[906] | 1 | /* -*- C++ -*- |
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[1435] | 2 | * lemon/dfs.h - Part of LEMON, a generic C++ optimization library |
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[906] | 3 | * |
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[1164] | 4 | * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
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[1359] | 5 | * (Egervary Research Group on Combinatorial Optimization, EGRES). |
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[906] | 6 | * |
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| 7 | * Permission to use, modify and distribute this software is granted |
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| 8 | * provided that this copyright notice appears in all copies. For |
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| 9 | * precise terms see the accompanying LICENSE file. |
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| 10 | * |
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| 11 | * This software is provided "AS IS" with no warranty of any kind, |
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| 12 | * express or implied, and with no claim as to its suitability for any |
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| 13 | * purpose. |
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| 14 | * |
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| 15 | */ |
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| 16 | |
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[921] | 17 | #ifndef LEMON_DFS_H |
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| 18 | #define LEMON_DFS_H |
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[780] | 19 | |
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| 20 | ///\ingroup flowalgs |
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| 21 | ///\file |
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[1218] | 22 | ///\brief Dfs algorithm. |
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[780] | 23 | |
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[1218] | 24 | #include <lemon/list_graph.h> |
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[946] | 25 | #include <lemon/graph_utils.h> |
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[921] | 26 | #include <lemon/invalid.h> |
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[1218] | 27 | #include <lemon/error.h> |
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| 28 | #include <lemon/maps.h> |
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[780] | 29 | |
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[1749] | 30 | #include <lemon/concept_check.h> |
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| 31 | |
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[921] | 32 | namespace lemon { |
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[780] | 33 | |
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[1218] | 34 | |
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| 35 | ///Default traits class of Dfs class. |
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| 36 | |
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| 37 | ///Default traits class of Dfs class. |
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| 38 | ///\param GR Graph type. |
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| 39 | template<class GR> |
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| 40 | struct DfsDefaultTraits |
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| 41 | { |
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| 42 | ///The graph type the algorithm runs on. |
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| 43 | typedef GR Graph; |
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| 44 | ///\brief The type of the map that stores the last |
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| 45 | ///edges of the %DFS paths. |
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| 46 | /// |
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| 47 | ///The type of the map that stores the last |
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| 48 | ///edges of the %DFS paths. |
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| 49 | ///It must meet the \ref concept::WriteMap "WriteMap" concept. |
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| 50 | /// |
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| 51 | typedef typename Graph::template NodeMap<typename GR::Edge> PredMap; |
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| 52 | ///Instantiates a PredMap. |
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| 53 | |
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| 54 | ///This function instantiates a \ref PredMap. |
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| 55 | ///\param G is the graph, to which we would like to define the PredMap. |
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| 56 | ///\todo The graph alone may be insufficient to initialize |
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| 57 | static PredMap *createPredMap(const GR &G) |
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| 58 | { |
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| 59 | return new PredMap(G); |
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| 60 | } |
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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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| 65 | ///It must meet the \ref concept::WriteMap "WriteMap" concept. |
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| 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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| 84 | ///It must meet the \ref concept::WriteMap "WriteMap" concept. |
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| 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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| 99 | ///It must meet the \ref concept::WriteMap "WriteMap" concept. |
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| 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 | ///%DFS 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 %DFS algorithm. |
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[780] | 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 Dfs, it |
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| 119 | ///is only passed to \ref DfsDefaultTraits. |
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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 DfsDefaultTraits "DfsDefaultTraits<GR>". |
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| 123 | ///See \ref DfsDefaultTraits for the documentation of |
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| 124 | ///a Dfs traits class. |
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[780] | 125 | /// |
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[1218] | 126 | ///\author Jacint Szabo and Alpar Juttner |
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[780] | 127 | #ifdef DOXYGEN |
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[1218] | 128 | template <typename GR, |
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| 129 | typename TR> |
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[780] | 130 | #else |
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[1218] | 131 | template <typename GR=ListGraph, |
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| 132 | typename TR=DfsDefaultTraits<GR> > |
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[780] | 133 | #endif |
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[1218] | 134 | class Dfs { |
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[780] | 135 | public: |
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[1218] | 136 | /** |
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| 137 | * \brief \ref Exception for uninitialized parameters. |
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| 138 | * |
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| 139 | * This error represents problems in the initialization |
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| 140 | * of the parameters of the algorithms. |
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| 141 | */ |
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| 142 | class UninitializedParameter : public lemon::UninitializedParameter { |
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| 143 | public: |
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| 144 | virtual const char* exceptionName() const { |
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| 145 | return "lemon::Dfs::UninitializedParameter"; |
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| 146 | } |
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| 147 | }; |
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| 148 | |
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| 149 | typedef TR Traits; |
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[780] | 150 | ///The type of the underlying graph. |
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[1218] | 151 | typedef typename TR::Graph Graph; |
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[911] | 152 | ///\e |
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[780] | 153 | typedef typename Graph::Node Node; |
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[911] | 154 | ///\e |
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[780] | 155 | typedef typename Graph::NodeIt NodeIt; |
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[911] | 156 | ///\e |
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[780] | 157 | typedef typename Graph::Edge Edge; |
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[911] | 158 | ///\e |
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[780] | 159 | typedef typename Graph::OutEdgeIt OutEdgeIt; |
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| 160 | |
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| 161 | ///\brief The type of the map that stores the last |
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[1218] | 162 | ///edges of the %DFS paths. |
