[906] | 1 | /* -*- C++ -*- |
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[921] | 2 | * src/lemon/path.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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[819] | 16 | |
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| 17 | /** |
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| 18 | @defgroup paths Path Structures |
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| 19 | @ingroup datas |
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[921] | 20 | \brief Path structures implemented in LEMON. |
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[819] | 21 | |
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[921] | 22 | LEMON provides flexible data structures |
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[819] | 23 | to work with paths. |
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| 24 | |
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| 25 | All of them have the same interface, especially they can be built or extended |
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| 26 | using a standard Builder subclass. This make is easy to have e.g. the Dijkstra |
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| 27 | algorithm to store its result in any kind of path structure. |
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| 28 | |
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[959] | 29 | \sa lemon::concept::Path |
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[819] | 30 | |
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| 31 | */ |
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| 32 | |
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| 33 | ///\ingroup paths |
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| 34 | ///\file |
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| 35 | ///\brief Classes for representing paths in graphs. |
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[1151] | 36 | /// |
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| 37 | ///\todo Iterators have obsolete style |
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[819] | 38 | |
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[921] | 39 | #ifndef LEMON_PATH_H |
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| 40 | #define LEMON_PATH_H |
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[819] | 41 | |
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| 42 | #include <deque> |
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| 43 | #include <vector> |
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| 44 | #include <algorithm> |
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| 45 | |
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[921] | 46 | #include <lemon/invalid.h> |
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[819] | 47 | |
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[921] | 48 | namespace lemon { |
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[819] | 49 | |
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| 50 | /// \addtogroup paths |
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| 51 | /// @{ |
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| 52 | |
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| 53 | |
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| 54 | //! \brief A structure for representing directed paths in a graph. |
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| 55 | //! |
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| 56 | //! A structure for representing directed path in a graph. |
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| 57 | //! \param Graph The graph type in which the path is. |
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| 58 | //! \param DM DebugMode, defaults to DefaultDebugMode. |
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[837] | 59 | //! |
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[819] | 60 | //! In a sense, the path can be treated as a graph, for is has \c NodeIt |
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| 61 | //! and \c EdgeIt with the same usage. These types converts to the \c Node |
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| 62 | //! and \c Edge of the original graph. |
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| 63 | //! |
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| 64 | //! \todo Thoroughfully check all the range and consistency tests. |
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[831] | 65 | template<typename Graph> |
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[819] | 66 | class DirPath { |
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| 67 | public: |
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| 68 | /// Edge type of the underlying graph. |
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[837] | 69 | typedef typename Graph::Edge GraphEdge; |
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[819] | 70 | /// Node type of the underlying graph. |
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| 71 | typedef typename Graph::Node GraphNode; |
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| 72 | class NodeIt; |
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| 73 | class EdgeIt; |
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| 74 | |
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| 75 | protected: |
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| 76 | const Graph *gr; |
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| 77 | typedef std::vector<GraphEdge> Container; |
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| 78 | Container edges; |
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| 79 | |
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| 80 | public: |
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| 81 | |
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| 82 | /// \param _G The graph in which the path is. |
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| 83 | /// |
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| 84 | DirPath(const Graph &_G) : gr(&_G) {} |
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| 85 | |
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| 86 | /// \brief Subpath constructor. |
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| 87 | /// |
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| 88 | /// Subpath defined by two nodes. |
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| 89 | /// \warning It is an error if the two edges are not in order! |
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| 90 | DirPath(const DirPath &P, const NodeIt &a, const NodeIt &b) { |
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| 91 | gr = P.gr; |
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| 92 | edges.insert(edges.end(), P.edges.begin()+a.idx, P.edges.begin()+b.idx); |
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| 93 | } |
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| 94 | |
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| 95 | /// \brief Subpath constructor. |
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| 96 | /// |
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| 97 | /// Subpath defined by two edges. Contains edges in [a,b) |
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| 98 | /// \warning It is an error if the two edges are not in order! |
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| 99 | DirPath(const DirPath &P, const EdgeIt &a, const EdgeIt &b) { |
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| 100 | gr = P.gr; |
