[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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| 5 | * Copyright (C) 2003-2006 |
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| 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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| 22 | ///\ingroup flowalgs |
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| 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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[1993] | 28 | #include <lemon/bits/invalid.h> |
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[1218] | 29 | #include <lemon/error.h> |
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| 30 | #include <lemon/maps.h> |
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[774] | 31 | |
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[921] | 32 | namespace lemon { |
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[774] | 33 | |
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| 34 | |
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[1218] | 35 | |
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| 36 | ///Default traits class of Bfs class. |
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| 37 | |
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| 38 | ///Default traits class of Bfs class. |
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| 39 | ///\param GR Graph type. |
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| 40 | template<class GR> |
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| 41 | struct BfsDefaultTraits |
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| 42 | { |
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| 43 | ///The graph type the algorithm runs on. |
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| 44 | typedef GR Graph; |
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| 45 | ///\brief The type of the map that stores the last |
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| 46 | ///edges of the shortest paths. |
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| 47 | /// |
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| 48 | ///The type of the map that stores the last |
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| 49 | ///edges of the shortest paths. |
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[2260] | 50 | ///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
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[1218] | 51 | /// |
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| 52 | typedef typename Graph::template NodeMap<typename GR::Edge> PredMap; |
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| 53 | ///Instantiates a PredMap. |
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| 54 | |
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| 55 | ///This function instantiates a \ref PredMap. |
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| 56 | ///\param G is the graph, to which we would like to define the PredMap. |
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| 57 | ///\todo The graph alone may be insufficient to initialize |
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| 58 | static PredMap *createPredMap(const GR &G) |
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| 59 | { |
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| 60 | return new PredMap(G); |
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| 61 | } |
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| 62 | ///The type of the map that indicates which nodes are processed. |
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| 63 | |
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| 64 | ///The type of the map that indicates which nodes are processed. |
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[2260] | 65 | ///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
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[1218] | 66 | ///\todo named parameter to set this type, function to read and write. |
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| 67 | typedef NullMap<typename Graph::Node,bool> ProcessedMap; |
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| 68 | ///Instantiates a ProcessedMap. |
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| 69 | |
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| 70 | ///This function instantiates a \ref ProcessedMap. |
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[1536] | 71 | ///\param g is the graph, to which |
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[1218] | 72 | ///we would like to define the \ref ProcessedMap |
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[1536] | 73 | #ifdef DOXYGEN |
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| 74 | static ProcessedMap *createProcessedMap(const GR &g) |
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| 75 | #else |
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[1367] | 76 | static ProcessedMap *createProcessedMap(const GR &) |
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[1536] | 77 | #endif |
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[1218] | 78 | { |
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| 79 | return new ProcessedMap(); |
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| 80 | } |
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| 81 | ///The type of the map that indicates which nodes are reached. |
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| 82 | |
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| 83 | ///The type of the map that indicates which nodes are reached. |
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[2260] | 84 | ///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
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[1218] | 85 | ///\todo named parameter to set this type, function to read and write. |
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| 86 | typedef typename Graph::template NodeMap<bool> ReachedMap; |
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| 87 | ///Instantiates a ReachedMap. |
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| 88 | |
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| 89 | ///This function instantiates a \ref ReachedMap. |
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| 90 | ///\param G is the graph, to which |
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| 91 | ///we would like to define the \ref ReachedMap. |
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| 92 | static ReachedMap *createReachedMap(const GR &G) |
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| 93 | { |
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| 94 | return new ReachedMap(G); |
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| 95 | } |
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| 96 | ///The type of the map that stores the dists of the nodes. |
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| 97 | |
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| 98 | ///The type of the map that stores the dists of the nodes. |
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[2260] | 99 | ///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
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[1218] | 100 | /// |
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| 101 | typedef typename Graph::template NodeMap<int> DistMap; |
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| 102 | ///Instantiates a DistMap. |
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| 103 | |
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| 104 | ///This function instantiates a \ref DistMap. |
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| 105 | ///\param G is the graph, to which we would like to define the \ref DistMap |
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| 106 | static DistMap *createDistMap(const GR &G) |
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| 107 | { |
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| 108 | return new DistMap(G); |
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| 109 | } |
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| 110 | }; |
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| 111 | |
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[781] | 112 | ///%BFS algorithm class. |
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[1218] | 113 | |
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| 114 | ///\ingroup flowalgs |
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| 115 | ///This class provides an efficient implementation of the %BFS algorithm. |
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[774] | 116 | /// |
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[1218] | 117 | ///\param GR The graph type the algorithm runs on. The default value is |
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| 118 | ///\ref ListGraph. The value of GR is not used directly by Bfs, it |
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| 119 | ///is only passed to \ref BfsDefaultTraits. |
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| 120 | ///\param TR Traits class to set various data types used by the algorithm. |
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| 121 | ///The default traits class is |
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| 122 | ///\ref BfsDefaultTraits "BfsDefaultTraits<GR>". |
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| 123 | ///See \ref BfsDefaultTraits for the documentation of |
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| 124 | ///a Bfs traits class. |
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| 125 | /// |
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[1270] | 126 | ///\author Alpar Juttner |
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[774] | 127 | |
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| 128 | #ifdef DOXYGEN |
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[1218] | 129 | template <typename GR, |
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| 130 | typename TR> |
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[774] | 131 | #else |
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[1218] | 132 | template <typename GR=ListGraph, |
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| 133 | typename TR=BfsDefaultTraits<GR> > |
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[774] | 134 | #endif |
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[1218] | 135 | class Bfs { |
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[774] | 136 | public: |
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[1218] | 137 | /** |
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| 138 | * \brief \ref Exception for uninitialized parameters. |
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| 139 | * |
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| 140 | * This error represents problems in the initialization |
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| 141 | * of the parameters of the algorithms. |
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| 142 | */ |