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| 163 | typedef typename TR::PredMap PredMap; |
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| 164 | ///The type of the map indicating which nodes are reached. |
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| 165 | typedef typename TR::ReachedMap ReachedMap; |
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| 166 | ///The type of the map indicating which nodes are processed. |
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| 167 | typedef typename TR::ProcessedMap ProcessedMap; |
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| 168 | ///The type of the map that stores the dists of the nodes. |
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| 169 | typedef typename TR::DistMap DistMap; |
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[780] | 170 | private: |
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[802] | 171 | /// Pointer to the underlying graph. |
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[780] | 172 | const Graph *G; |
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[802] | 173 | ///Pointer to the map of predecessors edges. |
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[1218] | 174 | PredMap *_pred; |
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| 175 | ///Indicates if \ref _pred is locally allocated (\c true) or not. |
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| 176 | bool local_pred; |
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[802] | 177 | ///Pointer to the map of distances. |
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[1218] | 178 | DistMap *_dist; |
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| 179 | ///Indicates if \ref _dist is locally allocated (\c true) or not. |
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| 180 | bool local_dist; |
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| 181 | ///Pointer to the map of reached status of the nodes. |
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| 182 | ReachedMap *_reached; |
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| 183 | ///Indicates if \ref _reached is locally allocated (\c true) or not. |
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| 184 | bool local_reached; |
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| 185 | ///Pointer to the map of processed status of the nodes. |
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| 186 | ProcessedMap *_processed; |
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| 187 | ///Indicates if \ref _processed is locally allocated (\c true) or not. |
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| 188 | bool local_processed; |
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[780] | 189 | |
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[1218] | 190 | std::vector<typename Graph::OutEdgeIt> _stack; |
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| 191 | int _stack_head; |
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[780] | 192 | |
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[1218] | 193 | ///Creates the maps if necessary. |
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| 194 | |
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| 195 | ///\todo Better memory allocation (instead of new). |
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| 196 | void create_maps() |
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[780] | 197 | { |
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[1218] | 198 | if(!_pred) { |
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| 199 | local_pred = true; |
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| 200 | _pred = Traits::createPredMap(*G); |
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[780] | 201 | } |
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[1218] | 202 | if(!_dist) { |
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| 203 | local_dist = true; |
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| 204 | _dist = Traits::createDistMap(*G); |
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[780] | 205 | } |
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[1218] | 206 | if(!_reached) { |
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| 207 | local_reached = true; |
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| 208 | _reached = Traits::createReachedMap(*G); |
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| 209 | } |
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| 210 | if(!_processed) { |
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| 211 | local_processed = true; |
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| 212 | _processed = Traits::createProcessedMap(*G); |
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[780] | 213 | } |
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| 214 | } |
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[1710] | 215 | |
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| 216 | protected: |
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| 217 | |
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| 218 | Dfs() {} |
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[780] | 219 | |
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[1710] | 220 | public: |
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[1709] | 221 | |
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| 222 | typedef Dfs Create; |
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| 223 | |
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[1218] | 224 | ///\name Named template parameters |
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| 225 | |
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| 226 | ///@{ |
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| 227 | |
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| 228 | template <class T> |
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| 229 | struct DefPredMapTraits : public Traits { |
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| 230 | typedef T PredMap; |
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| 231 | static PredMap *createPredMap(const Graph &G) |
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| 232 | { |
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| 233 | throw UninitializedParameter(); |
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| 234 | } |
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| 235 | }; |
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| 236 | ///\ref named-templ-param "Named parameter" for setting PredMap type |
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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 | template <class T> |
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[1709] | 241 | struct DefPredMap : public Dfs<Graph, DefPredMapTraits<T> > { |
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| 242 | typedef Dfs<Graph, DefPredMapTraits<T> > Create; |
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| 243 | }; |
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[1218] | 244 | |
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| 245 | |
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| 246 | template <class T> |
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| 247 | struct DefDistMapTraits : public Traits { |
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| 248 | typedef T DistMap; |
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| 249 | static DistMap *createDistMap(const Graph &G) |
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| 250 | { |
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| 251 | throw UninitializedParameter(); |
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| 252 | } |
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| 253 | }; |
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| 254 | ///\ref named-templ-param "Named parameter" for setting DistMap type |
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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 | template <class T> |
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[1709] | 259 | struct DefDistMap { |
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| 260 | typedef Dfs<Graph, DefDistMapTraits<T> > Create; |
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| 261 | }; |
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[1218] | 262 | |
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| 263 | template <class T> |
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| 264 | struct DefReachedMapTraits : public Traits { |
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| 265 | typedef T ReachedMap; |
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| 266 | static ReachedMap *createReachedMap(const Graph &G) |
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| 267 | { |
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| 268 | throw UninitializedParameter(); |
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| 269 | } |
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| 270 | }; |
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| 271 | ///\ref named-templ-param "Named parameter" for setting ReachedMap type |
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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 | template <class T> |
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[1749] | 276 | struct DefReachedMap : public Dfs< Graph, DefReachedMapTraits<T> > { |
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[1709] | 277 | typedef Dfs< Graph, DefReachedMapTraits<T> > Create; |
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[1218] | 278 | }; |
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[1709] | 279 | |
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[1218] | 280 | template <class T> |
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| 281 | struct DefProcessedMapTraits : public Traits { |
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| 282 | typedef T ProcessedMap; |
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| 283 | static ProcessedMap *createProcessedMap(const Graph &G) |
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| 284 | { |