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| 101 | edges.insert(edges.end(), P.edges.begin()+a.idx, P.edges.begin()+b.idx); |
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| 102 | } |
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| 103 | |
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| 104 | /// Length of the path. |
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[1282] | 105 | int length() const { return edges.size(); } |
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[819] | 106 | /// Returns whether the path is empty. |
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| 107 | bool empty() const { return edges.empty(); } |
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| 108 | |
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| 109 | /// Resets the path to an empty path. |
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| 110 | void clear() { edges.clear(); } |
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| 111 | |
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| 112 | /// \brief Starting point of the path. |
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| 113 | /// |
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| 114 | /// Starting point of the path. |
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| 115 | /// Returns INVALID if the path is empty. |
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[986] | 116 | GraphNode source() const { |
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| 117 | return empty() ? INVALID : gr->source(edges[0]); |
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[819] | 118 | } |
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| 119 | /// \brief End point of the path. |
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| 120 | /// |
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| 121 | /// End point of the path. |
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| 122 | /// Returns INVALID if the path is empty. |
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[986] | 123 | GraphNode target() const { |
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| 124 | return empty() ? INVALID : gr->target(edges[length()-1]); |
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[819] | 125 | } |
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| 126 | |
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| 127 | /// \brief Initializes node or edge iterator to point to the first |
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| 128 | /// node or edge. |
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| 129 | /// |
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| 130 | /// \sa nth |
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| 131 | template<typename It> |
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| 132 | It& first(It &i) const { return i=It(*this); } |
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| 133 | |
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| 134 | /// \brief Initializes node iterator to point to the node of a given index. |
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| 135 | NodeIt& nth(NodeIt &i, int n) const { |
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| 136 | return i=NodeIt(*this, n); |
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| 137 | } |
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| 138 | |
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| 139 | /// \brief Initializes edge iterator to point to the edge of a given index. |
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| 140 | EdgeIt& nth(EdgeIt &i, int n) const { |
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| 141 | return i=EdgeIt(*this, n); |
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| 142 | } |
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| 143 | |
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[986] | 144 | /// \brief Returns node iterator pointing to the target node of the |
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[819] | 145 | /// given edge iterator. |
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[986] | 146 | NodeIt target(const EdgeIt& e) const { |
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[819] | 147 | return NodeIt(*this, e.idx+1); |
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| 148 | } |
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| 149 | |
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[986] | 150 | /// \brief Returns node iterator pointing to the source node of the |
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[819] | 151 | /// given edge iterator. |
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[986] | 152 | NodeIt source(const EdgeIt& e) const { |
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[819] | 153 | return NodeIt(*this, e.idx); |
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| 154 | } |
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| 155 | |
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| 156 | |
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| 157 | /* Iterator classes */ |
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| 158 | |
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| 159 | /** |
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| 160 | * \brief Iterator class to iterate on the edges of the paths |
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[837] | 161 | * |
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[819] | 162 | * This class is used to iterate on the edges of the paths |
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| 163 | * |
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| 164 | * Of course it converts to Graph::Edge |
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[837] | 165 | * |
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[819] | 166 | */ |
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| 167 | class EdgeIt { |
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| 168 | friend class DirPath; |
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| 169 | |
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| 170 | int idx; |
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| 171 | const DirPath *p; |
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| 172 | public: |
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| 173 | /// Default constructor |
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| 174 | EdgeIt() {} |
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| 175 | /// Invalid constructor |
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| 176 | EdgeIt(Invalid) : idx(-1), p(0) {} |
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| 177 | /// Constructor with starting point |
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| 178 | EdgeIt(const DirPath &_p, int _idx = 0) : |
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| 179 | idx(_idx), p(&_p) { validate(); } |
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| 180 | |
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| 181 | ///Validity check |
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| 182 | bool valid() const { return idx!=-1; } |
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| 183 | |
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| 184 | ///Conversion to Graph::Edge |
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| 185 | operator GraphEdge () const { |
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| 186 | return valid() ? p->edges[idx] : INVALID; |
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| 187 | } |
