(*_graph); it != INVALID; ++it) { |
---|
| 1564 | if (!reached(it)) { |
---|
| 1565 | addSource(it); |
---|
| 1566 | start(); |
---|
| 1567 | } |
---|
| 1568 | } |
---|
| 1569 | } |
---|
| 1570 | ///@} |
---|
| 1571 | |
---|
| 1572 | /// \name Query Functions |
---|
| 1573 | /// The result of the %BFS algorithm can be obtained using these |
---|
| 1574 | /// functions.\n |
---|
| 1575 | /// Before the use of these functions, |
---|
| 1576 | /// either run() or start() must be called. |
---|
| 1577 | ///@{ |
---|
| 1578 | |
---|
| 1579 | /// \brief Checks if a node is reachable from the root. |
---|
| 1580 | /// |
---|
| 1581 | /// Returns \c true if \c v is reachable from the root(s). |
---|
| 1582 | /// \warning The source nodes are inditated as unreachable. |
---|
| 1583 | /// \pre Either \ref run() or \ref start() |
---|
| 1584 | /// must be called before using this function. |
---|
| 1585 | /// |
---|
| 1586 | bool reached(Node v) { return (*_reached)[v]; } |
---|
| 1587 | ///@} |
---|
| 1588 | }; |
---|
| 1589 | |
---|
[921] | 1590 | } //END OF NAMESPACE LEMON |
---|
[774] | 1591 | |
---|
| 1592 | #endif |
---|
| 1593 | |
---|