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| 285 | throw UninitializedParameter(); |
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| 286 | } |
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| 287 | }; |
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| 288 | ///\ref named-templ-param "Named parameter" for setting ProcessedMap type |
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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 | template <class T> |
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[1694] | 293 | struct DefProcessedMap : public Dfs< Graph, DefProcessedMapTraits<T> > { |
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[1709] | 294 | typedef Dfs< Graph, DefProcessedMapTraits<T> > Create; |
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[1694] | 295 | }; |
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[1218] | 296 | |
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| 297 | struct DefGraphProcessedMapTraits : public Traits { |
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| 298 | typedef typename Graph::template NodeMap<bool> ProcessedMap; |
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| 299 | static ProcessedMap *createProcessedMap(const Graph &G) |
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| 300 | { |
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| 301 | return new ProcessedMap(G); |
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| 302 | } |
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| 303 | }; |
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| 304 | ///\brief \ref named-templ-param "Named parameter" |
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| 305 | ///for setting the ProcessedMap type to be Graph::NodeMap<bool>. |
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| 306 | /// |
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| 307 | ///\ref named-templ-param "Named parameter" |
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| 308 | ///for setting the ProcessedMap type to be Graph::NodeMap<bool>. |
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| 309 | ///If you don't set it explicitely, it will be automatically allocated. |
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| 310 | template <class T> |
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| 311 | class DefProcessedMapToBeDefaultMap : |
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[1709] | 312 | public Dfs< Graph, DefGraphProcessedMapTraits> { |
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| 313 | typedef Dfs< Graph, DefGraphProcessedMapTraits> Create; |
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| 314 | }; |
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[1218] | 315 | |
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| 316 | ///@} |
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| 317 | |
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| 318 | public: |
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| 319 | |
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[802] | 320 | ///Constructor. |
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| 321 | |
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| 322 | ///\param _G the graph the algorithm will run on. |
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[911] | 323 | /// |
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[780] | 324 | Dfs(const Graph& _G) : |
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| 325 | G(&_G), |
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[1218] | 326 | _pred(NULL), local_pred(false), |
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| 327 | _dist(NULL), local_dist(false), |
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| 328 | _reached(NULL), local_reached(false), |
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| 329 | _processed(NULL), local_processed(false) |
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[780] | 330 | { } |
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| 331 | |
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[802] | 332 | ///Destructor. |
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[780] | 333 | ~Dfs() |
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| 334 | { |
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[1218] | 335 | if(local_pred) delete _pred; |
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| 336 | if(local_dist) delete _dist; |
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| 337 | if(local_reached) delete _reached; |
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| 338 | if(local_processed) delete _processed; |
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[780] | 339 | } |
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| 340 | |
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| 341 | ///Sets the map storing the predecessor edges. |
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| 342 | |
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| 343 | ///Sets the map storing the predecessor edges. |
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| 344 | ///If you don't use this function before calling \ref run(), |
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| 345 | ///it will allocate one. The destuctor deallocates this |
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| 346 | ///automatically allocated map, of course. |
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| 347 | ///\return <tt> (*this) </tt> |
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[1218] | 348 | Dfs &predMap(PredMap &m) |
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[780] | 349 | { |
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[1218] | 350 | if(local_pred) { |
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| 351 | delete _pred; |
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| 352 | local_pred=false; |
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[780] | 353 | } |
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[1218] | 354 | _pred = &m; |
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[780] | 355 | return *this; |
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| 356 | } |
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| 357 | |
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| 358 | ///Sets the map storing the distances calculated by the algorithm. |
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| 359 | |
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| 360 | ///Sets the map storing the distances calculated by the algorithm. |
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| 361 | ///If you don't use this function before calling \ref run(), |
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| 362 | ///it will allocate one. The destuctor deallocates this |
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| 363 | ///automatically allocated map, of course. |
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| 364 | ///\return <tt> (*this) </tt> |
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[1218] | 365 | Dfs &distMap(DistMap &m) |
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[780] | 366 | { |
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[1218] | 367 | if(local_dist) { |
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| 368 | delete _dist; |
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| 369 | local_dist=false; |
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[780] | 370 | } |
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[1218] | 371 | _dist = &m; |
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[780] | 372 | return *this; |
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| 373 | } |
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| 374 | |
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[1220] | 375 | ///Sets the map indicating if a node is reached. |
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| 376 | |
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| 377 | ///Sets the map indicating if a node is reached. |
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| 378 | ///If you don't use this function before calling \ref run(), |
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| 379 | ///it will allocate one. The destuctor deallocates this |
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| 380 | ///automatically allocated map, of course. |
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| 381 | ///\return <tt> (*this) </tt> |
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| 382 | Dfs &reachedMap(ReachedMap &m) |
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| 383 | { |
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| 384 | if(local_reached) { |
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| 385 | delete _reached; |
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| 386 | local_reached=false; |
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| 387 | } |
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| 388 | _reached = &m; |
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| 389 | return *this; |
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| 390 | } |
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| 391 | |
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| 392 | ///Sets the map indicating if a node is processed. |
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| 393 | |
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| 394 | ///Sets the map indicating if a node is processed. |
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| 395 | ///If you don't use this function before calling \ref run(), |
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| 396 | ///it will allocate one. The destuctor deallocates this |
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| 397 | ///automatically allocated map, of course. |
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| 398 | ///\return <tt> (*this) </tt> |
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| 399 | Dfs &processedMap(ProcessedMap &m) |
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| 400 | { |