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| 188 | |
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| 189 | /// Next edge |
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| 190 | EdgeIt& operator++() { ++idx; validate(); return *this; } |
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| 191 | |
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| 192 | /// Comparison operator |
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| 193 | bool operator==(const EdgeIt& e) const { return idx==e.idx; } |
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| 194 | /// Comparison operator |
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| 195 | bool operator!=(const EdgeIt& e) const { return idx!=e.idx; } |
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| 196 | /// Comparison operator |
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| 197 | bool operator<(const EdgeIt& e) const { return idx<e.idx; } |
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| 198 | |
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| 199 | private: |
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[1282] | 200 | void validate() { if(idx >= p->length() ) idx=-1; } |
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[819] | 201 | }; |
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| 202 | |
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| 203 | /** |
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| 204 | * \brief Iterator class to iterate on the nodes of the paths |
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[837] | 205 | * |
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[819] | 206 | * This class is used to iterate on the nodes of the paths |
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| 207 | * |
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| 208 | * Of course it converts to Graph::Node |
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[837] | 209 | * |
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[819] | 210 | */ |
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| 211 | class NodeIt { |
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| 212 | friend class DirPath; |
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| 213 | |
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| 214 | int idx; |
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| 215 | const DirPath *p; |
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| 216 | public: |
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| 217 | /// Default constructor |
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| 218 | NodeIt() {} |
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| 219 | /// Invalid constructor |
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| 220 | NodeIt(Invalid) : idx(-1), p(0) {} |
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| 221 | /// Constructor with starting point |
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| 222 | NodeIt(const DirPath &_p, int _idx = 0) : |
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| 223 | idx(_idx), p(&_p) { validate(); } |
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| 224 | |
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| 225 | ///Validity check |
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| 226 | bool valid() const { return idx!=-1; } |
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| 227 | |
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| 228 | ///Conversion to Graph::Node |
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| 229 | operator const GraphNode& () const { |
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| 230 | if(idx >= p->length()) |
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[986] | 231 | return p->target(); |
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[819] | 232 | else if(idx >= 0) |
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[986] | 233 | return p->gr->source(p->edges[idx]); |
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[819] | 234 | else |
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| 235 | return INVALID; |
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| 236 | } |
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| 237 | /// Next node |
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| 238 | NodeIt& operator++() { ++idx; validate(); return *this; } |
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| 239 | |
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| 240 | /// Comparison operator |
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| 241 | bool operator==(const NodeIt& e) const { return idx==e.idx; } |
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| 242 | /// Comparison operator |
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| 243 | bool operator!=(const NodeIt& e) const { return idx!=e.idx; } |
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| 244 | /// Comparison operator |
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| 245 | bool operator<(const NodeIt& e) const { return idx<e.idx; } |
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| 246 | |
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| 247 | private: |
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[1282] | 248 | void validate() { if(idx > p->length() ) idx=-1; } |
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[819] | 249 | }; |
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| 250 | |
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[837] | 251 | friend class Builder; |
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[819] | 252 | |
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| 253 | /** |
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| 254 | * \brief Class to build paths |
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[837] | 255 | * |
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[819] | 256 | * This class is used to fill a path with edges. |
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| 257 | * |
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| 258 | * You can push new edges to the front and to the back of the path in |
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| 259 | * arbitrary order then you should commit these changes to the graph. |
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| 260 | * |
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| 261 | * Fundamentally, for most "Paths" (classes fulfilling the |
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| 262 | * PathConcept) while the builder is active (after the first modifying |
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| 263 | * operation and until the commit()) the original Path is in a |
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| 264 | * "transitional" state (operations on it have undefined result). But |
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| 265 | * in the case of DirPath the original path remains unchanged until the |
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| 266 | * commit. However we don't recomend that you use this feature. |
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| 267 | */ |
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| 268 | class Builder { |
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| 269 | DirPath &P; |
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| 270 | Container front, back; |
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| 271 | |
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| 272 | public: |
