[906] | 1 | /* -*- C++ -*- |
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| 2 | * |
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[1956] | 3 | * This file is a part of LEMON, a generic C++ optimization library |
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| 4 | * |
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| 5 | * Copyright (C) 2003-2006 |
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| 6 | * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
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[1359] | 7 | * (Egervary Research Group on Combinatorial Optimization, EGRES). |
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[906] | 8 | * |
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| 9 | * Permission to use, modify and distribute this software is granted |
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| 10 | * provided that this copyright notice appears in all copies. For |
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| 11 | * precise terms see the accompanying LICENSE file. |
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| 12 | * |
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| 13 | * This software is provided "AS IS" with no warranty of any kind, |
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| 14 | * express or implied, and with no claim as to its suitability for any |
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| 15 | * purpose. |
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| 16 | * |
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| 17 | */ |
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[819] | 18 | |
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| 19 | /** |
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| 20 | @defgroup paths Path Structures |
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| 21 | @ingroup datas |
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[921] | 22 | \brief Path structures implemented in LEMON. |
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[819] | 23 | |
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[921] | 24 | LEMON provides flexible data structures |
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[819] | 25 | to work with paths. |
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| 26 | |
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| 27 | All of them have the same interface, especially they can be built or extended |
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| 28 | using a standard Builder subclass. This make is easy to have e.g. the Dijkstra |
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| 29 | algorithm to store its result in any kind of path structure. |
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| 30 | |
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[959] | 31 | \sa lemon::concept::Path |
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[819] | 32 | |
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| 33 | */ |
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| 34 | |
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| 35 | ///\ingroup paths |
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| 36 | ///\file |
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| 37 | ///\brief Classes for representing paths in graphs. |
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[1151] | 38 | /// |
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| 39 | ///\todo Iterators have obsolete style |
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[819] | 40 | |
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[921] | 41 | #ifndef LEMON_PATH_H |
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| 42 | #define LEMON_PATH_H |
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[819] | 43 | |
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| 44 | #include <deque> |
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| 45 | #include <vector> |
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| 46 | #include <algorithm> |
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| 47 | |
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[921] | 48 | #include <lemon/invalid.h> |
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[819] | 49 | |
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[921] | 50 | namespace lemon { |
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[819] | 51 | |
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| 52 | /// \addtogroup paths |
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| 53 | /// @{ |
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| 54 | |
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| 55 | |
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| 56 | //! \brief A structure for representing directed paths in a graph. |
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| 57 | //! |
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| 58 | //! A structure for representing directed path in a graph. |
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| 59 | //! \param Graph The graph type in which the path is. |
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| 60 | //! \param DM DebugMode, defaults to DefaultDebugMode. |
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[837] | 61 | //! |
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[819] | 62 | //! In a sense, the path can be treated as a graph, for is has \c NodeIt |
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| 63 | //! and \c EdgeIt with the same usage. These types converts to the \c Node |
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| 64 | //! and \c Edge of the original graph. |
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| 65 | //! |
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| 66 | //! \todo Thoroughfully check all the range and consistency tests. |
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[831] | 67 | template<typename Graph> |
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[819] | 68 | class DirPath { |
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| 69 | public: |
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| 70 | /// Edge type of the underlying graph. |
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[837] | 71 | typedef typename Graph::Edge GraphEdge; |
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[819] | 72 | /// Node type of the underlying graph. |
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| 73 | typedef typename Graph::Node GraphNode; |
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| 74 | class NodeIt; |
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| 75 | class EdgeIt; |
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| 76 | |
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| 77 | protected: |
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| 78 | const Graph *gr; |
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| 79 | typedef std::vector<GraphEdge> Container; |
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| 80 | Container edges; |
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| 81 | |
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| 82 | public: |
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| 83 | |
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| 84 | /// \param _G The graph in which the path is. |
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| 85 | /// |
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| 86 | DirPath(const Graph &_G) : gr(&_G) {} |
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| 87 | |
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| 88 | /// \brief Subpath constructor. |
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| 89 | /// |
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| 90 | /// Subpath defined by two nodes. |
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| 91 | /// \warning It is an error if the two edges are not in order! |
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| 92 | DirPath(const DirPath &P, const NodeIt &a, const NodeIt &b) { |
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| 93 | gr = P.gr; |
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| 94 | edges.insert(edges.end(), P.edges.begin()+a.idx, P.edges.begin()+b.idx); |
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| 95 | } |
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| 96 | |
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| 97 | /// \brief Subpath constructor. |
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| 98 | /// |
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| 99 | /// Subpath defined by two edges. Contains edges in [a,b) |
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| 100 | /// \warning It is an error if the two edges are not in order! |
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| 101 | DirPath(const DirPath &P, const EdgeIt &a, const EdgeIt &b) { |
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| 102 | gr = P.gr; |
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| 103 | edges.insert(edges.end(), P.edges.begin()+a.idx, P.edges.begin()+b.idx); |
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| 104 | } |
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| 105 | |
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| 106 | /// Length of the path. |