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| 401 | if(local_processed) { |
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| 402 | delete _processed; |
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| 403 | local_processed=false; |
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| 404 | } |
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| 405 | _processed = &m; |
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| 406 | return *this; |
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| 407 | } |
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| 408 | |
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[1218] | 409 | public: |
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| 410 | ///\name Execution control |
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| 411 | ///The simplest way to execute the algorithm is to use |
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| 412 | ///one of the member functions called \c run(...). |
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| 413 | ///\n |
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| 414 | ///If you need more control on the execution, |
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[1761] | 415 | ///first you must call \ref init(), then you can add a source node |
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[1218] | 416 | ///with \ref addSource(). |
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| 417 | ///Finally \ref start() will perform the actual path |
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| 418 | ///computation. |
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| 419 | |
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| 420 | ///@{ |
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| 421 | |
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| 422 | ///Initializes the internal data structures. |
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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 | void init() |
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| 427 | { |
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| 428 | create_maps(); |
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| 429 | _stack.resize(countNodes(*G)); |
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| 430 | _stack_head=-1; |
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[780] | 431 | for ( NodeIt u(*G) ; u!=INVALID ; ++u ) { |
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[1218] | 432 | _pred->set(u,INVALID); |
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| 433 | // _predNode->set(u,INVALID); |
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| 434 | _reached->set(u,false); |
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| 435 | _processed->set(u,false); |
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[780] | 436 | } |
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| 437 | } |
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| 438 | |
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[1218] | 439 | ///Adds a new source node. |
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[780] | 440 | |
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[1218] | 441 | ///Adds a new source node to the set of nodes to be processed. |
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| 442 | /// |
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[1443] | 443 | ///\bug dists are wrong (or at least strange) in case of multiple sources. |
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[1218] | 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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[1664] | 450 | OutEdgeIt e(*G,s); |
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[1666] | 451 | if(e!=INVALID) { |
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| 452 | _stack[++_stack_head]=e; |
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| 453 | _dist->set(s,_stack_head); |
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| 454 | } |
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| 455 | else { |
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| 456 | _processed->set(s,true); |
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| 457 | _dist->set(s,0); |
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| 458 | } |
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[1218] | 459 | } |
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| 460 | } |
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| 461 | |
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[1529] | 462 | ///Processes the next edge. |
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[1218] | 463 | |
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[1529] | 464 | ///Processes the next edge. |
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[1218] | 465 | /// |
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[1516] | 466 | ///\return The processed edge. |
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| 467 | /// |
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[1443] | 468 | ///\pre The stack must not be empty! |
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[1516] | 469 | Edge processNextEdge() |
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[1218] | 470 | { |
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| 471 | Node m; |
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| 472 | Edge e=_stack[_stack_head]; |
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| 473 | if(!(*_reached)[m=G->target(e)]) { |
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| 474 | _pred->set(m,e); |
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| 475 | _reached->set(m,true); |
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[1233] | 476 | ++_stack_head; |
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| 477 | _stack[_stack_head] = OutEdgeIt(*G, m); |
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[1218] | 478 | _dist->set(m,_stack_head); |
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| 479 | } |
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| 480 | else { |
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[1663] | 481 | m=G->source(e); |
---|
| 482 | ++_stack[_stack_head]; |
---|
| 483 | } |
---|
| 484 | while(_stack_head>=0 && _stack[_stack_head]==INVALID) { |
---|
| 485 | _processed->set(m,true); |
---|
| 486 | --_stack_head; |
---|
| 487 | if(_stack_head>=0) { |
---|
| 488 | m=G->source(_stack[_stack_head]); |
---|
| 489 | ++_stack[_stack_head]; |
---|
| 490 | } |
---|
[1218] | 491 | } |
---|
[1516] | 492 | return e; |
---|
[1218] | 493 | } |
---|
[1665] | 494 | ///Next edge to be processed. |
---|
| 495 | |
---|
| 496 | ///Next edge to be processed. |
---|
| 497 | /// |
---|
| 498 | ///\return The next edge to be processed or INVALID if the stack is |
---|
| 499 | /// empty. |
---|
[1694] | 500 | OutEdgeIt nextEdge() |
---|
[1665] | 501 | { |
---|
| 502 | return _stack_head>=0?_stack[_stack_head]:INVALID; |
---|
| 503 | } |
---|
[1694] | 504 | |
---|
[1218] | 505 | ///\brief Returns \c false if there are nodes |
---|
| 506 | ///to be processed in the queue |
---|
| 507 | /// |
---|
| 508 | ///Returns \c false if there are nodes |
---|
| 509 | ///to be processed in the queue |
---|
| 510 | bool emptyQueue() { return _stack_head<0; } |
---|
| 511 | ///Returns the number of the nodes to be processed. |
---|
| 512 | |
---|
| 513 | ///Returns the number of the nodes to be processed in the queue. |
---|
| 514 | int queueSize() { return _stack_head+1; } |
---|
| 515 | |
---|
| 516 | ///Executes the algorithm. |
---|
| 517 | |
---|
| 518 | ///Executes the algorithm. |
---|
| 519 | /// |
---|
| 520 | ///\pre init() must be called and at least one node should be added |
---|
| 521 | ///with addSource() before using this function. |
---|
| 522 | /// |
---|
| 523 | ///This method runs the %DFS algorithm from the root node(s) |
---|
| 524 | ///in order to |
---|
| 525 | ///compute the |
---|
| 526 | ///%DFS path to each node. The algorithm computes |
---|
| 527 | ///- The %DFS tree. |
---|
[1443] | 528 | ///- The distance of each node from the root(s) in the %DFS tree. |
---|
[1218] | 529 | /// |
---|
| 530 | void start() |
---|
| 531 | { |
---|
| 532 | while ( !emptyQueue() ) processNextEdge(); |
---|
| 533 | } |
---|
| 534 | |
---|
| 535 | ///Executes the algorithm until \c dest is reached. |
---|
| 536 | |
---|
| 537 | ///Executes the algorithm until \c dest is reached. |
---|
| 538 | /// |
---|
| 539 | ///\pre init() must be called and at least one node should be added |
---|
| 540 | ///with addSource() before using this function. |
---|
| 541 | /// |
---|
| 542 | ///This method runs the %DFS algorithm from the root node(s) |
---|
| 543 | ///in order to |
---|
| 544 | ///compute the |
---|
| 545 | ///%DFS path to \c dest. The algorithm computes |
---|
| 546 | ///- The %DFS path to \c dest. |
---|
[1443] | 547 | ///- The distance of \c dest from the root(s) in the %DFS tree. |
---|
[1218] | 548 | /// |
---|
| 549 | void start(Node dest) |
---|
| 550 | { |
---|
[1233] | 551 | while ( !emptyQueue() && G->target(_stack[_stack_head])!=dest ) |
---|
| 552 | processNextEdge(); |
---|
[1218] | 553 | } |
---|
| 554 | |
---|
| 555 | ///Executes the algorithm until a condition is met. |
---|
| 556 | |
---|
| 557 | ///Executes the algorithm until a condition is met. |
---|
| 558 | /// |
---|
| 559 | ///\pre init() must be called and at least one node should be added |
---|
| 560 | ///with addSource() before using this function. |
---|
| 561 | /// |
---|
[1233] | 562 | ///\param nm must be a bool (or convertible) edge map. The algorithm |
---|
[1438] | 563 | ///will stop when it reaches an edge \c e with <tt>nm[e]==true</tt>. |
---|
[1443] | 564 | /// |
---|
[1749] | 565 | ///\warning Contrary to \ref Dfs and \ref Dijkstra, \c em is an edge map, |
---|
[1233] | 566 | ///not a node map. |
---|
[1749] | 567 | template<class EM> |
---|
| 568 | void start(const EM &em) |
---|
| 569 | { |
---|
| 570 | while ( !emptyQueue() && !em[_stack[_stack_head]] ) processNextEdge(); |
---|
| 571 | } |
---|
| 572 | |
---|
[1218] | 573 | ///Runs %DFS algorithm from node \c s. |
---|