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[1228] | 273 | ///\param _p the path you want to fill in. |
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[819] | 274 | /// |
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[1228] | 275 | Builder(DirPath &_p) : P(_p) {} |
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[819] | 276 | |
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| 277 | /// Sets the starting node of the path. |
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[837] | 278 | |
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[819] | 279 | /// Sets the starting node of the path. Edge added to the path |
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| 280 | /// afterwards have to be incident to this node. |
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[900] | 281 | /// It should be called if and only if |
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| 282 | /// the path is empty and before any call to |
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[819] | 283 | /// \ref pushFront() or \ref pushBack() |
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| 284 | void setStartNode(const GraphNode &) {} |
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| 285 | |
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| 286 | ///Push a new edge to the front of the path |
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| 287 | |
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| 288 | ///Push a new edge to the front of the path. |
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| 289 | ///\sa setStartNode |
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| 290 | void pushFront(const GraphEdge& e) { |
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| 291 | front.push_back(e); |
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| 292 | } |
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| 293 | |
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| 294 | ///Push a new edge to the back of the path |
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| 295 | |
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| 296 | ///Push a new edge to the back of the path. |
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| 297 | ///\sa setStartNode |
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| 298 | void pushBack(const GraphEdge& e) { |
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| 299 | back.push_back(e); |
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| 300 | } |
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| 301 | |
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| 302 | ///Commit the changes to the path. |
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| 303 | void commit() { |
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[837] | 304 | if( !front.empty() || !back.empty() ) { |
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[819] | 305 | Container tmp; |
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| 306 | tmp.reserve(front.size()+back.size()+P.length()); |
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| 307 | tmp.insert(tmp.end(), front.rbegin(), front.rend()); |
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| 308 | tmp.insert(tmp.end(), P.edges.begin(), P.edges.end()); |
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| 309 | tmp.insert(tmp.end(), back.begin(), back.end()); |
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| 310 | P.edges.swap(tmp); |
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| 311 | front.clear(); |
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| 312 | back.clear(); |
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| 313 | } |
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| 314 | } |
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| 315 | |
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| 316 | ///Reserve storage for the builder in advance. |
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| 317 | |
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[837] | 318 | ///If you know a reasonable upper bound of the number of the edges |
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| 319 | ///to add to the front, using this function you can speed up the building. |
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[819] | 320 | |
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[837] | 321 | void reserveFront(size_t r) {front.reserve(r);} |
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| 322 | |
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| 323 | ///Reserve storage for the builder in advance. |
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| 324 | |
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| 325 | ///If you know a reasonable upper bound of the number of the edges |
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| 326 | ///to add to the back, using this function you can speed up the building. |
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| 327 | |
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| 328 | void reserveBack(size_t r) {back.reserve(r);} |
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[831] | 329 | |
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[819] | 330 | private: |
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| 331 | bool empty() { |
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| 332 | return front.empty() && back.empty() && P.empty(); |
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| 333 | } |
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| 334 | |
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[986] | 335 | GraphNode source() const { |
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[819] | 336 | if( ! front.empty() ) |
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[986] | 337 | return P.gr->source(front[front.size()-1]); |
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[819] | 338 | else if( ! P.empty() ) |
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[986] | 339 | return P.gr->source(P.edges[0]); |
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[819] | 340 | else if( ! back.empty() ) |
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[986] | 341 | return P.gr->source(back[0]); |
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[819] | 342 | else |
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| 343 | return INVALID; |
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| 344 | } |
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[986] | 345 | GraphNode target() const { |
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[819] | 346 | if( ! back.empty() ) |
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[986] | 347 | return P.gr->target(back[back.size()-1]); |
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[819] | 348 | else if( ! P.empty() ) |
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[986] | 349 | return P.gr->target(P.edges[P.length()-1]); |
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[819] | 350 | else if( ! front.empty() ) |
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[986] | 351 | return P.gr->target(front[0]); |
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[819] | 352 | else |
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| 353 | return INVALID; |
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| 354 | } |
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| 355 | |
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| 356 | }; |
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| 357 | |
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| 358 | }; |