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| 143 | class UninitializedParameter : public lemon::UninitializedParameter { |
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| 144 | public: |
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[2151] | 145 | virtual const char* what() const throw() { |
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[1218] | 146 | return "lemon::Bfs::UninitializedParameter"; |
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| 147 | } |
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| 148 | }; |
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| 149 | |
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| 150 | typedef TR Traits; |
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[774] | 151 | ///The type of the underlying graph. |
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[1218] | 152 | typedef typename TR::Graph Graph; |
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[911] | 153 | ///\e |
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[774] | 154 | typedef typename Graph::Node Node; |
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[911] | 155 | ///\e |
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[774] | 156 | typedef typename Graph::NodeIt NodeIt; |
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[911] | 157 | ///\e |
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[774] | 158 | typedef typename Graph::Edge Edge; |
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[911] | 159 | ///\e |
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[774] | 160 | typedef typename Graph::OutEdgeIt OutEdgeIt; |
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| 161 | |
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| 162 | ///\brief The type of the map that stores the last |
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| 163 | ///edges of the shortest paths. |
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[1218] | 164 | typedef typename TR::PredMap PredMap; |
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| 165 | ///The type of the map indicating which nodes are reached. |
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| 166 | typedef typename TR::ReachedMap ReachedMap; |
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| 167 | ///The type of the map indicating which nodes are processed. |
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| 168 | typedef typename TR::ProcessedMap ProcessedMap; |
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[774] | 169 | ///The type of the map that stores the dists of the nodes. |
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[1218] | 170 | typedef typename TR::DistMap DistMap; |
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[774] | 171 | private: |
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[802] | 172 | /// Pointer to the underlying graph. |
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[774] | 173 | const Graph *G; |
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[802] | 174 | ///Pointer to the map of predecessors edges. |
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[1218] | 175 | PredMap *_pred; |
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| 176 | ///Indicates if \ref _pred is locally allocated (\c true) or not. |
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| 177 | bool local_pred; |
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[802] | 178 | ///Pointer to the map of distances. |
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[1218] | 179 | DistMap *_dist; |
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| 180 | ///Indicates if \ref _dist is locally allocated (\c true) or not. |
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| 181 | bool local_dist; |
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| 182 | ///Pointer to the map of reached status of the nodes. |
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| 183 | ReachedMap *_reached; |
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| 184 | ///Indicates if \ref _reached is locally allocated (\c true) or not. |
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| 185 | bool local_reached; |
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| 186 | ///Pointer to the map of processed status of the nodes. |
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| 187 | ProcessedMap *_processed; |
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| 188 | ///Indicates if \ref _processed is locally allocated (\c true) or not. |
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| 189 | bool local_processed; |
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[774] | 190 | |
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[1218] | 191 | std::vector<typename Graph::Node> _queue; |
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| 192 | int _queue_head,_queue_tail,_queue_next_dist; |
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| 193 | int _curr_dist; |
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[774] | 194 | |
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[1218] | 195 | ///Creates the maps if necessary. |
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| 196 | |
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| 197 | ///\todo Better memory allocation (instead of new). |
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| 198 | void create_maps() |
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[774] | 199 | { |
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[1218] | 200 | if(!_pred) { |
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| 201 | local_pred = true; |
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| 202 | _pred = Traits::createPredMap(*G); |
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[774] | 203 | } |
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[1218] | 204 | if(!_dist) { |
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| 205 | local_dist = true; |
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| 206 | _dist = Traits::createDistMap(*G); |
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[774] | 207 | } |
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[1218] | 208 | if(!_reached) { |
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| 209 | local_reached = true; |
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| 210 | _reached = Traits::createReachedMap(*G); |
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| 211 | } |
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| 212 | if(!_processed) { |
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| 213 | local_processed = true; |
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| 214 | _processed = Traits::createProcessedMap(*G); |
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[774] | 215 | } |
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| 216 | } |
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[1710] | 217 | |
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| 218 | protected: |
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[774] | 219 | |
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[1710] | 220 | Bfs() {} |
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| 221 | |
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| 222 | public: |
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[1218] | 223 | |
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[1710] | 224 | typedef Bfs Create; |
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| 225 | |
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[1218] | 226 | ///\name Named template parameters |
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| 227 | |
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| 228 | ///@{ |
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| 229 | |
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| 230 | template <class T> |
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| 231 | struct DefPredMapTraits : public Traits { |
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| 232 | typedef T PredMap; |
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[1799] | 233 | static PredMap *createPredMap(const Graph &) |
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[1218] | 234 | { |
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| 235 | throw UninitializedParameter(); |
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| 236 | } |
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| 237 | }; |
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| 238 | ///\ref named-templ-param "Named parameter" for setting PredMap type |
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| 239 | |
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| 240 | ///\ref named-templ-param "Named parameter" for setting PredMap type |
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| 241 | /// |
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| 242 | template <class T> |
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[1709] | 243 | struct DefPredMap : public Bfs< Graph, DefPredMapTraits<T> > { |
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| 244 | typedef Bfs< Graph, DefPredMapTraits<T> > Create; |
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| 245 | }; |
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[1218] | 246 | |
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| 247 | template <class T> |
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| 248 | struct DefDistMapTraits : public Traits { |
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| 249 | typedef T DistMap; |
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[1799] | 250 | static DistMap *createDistMap(const Graph &) |
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[1218] | 251 | { |
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| 252 | throw UninitializedParameter(); |
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| 253 | } |
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| 254 | }; |
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| 255 | ///\ref named-templ-param "Named parameter" for setting DistMap type |
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| 256 | |
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| 257 | ///\ref named-templ-param "Named parameter" for setting DistMap type |
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| 258 | /// |
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| 259 | template <class T> |
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[1709] | 260 | struct DefDistMap : public Bfs< Graph, DefDistMapTraits<T> > { |
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| 261 | typedef Bfs< Graph, DefDistMapTraits<T> > Create; |
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| 262 | }; |
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[1218] | 263 | |
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| 264 | template <class T> |
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| 265 | struct DefReachedMapTraits : public Traits { |
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| 266 | typedef T ReachedMap; |