| 574 | |
---|
| 575 | ///This method runs the %DFS algorithm from a root node \c s |
---|
| 576 | ///in order to |
---|
| 577 | ///compute the |
---|
| 578 | ///%DFS path to each node. The algorithm computes |
---|
| 579 | ///- The %DFS tree. |
---|
[1443] | 580 | ///- The distance of each node from the root in the %DFS tree. |
---|
[1218] | 581 | /// |
---|
| 582 | ///\note d.run(s) is just a shortcut of the following code. |
---|
| 583 | ///\code |
---|
| 584 | /// d.init(); |
---|
| 585 | /// d.addSource(s); |
---|
| 586 | /// d.start(); |
---|
| 587 | ///\endcode |
---|
| 588 | void run(Node s) { |
---|
| 589 | init(); |
---|
| 590 | addSource(s); |
---|
| 591 | start(); |
---|
| 592 | } |
---|
| 593 | |
---|
| 594 | ///Finds the %DFS path between \c s and \c t. |
---|
| 595 | |
---|
| 596 | ///Finds the %DFS path between \c s and \c t. |
---|
| 597 | /// |
---|
| 598 | ///\return The length of the %DFS s---t path if there exists one, |
---|
| 599 | ///0 otherwise. |
---|
[1540] | 600 | ///\note Apart from the return value, d.run(s,t) is |
---|
[1218] | 601 | ///just a shortcut of the following code. |
---|
| 602 | ///\code |
---|
| 603 | /// d.init(); |
---|
| 604 | /// d.addSource(s); |
---|
| 605 | /// d.start(t); |
---|
| 606 | ///\endcode |
---|
| 607 | int run(Node s,Node t) { |
---|
| 608 | init(); |
---|
| 609 | addSource(s); |
---|
| 610 | start(t); |
---|
[1233] | 611 | return reached(t)?_stack_head+1:0; |
---|
[1218] | 612 | } |
---|
| 613 | |
---|
| 614 | ///@} |
---|
| 615 | |
---|
| 616 | ///\name Query Functions |
---|
| 617 | ///The result of the %DFS algorithm can be obtained using these |
---|
| 618 | ///functions.\n |
---|
| 619 | ///Before the use of these functions, |
---|
| 620 | ///either run() or start() must be called. |
---|
| 621 | |
---|
| 622 | ///@{ |
---|
| 623 | |
---|
[1283] | 624 | ///Copies the path to \c t on the DFS tree into \c p |
---|
| 625 | |
---|
[1443] | 626 | ///This function copies the path to \c t on the DFS tree into \c p. |
---|
[1438] | 627 | ///If \c t is a source itself or unreachable, then it does not |
---|
[1283] | 628 | ///alter \c p. |
---|
[1438] | 629 | /// |
---|
[1283] | 630 | ///\return Returns \c true if a path to \c t was actually copied to \c p, |
---|
| 631 | ///\c false otherwise. |
---|
| 632 | ///\sa DirPath |
---|
| 633 | template<class P> |
---|
| 634 | bool getPath(P &p,Node t) |
---|
| 635 | { |
---|
| 636 | if(reached(t)) { |
---|
| 637 | p.clear(); |
---|
| 638 | typename P::Builder b(p); |
---|
[1763] | 639 | for(b.setStartNode(t);predEdge(t)!=INVALID;t=predNode(t)) |
---|
| 640 | b.pushFront(predEdge(t)); |
---|
[1283] | 641 | b.commit(); |
---|
| 642 | return true; |
---|
| 643 | } |
---|
| 644 | return false; |
---|
| 645 | } |
---|
| 646 | |
---|
[1218] | 647 | ///The distance of a node from the root(s). |
---|
| 648 | |
---|
| 649 | ///Returns the distance of a node from the root(s). |
---|
[780] | 650 | ///\pre \ref run() must be called before using this function. |
---|
[1438] | 651 | ///\warning If node \c v is unreachable from the root(s) then the return value |
---|
[780] | 652 | ///of this funcion is undefined. |
---|
[1218] | 653 | int dist(Node v) const { return (*_dist)[v]; } |
---|
[780] | 654 | |
---|
[1218] | 655 | ///Returns the 'previous edge' of the %DFS tree. |
---|
[780] | 656 | |
---|
[1218] | 657 | ///For a node \c v it returns the 'previous edge' |
---|
| 658 | ///of the %DFS path, |
---|
| 659 | ///i.e. it returns the last edge of a %DFS path from the root(s) to \c |
---|
[780] | 660 | ///v. It is \ref INVALID |
---|
[1218] | 661 | ///if \c v is unreachable from the root(s) or \c v is a root. The |
---|
[781] | 662 | ///%DFS tree used here is equal to the %DFS tree used in |
---|
[1631] | 663 | ///\ref predNode(). |
---|
[1218] | 664 | ///\pre Either \ref run() or \ref start() must be called before using |
---|
[780] | 665 | ///this function. |
---|
[1763] | 666 | Edge predEdge(Node v) const { return (*_pred)[v];} |
---|
[780] | 667 | |
---|
[781] | 668 | ///Returns the 'previous node' of the %DFS tree. |
---|
[780] | 669 | |
---|
[1218] | 670 | ///For a node \c v it returns the 'previous node' |
---|
| 671 | ///of the %DFS tree, |
---|
| 672 | ///i.e. it returns the last but one node from a %DFS path from the |
---|
| 673 | ///root(a) to \c /v. |
---|
| 674 | ///It is INVALID if \c v is unreachable from the root(s) or |
---|
| 675 | ///if \c v itself a root. |
---|
| 676 | ///The %DFS tree used here is equal to the %DFS |
---|
[1763] | 677 | ///tree used in \ref predEdge(). |
---|
[1218] | 678 | ///\pre Either \ref run() or \ref start() must be called before |
---|
[780] | 679 | ///using this function. |
---|
[1218] | 680 | Node predNode(Node v) const { return (*_pred)[v]==INVALID ? INVALID: |
---|
| 681 | G->source((*_pred)[v]); } |
---|
[780] | 682 | |
---|
[1218] | 683 | ///Returns a reference to the NodeMap of distances. |
---|
| 684 | |
---|
| 685 | ///Returns a reference to the NodeMap of distances. |
---|
| 686 | ///\pre Either \ref run() or \ref init() must |
---|
[780] | 687 | ///be called before using this function. |
---|
[1218] | 688 | const DistMap &distMap() const { return *_dist;} |
---|
[780] | 689 | |
---|
[1218] | 690 | ///Returns a reference to the %DFS edge-tree map. |
---|
[780] | 691 | |
---|
| 692 | ///Returns a reference to the NodeMap of the edges of the |
---|
[781] | 693 | ///%DFS tree. |
---|
[1218] | 694 | ///\pre Either \ref run() or \ref init() |
---|
| 695 | ///must be called before using this function. |
---|
| 696 | const PredMap &predMap() const { return *_pred;} |
---|
[780] | 697 | |
---|
| 698 | ///Checks if a node is reachable from the root. |
---|
| 699 | |
---|
[1438] | 700 | ///Returns \c true if \c v is reachable from the root(s). |
---|
| 701 | ///\warning The source nodes are inditated as unreachable. |
---|
[1218] | 702 | ///\pre Either \ref run() or \ref start() |
---|
| 703 | ///must be called before using this function. |
---|
[780] | 704 | /// |
---|
[1218] | 705 | bool reached(Node v) { return (*_reached)[v]; } |
---|
| 706 | |
---|
| 707 | ///@} |
---|
| 708 | }; |
---|
| 709 | |
---|
| 710 | ///Default traits class of Dfs function. |
---|
| 711 | |
---|
| 712 | ///Default traits class of Dfs function. |
---|
| 713 | ///\param GR Graph type. |
---|
| 714 | template<class GR> |
---|
| 715 | struct DfsWizardDefaultTraits |
---|
| 716 | { |
---|
| 717 | ///The graph type the algorithm runs on. |
---|
| 718 | typedef GR Graph; |
---|
| 719 | ///\brief The type of the map that stores the last |
---|
| 720 | ///edges of the %DFS paths. |
---|
| 721 | /// |
---|
| 722 | ///The type of the map that stores the last |
---|
| 723 | ///edges of the %DFS paths. |
---|
| 724 | ///It must meet the \ref concept::WriteMap "WriteMap" concept. |
---|
[780] | 725 | /// |
---|
[1218] | 726 | typedef NullMap<typename Graph::Node,typename GR::Edge> PredMap; |
---|
| 727 | ///Instantiates a PredMap. |
---|
| 728 | |
---|
| 729 | ///This function instantiates a \ref PredMap. |
---|
[1536] | 730 | ///\param g is the graph, to which we would like to define the PredMap. |
---|
[1218] | 731 | ///\todo The graph alone may be insufficient to initialize |
---|
[1536] | 732 | #ifdef DOXYGEN |
---|
| 733 | static PredMap *createPredMap(const GR &g) |
---|
| 734 | #else |
---|
[1367] | 735 | static PredMap *createPredMap(const GR &) |
---|
[1536] | 736 | #endif |
---|
[1218] | 737 | { |
---|
| 738 | return new PredMap(); |
---|
| 739 | } |
---|
| 740 | |
---|
| 741 | ///The type of the map that indicates which nodes are processed. |
---|
| 742 | |
---|
| 743 | ///The type of the map that indicates which nodes are processed. |
---|
| 744 | ///It must meet the \ref concept::WriteMap "WriteMap" concept. |
---|
| 745 | ///\todo named parameter to set this type, function to read and write. |
---|
| 746 | typedef NullMap<typename Graph::Node,bool> ProcessedMap; |
---|
| 747 | ///Instantiates a ProcessedMap. |
---|
| 748 | |
---|
| 749 | ///This function instantiates a \ref ProcessedMap. |
---|
[1536] | 750 | ///\param g is the graph, to which |
---|
[1218] | 751 | ///we would like to define the \ref ProcessedMap |
---|
[1536] | 752 | #ifdef DOXYGEN |
---|
| 753 | static ProcessedMap *createProcessedMap(const GR &g) |
---|
| 754 | #else |
---|
[1367] | 755 | static ProcessedMap *createProcessedMap(const GR &) |
---|
[1536] | 756 | #endif |
---|
[1218] | 757 | { |
---|
| 758 | return new ProcessedMap(); |
---|
| 759 | } |
---|
| 760 | ///The type of the map that indicates which nodes are reached. |
---|
| 761 | |
---|
| 762 | ///The type of the map that indicates which nodes are reached. |
---|
| 763 | ///It must meet the \ref concept::WriteMap "WriteMap" concept. |
---|
| 764 | ///\todo named parameter to set this type, function to read and write. |
---|
| 765 | typedef typename Graph::template NodeMap<bool> ReachedMap; |
---|
| 766 | ///Instantiates a ReachedMap. |
---|
| 767 | |
---|
| 768 | ///This function instantiates a \ref ReachedMap. |
---|
| 769 | ///\param G is the graph, to which |
---|
| 770 | ///we would like to define the \ref ReachedMap. |
---|
| 771 | static ReachedMap *createReachedMap(const GR &G) |
---|
| 772 | { |
---|
| 773 | return new ReachedMap(G); |
---|
| 774 | } |
---|
| 775 | ///The type of the map that stores the dists of the nodes. |
---|
| 776 | |
---|
| 777 | ///The type of the map that stores the dists of the nodes. |
---|
| 778 | ///It must meet the \ref concept::WriteMap "WriteMap" concept. |
---|
| 779 | /// |
---|
| 780 | typedef NullMap<typename Graph::Node,int> DistMap; |
---|
| 781 | ///Instantiates a DistMap. |
---|
| 782 | |
---|
| 783 | ///This function instantiates a \ref DistMap. |
---|
[1536] | 784 | ///\param g is the graph, to which we would like to define the \ref DistMap |
---|
| 785 | #ifdef DOXYGEN |
---|
| 786 | static DistMap *createDistMap(const GR &g) |
---|
| 787 | #else |
---|
[1367] | 788 | static DistMap *createDistMap(const GR &) |
---|
[1536] | 789 | #endif |
---|
[1218] | 790 | { |
---|
| 791 | return new DistMap(); |
---|
| 792 | } |
---|
| 793 | }; |
---|
| 794 | |
---|
| 795 | /// Default traits used by \ref DfsWizard |
---|
| 796 | |
---|
| 797 | /// To make it easier to use Dfs algorithm |
---|