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| 359 | |
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| 360 | |
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| 361 | |
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| 362 | |
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| 363 | |
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| 364 | |
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| 365 | |
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| 366 | |
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| 367 | |
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| 368 | |
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| 369 | /**********************************************************************/ |
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| 370 | |
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| 371 | |
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| 372 | //! \brief A structure for representing undirected path in a graph. |
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| 373 | //! |
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| 374 | //! A structure for representing undirected path in a graph. Ie. this is |
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| 375 | //! a path in a \e directed graph but the edges should not be directed |
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| 376 | //! forward. |
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| 377 | //! |
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| 378 | //! \param Graph The graph type in which the path is. |
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| 379 | //! \param DM DebugMode, defaults to DefaultDebugMode. |
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[837] | 380 | //! |
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[819] | 381 | //! In a sense, the path can be treated as a graph, for is has \c NodeIt |
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| 382 | //! and \c EdgeIt with the same usage. These types converts to the \c Node |
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| 383 | //! and \c Edge of the original graph. |
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| 384 | //! |
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| 385 | //! \todo Thoroughfully check all the range and consistency tests. |
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[831] | 386 | template<typename Graph> |
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[819] | 387 | class UndirPath { |
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| 388 | public: |
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| 389 | /// Edge type of the underlying graph. |
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| 390 | typedef typename Graph::Edge GraphEdge; |
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| 391 | /// Node type of the underlying graph. |
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| 392 | typedef typename Graph::Node GraphNode; |
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| 393 | class NodeIt; |
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| 394 | class EdgeIt; |
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| 395 | |
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| 396 | protected: |
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| 397 | const Graph *gr; |
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| 398 | typedef std::vector<GraphEdge> Container; |
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| 399 | Container edges; |
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| 400 | |
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| 401 | public: |
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| 402 | |
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| 403 | /// \param _G The graph in which the path is. |
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| 404 | /// |
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| 405 | UndirPath(const Graph &_G) : gr(&_G) {} |
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| 406 | |
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| 407 | /// \brief Subpath constructor. |
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| 408 | /// |
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| 409 | /// Subpath defined by two nodes. |
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| 410 | /// \warning It is an error if the two edges are not in order! |
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| 411 | UndirPath(const UndirPath &P, const NodeIt &a, const NodeIt &b) { |
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| 412 | gr = P.gr; |
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| 413 | edges.insert(edges.end(), P.edges.begin()+a.idx, P.edges.begin()+b.idx); |
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| 414 | } |
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| 415 | |
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| 416 | /// \brief Subpath constructor. |
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| 417 | /// |
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| 418 | /// Subpath defined by two edges. Contains edges in [a,b) |
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| 419 | /// \warning It is an error if the two edges are not in order! |
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| 420 | UndirPath(const UndirPath &P, const EdgeIt &a, const EdgeIt &b) { |
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| 421 | gr = P.gr; |
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| 422 | edges.insert(edges.end(), P.edges.begin()+a.idx, P.edges.begin()+b.idx); |
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| 423 | } |
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| 424 | |
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| 425 | /// Length of the path. |
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| 426 | size_t length() const { return edges.size(); } |
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| 427 | /// Returns whether the path is empty. |
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| 428 | bool empty() const { return edges.empty(); } |
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| 429 | |
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| 430 | /// Resets the path to an empty path. |
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| 431 | void clear() { edges.clear(); } |
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| 432 | |
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| 433 | /// \brief Starting point of the path. |
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| 434 | /// |
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| 435 | /// Starting point of the path. |
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| 436 | /// Returns INVALID if the path is empty. |
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[986] | 437 | GraphNode source() const { |
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| 438 | return empty() ? INVALID : gr->source(edges[0]); |
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[819] | 439 | } |
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| 440 | /// \brief End point of the path. |
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| 441 | /// |
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| 442 | /// End point of the path. |
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| 443 | /// Returns INVALID if the path is empty. |
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[986] | 444 | GraphNode target() const { |