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[1799] | 267 | static ReachedMap *createReachedMap(const Graph &) |
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[1218] | 268 | { |
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| 269 | throw UninitializedParameter(); |
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| 270 | } |
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| 271 | }; |
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| 272 | ///\ref named-templ-param "Named parameter" for setting ReachedMap type |
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| 273 | |
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| 274 | ///\ref named-templ-param "Named parameter" for setting ReachedMap type |
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| 275 | /// |
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| 276 | template <class T> |
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[1709] | 277 | struct DefReachedMap : public Bfs< Graph, DefReachedMapTraits<T> > { |
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| 278 | typedef Bfs< Graph, DefReachedMapTraits<T> > Create; |
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| 279 | }; |
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[1218] | 280 | |
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| 281 | template <class T> |
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| 282 | struct DefProcessedMapTraits : public Traits { |
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| 283 | typedef T ProcessedMap; |
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[2033] | 284 | static ProcessedMap *createProcessedMap(const Graph &) |
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[1218] | 285 | { |
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| 286 | throw UninitializedParameter(); |
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| 287 | } |
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| 288 | }; |
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| 289 | ///\ref named-templ-param "Named parameter" for setting ProcessedMap type |
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| 290 | |
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| 291 | ///\ref named-templ-param "Named parameter" for setting ProcessedMap type |
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| 292 | /// |
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| 293 | template <class T> |
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[1709] | 294 | struct DefProcessedMap : public Bfs< Graph, DefProcessedMapTraits<T> > { |
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| 295 | typedef Bfs< Graph, DefProcessedMapTraits<T> > Create; |
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| 296 | }; |
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[1218] | 297 | |
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| 298 | struct DefGraphProcessedMapTraits : public Traits { |
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| 299 | typedef typename Graph::template NodeMap<bool> ProcessedMap; |
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| 300 | static ProcessedMap *createProcessedMap(const Graph &G) |
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| 301 | { |
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| 302 | return new ProcessedMap(G); |
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| 303 | } |
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| 304 | }; |
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| 305 | ///\brief \ref named-templ-param "Named parameter" |
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| 306 | ///for setting the ProcessedMap type to be Graph::NodeMap<bool>. |
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| 307 | /// |
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| 308 | ///\ref named-templ-param "Named parameter" |
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| 309 | ///for setting the ProcessedMap type to be Graph::NodeMap<bool>. |
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[1270] | 310 | ///If you don't set it explicitly, it will be automatically allocated. |
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[1218] | 311 | template <class T> |
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[1709] | 312 | struct DefProcessedMapToBeDefaultMap : |
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| 313 | public Bfs< Graph, DefGraphProcessedMapTraits> { |
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| 314 | typedef Bfs< Graph, DefGraphProcessedMapTraits> Create; |
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| 315 | }; |
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[1218] | 316 | |
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| 317 | ///@} |
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| 318 | |
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| 319 | public: |
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| 320 | |
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[802] | 321 | ///Constructor. |
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| 322 | |
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| 323 | ///\param _G the graph the algorithm will run on. |
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[911] | 324 | /// |
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[774] | 325 | Bfs(const Graph& _G) : |
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| 326 | G(&_G), |
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[1218] | 327 | _pred(NULL), local_pred(false), |
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| 328 | _dist(NULL), local_dist(false), |
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| 329 | _reached(NULL), local_reached(false), |
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| 330 | _processed(NULL), local_processed(false) |
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[774] | 331 | { } |
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| 332 | |
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[802] | 333 | ///Destructor. |
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[774] | 334 | ~Bfs() |
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| 335 | { |
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[1218] | 336 | if(local_pred) delete _pred; |
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| 337 | if(local_dist) delete _dist; |
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| 338 | if(local_reached) delete _reached; |
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| 339 | if(local_processed) delete _processed; |
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[774] | 340 | } |
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| 341 | |
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| 342 | ///Sets the map storing the predecessor edges. |
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| 343 | |
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| 344 | ///Sets the map storing the predecessor edges. |
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| 345 | ///If you don't use this function before calling \ref run(), |
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[1270] | 346 | ///it will allocate one. The destructor deallocates this |
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[774] | 347 | ///automatically allocated map, of course. |
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| 348 | ///\return <tt> (*this) </tt> |
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[1218] | 349 | Bfs &predMap(PredMap &m) |
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[774] | 350 | { |
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[1218] | 351 | if(local_pred) { |
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| 352 | delete _pred; |
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| 353 | local_pred=false; |
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[774] | 354 | } |
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[1218] | 355 | _pred = &m; |
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[774] | 356 | return *this; |
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| 357 | } |
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| 358 | |
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[1218] | 359 | ///Sets the map indicating the reached nodes. |
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[774] | 360 | |
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[1218] | 361 | ///Sets the map indicating the reached nodes. |
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[774] | 362 | ///If you don't use this function before calling \ref run(), |
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[1270] | 363 | ///it will allocate one. The destructor deallocates this |
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[774] | 364 | ///automatically allocated map, of course. |
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| 365 | ///\return <tt> (*this) </tt> |
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[1218] | 366 | Bfs &reachedMap(ReachedMap &m) |
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[774] | 367 | { |
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[1218] | 368 | if(local_reached) { |
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| 369 | delete _reached; |
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| 370 | local_reached=false; |
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[774] | 371 | } |
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[1218] | 372 | _reached = &m; |
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[774] | 373 | return *this; |
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| 374 | } |
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| 375 | |
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[1218] | 376 | ///Sets the map indicating the processed nodes. |
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| 377 | |
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| 378 | ///Sets the map indicating the processed nodes. |
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| 379 | ///If you don't use this function before calling \ref run(), |
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[1270] | 380 | ///it will allocate one. The destructor deallocates this |
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[1218] | 381 | ///automatically allocated map, of course. |
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| 382 | ///\return <tt> (*this) </tt> |
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| 383 | Bfs &processedMap(ProcessedMap &m) |
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| 384 | { |
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| 385 | if(local_processed) { |
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| 386 | delete _processed; |
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| 387 | local_processed=false; |
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| 388 | } |
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| 389 | _processed = &m; |