| 798 | ///we have created a wizard class. |
---|
| 799 | /// This \ref DfsWizard class needs default traits, |
---|
| 800 | ///as well as the \ref Dfs class. |
---|
| 801 | /// The \ref DfsWizardBase is a class to be the default traits of the |
---|
| 802 | /// \ref DfsWizard class. |
---|
| 803 | template<class GR> |
---|
| 804 | class DfsWizardBase : public DfsWizardDefaultTraits<GR> |
---|
| 805 | { |
---|
| 806 | |
---|
| 807 | typedef DfsWizardDefaultTraits<GR> Base; |
---|
| 808 | protected: |
---|
| 809 | /// Type of the nodes in the graph. |
---|
| 810 | typedef typename Base::Graph::Node Node; |
---|
| 811 | |
---|
| 812 | /// Pointer to the underlying graph. |
---|
| 813 | void *_g; |
---|
| 814 | ///Pointer to the map of reached nodes. |
---|
| 815 | void *_reached; |
---|
| 816 | ///Pointer to the map of processed nodes. |
---|
| 817 | void *_processed; |
---|
| 818 | ///Pointer to the map of predecessors edges. |
---|
| 819 | void *_pred; |
---|
| 820 | ///Pointer to the map of distances. |
---|
| 821 | void *_dist; |
---|
| 822 | ///Pointer to the source node. |
---|
| 823 | Node _source; |
---|
| 824 | |
---|
| 825 | public: |
---|
| 826 | /// Constructor. |
---|
| 827 | |
---|
| 828 | /// This constructor does not require parameters, therefore it initiates |
---|
| 829 | /// all of the attributes to default values (0, INVALID). |
---|
| 830 | DfsWizardBase() : _g(0), _reached(0), _processed(0), _pred(0), |
---|
| 831 | _dist(0), _source(INVALID) {} |
---|
| 832 | |
---|
| 833 | /// Constructor. |
---|
| 834 | |
---|
| 835 | /// This constructor requires some parameters, |
---|
| 836 | /// listed in the parameters list. |
---|
| 837 | /// Others are initiated to 0. |
---|
| 838 | /// \param g is the initial value of \ref _g |
---|
| 839 | /// \param s is the initial value of \ref _source |
---|
| 840 | DfsWizardBase(const GR &g, Node s=INVALID) : |
---|
| 841 | _g((void *)&g), _reached(0), _processed(0), _pred(0), |
---|
| 842 | _dist(0), _source(s) {} |
---|
| 843 | |
---|
| 844 | }; |
---|
| 845 | |
---|
[1443] | 846 | /// A class to make the usage of the Dfs algorithm easier |
---|
[1218] | 847 | |
---|
[1443] | 848 | /// This class is created to make it easier to use the Dfs algorithm. |
---|
[1218] | 849 | /// It uses the functions and features of the plain \ref Dfs, |
---|
| 850 | /// but it is much simpler to use it. |
---|
| 851 | /// |
---|
| 852 | /// Simplicity means that the way to change the types defined |
---|
| 853 | /// in the traits class is based on functions that returns the new class |
---|
| 854 | /// and not on templatable built-in classes. |
---|
| 855 | /// When using the plain \ref Dfs |
---|
| 856 | /// the new class with the modified type comes from |
---|
| 857 | /// the original class by using the :: |
---|
| 858 | /// operator. In the case of \ref DfsWizard only |
---|
| 859 | /// a function have to be called and it will |
---|
| 860 | /// return the needed class. |
---|
| 861 | /// |
---|
| 862 | /// It does not have own \ref run method. When its \ref run method is called |
---|
[1438] | 863 | /// it initiates a plain \ref Dfs object, and calls the \ref Dfs::run |
---|
[1218] | 864 | /// method of it. |
---|
| 865 | template<class TR> |
---|
| 866 | class DfsWizard : public TR |
---|
| 867 | { |
---|
| 868 | typedef TR Base; |
---|
| 869 | |
---|
| 870 | ///The type of the underlying graph. |
---|
| 871 | typedef typename TR::Graph Graph; |
---|
| 872 | //\e |
---|
| 873 | typedef typename Graph::Node Node; |
---|
| 874 | //\e |
---|
| 875 | typedef typename Graph::NodeIt NodeIt; |
---|
| 876 | //\e |
---|
| 877 | typedef typename Graph::Edge Edge; |
---|
| 878 | //\e |
---|
| 879 | typedef typename Graph::OutEdgeIt OutEdgeIt; |
---|
| 880 | |
---|
| 881 | ///\brief The type of the map that stores |
---|
| 882 | ///the reached nodes |
---|
| 883 | typedef typename TR::ReachedMap ReachedMap; |
---|
| 884 | ///\brief The type of the map that stores |
---|
| 885 | ///the processed nodes |
---|
| 886 | typedef typename TR::ProcessedMap ProcessedMap; |
---|
| 887 | ///\brief The type of the map that stores the last |
---|
| 888 | ///edges of the %DFS paths. |
---|
| 889 | typedef typename TR::PredMap PredMap; |
---|
[1443] | 890 | ///The type of the map that stores the distances of the nodes. |
---|
[1218] | 891 | typedef typename TR::DistMap DistMap; |
---|
| 892 | |
---|
| 893 | public: |
---|
| 894 | /// Constructor. |
---|
| 895 | DfsWizard() : TR() {} |
---|
| 896 | |
---|
| 897 | /// Constructor that requires parameters. |
---|
| 898 | |
---|
| 899 | /// Constructor that requires parameters. |
---|
| 900 | /// These parameters will be the default values for the traits class. |
---|
| 901 | DfsWizard(const Graph &g, Node s=INVALID) : |
---|
| 902 | TR(g,s) {} |
---|
| 903 | |
---|
| 904 | ///Copy constructor |
---|
| 905 | DfsWizard(const TR &b) : TR(b) {} |
---|
| 906 | |
---|
| 907 | ~DfsWizard() {} |
---|
| 908 | |
---|
| 909 | ///Runs Dfs algorithm from a given node. |
---|
| 910 | |
---|
| 911 | ///Runs Dfs algorithm from a given node. |
---|
| 912 | ///The node can be given by the \ref source function. |
---|
| 913 | void run() |
---|
| 914 | { |
---|
| 915 | if(Base::_source==INVALID) throw UninitializedParameter(); |
---|
| 916 | Dfs<Graph,TR> alg(*(Graph*)Base::_g); |
---|
| 917 | if(Base::_reached) alg.reachedMap(*(ReachedMap*)Base::_reached); |
---|
| 918 | if(Base::_processed) alg.processedMap(*(ProcessedMap*)Base::_processed); |
---|
| 919 | if(Base::_pred) alg.predMap(*(PredMap*)Base::_pred); |
---|
| 920 | if(Base::_dist) alg.distMap(*(DistMap*)Base::_dist); |
---|
| 921 | alg.run(Base::_source); |
---|
| 922 | } |
---|
| 923 | |
---|
| 924 | ///Runs Dfs algorithm from the given node. |
---|
| 925 | |
---|
| 926 | ///Runs Dfs algorithm from the given node. |
---|
| 927 | ///\param s is the given source. |
---|
| 928 | void run(Node s) |
---|
| 929 | { |
---|
| 930 | Base::_source=s; |
---|
| 931 | run(); |
---|
| 932 | } |
---|
| 933 | |
---|
| 934 | template<class T> |
---|
| 935 | struct DefPredMapBase : public Base { |
---|
| 936 | typedef T PredMap; |
---|
[1367] | 937 | static PredMap *createPredMap(const Graph &) { return 0; }; |
---|
[1236] | 938 | DefPredMapBase(const TR &b) : TR(b) {} |
---|
[1218] | 939 | }; |
---|
| 940 | |
---|
| 941 | ///\brief \ref named-templ-param "Named parameter" |
---|
| 942 | ///function for setting PredMap type |
---|
| 943 | /// |
---|
| 944 | /// \ref named-templ-param "Named parameter" |
---|
| 945 | ///function for setting PredMap type |
---|
| 946 | /// |
---|
| 947 | template<class T> |
---|
| 948 | DfsWizard<DefPredMapBase<T> > predMap(const T &t) |
---|
| 949 | { |
---|
| 950 | Base::_pred=(void *)&t; |
---|
| 951 | return DfsWizard<DefPredMapBase<T> >(*this); |
---|
| 952 | } |
---|
| 953 | |
---|
| 954 | |
---|
| 955 | template<class T> |
---|
| 956 | struct DefReachedMapBase : public Base { |
---|
| 957 | typedef T ReachedMap; |
---|
[1367] | 958 | static ReachedMap *createReachedMap(const Graph &) { return 0; }; |
---|
[1236] | 959 | DefReachedMapBase(const TR &b) : TR(b) {} |
---|
[1218] | 960 | }; |
---|
| 961 | |
---|
| 962 | ///\brief \ref named-templ-param "Named parameter" |
---|
| 963 | ///function for setting ReachedMap |
---|
| 964 | /// |
---|
| 965 | /// \ref named-templ-param "Named parameter" |
---|
| 966 | ///function for setting ReachedMap |
---|
| 967 | /// |
---|
| 968 | template<class T> |
---|
| 969 | DfsWizard<DefReachedMapBase<T> > reachedMap(const T &t) |
---|
| 970 | { |
---|
| 971 | Base::_pred=(void *)&t; |
---|
| 972 | return DfsWizard<DefReachedMapBase<T> >(*this); |
---|
| 973 | } |
---|
| 974 | |
---|
| 975 | |
---|
| 976 | template<class T> |
---|
| 977 | struct DefProcessedMapBase : public Base { |
---|
| 978 | typedef T ProcessedMap; |
---|
[1367] | 979 | static ProcessedMap *createProcessedMap(const Graph &) { return 0; }; |
---|
[1236] | 980 | DefProcessedMapBase(const TR &b) : TR(b) {} |
---|
[1218] | 981 | }; |
---|
| 982 | |
---|
| 983 | ///\brief \ref named-templ-param "Named parameter" |
---|
| 984 | ///function for setting ProcessedMap |
---|
| 985 | /// |
---|
| 986 | /// \ref named-templ-param "Named parameter" |
---|
| 987 | ///function for setting ProcessedMap |
---|
| 988 | /// |
---|
| 989 | template<class T> |
---|
| 990 | DfsWizard<DefProcessedMapBase<T> > processedMap(const T &t) |
---|
| 991 | { |
---|
| 992 | Base::_pred=(void *)&t; |
---|
| 993 | return DfsWizard<DefProcessedMapBase<T> >(*this); |
---|
| 994 | } |
---|
| 995 | |
---|
| 996 | template<class T> |
---|
| 997 | struct DefDistMapBase : public Base { |
---|
| 998 | typedef T DistMap; |
---|
[1367] | 999 | static DistMap *createDistMap(const Graph &) { return 0; }; |
---|
[1236] | 1000 | DefDistMapBase(const TR &b) : TR(b) {} |
---|
[1218] | 1001 | }; |
---|
| 1002 | |
---|
| 1003 | ///\brief \ref named-templ-param "Named parameter" |
---|
| 1004 | ///function for setting DistMap type |
---|
| 1005 | /// |
---|
| 1006 | /// \ref named-templ-param "Named parameter" |
---|
| 1007 | ///function for setting DistMap type |
---|
| 1008 | /// |
---|
| 1009 | template<class T> |
---|
| 1010 | DfsWizard<DefDistMapBase<T> > distMap(const T &t) |
---|
| 1011 | { |
---|
| 1012 | Base::_dist=(void *)&t; |
---|
| 1013 | return DfsWizard<DefDistMapBase<T> >(*this); |
---|
| 1014 | } |
---|
| 1015 | |
---|
| 1016 | /// Sets the source node, from which the Dfs algorithm runs. |
---|
| 1017 | |
---|
| 1018 | /// Sets the source node, from which the Dfs algorithm runs. |
---|
| 1019 | /// \param s is the source node. |
---|
| 1020 | DfsWizard<TR> &source(Node s) |
---|
| 1021 | { |
---|
| 1022 | Base::_source=s; |
---|
| 1023 | return *this; |
---|
| 1024 | } |
---|
[780] | 1025 | |
---|
| 1026 | }; |
---|
| 1027 | |
---|
[1218] | 1028 | ///Function type interface for Dfs algorithm. |
---|
| 1029 | |
---|
| 1030 | /// \ingroup flowalgs |
---|
| 1031 | ///Function type interface for Dfs algorithm. |
---|
| 1032 | /// |
---|
| 1033 | ///This function also has several |
---|
| 1034 | ///\ref named-templ-func-param "named parameters", |
---|
| 1035 | ///they are declared as the members of class \ref DfsWizard. |
---|
| 1036 | ///The following |
---|