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| 445 | return empty() ? INVALID : gr->target(edges[length()-1]); |
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[819] | 446 | } |
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| 447 | |
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| 448 | /// \brief Initializes node or edge iterator to point to the first |
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| 449 | /// node or edge. |
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| 450 | /// |
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| 451 | /// \sa nth |
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| 452 | template<typename It> |
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| 453 | It& first(It &i) const { return i=It(*this); } |
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| 454 | |
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| 455 | /// \brief Initializes node iterator to point to the node of a given index. |
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| 456 | NodeIt& nth(NodeIt &i, int n) const { |
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| 457 | return i=NodeIt(*this, n); |
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| 458 | } |
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| 459 | |
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| 460 | /// \brief Initializes edge iterator to point to the edge of a given index. |
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| 461 | EdgeIt& nth(EdgeIt &i, int n) const { |
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| 462 | return i=EdgeIt(*this, n); |
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| 463 | } |
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| 464 | |
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| 465 | /// Checks validity of a node or edge iterator. |
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| 466 | template<typename It> |
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| 467 | static |
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| 468 | bool valid(const It &i) { return i.valid(); } |
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| 469 | |
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| 470 | /// Steps the given node or edge iterator. |
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| 471 | template<typename It> |
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| 472 | static |
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| 473 | It& next(It &e) { |
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| 474 | return ++e; |
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| 475 | } |
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| 476 | |
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[986] | 477 | /// \brief Returns node iterator pointing to the target node of the |
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[819] | 478 | /// given edge iterator. |
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[986] | 479 | NodeIt target(const EdgeIt& e) const { |
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[819] | 480 | return NodeIt(*this, e.idx+1); |
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| 481 | } |
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| 482 | |
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[986] | 483 | /// \brief Returns node iterator pointing to the source node of the |
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[819] | 484 | /// given edge iterator. |
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[986] | 485 | NodeIt source(const EdgeIt& e) const { |
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[819] | 486 | return NodeIt(*this, e.idx); |
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| 487 | } |
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| 488 | |
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| 489 | |
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| 490 | |
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| 491 | /** |
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| 492 | * \brief Iterator class to iterate on the edges of the paths |
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[837] | 493 | * |
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[819] | 494 | * This class is used to iterate on the edges of the paths |
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| 495 | * |
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| 496 | * Of course it converts to Graph::Edge |
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[837] | 497 | * |
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[819] | 498 | * \todo Its interface differs from the standard edge iterator. |
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| 499 | * Yes, it shouldn't. |
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| 500 | */ |
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| 501 | class EdgeIt { |
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| 502 | friend class UndirPath; |
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| 503 | |
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| 504 | int idx; |
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| 505 | const UndirPath *p; |
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| 506 | public: |
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| 507 | /// Default constructor |
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| 508 | EdgeIt() {} |
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| 509 | /// Invalid constructor |
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| 510 | EdgeIt(Invalid) : idx(-1), p(0) {} |
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| 511 | /// Constructor with starting point |
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| 512 | EdgeIt(const UndirPath &_p, int _idx = 0) : |
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| 513 | idx(_idx), p(&_p) { validate(); } |
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| 514 | |
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| 515 | ///Validity check |
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| 516 | bool valid() const { return idx!=-1; } |
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| 517 | |
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| 518 | ///Conversion to Graph::Edge |
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| 519 | operator GraphEdge () const { |
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| 520 | return valid() ? p->edges[idx] : INVALID; |
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| 521 | } |
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| 522 | /// Next edge |
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| 523 | EdgeIt& operator++() { ++idx; validate(); return *this; } |
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| 524 | |
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| 525 | /// Comparison operator |
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| 526 | bool operator==(const EdgeIt& e) const { return idx==e.idx; } |
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| 527 | /// Comparison operator |
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| 528 | bool operator!=(const EdgeIt& e) const { return idx!=e.idx; } |
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| 529 | /// Comparison operator |
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| 530 | bool operator<(const EdgeIt& e) const { return idx<e.idx; } |
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| 531 | |