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| 390 | return *this; |
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| 391 | } |
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| 392 | |
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[774] | 393 | ///Sets the map storing the distances calculated by the algorithm. |
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| 394 | |
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| 395 | ///Sets the map storing the distances calculated by the algorithm. |
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| 396 | ///If you don't use this function before calling \ref run(), |
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[1270] | 397 | ///it will allocate one. The destructor deallocates this |
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[774] | 398 | ///automatically allocated map, of course. |
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| 399 | ///\return <tt> (*this) </tt> |
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[1218] | 400 | Bfs &distMap(DistMap &m) |
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[774] | 401 | { |
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[1218] | 402 | if(local_dist) { |
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| 403 | delete _dist; |
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| 404 | local_dist=false; |
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[774] | 405 | } |
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[1218] | 406 | _dist = &m; |
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[774] | 407 | return *this; |
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| 408 | } |
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| 409 | |
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[1218] | 410 | public: |
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| 411 | ///\name Execution control |
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| 412 | ///The simplest way to execute the algorithm is to use |
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| 413 | ///one of the member functions called \c run(...). |
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| 414 | ///\n |
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| 415 | ///If you need more control on the execution, |
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| 416 | ///first you must call \ref init(), then you can add several source nodes |
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| 417 | ///with \ref addSource(). |
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| 418 | ///Finally \ref start() will perform the actual path |
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| 419 | ///computation. |
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| 420 | |
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| 421 | ///@{ |
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| 422 | |
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| 423 | ///Initializes the internal data structures. |
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| 424 | |
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| 425 | ///Initializes the internal data structures. |
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| 426 | /// |
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| 427 | void init() |
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| 428 | { |
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| 429 | create_maps(); |
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| 430 | _queue.resize(countNodes(*G)); |
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| 431 | _queue_head=_queue_tail=0; |
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| 432 | _curr_dist=1; |
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[774] | 433 | for ( NodeIt u(*G) ; u!=INVALID ; ++u ) { |
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[1218] | 434 | _pred->set(u,INVALID); |
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| 435 | _reached->set(u,false); |
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| 436 | _processed->set(u,false); |
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[774] | 437 | } |
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| 438 | } |
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| 439 | |
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[1218] | 440 | ///Adds a new source node. |
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[774] | 441 | |
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[1218] | 442 | ///Adds a new source node to the set of nodes to be processed. |
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| 443 | /// |
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| 444 | void addSource(Node s) |
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| 445 | { |
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| 446 | if(!(*_reached)[s]) |
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| 447 | { |
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| 448 | _reached->set(s,true); |
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| 449 | _pred->set(s,INVALID); |
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| 450 | _dist->set(s,0); |
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| 451 | _queue[_queue_head++]=s; |
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| 452 | _queue_next_dist=_queue_head; |
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| 453 | } |
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| 454 | } |
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| 455 | |
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| 456 | ///Processes the next node. |
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| 457 | |
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| 458 | ///Processes the next node. |
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| 459 | /// |
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[1516] | 460 | ///\return The processed node. |
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| 461 | /// |
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[1218] | 462 | ///\warning The queue must not be empty! |
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[1516] | 463 | Node processNextNode() |
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[1218] | 464 | { |
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| 465 | if(_queue_tail==_queue_next_dist) { |
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| 466 | _curr_dist++; |
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| 467 | _queue_next_dist=_queue_head; |
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| 468 | } |
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| 469 | Node n=_queue[_queue_tail++]; |
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| 470 | _processed->set(n,true); |
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| 471 | Node m; |
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| 472 | for(OutEdgeIt e(*G,n);e!=INVALID;++e) |
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| 473 | if(!(*_reached)[m=G->target(e)]) { |
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| 474 | _queue[_queue_head++]=m; |
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| 475 | _reached->set(m,true); |
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| 476 | _pred->set(m,e); |
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| 477 | _dist->set(m,_curr_dist); |
---|
| 478 | } |
---|
[1516] | 479 | return n; |
---|
[1218] | 480 | } |
---|
[2300] | 481 | |
---|
| 482 | ///Processes the next node. |
---|
| 483 | |
---|
| 484 | ///Processes the next node. And checks that the given target node |
---|
| 485 | ///is reached. If the target node is reachable from the processed |
---|
| 486 | ///node then the reached parameter will be set true. The reached |
---|
| 487 | ///parameter should be initially false. |
---|
| 488 | /// |
---|
| 489 | ///\param target The target node. |
---|
| 490 | ///\retval reached Indicates that the target node is reached. |
---|
| 491 | ///\return The processed node. |
---|
| 492 | /// |
---|
| 493 | ///\warning The queue must not be empty! |
---|
| 494 | Node processNextNode(Node target, bool& reached) |
---|
| 495 | { |
---|
| 496 | if(_queue_tail==_queue_next_dist) { |
---|
| 497 | _curr_dist++; |
---|
| 498 | _queue_next_dist=_queue_head; |
---|
| 499 | } |
---|
| 500 | Node n=_queue[_queue_tail++]; |
---|
| 501 | _processed->set(n,true); |
---|
| 502 | Node m; |
---|
| 503 | for(OutEdgeIt e(*G,n);e!=INVALID;++e) |
---|
| 504 | if(!(*_reached)[m=G->target(e)]) { |
---|
| 505 | _queue[_queue_head++]=m; |
---|
| 506 | _reached->set(m,true); |
---|
| 507 | _pred->set(m,e); |
---|
| 508 | _dist->set(m,_curr_dist); |
---|
| 509 | reached = reached || (target == m); |
---|
| 510 | } |
---|
| 511 | return n; |
---|
| 512 | } |
---|
| 513 | |
---|
| 514 | ///Processes the next node. |
---|
| 515 | |
---|
| 516 | ///Processes the next node. And checks that at least one of |
---|
| 517 | ///reached node has true value in the \c nm nodemap. If one node |
---|
| 518 | ///with true value is reachable from the processed node then the |
---|
| 519 | ///reached parameter will be set true. The reached parameter |
---|
| 520 | ///should be initially false. |
---|
| 521 | /// |
---|
| 522 | ///\param target The nodemaps of possible targets. |
---|
| 523 | ///\retval reached Indicates that one of the target nodes is reached. |
---|
| 524 | ///\return The processed node. |
---|
| 525 | /// |
---|
| 526 | ///\warning The queue must not be empty! |
---|
| 527 | template<class NM> |
---|
| 528 | Node processNextNode(const NM& nm, bool& reached) |
---|
| 529 | { |
---|
| 530 | if(_queue_tail==_queue_next_dist) { |
---|
| 531 | _curr_dist++; |
---|
| 532 | _queue_next_dist=_queue_head; |
---|
| 533 | } |
---|
| 534 | Node n=_queue[_queue_tail++]; |
---|
| 535 | _processed->set(n,true); |
---|
| 536 | Node m; |
---|
| 537 | for(OutEdgeIt e(*G,n);e!=INVALID;++e) |
---|
| 538 | if(!(*_reached)[m=G->target(e)]) { |
---|
| 539 | _queue[_queue_head++]=m; |
---|
| 540 | _reached->set(m,true); |
---|
| 541 | _pred->set(m,e); |
---|
| 542 | _dist->set(m,_curr_dist); |
---|
| 543 | reached = reached || nm[m]; |
---|
| 544 | } |
---|
| 545 | return n; |
---|
| 546 | } |
---|
[1218] | 547 | |
---|
[1665] | 548 | ///Next node to be processed. |
---|
| 549 | |
---|
| 550 | ///Next node to be processed. |
---|
| 551 | /// |
---|
| 552 | ///\return The next node to be processed or INVALID if the queue is |
---|
| 553 | /// empty. |
---|
[1694] | 554 | Node nextNode() |
---|
[1665] | 555 | { |
---|
| 556 | return _queue_tail<_queue_head?_queue[_queue_tail]:INVALID; |
---|
| 557 | } |
---|
| 558 | |
---|
[1218] | 559 | ///\brief Returns \c false if there are nodes |
---|
| 560 | ///to be processed in the queue |
---|
| 561 | /// |
---|
| 562 | ///Returns \c false if there are nodes |
---|
| 563 | ///to be processed in the queue |
---|
| 564 | bool emptyQueue() { return _queue_tail==_queue_head; } |
---|
| 565 | ///Returns the number of the nodes to be processed. |
---|
| 566 | |
---|