| 1037 | ///example shows how to use these parameters. |
---|
| 1038 | ///\code |
---|
| 1039 | /// dfs(g,source).predMap(preds).run(); |
---|
| 1040 | ///\endcode |
---|
| 1041 | ///\warning Don't forget to put the \ref DfsWizard::run() "run()" |
---|
| 1042 | ///to the end of the parameter list. |
---|
| 1043 | ///\sa DfsWizard |
---|
| 1044 | ///\sa Dfs |
---|
| 1045 | template<class GR> |
---|
| 1046 | DfsWizard<DfsWizardBase<GR> > |
---|
| 1047 | dfs(const GR &g,typename GR::Node s=INVALID) |
---|
| 1048 | { |
---|
| 1049 | return DfsWizard<DfsWizardBase<GR> >(g,s); |
---|
| 1050 | } |
---|
| 1051 | |
---|
[1799] | 1052 | #ifdef DOXYGEN |
---|
[1749] | 1053 | /// \brief Visitor class for dfs. |
---|
| 1054 | /// |
---|
| 1055 | /// It gives a simple interface for a functional interface for dfs |
---|
| 1056 | /// traversal. The traversal on a linear data structure. |
---|
| 1057 | template <typename _Graph> |
---|
| 1058 | struct DfsVisitor { |
---|
| 1059 | typedef _Graph Graph; |
---|
| 1060 | typedef typename Graph::Edge Edge; |
---|
| 1061 | typedef typename Graph::Node Node; |
---|
| 1062 | /// \brief Called when the edge reach a node. |
---|
| 1063 | /// |
---|
| 1064 | /// It is called when the dfs find an edge which target is not |
---|
| 1065 | /// reached yet. |
---|
| 1066 | void discover(const Edge& edge) {} |
---|
| 1067 | /// \brief Called when the node reached first time. |
---|
| 1068 | /// |
---|
| 1069 | /// It is Called when the node reached first time. |
---|
| 1070 | void reach(const Node& node) {} |
---|
| 1071 | /// \brief Called when we step back on an edge. |
---|
| 1072 | /// |
---|
| 1073 | /// It is called when the dfs should step back on the edge. |
---|
| 1074 | void backtrack(const Edge& edge) {} |
---|
| 1075 | /// \brief Called when we step back from the node. |
---|
| 1076 | /// |
---|
| 1077 | /// It is called when we step back from the node. |
---|
| 1078 | void leave(const Node& node) {} |
---|
| 1079 | /// \brief Called when the edge examined but target of the edge |
---|
| 1080 | /// already discovered. |
---|
| 1081 | /// |
---|
| 1082 | /// It called when the edge examined but the target of the edge |
---|
| 1083 | /// already discovered. |
---|
| 1084 | void examine(const Edge& edge) {} |
---|
| 1085 | /// \brief Called for the source node of the dfs. |
---|
| 1086 | /// |
---|
| 1087 | /// It is called for the source node of the dfs. |
---|
[1799] | 1088 | void start(const Node& node) {} |
---|
[1749] | 1089 | /// \brief Called when we leave the source node of the dfs. |
---|
| 1090 | /// |
---|
| 1091 | /// It is called when we leave the source node of the dfs. |
---|
[1799] | 1092 | void stop(const Node& node) {} |
---|
| 1093 | |
---|
| 1094 | }; |
---|
| 1095 | #else |
---|
| 1096 | template <typename _Graph> |
---|
| 1097 | struct DfsVisitor { |
---|
| 1098 | typedef _Graph Graph; |
---|
| 1099 | typedef typename Graph::Edge Edge; |
---|
| 1100 | typedef typename Graph::Node Node; |
---|
| 1101 | void discover(const Edge&) {} |
---|
| 1102 | void reach(const Node&) {} |
---|
| 1103 | void backtrack(const Edge&) {} |
---|
| 1104 | void leave(const Node&) {} |
---|
| 1105 | void examine(const Edge&) {} |
---|
| 1106 | void start(const Node&) {} |
---|
[1749] | 1107 | void stop(const Node&) {} |
---|
| 1108 | |
---|
| 1109 | template <typename _Visitor> |
---|
| 1110 | struct Constraints { |
---|
| 1111 | void constraints() { |
---|
| 1112 | Edge edge; |
---|
| 1113 | Node node; |
---|
| 1114 | visitor.discover(edge); |
---|
| 1115 | visitor.reach(node); |
---|
| 1116 | visitor.backtrack(edge); |
---|
| 1117 | visitor.leave(node); |
---|
| 1118 | visitor.examine(edge); |
---|
| 1119 | visitor.start(node); |
---|
| 1120 | visitor.stop(edge); |
---|
| 1121 | } |
---|
| 1122 | _Visitor& visitor; |
---|
| 1123 | }; |
---|
| 1124 | }; |
---|
[1799] | 1125 | #endif |
---|
[1749] | 1126 | |
---|
| 1127 | /// \brief Default traits class of DfsVisit class. |
---|
| 1128 | /// |
---|
| 1129 | /// Default traits class of DfsVisit class. |
---|
| 1130 | /// \param _Graph Graph type. |
---|
| 1131 | template<class _Graph> |
---|
| 1132 | struct DfsVisitDefaultTraits { |
---|
| 1133 | |
---|
| 1134 | /// \brief The graph type the algorithm runs on. |
---|
| 1135 | typedef _Graph Graph; |
---|
| 1136 | |
---|
| 1137 | /// \brief The type of the map that indicates which nodes are reached. |
---|
| 1138 | /// |
---|
| 1139 | /// The type of the map that indicates which nodes are reached. |
---|
| 1140 | /// It must meet the \ref concept::WriteMap "WriteMap" concept. |
---|
| 1141 | /// \todo named parameter to set this type, function to read and write. |
---|
| 1142 | typedef typename Graph::template NodeMap<bool> ReachedMap; |
---|
| 1143 | |
---|
| 1144 | /// \brief Instantiates a ReachedMap. |
---|
| 1145 | /// |
---|
| 1146 | /// This function instantiates a \ref ReachedMap. |
---|
| 1147 | /// \param G is the graph, to which |
---|
| 1148 | /// we would like to define the \ref ReachedMap. |
---|
| 1149 | static ReachedMap *createReachedMap(const Graph &graph) { |
---|
| 1150 | return new ReachedMap(graph); |
---|
| 1151 | } |
---|
| 1152 | |
---|
| 1153 | }; |
---|
| 1154 | |
---|
| 1155 | /// %DFS Visit algorithm class. |
---|
| 1156 | |
---|
| 1157 | /// \ingroup flowalgs |
---|
| 1158 | /// This class provides an efficient implementation of the %DFS algorithm |
---|
| 1159 | /// with visitor interface. |
---|
| 1160 | /// |
---|
| 1161 | /// The %DfsVisit class provides an alternative interface to the Dfs |
---|
| 1162 | /// class. It works with callback mechanism, the DfsVisit object calls |
---|
| 1163 | /// on every dfs event the \c Visitor class member functions. |
---|
| 1164 | /// |
---|
| 1165 | /// \param _Graph The graph type the algorithm runs on. The default value is |
---|
| 1166 | /// \ref ListGraph. The value of _Graph is not used directly by Dfs, it |
---|
| 1167 | /// is only passed to \ref DfsDefaultTraits. |
---|
| 1168 | /// \param _Visitor The Visitor object for the algorithm. The |
---|
| 1169 | /// \ref DfsVisitor "DfsVisitor<_Graph>" is an empty Visitor which |
---|
| 1170 | /// does not observe the Dfs events. If you want to observe the dfs |
---|
| 1171 | /// events you should implement your own Visitor class. |
---|
| 1172 | /// \param _Traits Traits class to set various data types used by the |
---|
| 1173 | /// algorithm. The default traits class is |
---|
| 1174 | /// \ref DfsVisitDefaultTraits "DfsVisitDefaultTraits<_Graph>". |
---|
| 1175 | /// See \ref DfsVisitDefaultTraits for the documentation of |
---|
| 1176 | /// a Dfs visit traits class. |
---|
| 1177 | /// |
---|
| 1178 | /// \author Jacint Szabo, Alpar Juttner and Balazs Dezso |
---|
| 1179 | #ifdef DOXYGEN |
---|
| 1180 | template <typename _Graph, typename _Visitor, typename _Traits> |
---|
| 1181 | #else |
---|
| 1182 | template <typename _Graph = ListGraph, |
---|
| 1183 | typename _Visitor = DfsVisitor<_Graph>, |
---|
| 1184 | typename _Traits = DfsDefaultTraits<_Graph> > |
---|
| 1185 | #endif |
---|
| 1186 | class DfsVisit { |
---|
| 1187 | public: |
---|
| 1188 | |
---|
| 1189 | /// \brief \ref Exception for uninitialized parameters. |
---|
| 1190 | /// |
---|
| 1191 | /// This error represents problems in the initialization |
---|
| 1192 | /// of the parameters of the algorithms. |
---|
| 1193 | class UninitializedParameter : public lemon::UninitializedParameter { |
---|
| 1194 | public: |
---|
| 1195 | virtual const char* exceptionName() const { |
---|
| 1196 | return "lemon::DfsVisit::UninitializedParameter"; |
---|
| 1197 | } |
---|
| 1198 | }; |
---|
| 1199 | |
---|
| 1200 | typedef _Traits Traits; |
---|
| 1201 | |
---|
| 1202 | typedef typename Traits::Graph Graph; |
---|
| 1203 | |
---|
| 1204 | typedef _Visitor Visitor; |
---|
| 1205 | |
---|
| 1206 | ///The type of the map indicating which nodes are reached. |
---|
| 1207 | typedef typename Traits::ReachedMap ReachedMap; |
---|
| 1208 | |
---|
| 1209 | private: |
---|
| 1210 | |
---|
| 1211 | typedef typename Graph::Node Node; |
---|
| 1212 | typedef typename Graph::NodeIt NodeIt; |
---|
| 1213 | typedef typename Graph::Edge Edge; |
---|
| 1214 | typedef typename Graph::OutEdgeIt OutEdgeIt; |
---|
| 1215 | |
---|
| 1216 | /// Pointer to the underlying graph. |
---|
| 1217 | const Graph *_graph; |
---|
| 1218 | /// Pointer to the visitor object. |
---|
| 1219 | Visitor *_visitor; |
---|
| 1220 | ///Pointer to the map of reached status of the nodes. |
---|
| 1221 | ReachedMap *_reached; |
---|
| 1222 | ///Indicates if \ref _reached is locally allocated (\c true) or not. |
---|
| 1223 | bool local_reached; |
---|
| 1224 | |
---|
| 1225 | std::vector<typename Graph::Edge> _stack; |
---|
| 1226 | int _stack_head; |
---|
| 1227 | |
---|
| 1228 | /// \brief Creates the maps if necessary. |
---|
| 1229 | /// |
---|
| 1230 | /// Creates the maps if necessary. |
---|
| 1231 | void create_maps() { |
---|
| 1232 | if(!_reached) { |
---|
| 1233 | local_reached = true; |
---|
| 1234 | _reached = Traits::createReachedMap(*_graph); |
---|
| 1235 | } |
---|
| 1236 | } |
---|
| 1237 | |
---|
| 1238 | protected: |
---|
| 1239 | |
---|
| 1240 | DfsVisit() {} |
---|
| 1241 | |
---|
| 1242 | public: |
---|
| 1243 | |
---|
| 1244 | typedef DfsVisit Create; |
---|
| 1245 | |
---|
| 1246 | /// \name Named template parameters |
---|
| 1247 | |
---|
| 1248 | ///@{ |
---|
| 1249 | template <class T> |
---|
| 1250 | struct DefReachedMapTraits : public Traits { |
---|
| 1251 | typedef T ReachedMap; |
---|
| 1252 | static ReachedMap *createReachedMap(const Graph &graph) { |
---|
| 1253 | throw UninitializedParameter(); |
---|
| 1254 | } |
---|
| 1255 | }; |
---|
| 1256 | /// \brief \ref named-templ-param "Named parameter" for setting |
---|
| 1257 | /// ReachedMap type |
---|
| 1258 | /// |
---|
| 1259 | /// \ref named-templ-param "Named parameter" for setting ReachedMap type |
---|
| 1260 | template <class T> |
---|
[1773] | 1261 | struct DefReachedMap : public DfsVisit< Graph, Visitor, |
---|
| 1262 | DefReachedMapTraits<T> > { |
---|
| 1263 | typedef DfsVisit< Graph, Visitor, DefReachedMapTraits<T> > Create; |
---|
[1749] | 1264 | }; |
---|
| 1265 | ///@} |
---|
| 1266 | |
---|
| 1267 | public: |
---|
| 1268 | |
---|