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| 532 | private: |
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| 533 | // FIXME: comparison between signed and unsigned... |
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| 534 | // Jo ez igy? Vagy esetleg legyen a length() int? |
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| 535 | void validate() { if( size_t(idx) >= p->length() ) idx=-1; } |
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| 536 | }; |
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| 537 | |
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| 538 | /** |
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| 539 | * \brief Iterator class to iterate on the nodes of the paths |
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[837] | 540 | * |
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[819] | 541 | * This class is used to iterate on the nodes of the paths |
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| 542 | * |
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| 543 | * Of course it converts to Graph::Node |
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[837] | 544 | * |
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[819] | 545 | * \todo Its interface differs from the standard node iterator. |
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| 546 | * Yes, it shouldn't. |
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| 547 | */ |
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| 548 | class NodeIt { |
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| 549 | friend class UndirPath; |
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| 550 | |
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| 551 | int idx; |
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| 552 | const UndirPath *p; |
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| 553 | public: |
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| 554 | /// Default constructor |
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| 555 | NodeIt() {} |
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| 556 | /// Invalid constructor |
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| 557 | NodeIt(Invalid) : idx(-1), p(0) {} |
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| 558 | /// Constructor with starting point |
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| 559 | NodeIt(const UndirPath &_p, int _idx = 0) : |
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| 560 | idx(_idx), p(&_p) { validate(); } |
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| 561 | |
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| 562 | ///Validity check |
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| 563 | bool valid() const { return idx!=-1; } |
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| 564 | |
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| 565 | ///Conversion to Graph::Node |
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| 566 | operator const GraphNode& () const { |
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| 567 | if(idx >= p->length()) |
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[986] | 568 | return p->target(); |
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[819] | 569 | else if(idx >= 0) |
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[986] | 570 | return p->gr->source(p->edges[idx]); |
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[819] | 571 | else |
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| 572 | return INVALID; |
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| 573 | } |
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| 574 | /// Next node |
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| 575 | NodeIt& operator++() { ++idx; validate(); return *this; } |
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| 576 | |
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| 577 | /// Comparison operator |
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| 578 | bool operator==(const NodeIt& e) const { return idx==e.idx; } |
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| 579 | /// Comparison operator |
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| 580 | bool operator!=(const NodeIt& e) const { return idx!=e.idx; } |
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| 581 | /// Comparison operator |
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| 582 | bool operator<(const NodeIt& e) const { return idx<e.idx; } |
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| 583 | |
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| 584 | private: |
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| 585 | void validate() { if( size_t(idx) > p->length() ) idx=-1; } |
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| 586 | }; |
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| 587 | |
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[837] | 588 | friend class Builder; |
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[819] | 589 | |
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| 590 | /** |
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| 591 | * \brief Class to build paths |
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[837] | 592 | * |
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[819] | 593 | * This class is used to fill a path with edges. |
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| 594 | * |
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| 595 | * You can push new edges to the front and to the back of the path in |
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| 596 | * arbitrary order then you should commit these changes to the graph. |
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| 597 | * |
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| 598 | * Fundamentally, for most "Paths" (classes fulfilling the |
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| 599 | * PathConcept) while the builder is active (after the first modifying |
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| 600 | * operation and until the commit()) the original Path is in a |
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| 601 | * "transitional" state (operations ot it have undefined result). But |
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| 602 | * in the case of UndirPath the original path is unchanged until the |
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| 603 | * commit. However we don't recomend that you use this feature. |
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| 604 | */ |
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| 605 | class Builder { |
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| 606 | UndirPath &P; |
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| 607 | Container front, back; |
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| 608 | |
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| 609 | public: |
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[1228] | 610 | ///\param _p the path you want to fill in. |
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[819] | 611 | /// |
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[1228] | 612 | Builder(UndirPath &_p) : P(_p) {} |
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[819] | 613 | |
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| 614 | /// Sets the starting node of the path. |
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[837] | 615 | |
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[819] | 616 | /// Sets the starting node of the path. Edge added to the path |