| 567 | ///Returns the number of the nodes to be processed in the queue. |
---|
| 568 | /// |
---|
| 569 | int queueSize() { return _queue_head-_queue_tail; } |
---|
| 570 | |
---|
| 571 | ///Executes the algorithm. |
---|
| 572 | |
---|
| 573 | ///Executes the algorithm. |
---|
| 574 | /// |
---|
| 575 | ///\pre init() must be called and at least one node should be added |
---|
| 576 | ///with addSource() before using this function. |
---|
| 577 | /// |
---|
| 578 | ///This method runs the %BFS algorithm from the root node(s) |
---|
| 579 | ///in order to |
---|
| 580 | ///compute the |
---|
| 581 | ///shortest path to each node. The algorithm computes |
---|
| 582 | ///- The shortest path tree. |
---|
| 583 | ///- The distance of each node from the root(s). |
---|
| 584 | /// |
---|
| 585 | void start() |
---|
| 586 | { |
---|
| 587 | while ( !emptyQueue() ) processNextNode(); |
---|
| 588 | } |
---|
| 589 | |
---|
[2307] | 590 | ///Executes the algorithm until \c dest is reached. |
---|
[1218] | 591 | |
---|
[2307] | 592 | ///Executes the algorithm until \c dest is reached. |
---|
[1218] | 593 | /// |
---|
| 594 | ///\pre init() must be called and at least one node should be added |
---|
| 595 | ///with addSource() before using this function. |
---|
| 596 | /// |
---|
| 597 | ///This method runs the %BFS algorithm from the root node(s) |
---|
| 598 | ///in order to |
---|
| 599 | ///compute the |
---|
| 600 | ///shortest path to \c dest. The algorithm computes |
---|
| 601 | ///- The shortest path to \c dest. |
---|
| 602 | ///- The distance of \c dest from the root(s). |
---|
| 603 | /// |
---|
| 604 | void start(Node dest) |
---|
| 605 | { |
---|
[2300] | 606 | bool reached = false; |
---|
| 607 | while ( !emptyQueue() && !reached) processNextNode(dest, reached); |
---|
[1218] | 608 | } |
---|
| 609 | |
---|
| 610 | ///Executes the algorithm until a condition is met. |
---|
| 611 | |
---|
| 612 | ///Executes the algorithm until a condition is met. |
---|
| 613 | /// |
---|
| 614 | ///\pre init() must be called and at least one node should be added |
---|
| 615 | ///with addSource() before using this function. |
---|
| 616 | /// |
---|
[2306] | 617 | ///\param nm must be a bool (or convertible) node map. The |
---|
[2307] | 618 | ///algorithm will stop when it reached a node \c v with |
---|
[2306] | 619 | ///<tt>nm[v]</tt> true. |
---|
[2300] | 620 | ///\todo query the reached target |
---|
[1218] | 621 | template<class NM> |
---|
[1755] | 622 | void start(const NM &nm) |
---|
| 623 | { |
---|
[2300] | 624 | bool reached = false; |
---|
| 625 | while ( !emptyQueue() && !reached) processNextNode(nm, reached); |
---|
[1755] | 626 | } |
---|
[1218] | 627 | |
---|
| 628 | ///Runs %BFS algorithm from node \c s. |
---|
| 629 | |
---|
| 630 | ///This method runs the %BFS algorithm from a root node \c s |
---|
| 631 | ///in order to |
---|
| 632 | ///compute the |
---|
| 633 | ///shortest path to each node. The algorithm computes |
---|
| 634 | ///- The shortest path tree. |
---|
| 635 | ///- The distance of each node from the root. |
---|
| 636 | /// |
---|
[2306] | 637 | ///\note b.run(s) is just a shortcut of the following code. |
---|
[1218] | 638 | ///\code |
---|
[2306] | 639 | /// b.init(); |
---|
| 640 | /// b.addSource(s); |
---|
| 641 | /// b.start(); |
---|
[1218] | 642 | ///\endcode |
---|
| 643 | void run(Node s) { |
---|
| 644 | init(); |
---|
| 645 | addSource(s); |
---|
| 646 | start(); |
---|
| 647 | } |
---|
| 648 | |
---|
| 649 | ///Finds the shortest path between \c s and \c t. |
---|
| 650 | |
---|
| 651 | ///Finds the shortest path between \c s and \c t. |
---|
| 652 | /// |
---|
| 653 | ///\return The length of the shortest s---t path if there exists one, |
---|
| 654 | ///0 otherwise. |
---|
[2306] | 655 | ///\note Apart from the return value, b.run(s) is |
---|
[1218] | 656 | ///just a shortcut of the following code. |
---|
| 657 | ///\code |
---|
[2306] | 658 | /// b.init(); |
---|
| 659 | /// b.addSource(s); |
---|
| 660 | /// b.start(t); |
---|
[1218] | 661 | ///\endcode |
---|
| 662 | int run(Node s,Node t) { |
---|
| 663 | init(); |
---|
| 664 | addSource(s); |
---|
| 665 | start(t); |
---|
[2300] | 666 | return reached(t)? _curr_dist : 0; |
---|
[1218] | 667 | } |
---|
| 668 | |
---|
| 669 | ///@} |
---|
| 670 | |
---|
| 671 | ///\name Query Functions |
---|
| 672 | ///The result of the %BFS algorithm can be obtained using these |
---|
| 673 | ///functions.\n |
---|
| 674 | ///Before the use of these functions, |
---|
[2306] | 675 | ///either run() or start() must be calleb. |
---|
[1218] | 676 | |
---|
| 677 | ///@{ |
---|
| 678 | |
---|
[1283] | 679 | ///Copies the shortest path to \c t into \c p |
---|
| 680 | |
---|
| 681 | ///This function copies the shortest path to \c t into \c p. |
---|
[1536] | 682 | ///If \c t is a source itself or unreachable, then it does not |
---|
[1283] | 683 | ///alter \c p. |
---|
| 684 | ///\return Returns \c true if a path to \c t was actually copied to \c p, |
---|
| 685 | ///\c false otherwise. |
---|
| 686 | ///\sa DirPath |
---|
| 687 | template<class P> |
---|
| 688 | bool getPath(P &p,Node t) |
---|
| 689 | { |
---|
| 690 | if(reached(t)) { |
---|
| 691 | p.clear(); |
---|
| 692 | typename P::Builder b(p); |
---|
[1763] | 693 | for(b.setStartNode(t);predEdge(t)!=INVALID;t=predNode(t)) |
---|
| 694 | b.pushFront(predEdge(t)); |
---|
[1283] | 695 | b.commit(); |
---|
| 696 | return true; |
---|
| 697 | } |
---|
| 698 | return false; |
---|
| 699 | } |
---|
| 700 | |
---|
[1218] | 701 | ///The distance of a node from the root(s). |
---|
| 702 | |
---|
| 703 | ///Returns the distance of a node from the root(s). |
---|
[774] | 704 | ///\pre \ref run() must be called before using this function. |
---|
[1218] | 705 | ///\warning If node \c v in unreachable from the root(s) the return value |
---|
[1270] | 706 | ///of this function is undefined. |
---|
[1218] | 707 | int dist(Node v) const { return (*_dist)[v]; } |
---|
[774] | 708 | |
---|
[1218] | 709 | ///Returns the 'previous edge' of the shortest path tree. |
---|
[774] | 710 | |
---|
[1218] | 711 | ///For a node \c v it returns the 'previous edge' |
---|
| 712 | ///of the shortest path tree, |
---|
| 713 | ///i.e. it returns the last edge of a shortest path from the root(s) to \c |
---|
[774] | 714 | ///v. It is \ref INVALID |
---|
[1218] | 715 | ///if \c v is unreachable from the root(s) or \c v is a root. The |
---|
| 716 | ///shortest path tree used here is equal to the shortest path tree used in |
---|
[1631] | 717 | ///\ref predNode(). |
---|
[1218] | 718 | ///\pre Either \ref run() or \ref start() must be called before using |
---|
[774] | 719 | ///this function. |
---|
[1763] | 720 | Edge predEdge(Node v) const { return (*_pred)[v];} |
---|
[774] | 721 | |
---|
[1218] | 722 | ///Returns the 'previous node' of the shortest path tree. |
---|
[774] | 723 | |
---|
[1218] | 724 | ///For a node \c v it returns the 'previous node' |
---|
| 725 | ///of the shortest path tree, |
---|
[774] | 726 | ///i.e. it returns the last but one node from a shortest path from the |
---|
[1218] | 727 | ///root(a) to \c /v. |
---|
| 728 | ///It is INVALID if \c v is unreachable from the root(s) or |
---|
| 729 | ///if \c v itself a root. |
---|
| 730 | ///The shortest path tree used here is equal to the shortest path |
---|
[1763] | 731 | ///tree used in \ref predEdge(). |
---|
[1218] | 732 | ///\pre Either \ref run() or \ref start() must be called before |
---|
[774] | 733 | ///using this function. |
---|
[1218] | 734 | Node predNode(Node v) const { return (*_pred)[v]==INVALID ? INVALID: |
---|
| 735 | G->source((*_pred)[v]); } |
---|
[774] | 736 | |
---|
| 737 | ///Returns a reference to the NodeMap of distances. |
---|
[1218] | 738 | |
---|
| 739 | ///Returns a reference to the NodeMap of distances. |
---|
| 740 | ///\pre Either \ref run() or \ref init() must |
---|
[774] | 741 | ///be called before using this function. |
---|
[1218] | 742 | const DistMap &distMap() const { return *_dist;} |
---|
[774] | 743 | |
---|
[1218] | 744 | ///Returns a reference to the shortest path tree map. |
---|
[774] | 745 | |
---|
| 746 | ///Returns a reference to the NodeMap of the edges of the |
---|
[1218] | 747 | ///shortest path tree. |
---|
| 748 | ///\pre Either \ref run() or \ref init() |
---|
| 749 | ///must be called before using this function. |
---|
| 750 | const PredMap &predMap() const { return *_pred;} |
---|
[774] | 751 | |
---|
| 752 | ///Checks if a node is reachable from the root. |
---|
| 753 | |
---|
| 754 | ///Returns \c true if \c v is reachable from the root. |
---|
[1270] | 755 | ///\warning The source nodes are indicated as unreached. |
---|
[1218] | 756 | ///\pre Either \ref run() or \ref start() |
---|
| 757 | ///must be called before using this function. |
---|
[774] | 758 | /// |
---|
[1218] | 759 | bool reached(Node v) { return (*_reached)[v]; } |
---|
| 760 | |
---|
| 761 | ///@} |
---|
| 762 | }; |
---|
| 763 | |
---|
| 764 | ///Default traits class of Bfs function. |
---|
| 765 | |
---|
| 766 | ///Default traits class of Bfs function. |
---|
| 767 | ///\param GR Graph type. |
---|
| 768 | template<class GR> |
---|
| 769 | struct BfsWizardDefaultTraits |
---|
| 770 | { |
---|
| 771 | ///The graph type the algorithm runs on. |
---|
| 772 | typedef GR Graph; |
---|
| 773 | ///\brief The type of the map that stores the last |
---|
| 774 | ///edges of the shortest paths. |
---|
| 775 | /// |
---|
| 776 | ///The type of the map that stores the last |
---|
| 777 | ///edges of the shortest paths. |
---|
[2260] | 778 | ///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
---|
[774] | 779 | /// |
---|
[1218] | 780 | typedef NullMap<typename Graph::Node,typename GR::Edge> PredMap; |
---|
| 781 | ///Instantiates a PredMap. |
---|
| 782 | |
---|
| 783 | ///This function instantiates a \ref PredMap. |
---|
[1536] | 784 | ///\param g is the graph, to which we would like to define the PredMap. |
---|
[1218] | 785 | ///\todo The graph alone may be insufficient to initialize |
---|
[1536] | 786 | #ifdef DOXYGEN |
---|
| 787 | static PredMap *createPredMap(const GR &g) |
---|
| 788 | #else |
---|
[1367] | 789 | static PredMap *createPredMap(const GR &) |
---|
[1536] | 790 | #endif |
---|
[1218] | 791 | { |
---|
| 792 | return new PredMap(); |
---|
| 793 | } |
---|
| 794 | |
---|
| 795 | ///The type of the map that indicates which nodes are processed. |
---|
| 796 | |
---|
| 797 | ///The type of the map that indicates which nodes are processed. |
---|
[2260] | 798 | ///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
---|
[1218] | 799 | ///\todo named parameter to set this type, function to read and write. |
---|
| 800 | typedef NullMap<typename Graph::Node,bool> ProcessedMap; |
---|
| 801 | ///Instantiates a ProcessedMap. |
---|
| 802 | |
---|
| 803 | ///This function instantiates a \ref ProcessedMap. |
---|
[1536] | 804 | ///\param g is the graph, to which |
---|
[1218] | 805 | ///we would like to define the \ref ProcessedMap |
---|
[1536] | 806 | #ifdef DOXYGEN |
---|
| 807 | static ProcessedMap *createProcessedMap(const GR &g) |
---|
| 808 | #else |
---|
[1367] | 809 | static ProcessedMap *createProcessedMap(const GR &) |
---|
[1536] | 810 | #endif |