| 1269 | /// \brief Constructor. |
---|
| 1270 | /// |
---|
| 1271 | /// Constructor. |
---|
| 1272 | /// |
---|
| 1273 | /// \param graph the graph the algorithm will run on. |
---|
| 1274 | /// \param visitor The visitor of the algorithm. |
---|
| 1275 | /// |
---|
| 1276 | DfsVisit(const Graph& graph, Visitor& visitor) |
---|
| 1277 | : _graph(&graph), _visitor(&visitor), |
---|
| 1278 | _reached(0), local_reached(false) {} |
---|
| 1279 | |
---|
| 1280 | /// \brief Destructor. |
---|
| 1281 | /// |
---|
| 1282 | /// Destructor. |
---|
| 1283 | ~DfsVisit() { |
---|
| 1284 | if(local_reached) delete _reached; |
---|
| 1285 | } |
---|
| 1286 | |
---|
| 1287 | /// \brief Sets the map indicating if a node is reached. |
---|
| 1288 | /// |
---|
| 1289 | /// Sets the map indicating if a node is reached. |
---|
| 1290 | /// If you don't use this function before calling \ref run(), |
---|
| 1291 | /// it will allocate one. The destuctor deallocates this |
---|
| 1292 | /// automatically allocated map, of course. |
---|
| 1293 | /// \return <tt> (*this) </tt> |
---|
| 1294 | DfsVisit &reachedMap(ReachedMap &m) { |
---|
| 1295 | if(local_reached) { |
---|
| 1296 | delete _reached; |
---|
| 1297 | local_reached=false; |
---|
| 1298 | } |
---|
| 1299 | _reached = &m; |
---|
| 1300 | return *this; |
---|
| 1301 | } |
---|
| 1302 | |
---|
| 1303 | public: |
---|
| 1304 | /// \name Execution control |
---|
| 1305 | /// The simplest way to execute the algorithm is to use |
---|
| 1306 | /// one of the member functions called \c run(...). |
---|
| 1307 | /// \n |
---|
| 1308 | /// If you need more control on the execution, |
---|
[1761] | 1309 | /// first you must call \ref init(), then you can adda source node |
---|
[1749] | 1310 | /// with \ref addSource(). |
---|
| 1311 | /// Finally \ref start() will perform the actual path |
---|
| 1312 | /// computation. |
---|
| 1313 | |
---|
| 1314 | /// @{ |
---|
| 1315 | /// \brief Initializes the internal data structures. |
---|
| 1316 | /// |
---|
| 1317 | /// Initializes the internal data structures. |
---|
| 1318 | /// |
---|
| 1319 | void init() { |
---|
| 1320 | create_maps(); |
---|
| 1321 | _stack.resize(countNodes(*_graph)); |
---|
| 1322 | _stack_head = -1; |
---|
| 1323 | for (NodeIt u(*_graph) ; u != INVALID ; ++u) { |
---|
| 1324 | _reached->set(u, false); |
---|
| 1325 | } |
---|
| 1326 | } |
---|
| 1327 | |
---|
| 1328 | /// \brief Adds a new source node. |
---|
| 1329 | /// |
---|
| 1330 | /// Adds a new source node to the set of nodes to be processed. |
---|
| 1331 | void addSource(Node s) { |
---|
| 1332 | if(!(*_reached)[s]) { |
---|
| 1333 | _reached->set(s,true); |
---|
| 1334 | _visitor->start(s); |
---|
| 1335 | _visitor->reach(s); |
---|
| 1336 | Edge e; |
---|
| 1337 | _graph->firstOut(e, s); |
---|
| 1338 | if (e != INVALID) { |
---|
| 1339 | _stack[++_stack_head] = e; |
---|
| 1340 | } else { |
---|
| 1341 | _visitor->leave(s); |
---|
| 1342 | } |
---|
| 1343 | } |
---|
| 1344 | } |
---|
| 1345 | |
---|
| 1346 | /// \brief Processes the next edge. |
---|
| 1347 | /// |
---|
| 1348 | /// Processes the next edge. |
---|
| 1349 | /// |
---|
| 1350 | /// \return The processed edge. |
---|
| 1351 | /// |
---|
| 1352 | /// \pre The stack must not be empty! |
---|
| 1353 | Edge processNextEdge() { |
---|
| 1354 | Edge e = _stack[_stack_head]; |
---|
| 1355 | Node m = _graph->target(e); |
---|
| 1356 | if(!(*_reached)[m]) { |
---|
| 1357 | _visitor->discover(e); |
---|
| 1358 | _visitor->reach(m); |
---|
| 1359 | _reached->set(m, true); |
---|
| 1360 | _graph->firstOut(_stack[++_stack_head], m); |
---|
| 1361 | } else { |
---|
| 1362 | _visitor->examine(e); |
---|
| 1363 | m = _graph->source(e); |
---|
| 1364 | _graph->nextOut(_stack[_stack_head]); |
---|
| 1365 | } |
---|
| 1366 | while (_stack_head>=0 && _stack[_stack_head] == INVALID) { |
---|
| 1367 | _visitor->leave(m); |
---|
| 1368 | --_stack_head; |
---|
| 1369 | if (_stack_head >= 0) { |
---|
| 1370 | _visitor->backtrack(_stack[_stack_head]); |
---|
| 1371 | m = _graph->source(_stack[_stack_head]); |
---|
| 1372 | _graph->nextOut(_stack[_stack_head]); |
---|
| 1373 | } else { |
---|
| 1374 | _visitor->stop(m); |
---|
| 1375 | } |
---|
| 1376 | } |
---|
| 1377 | return e; |
---|
| 1378 | } |
---|
| 1379 | |
---|
| 1380 | /// \brief Next edge to be processed. |
---|
| 1381 | /// |
---|
| 1382 | /// Next edge to be processed. |
---|
| 1383 | /// |
---|
| 1384 | /// \return The next edge to be processed or INVALID if the stack is |
---|
| 1385 | /// empty. |
---|
| 1386 | Edge nextEdge() { |
---|
| 1387 | return _stack_head >= 0 ? _stack[_stack_head] : INVALID; |
---|
| 1388 | } |
---|
| 1389 | |
---|
| 1390 | /// \brief Returns \c false if there are nodes |
---|
| 1391 | /// to be processed in the queue |
---|
| 1392 | /// |
---|
| 1393 | /// Returns \c false if there are nodes |
---|
| 1394 | /// to be processed in the queue |
---|
| 1395 | bool emptyQueue() { return _stack_head < 0; } |
---|
| 1396 | |
---|
| 1397 | /// \brief Returns the number of the nodes to be processed. |
---|
| 1398 | /// |
---|
| 1399 | /// Returns the number of the nodes to be processed in the queue. |
---|
| 1400 | int queueSize() { return _stack_head + 1; } |
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| 1401 | |
---|
| 1402 | /// \brief Executes the algorithm. |
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| 1403 | /// |
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| 1404 | /// Executes the algorithm. |
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| 1405 | /// |
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| 1406 | /// \pre init() must be called and at least one node should be added |
---|
| 1407 | /// with addSource() before using this function. |
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| 1408 | void start() { |
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| 1409 | while ( !emptyQueue() ) processNextEdge(); |
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| 1410 | } |
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| 1411 | |
---|
| 1412 | /// \brief Executes the algorithm until \c dest is reached. |
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| 1413 | /// |
---|
| 1414 | /// Executes the algorithm until \c dest is reached. |
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| 1415 | /// |
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| 1416 | /// \pre init() must be called and at least one node should be added |
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| 1417 | /// with addSource() before using this function. |
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| 1418 | void start(Node dest) { |
---|
| 1419 | while ( !emptyQueue() && _graph->target(_stack[_stack_head]) != dest) |
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| 1420 | processNextEdge(); |
---|
| 1421 | } |
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| 1422 | |
---|
| 1423 | /// \brief Executes the algorithm until a condition is met. |
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| 1424 | /// |
---|
| 1425 | /// Executes the algorithm until a condition is met. |
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| 1426 | /// |
---|
| 1427 | /// \pre init() must be called and at least one node should be added |
---|
| 1428 | /// with addSource() before using this function. |
---|
| 1429 | /// |
---|
| 1430 | /// \param nm must be a bool (or convertible) edge map. The algorithm |
---|
| 1431 | /// will stop when it reaches an edge \c e with <tt>nm[e]==true</tt>. |
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| 1432 | /// |
---|
| 1433 | /// \warning Contrary to \ref Dfs and \ref Dijkstra, \c em is an edge map, |
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| 1434 | /// not a node map. |
---|
| 1435 | template <typename EM> |
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| 1436 | void start(const EM &em) { |
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| 1437 | while (!emptyQueue() && !em[_stack[_stack_head]]) processNextEdge(); |
---|
| 1438 | } |
---|
| 1439 | |
---|
| 1440 | /// \brief Runs %DFS algorithm from node \c s. |
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| 1441 | /// |
---|
| 1442 | /// This method runs the %DFS algorithm from a root node \c s. |
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| 1443 | /// \note d.run(s) is just a shortcut of the following code. |
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| 1444 | /// \code |
---|
| 1445 | /// d.init(); |
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| 1446 | /// d.addSource(s); |
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| 1447 | /// d.start(); |
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| 1448 | /// \endcode |
---|
| 1449 | void run(Node s) { |
---|
| 1450 | init(); |
---|
| 1451 | addSource(s); |
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| 1452 | start(); |
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| 1453 | } |
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| 1454 | ///@} |
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| 1455 | |
---|
| 1456 | /// \name Query Functions |
---|
| 1457 | /// The result of the %DFS algorithm can be obtained using these |
---|
| 1458 | /// functions.\n |
---|
| 1459 | /// Before the use of these functions, |
---|
| 1460 | /// either run() or start() must be called. |
---|
| 1461 | ///@{ |
---|
| 1462 | /// \brief Checks if a node is reachable from the root. |
---|
| 1463 | /// |
---|
| 1464 | /// Returns \c true if \c v is reachable from the root(s). |
---|
| 1465 | /// \warning The source nodes are inditated as unreachable. |
---|
| 1466 | /// \pre Either \ref run() or \ref start() |
---|
| 1467 | /// must be called before using this function. |
---|
| 1468 | /// |
---|
| 1469 | bool reached(Node v) { return (*_reached)[v]; } |
---|
| 1470 | ///@} |
---|
| 1471 | }; |
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| 1472 | |
---|
| 1473 | |
---|
[921] | 1474 | } //END OF NAMESPACE LEMON |
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[780] | 1475 | |
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| 1476 | #endif |
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| 1477 | |
---|