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| 617 | /// afterwards have to be incident to this node. |
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[900] | 618 | /// It should be called if and only if |
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| 619 | /// the path is empty and before any call to |
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[819] | 620 | /// \ref pushFront() or \ref pushBack() |
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| 621 | void setStartNode(const GraphNode &) {} |
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| 622 | |
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| 623 | ///Push a new edge to the front of the path |
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| 624 | |
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| 625 | ///Push a new edge to the front of the path. |
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| 626 | ///\sa setStartNode |
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| 627 | void pushFront(const GraphEdge& e) { |
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| 628 | front.push_back(e); |
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| 629 | } |
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| 630 | |
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| 631 | ///Push a new edge to the back of the path |
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| 632 | |
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| 633 | ///Push a new edge to the back of the path. |
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| 634 | ///\sa setStartNode |
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| 635 | void pushBack(const GraphEdge& e) { |
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| 636 | back.push_back(e); |
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| 637 | } |
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| 638 | |
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| 639 | ///Commit the changes to the path. |
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| 640 | void commit() { |
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| 641 | if( !(front.empty() && back.empty()) ) { |
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| 642 | Container tmp; |
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| 643 | tmp.reserve(front.size()+back.size()+P.length()); |
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| 644 | tmp.insert(tmp.end(), front.rbegin(), front.rend()); |
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| 645 | tmp.insert(tmp.end(), P.edges.begin(), P.edges.end()); |
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| 646 | tmp.insert(tmp.end(), back.begin(), back.end()); |
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| 647 | P.edges.swap(tmp); |
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| 648 | front.clear(); |
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| 649 | back.clear(); |
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| 650 | } |
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| 651 | } |
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| 652 | |
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| 653 | |
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| 654 | ///Reserve storage for the builder in advance. |
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| 655 | |
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[837] | 656 | ///If you know a reasonable upper bound of the number of the edges |
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| 657 | ///to add to the front, using this function you can speed up the building. |
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[819] | 658 | |
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[837] | 659 | void reserveFront(size_t r) {front.reserve(r);} |
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| 660 | |
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| 661 | ///Reserve storage for the builder in advance. |
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| 662 | |
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| 663 | ///If you know a reasonable upper bound of the number of the edges |
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| 664 | ///to add to the back, using this function you can speed up the building. |
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| 665 | |
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| 666 | void reserveBack(size_t r) {back.reserve(r);} |
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[831] | 667 | |
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[819] | 668 | private: |
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| 669 | bool empty() { |
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| 670 | return front.empty() && back.empty() && P.empty(); |
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| 671 | } |
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| 672 | |
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[986] | 673 | GraphNode source() const { |
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[819] | 674 | if( ! front.empty() ) |
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[986] | 675 | return P.gr->source(front[front.size()-1]); |
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[819] | 676 | else if( ! P.empty() ) |
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[986] | 677 | return P.gr->source(P.edges[0]); |
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[819] | 678 | else if( ! back.empty() ) |
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[986] | 679 | return P.gr->source(back[0]); |
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[819] | 680 | else |
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| 681 | return INVALID; |
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| 682 | } |
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[986] | 683 | GraphNode target() const { |
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[819] | 684 | if( ! back.empty() ) |
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[986] | 685 | return P.gr->target(back[back.size()-1]); |
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[819] | 686 | else if( ! P.empty() ) |
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[986] | 687 | return P.gr->target(P.edges[P.length()-1]); |
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[819] | 688 | else if( ! front.empty() ) |
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[986] | 689 | return P.gr->target(front[0]); |
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[819] | 690 | else |
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| 691 | return INVALID; |
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| 692 | } |
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| 693 | |
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| 694 | }; |
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| 695 | |
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| 696 | }; |
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| 697 | |
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| 698 | |
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| 699 | ///@} |
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| 700 | |
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[921] | 701 | } // namespace lemon |
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[819] | 702 | |
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[921] | 703 | #endif // LEMON_PATH_H |
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