---|
[1218] | 811 | { |
---|
| 812 | return new ProcessedMap(); |
---|
| 813 | } |
---|
| 814 | ///The type of the map that indicates which nodes are reached. |
---|
| 815 | |
---|
| 816 | ///The type of the map that indicates which nodes are reached. |
---|
[2260] | 817 | ///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
---|
[1218] | 818 | ///\todo named parameter to set this type, function to read and write. |
---|
| 819 | typedef typename Graph::template NodeMap<bool> ReachedMap; |
---|
| 820 | ///Instantiates a ReachedMap. |
---|
| 821 | |
---|
| 822 | ///This function instantiates a \ref ReachedMap. |
---|
| 823 | ///\param G is the graph, to which |
---|
| 824 | ///we would like to define the \ref ReachedMap. |
---|
| 825 | static ReachedMap *createReachedMap(const GR &G) |
---|
| 826 | { |
---|
| 827 | return new ReachedMap(G); |
---|
| 828 | } |
---|
| 829 | ///The type of the map that stores the dists of the nodes. |
---|
| 830 | |
---|
| 831 | ///The type of the map that stores the dists of the nodes. |
---|
[2260] | 832 | ///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
---|
[1218] | 833 | /// |
---|
| 834 | typedef NullMap<typename Graph::Node,int> DistMap; |
---|
| 835 | ///Instantiates a DistMap. |
---|
| 836 | |
---|
| 837 | ///This function instantiates a \ref DistMap. |
---|
[1536] | 838 | ///\param g is the graph, to which we would like to define the \ref DistMap |
---|
| 839 | #ifdef DOXYGEN |
---|
| 840 | static DistMap *createDistMap(const GR &g) |
---|
| 841 | #else |
---|
[1367] | 842 | static DistMap *createDistMap(const GR &) |
---|
[1536] | 843 | #endif |
---|
[1218] | 844 | { |
---|
| 845 | return new DistMap(); |
---|
| 846 | } |
---|
| 847 | }; |
---|
| 848 | |
---|
| 849 | /// Default traits used by \ref BfsWizard |
---|
| 850 | |
---|
| 851 | /// To make it easier to use Bfs algorithm |
---|
| 852 | ///we have created a wizard class. |
---|
| 853 | /// This \ref BfsWizard class needs default traits, |
---|
| 854 | ///as well as the \ref Bfs class. |
---|
| 855 | /// The \ref BfsWizardBase is a class to be the default traits of the |
---|
| 856 | /// \ref BfsWizard class. |
---|
| 857 | template<class GR> |
---|
| 858 | class BfsWizardBase : public BfsWizardDefaultTraits<GR> |
---|
| 859 | { |
---|
| 860 | |
---|
| 861 | typedef BfsWizardDefaultTraits<GR> Base; |
---|
| 862 | protected: |
---|
| 863 | /// Type of the nodes in the graph. |
---|
| 864 | typedef typename Base::Graph::Node Node; |
---|
| 865 | |
---|
| 866 | /// Pointer to the underlying graph. |
---|
| 867 | void *_g; |
---|
| 868 | ///Pointer to the map of reached nodes. |
---|
| 869 | void *_reached; |
---|
| 870 | ///Pointer to the map of processed nodes. |
---|
| 871 | void *_processed; |
---|
| 872 | ///Pointer to the map of predecessors edges. |
---|
| 873 | void *_pred; |
---|
| 874 | ///Pointer to the map of distances. |
---|
| 875 | void *_dist; |
---|
| 876 | ///Pointer to the source node. |
---|
| 877 | Node _source; |
---|
| 878 | |
---|
| 879 | public: |
---|
| 880 | /// Constructor. |
---|
| 881 | |
---|
| 882 | /// This constructor does not require parameters, therefore it initiates |
---|
| 883 | /// all of the attributes to default values (0, INVALID). |
---|
| 884 | BfsWizardBase() : _g(0), _reached(0), _processed(0), _pred(0), |
---|
| 885 | _dist(0), _source(INVALID) {} |
---|
| 886 | |
---|
| 887 | /// Constructor. |
---|
| 888 | |
---|
| 889 | /// This constructor requires some parameters, |
---|
| 890 | /// listed in the parameters list. |
---|
| 891 | /// Others are initiated to 0. |
---|
| 892 | /// \param g is the initial value of \ref _g |
---|
| 893 | /// \param s is the initial value of \ref _source |
---|
| 894 | BfsWizardBase(const GR &g, Node s=INVALID) : |
---|
| 895 | _g((void *)&g), _reached(0), _processed(0), _pred(0), |
---|
| 896 | _dist(0), _source(s) {} |
---|
| 897 | |
---|
| 898 | }; |
---|
| 899 | |
---|
| 900 | /// A class to make the usage of Bfs algorithm easier |
---|
| 901 | |
---|
| 902 | /// This class is created to make it easier to use Bfs algorithm. |
---|
| 903 | /// It uses the functions and features of the plain \ref Bfs, |
---|
| 904 | /// but it is much simpler to use it. |
---|
| 905 | /// |
---|
| 906 | /// Simplicity means that the way to change the types defined |
---|
| 907 | /// in the traits class is based on functions that returns the new class |
---|
| 908 | /// and not on templatable built-in classes. |
---|
| 909 | /// When using the plain \ref Bfs |
---|
| 910 | /// the new class with the modified type comes from |
---|
| 911 | /// the original class by using the :: |
---|
| 912 | /// operator. In the case of \ref BfsWizard only |
---|
| 913 | /// a function have to be called and it will |
---|
| 914 | /// return the needed class. |
---|
| 915 | /// |
---|
| 916 | /// It does not have own \ref run method. When its \ref run method is called |
---|
| 917 | /// it initiates a plain \ref Bfs class, and calls the \ref Bfs::run |
---|
| 918 | /// method of it. |
---|
| 919 | template<class TR> |
---|
| 920 | class BfsWizard : public TR |
---|
| 921 | { |
---|
| 922 | typedef TR Base; |
---|
| 923 | |
---|
| 924 | ///The type of the underlying graph. |
---|
| 925 | typedef typename TR::Graph Graph; |
---|
| 926 | //\e |
---|
| 927 | typedef typename Graph::Node Node; |
---|
| 928 | //\e |
---|
| 929 | typedef typename Graph::NodeIt NodeIt; |
---|
| 930 | //\e |
---|
| 931 | typedef typename Graph::Edge Edge; |
---|
| 932 | //\e |
---|
| 933 | typedef typename Graph::OutEdgeIt OutEdgeIt; |
---|
| 934 | |
---|
| 935 | ///\brief The type of the map that stores |
---|
| 936 | ///the reached nodes |
---|
| 937 | typedef typename TR::ReachedMap ReachedMap; |
---|
| 938 | ///\brief The type of the map that stores |
---|
| 939 | ///the processed nodes |
---|
| 940 | typedef typename TR::ProcessedMap ProcessedMap; |
---|
| 941 | ///\brief The type of the map that stores the last |
---|
| 942 | ///edges of the shortest paths. |
---|
| 943 | typedef typename TR::PredMap PredMap; |
---|
| 944 | ///The type of the map that stores the dists of the nodes. |
---|
| 945 | typedef typename TR::DistMap DistMap; |
---|
| 946 | |
---|
[2306] | 947 | public: |
---|
[1218] | 948 | /// Constructor. |
---|
| 949 | BfsWizard() : TR() {} |
---|
| 950 | |
---|
| 951 | /// Constructor that requires parameters. |
---|
| 952 | |
---|
| 953 | /// Constructor that requires parameters. |
---|
| 954 | /// These parameters will be the default values for the traits class. |
---|
| 955 | BfsWizard(const Graph &g, Node s=INVALID) : |
---|
| 956 | TR(g,s) {} |
---|
| 957 | |
---|
| 958 | ///Copy constructor |
---|
| 959 | BfsWizard(const TR &b) : TR(b) {} |
---|
| 960 | |
---|
| 961 | ~BfsWizard() {} |
---|
| 962 | |
---|
| 963 | ///Runs Bfs algorithm from a given node. |
---|
| 964 | |
---|
| 965 | ///Runs Bfs algorithm from a given node. |
---|
| 966 | ///The node can be given by the \ref source function. |
---|
| 967 | void run() |
---|
| 968 | { |
---|
| 969 | if(Base::_source==INVALID) throw UninitializedParameter(); |
---|
| 970 | Bfs<Graph,TR> alg(*(Graph*)Base::_g); |
---|
| 971 | if(Base::_reached) |
---|
| 972 | alg.reachedMap(*(ReachedMap*)Base::_reached); |
---|
| 973 | if(Base::_processed) alg.processedMap(*(ProcessedMap*)Base::_processed); |
---|
| 974 | if(Base::_pred) alg.predMap(*(PredMap*)Base::_pred); |
---|
| 975 | if(Base::_dist) alg.distMap(*(DistMap*)Base::_dist); |
---|
| 976 | alg.run(Base::_source); |
---|
| 977 | } |
---|
| 978 | |
---|
| 979 | ///Runs Bfs algorithm from the given node. |
---|
| 980 | |
---|
| 981 | ///Runs Bfs algorithm from the given node. |
---|
| 982 | ///\param s is the given source. |
---|
| 983 | void run(Node s) |
---|
| 984 | { |
---|
| 985 | Base::_source=s; |
---|
| 986 | run(); |
---|
| 987 | } |
---|
| 988 | |
---|
| 989 | template<class T> |
---|
| 990 | struct DefPredMapBase : public Base { |
---|
| 991 | typedef T PredMap; |
---|
[1367] | 992 | static PredMap *createPredMap(const Graph &) { return 0; }; |
---|
[1236] | 993 | DefPredMapBase(const TR &b) : TR(b) {} |
---|
[1218] | 994 | }; |
---|
| 995 | |
---|
| 996 | ///\brief \ref named-templ-param "Named parameter" |
---|
| 997 | ///function for setting PredMap |
---|
| 998 | /// |
---|
| 999 | /// \ref named-templ-param "Named parameter" |
---|
| 1000 | ///function for setting PredMap |
---|
| 1001 | /// |
---|
| 1002 | template<class T> |
---|
| 1003 | BfsWizard<DefPredMapBase<T> > predMap(const T &t) |
---|
| 1004 | { |
---|
| 1005 | Base::_pred=(void *)&t; |
---|
| 1006 | return BfsWizard<DefPredMapBase<T> >(*this); |
---|
| 1007 | } |
---|
| 1008 | |
---|
| 1009 | |
---|
| 1010 | template<class T> |
---|
| 1011 | struct DefReachedMapBase : public Base { |
---|
| 1012 | typedef T ReachedMap; |
---|
[1367] | 1013 | static ReachedMap *createReachedMap(const Graph &) { return 0; }; |
---|
[1236] | 1014 | DefReachedMapBase(const TR &b) : TR(b) {} |
---|
[1218] | 1015 | }; |
---|
| 1016 | |
---|
| 1017 | ///\brief \ref named-templ-param "Named parameter" |
---|
| 1018 | ///function for setting ReachedMap |
---|
| 1019 | /// |
---|
| 1020 | /// \ref named-templ-param "Named parameter" |
---|
| 1021 | ///function for setting ReachedMap |
---|
| 1022 | /// |
---|
| 1023 | template<class T> |
---|
| 1024 | BfsWizard<DefReachedMapBase<T> > reachedMap(const T &t) |
---|
| 1025 | { |
---|
| 1026 | Base::_pred=(void *)&t; |
---|
| 1027 | return BfsWizard<DefReachedMapBase<T> >(*this); |
---|
| 1028 | } |
---|
| 1029 | |
---|
| 1030 | |
---|
| 1031 | template<class T> |
---|
| 1032 | struct DefProcessedMapBase : public Base { |
---|
| 1033 | typedef T ProcessedMap; |
---|
[1367] | 1034 | static ProcessedMap *createProcessedMap(const Graph &) { return 0; }; |
---|
[1236] | 1035 | DefProcessedMapBase(const TR &b) : TR(b) {} |
---|
[1218] | 1036 | }; |
---|
| 1037 | |
---|
| 1038 | ///\brief \ref named-templ-param "Named parameter" |
---|
| 1039 | ///function for setting ProcessedMap |
---|
| 1040 | /// |
---|
| 1041 | /// \ref named-templ-param "Named parameter" |
---|
| 1042 | ///function for setting ProcessedMap |
---|
| 1043 | /// |
---|
| 1044 | template<class T> |
---|
| 1045 | BfsWizard<DefProcessedMapBase<T> > processedMap(const T &t) |
---|
| 1046 | { |
---|
| 1047 | Base::_pred=(void *)&t; |
---|
| 1048 | return BfsWizard<DefProcessedMapBase<T> >(*this); |
---|
| 1049 | } |
---|
| 1050 | |
---|
| 1051 | |
---|
| 1052 | template<class T> |
---|
| 1053 | struct DefDistMapBase : public Base { |
---|
| 1054 | typedef T DistMap; |
---|
[1367] | 1055 | static DistMap *createDistMap(const Graph &) { return 0; }; |
---|
[1236] | 1056 | DefDistMapBase(const TR &b) : TR(b) {} |
---|
[1218] | 1057 | }; |
---|
| 1058 | |
---|
| 1059 | ///\brief \ref named-templ-param "Named parameter" |
---|
| 1060 | ///function for setting DistMap type |
---|
| 1061 | /// |
---|
| 1062 | /// \ref named-templ-param "Named parameter" |
---|
| 1063 | ///function for setting DistMap type |
---|
| 1064 | /// |
---|
| 1065 | template<class T> |
---|
| 1066 | BfsWizard<DefDistMapBase<T> > distMap(const T &t) |
---|
| 1067 | { |
---|
| 1068 | Base::_dist=(void *)&t; |
---|
| 1069 | return BfsWizard<DefDistMapBase<T> >(*this); |
---|
| 1070 | } |
---|
| 1071 | |
---|
| 1072 | /// Sets the source node, from which the Bfs algorithm runs. |
---|
| 1073 | |
---|
| 1074 | /// Sets the source node, from which the Bfs algorithm runs. |
---|
| 1075 | /// \param s is the source node. |
---|
| 1076 | BfsWizard<TR> &source(Node s) |
---|
| 1077 | { |
---|
| 1078 | Base::_source=s; |
---|
| 1079 | return *this; |
---|
| 1080 | } |
---|
[774] | 1081 | |
---|
| 1082 | }; |
---|
| 1083 | |
---|
[1218] | 1084 | ///Function type interface for Bfs algorithm. |
---|
| 1085 | |
---|
| 1086 | /// \ingroup flowalgs |
---|
| 1087 | ///Function type interface for Bfs algorithm. |
---|
| 1088 | /// |
---|
| 1089 | ///This function also has several |
---|
| 1090 | ///\ref named-templ-func-param "named parameters", |
---|
| 1091 | ///they are declared as the members of class \ref BfsWizard. |
---|
| 1092 | ///The following |
---|
| 1093 | ///example shows how to use these parameters. |
---|
| 1094 | ///\code |
---|
| 1095 | /// bfs(g,source).predMap(preds).run(); |
---|
| 1096 | ///\endcode |
---|
| 1097 | ///\warning Don't forget to put the \ref BfsWizard::run() "run()" |
---|
| 1098 | ///to the end of the parameter list. |
---|
| 1099 | ///\sa BfsWizard |
---|
| 1100 | ///\sa Bfs |
---|
| 1101 | template<class GR> |
---|
| 1102 | BfsWizard<BfsWizardBase<GR> > |
---|
| 1103 | bfs(const GR &g,typename GR::Node s=INVALID) |
---|
| 1104 | { |
---|
| 1105 | return BfsWizard<BfsWizardBase<GR> >(g,s); |
---|
| 1106 | } |
---|
| 1107 | |
---|
[2306] | 1108 | #ifdef DOXYGEN |
---|
| 1109 | /// \brief Visitor class for bfs. |
---|
| 1110 | /// |
---|
| 1111 | /// It gives a simple interface for a functional interface for bfs |
---|
| 1112 | /// traversal. The traversal on a linear data structure. |
---|
| 1113 | template <typename _Graph> |
---|
| 1114 | struct BfsVisitor { |
---|
| 1115 | typedef _Graph Graph; |
---|
| 1116 | typedef typename Graph::Edge Edge; |
---|
| 1117 | typedef typename Graph::Node Node; |
---|
| 1118 | /// \brief Called when the edge reach a node. |
---|
| 1119 | /// |
---|
| 1120 | /// It is called when the bfs find an edge which target is not |
---|
| 1121 | /// reached yet. |
---|
| 1122 | void discover(const Edge& edge) {} |
---|
| 1123 | /// \brief Called when the node reached first time. |
---|
| 1124 | /// |
---|
| 1125 | /// It is Called when the node reached first time. |
---|
| 1126 | void reach(const Node& node) {} |
---|
| 1127 | /// \brief Called when the edge examined but target of the edge |
---|
| 1128 | /// already discovered. |
---|
| 1129 | /// |
---|
| 1130 | /// It called when the edge examined but the target of the edge |
---|
| 1131 | /// already discovered. |
---|
| 1132 | void examine(const Edge& edge) {} |
---|
| 1133 | /// \brief Called for the source node of the bfs. |
---|
| 1134 | /// |
---|
| 1135 | /// It is called for the source node of the bfs. |
---|
| 1136 | void start(const Node& node) {} |
---|
| 1137 | /// \brief Called when the node processed. |
---|
| 1138 | /// |
---|
| 1139 | /// It is Called when the node processed. |
---|
| 1140 | void process(const Node& node) {} |
---|
| 1141 | }; |
---|
| 1142 | #else |
---|
| 1143 | template <typename _Graph> |
---|
| 1144 | struct BfsVisitor { |
---|
| 1145 | typedef _Graph Graph; |
---|
| 1146 | typedef typename Graph::Edge Edge; |
---|
| 1147 | typedef typename Graph::Node Node; |
---|
| 1148 | void discover(const Edge&) {} |
---|
| 1149 | void reach(const Node&) {} |
---|
| 1150 | void examine(const Edge&) {} |
---|
| 1151 | void start(const Node&) {} |
---|
| 1152 | void process(const Node&) {} |
---|
| 1153 | |
---|
| 1154 | template <typename _Visitor> |
---|
| 1155 | struct Constraints { |
---|
| 1156 | void constraints() { |
---|
| 1157 | Edge edge; |
---|
| 1158 | Node node; |
---|
| 1159 | visitor.discover(edge); |
---|
| 1160 | visitor.reach(node); |
---|
| 1161 | visitor.examine(edge); |
---|
| 1162 | visitor.start(node); |
---|
| 1163 | visitor.process(node); |
---|
| 1164 | } |
---|
| 1165 | _Visitor& visitor; |
---|
| 1166 | }; |
---|
| 1167 | }; |
---|
| 1168 | #endif |
---|
| 1169 | |
---|
| 1170 | /// \brief Default traits class of BfsVisit class. |
---|
| 1171 | /// |
---|
| 1172 | /// Default traits class of BfsVisit class. |
---|
| 1173 | /// \param _Graph Graph type. |
---|
| 1174 | template<class _Graph> |
---|
| 1175 | struct BfsVisitDefaultTraits { |
---|
| 1176 | |
---|
| 1177 | /// \brief The graph type the algorithm runs on. |
---|
| 1178 | typedef _Graph Graph; |
---|
| 1179 | |
---|
| 1180 | /// \brief The type of the map that indicates which nodes are reached. |
---|
| 1181 | /// |
---|
| 1182 | /// The type of the map that indicates which nodes are reached. |
---|
| 1183 | /// It must meet the \ref concepts::WriteMap "WriteMap" concept. |
---|
| 1184 | /// \todo named parameter to set this type, function to read and write. |
---|
| 1185 | typedef typename Graph::template NodeMap<bool> ReachedMap; |
---|
| 1186 | |
---|
| 1187 | /// \brief Instantiates a ReachedMap. |
---|
| 1188 | /// |
---|
| 1189 | /// This function instantiates a \ref ReachedMap. |
---|
| 1190 | /// \param graph is the graph, to which |
---|
| 1191 | /// we would like to define the \ref ReachedMap. |
---|
| 1192 | static ReachedMap *createReachedMap(const Graph &graph) { |
---|
| 1193 | return new ReachedMap(graph); |
---|
| 1194 | } |
---|
| 1195 | |
---|
| 1196 | }; |
---|
| 1197 | |
---|
| 1198 | /// %BFS Visit algorithm class. |
---|
| 1199 | |
---|
| 1200 | /// \ingroup flowalgs |
---|
| 1201 | /// This class provides an efficient implementation of the %BFS algorithm |
---|
| 1202 | /// with visitor interface. |
---|
| 1203 | /// |
---|
| 1204 | /// The %BfsVisit class provides an alternative interface to the Bfs |
---|
| 1205 | /// class. It works with callback mechanism, the BfsVisit object calls |
---|
| 1206 | /// on every bfs event the \c Visitor class member functions. |
---|
| 1207 | /// |
---|
| 1208 | /// \param _Graph The graph type the algorithm runs on. The default value is |
---|
| 1209 | /// \ref ListGraph. The value of _Graph is not used directly by Bfs, it |
---|
| 1210 | /// is only passed to \ref BfsDefaultTraits. |
---|
| 1211 | /// \param _Visitor The Visitor object for the algorithm. The |
---|
| 1212 | /// \ref BfsVisitor "BfsVisitor<_Graph>" is an empty Visitor which |
---|
| 1213 | /// does not observe the Bfs events. If you want to observe the bfs |
---|
| 1214 | /// events you should implement your own Visitor class. |
---|
| 1215 | /// \param _Traits Traits class to set various data types used by the |
---|
| 1216 | /// algorithm. The default traits class is |
---|
| 1217 | /// \ref BfsVisitDefaultTraits "BfsVisitDefaultTraits<_Graph>". |
---|
| 1218 | /// See \ref BfsVisitDefaultTraits for the documentation of |
---|
| 1219 | /// a Bfs visit traits class. |
---|
| 1220 | /// |
---|
| 1221 | /// \author Jacint Szabo, Alpar Juttner and Balazs Dezso |
---|
| 1222 | #ifdef DOXYGEN |
---|
| 1223 | template <typename _Graph, typename _Visitor, typename _Traits> |
---|
| 1224 | #else |
---|
| 1225 | template <typename _Graph = ListGraph, |
---|
| 1226 | typename _Visitor = BfsVisitor<_Graph>, |
---|
| 1227 | typename _Traits = BfsDefaultTraits<_Graph> > |
---|
| 1228 | #endif |
---|
| 1229 | class BfsVisit { |
---|
| 1230 | public: |
---|
| 1231 | |
---|
| 1232 | /// \brief \ref Exception for uninitialized parameters. |
---|
| 1233 | /// |
---|
| 1234 | /// This error represents problems in the initialization |
---|
| 1235 | /// of the parameters of the algorithms. |
---|
| 1236 | class UninitializedParameter : public lemon::UninitializedParameter { |
---|
| 1237 | public: |
---|
| 1238 | virtual const char* what() const throw() |
---|
| 1239 | { |
---|
| 1240 | return "lemon::BfsVisit::UninitializedParameter"; |
---|
| 1241 | } |
---|
| 1242 | }; |
---|
| 1243 | |
---|
| 1244 | typedef _Traits Traits; |
---|
| 1245 | |
---|
| 1246 | typedef typename Traits::Graph Graph; |
---|
| 1247 | |
---|
| 1248 | typedef _Visitor Visitor; |
---|
| 1249 | |
---|
| 1250 | ///The type of the map indicating which nodes are reached. |
---|
| 1251 | typedef typename Traits::ReachedMap ReachedMap; |
---|
| 1252 | |
---|
| 1253 | private: |
---|
| 1254 | |
---|
| 1255 | typedef typename Graph::Node Node; |
---|
| 1256 | typedef typename Graph::NodeIt NodeIt; |
---|
| 1257 | typedef typename Graph::Edge Edge; |
---|
| 1258 | typedef typename Graph::OutEdgeIt OutEdgeIt; |
---|
| 1259 | |
---|
| 1260 | /// Pointer to the underlying graph. |
---|
| 1261 | const Graph *_graph; |
---|
| 1262 | /// Pointer to the visitor object. |
---|
| 1263 | Visitor *_visitor; |
---|
| 1264 | ///Pointer to the map of reached status of the nodes. |
---|
| 1265 | ReachedMap *_reached; |
---|
| 1266 | ///Indicates if \ref _reached is locally allocated (\c true) or not. |
---|
| 1267 | bool local_reached; |
---|
| 1268 | |
---|
| 1269 | std::vector<typename Graph::Node> _list; |
---|
| 1270 | int _list_front, _list_back; |
---|
| 1271 | |
---|
| 1272 | /// \brief Creates the maps if necessary. |
---|
| 1273 | /// |
---|
| 1274 | /// Creates the maps if necessary. |
---|
| 1275 | void create_maps() { |
---|
| 1276 | if(!_reached) { |
---|
| 1277 | local_reached = true; |
---|
| 1278 | _reached = Traits::createReachedMap(*_graph); |
---|
| 1279 | } |
---|
| 1280 | } |
---|
| 1281 | |
---|
| 1282 | protected: |
---|
| 1283 | |
---|
| 1284 | BfsVisit() {} |
---|
| 1285 | |
---|
| 1286 | public: |
---|
| 1287 | |
---|
| 1288 | typedef BfsVisit Create; |
---|
| 1289 | |
---|
| 1290 | /// \name Named template parameters |
---|
| 1291 | |
---|
| 1292 | ///@{ |
---|
| 1293 | template <class T> |
---|
| 1294 | struct DefReachedMapTraits : public Traits { |
---|
| 1295 | typedef T ReachedMap; |
---|
| 1296 | static ReachedMap *createReachedMap(const Graph &graph) { |
---|
| 1297 | throw UninitializedParameter(); |
---|
| 1298 | } |
---|
| 1299 | }; |
---|
| 1300 | /// \brief \ref named-templ-param "Named parameter" for setting |
---|
| 1301 | /// ReachedMap type |
---|
| 1302 | /// |
---|
| 1303 | /// \ref named-templ-param "Named parameter" for setting ReachedMap type |
---|
| 1304 | template <class T> |
---|
| 1305 | struct DefReachedMap : public BfsVisit< Graph, Visitor, |
---|
| 1306 | DefReachedMapTraits<T> > { |
---|
| 1307 | typedef BfsVisit< Graph, Visitor, DefReachedMapTraits<T> > Create; |
---|
| 1308 | }; |
---|
| 1309 | ///@} |
---|
| 1310 | |
---|
| 1311 | public: |
---|
| 1312 | |
---|
| 1313 | /// \brief Constructor. |
---|
| 1314 | /// |
---|
| 1315 | /// Constructor. |
---|
| 1316 | /// |
---|
| 1317 | /// \param graph the graph the algorithm will run on. |
---|
| 1318 | /// \param visitor The visitor of the algorithm. |
---|
| 1319 | /// |
---|
| 1320 | BfsVisit(const Graph& graph, Visitor& visitor) |
---|
| 1321 | : _graph(&graph), _visitor(&visitor), |
---|
| 1322 | _reached(0), local_reached(false) {} |
---|
| 1323 | |
---|
| 1324 | /// \brief Destructor. |
---|
| 1325 | /// |
---|
| 1326 | /// Destructor. |
---|
| 1327 | ~BfsVisit() { |
---|
| 1328 | if(local_reached) delete _reached; |
---|
| 1329 | } |
---|
| 1330 | |
---|
| 1331 | /// \brief Sets the map indicating if a node is reached. |
---|
| 1332 | /// |
---|
| 1333 | /// Sets the map indicating if a node is reached. |
---|
| 1334 | /// If you don't use this function before calling \ref run(), |
---|
| 1335 | /// it will allocate one. The destuctor deallocates this |
---|
| 1336 | /// automatically allocated map, of course. |
---|
| 1337 | /// \return <tt> (*this) </tt> |
---|
| 1338 | BfsVisit &reachedMap(ReachedMap &m) { |
---|
| 1339 | if(local_reached) { |
---|
| 1340 | delete _reached; |
---|
| 1341 | local_reached = false; |
---|
| 1342 | } |
---|
| 1343 | _reached = &m; |
---|
| 1344 | return *this; |
---|
| 1345 | } |
---|
| 1346 | |
---|
| 1347 | public: |
---|
| 1348 | /// \name Execution control |
---|
| 1349 | /// The simplest way to execute the algorithm is to use |
---|
| 1350 | /// one of the member functions called \c run(...). |
---|
| 1351 | /// \n |
---|
| 1352 | /// If you need more control on the execution, |
---|
| 1353 | /// first you must call \ref init(), then you can adda source node |
---|
| 1354 | /// with \ref addSource(). |
---|
| 1355 | /// Finally \ref start() will perform the actual path |
---|
| 1356 | /// computation. |
---|
| 1357 | |
---|
| 1358 | /// @{ |
---|
| 1359 | /// \brief Initializes the internal data structures. |
---|
| 1360 | /// |
---|
| 1361 | /// Initializes the internal data structures. |
---|
| 1362 | /// |
---|
| 1363 | void init() { |
---|
| 1364 | create_maps(); |
---|
| 1365 | _list.resize(countNodes(*_graph)); |
---|
| 1366 | _list_front = _list_back = -1; |
---|
| 1367 | for (NodeIt u(*_graph) ; u != INVALID ; ++u) { |
---|
| 1368 | _reached->set(u, false); |
---|
| 1369 | } |
---|
| 1370 | } |
---|
| 1371 | |
---|
| 1372 | /// \brief Adds a new source node. |
---|
| 1373 | /// |
---|
| 1374 | /// Adds a new source node to the set of nodes to be processed. |
---|
| 1375 | void addSource(Node s) { |
---|
| 1376 | if(!(*_reached)[s]) { |
---|
| 1377 | _reached->set(s,true); |
---|
| 1378 | _visitor->start(s); |
---|
| 1379 | _visitor->reach(s); |
---|
| 1380 | _list[++_list_back] = s; |
---|
| 1381 | } |
---|
| 1382 | } |
---|
| 1383 | |
---|
| 1384 | /// \brief Processes the next node. |
---|
| 1385 | /// |
---|
| 1386 | /// Processes the next node. |
---|
| 1387 | /// |
---|
| 1388 | /// \return The processed node. |
---|
| 1389 | /// |
---|
| 1390 | /// \pre The queue must not be empty! |
---|
| 1391 | Node processNextNode() { |
---|
| 1392 | Node n = _list[++_list_front]; |
---|
| 1393 | _visitor->process(n); |
---|
| 1394 | Edge e; |
---|
| 1395 | for (_graph->firstOut(e, n); e != INVALID; _graph->nextOut(e)) { |
---|
| 1396 | Node m = _graph->target(e); |
---|
| 1397 | if (!(*_reached)[m]) { |
---|
| 1398 | _visitor->discover(e); |
---|
| 1399 | _visitor->reach(m); |
---|
| 1400 | _reached->set(m, true); |
---|
| 1401 | _list[++_list_back] = m; |
---|
| 1402 | } else { |
---|
| 1403 | _visitor->examine(e); |
---|
| 1404 | } |
---|
| 1405 | } |
---|
| 1406 | return n; |
---|
| 1407 | } |
---|
| 1408 | |
---|
| 1409 | /// \brief Processes the next node. |
---|
| 1410 | /// |
---|
| 1411 | /// Processes the next node. And checks that the given target node |
---|
| 1412 | /// is reached. If the target node is reachable from the processed |
---|
| 1413 | /// node then the reached parameter will be set true. The reached |
---|
| 1414 | /// parameter should be initially false. |
---|
| 1415 | /// |
---|
| 1416 | /// \param target The target node. |
---|
| 1417 | /// \retval reached Indicates that the target node is reached. |
---|
| 1418 | /// \return The processed node. |
---|
| 1419 | /// |
---|
| 1420 | /// \warning The queue must not be empty! |
---|
| 1421 | Node processNextNode(Node target, bool& reached) { |
---|
| 1422 | Node n = _list[++_list_front]; |
---|
| 1423 | _visitor->process(n); |
---|
| 1424 | Edge e; |
---|
| 1425 | for (_graph->firstOut(e, n); e != INVALID; _graph->nextOut(e)) { |
---|
| 1426 | Node m = _graph->target(e); |
---|
| 1427 | if (!(*_reached)[m]) { |
---|
| 1428 | _visitor->discover(e); |
---|
| 1429 | _visitor->reach(m); |
---|
| 1430 | _reached->set(m, true); |
---|
| 1431 | _list[++_list_back] = m; |
---|
| 1432 | reached = reached || (target == m); |
---|
| 1433 | } else { |
---|
| 1434 | _visitor->examine(e); |
---|
| 1435 | } |
---|
| 1436 | } |
---|
| 1437 | return n; |
---|
| 1438 | } |
---|
| 1439 | |
---|
| 1440 | /// \brief Processes the next node. |
---|
| 1441 | /// |
---|
| 1442 | /// Processes the next node. And checks that at least one of |
---|
| 1443 | /// reached node has true value in the \c nm nodemap. If one node |
---|
| 1444 | /// with true value is reachable from the processed node then the |
---|
| 1445 | /// reached parameter will be set true. The reached parameter |
---|
| 1446 | /// should be initially false. |
---|
| 1447 | /// |
---|
| 1448 | /// \param target The nodemaps of possible targets. |
---|
| 1449 | /// \retval reached Indicates that one of the target nodes is reached. |
---|
| 1450 | /// \return The processed node. |
---|
| 1451 | /// |
---|
| 1452 | /// \warning The queue must not be empty! |
---|
| 1453 | template <typename NM> |
---|
| 1454 | Node processNextNode(const NM& nm, bool& reached) { |
---|
| 1455 | Node n = _list[++_list_front]; |
---|
| 1456 | _visitor->process(n); |
---|
| 1457 | Edge e; |
---|
| 1458 | for (_graph->firstOut(e, n); e != INVALID; _graph->nextOut(e)) { |
---|
| 1459 | Node m = _graph->target(e); |
---|
| 1460 | if (!(*_reached)[m]) { |
---|
| 1461 | _visitor->discover(e); |
---|
| 1462 | _visitor->reach(m); |
---|
| 1463 | _reached->set(m, true); |
---|
| 1464 | _list[++_list_back] = m; |
---|
| 1465 | reached = reached || nm[m]; |
---|
| 1466 | } else { |
---|
| 1467 | _visitor->examine(e); |
---|
| 1468 | } |
---|
| 1469 | } |
---|
| 1470 | return n; |
---|
| 1471 | } |
---|
| 1472 | |
---|
| 1473 | /// \brief Next node to be processed. |
---|
| 1474 | /// |
---|
| 1475 | /// Next node to be processed. |
---|
| 1476 | /// |
---|
| 1477 | /// \return The next node to be processed or INVALID if the stack is |
---|
| 1478 | /// empty. |
---|
| 1479 | Node nextNode() { |
---|
| 1480 | return _list_front != _list_back ? _list[_list_front + 1] : INVALID; |
---|
| 1481 | } |
---|
| 1482 | |
---|
| 1483 | /// \brief Returns \c false if there are nodes |
---|
| 1484 | /// to be processed in the queue |
---|
| 1485 | /// |
---|
| 1486 | /// Returns \c false if there are nodes |
---|
| 1487 | /// to be processed in the queue |
---|
| 1488 | bool emptyQueue() { return _list_front == _list_back; } |
---|
| 1489 | |
---|
| 1490 | /// \brief Returns the number of the nodes to be processed. |
---|
| 1491 | /// |
---|
| 1492 | /// Returns the number of the nodes to be processed in the queue. |
---|
| 1493 | int queueSize() { return _list_back - _list_front; } |
---|
| 1494 | |
---|
| 1495 | /// \brief Executes the algorithm. |
---|
| 1496 | /// |
---|
| 1497 | /// Executes the algorithm. |
---|
| 1498 | /// |
---|
| 1499 | /// \pre init() must be called and at least one node should be added |
---|
| 1500 | /// with addSource() before using this function. |
---|
| 1501 | void start() { |
---|
| 1502 | while ( !emptyQueue() ) processNextNode(); |
---|
| 1503 | } |
---|
| 1504 | |
---|
[2307] | 1505 | /// \brief Executes the algorithm until \c dest is reached. |
---|
[2306] | 1506 | /// |
---|
[2307] | 1507 | /// Executes the algorithm until \c dest is reached. |
---|
[2306] | 1508 | /// |
---|
| 1509 | /// \pre init() must be called and at least one node should be added |
---|
| 1510 | /// with addSource() before using this function. |
---|
| 1511 | void start(Node dest) { |
---|
| 1512 | bool reached = false; |
---|
| 1513 | while (!emptyQueue() && !reached) { |
---|
| 1514 | processNextNode(dest, reached); |
---|
| 1515 | } |
---|
| 1516 | } |
---|
| 1517 | |
---|
| 1518 | /// \brief Executes the algorithm until a condition is met. |
---|
| 1519 | /// |
---|
| 1520 | /// Executes the algorithm until a condition is met. |
---|
| 1521 | /// |
---|
| 1522 | /// \pre init() must be called and at least one node should be added |
---|
| 1523 | /// with addSource() before using this function. |
---|
| 1524 | /// |
---|
| 1525 | ///\param nm must be a bool (or convertible) node map. The |
---|
[2307] | 1526 | ///algorithm will stop when it reached a node \c v with |
---|
[2306] | 1527 | ///<tt>nm[v]</tt> true. |
---|
| 1528 | template <typename NM> |
---|
| 1529 | void start(const NM &nm) { |
---|
| 1530 | bool reached = false; |
---|
| 1531 | while (!emptyQueue() && !reached) { |
---|
| 1532 | processNextNode(nm, reached); |
---|
| 1533 | } |
---|
| 1534 | } |
---|
| 1535 | |
---|
| 1536 | /// \brief Runs %BFSVisit algorithm from node \c s. |
---|
| 1537 | /// |
---|
| 1538 | /// This method runs the %BFS algorithm from a root node \c s. |
---|
| 1539 | /// \note b.run(s) is just a shortcut of the following code. |
---|
| 1540 | ///\code |
---|
| 1541 | /// b.init(); |
---|
| 1542 | /// b.addSource(s); |
---|
| 1543 | /// b.start(); |
---|
| 1544 | ///\endcode |
---|
| 1545 | void run(Node s) { |
---|
| 1546 | init(); |
---|
| 1547 | addSource(s); |
---|
| 1548 | start(); |
---|
| 1549 | } |
---|
| 1550 | |
---|
| 1551 | /// \brief Runs %BFSVisit algorithm to visit all nodes in the graph. |
---|
| 1552 | /// |
---|
| 1553 | /// This method runs the %BFS algorithm in order to |
---|
| 1554 | /// compute the %BFS path to each node. The algorithm computes |
---|
| 1555 | /// - The %BFS tree. |
---|
| 1556 | /// - The distance of each node from the root in the %BFS tree. |
---|
| 1557 | /// |
---|
| 1558 | ///\note b.run() is just a shortcut of the following code. |
---|
| 1559 | ///\code |
---|
| 1560 | /// b.init(); |
---|
| 1561 | /// for (NodeIt it(graph); it != INVALID; ++it) { |
---|
| 1562 | /// if (!b.reached(it)) { |
---|
| 1563 | /// b.addSource(it); |
---|
| 1564 | /// b.start(); |
---|
| 1565 | /// } |
---|
| 1566 | /// } |
---|
| 1567 | ///\endcode |
---|
| 1568 | void run() { |
---|
| 1569 | init(); |
---|
| 1570 | for (NodeIt it(*_graph); it != INVALID; ++it) { |
---|
| 1571 | if (!reached(it)) { |
---|
| 1572 | addSource(it); |
---|
| 1573 | start(); |
---|
| 1574 | } |
---|
| 1575 | } |
---|
| 1576 | } |
---|
| 1577 | ///@} |
---|
| 1578 | |
---|
| 1579 | /// \name Query Functions |
---|
| 1580 | /// The result of the %BFS algorithm can be obtained using these |
---|
| 1581 | /// functions.\n |
---|
| 1582 | /// Before the use of these functions, |
---|
| 1583 | /// either run() or start() must be called. |
---|
| 1584 | ///@{ |
---|
| 1585 | |
---|
| 1586 | /// \brief Checks if a node is reachable from the root. |
---|
| 1587 | /// |
---|
| 1588 | /// Returns \c true if \c v is reachable from the root(s). |
---|
| 1589 | /// \warning The source nodes are inditated as unreachable. |
---|
| 1590 | /// \pre Either \ref run() or \ref start() |
---|
| 1591 | /// must be called before using this function. |
---|
| 1592 | /// |
---|
| 1593 | bool reached(Node v) { return (*_reached)[v]; } |
---|
| 1594 | ///@} |
---|
| 1595 | }; |
---|
| 1596 | |
---|
[921] | 1597 | } //END OF NAMESPACE LEMON |
---|
[774] | 1598 | |
---|
| 1599 | #endif |
---|
| 1600 | |
---|