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[1282] | 107 | int length() const { return edges.size(); } |
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[819] | 108 | /// Returns whether the path is empty. |
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| 109 | bool empty() const { return edges.empty(); } |
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| 110 | |
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| 111 | /// Resets the path to an empty path. |
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| 112 | void clear() { edges.clear(); } |
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| 113 | |
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| 114 | /// \brief Starting point of the path. |
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| 115 | /// |
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| 116 | /// Starting point of the path. |
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| 117 | /// Returns INVALID if the path is empty. |
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[986] | 118 | GraphNode source() const { |
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| 119 | return empty() ? INVALID : gr->source(edges[0]); |
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[819] | 120 | } |
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| 121 | /// \brief End point of the path. |
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| 122 | /// |
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| 123 | /// End point of the path. |
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| 124 | /// Returns INVALID if the path is empty. |
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[986] | 125 | GraphNode target() const { |
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| 126 | return empty() ? INVALID : gr->target(edges[length()-1]); |
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[819] | 127 | } |
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| 128 | |
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| 129 | /// \brief Initializes node or edge iterator to point to the first |
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| 130 | /// node or edge. |
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| 131 | /// |
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| 132 | /// \sa nth |
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| 133 | template<typename It> |
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| 134 | It& first(It &i) const { return i=It(*this); } |
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| 135 | |
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| 136 | /// \brief Initializes node iterator to point to the node of a given index. |
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| 137 | NodeIt& nth(NodeIt &i, int n) const { |
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| 138 | return i=NodeIt(*this, n); |
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| 139 | } |
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| 140 | |
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| 141 | /// \brief Initializes edge iterator to point to the edge of a given index. |
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| 142 | EdgeIt& nth(EdgeIt &i, int n) const { |
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| 143 | return i=EdgeIt(*this, n); |
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| 144 | } |
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| 145 | |
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[986] | 146 | /// \brief Returns node iterator pointing to the target node of the |
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[819] | 147 | /// given edge iterator. |
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[986] | 148 | NodeIt target(const EdgeIt& e) const { |
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[819] | 149 | return NodeIt(*this, e.idx+1); |
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| 150 | } |
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| 151 | |
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[986] | 152 | /// \brief Returns node iterator pointing to the source node of the |
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[819] | 153 | /// given edge iterator. |
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[986] | 154 | NodeIt source(const EdgeIt& e) const { |
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[819] | 155 | return NodeIt(*this, e.idx); |
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| 156 | } |
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| 157 | |
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| 158 | |
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| 159 | /* Iterator classes */ |
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| 160 | |
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| 161 | /** |
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| 162 | * \brief Iterator class to iterate on the edges of the paths |
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[837] | 163 | * |
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[819] | 164 | * This class is used to iterate on the edges of the paths |
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| 165 | * |
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| 166 | * Of course it converts to Graph::Edge |
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[837] | 167 | * |
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[819] | 168 | */ |
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| 169 | class EdgeIt { |
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| 170 | friend class DirPath; |
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| 171 | |
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| 172 | int idx; |
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| 173 | const DirPath *p; |
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| 174 | public: |
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| 175 | /// Default constructor |
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| 176 | EdgeIt() {} |
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| 177 | /// Invalid constructor |
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| 178 | EdgeIt(Invalid) : idx(-1), p(0) {} |
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| 179 | /// Constructor with starting point |
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| 180 | EdgeIt(const DirPath &_p, int _idx = 0) : |
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| 181 | idx(_idx), p(&_p) { validate(); } |
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| 182 | |
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| 183 | ///Validity check |
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| 184 | bool valid() const { return idx!=-1; } |
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| 185 | |
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| 186 | ///Conversion to Graph::Edge |
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| 187 | operator GraphEdge () const { |
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| 188 | return valid() ? p->edges[idx] : INVALID; |
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| 189 | } |
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| 190 | |
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| 191 | /// Next edge |
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| 192 | EdgeIt& operator++() { ++idx; validate(); return *this; } |
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| 193 | |
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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 | /// Comparison operator |
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| 199 | bool operator<(const EdgeIt& e) const { return idx<e.idx; } |
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| 200 | |
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| 201 | private: |
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[1282] | 202 | void validate() { if(idx >= p->length() ) idx=-1; } |
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[819] | 203 | }; |
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| 204 | |
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| 205 | /** |
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| 206 | * \brief Iterator class to iterate on the nodes of the paths |
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[837] | 207 | * |
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[819] | 208 | * This class is used to iterate on the nodes of the paths |
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| 209 | * |
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| 210 | * Of course it converts to Graph::Node |
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[837] | 211 | * |
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[819] | 212 | */ |
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| 213 | class NodeIt { |
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| 214 | friend class DirPath; |
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| 215 | |
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| 216 | int idx; |
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| 217 | const DirPath *p; |
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| 218 | public: |
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| 219 | /// Default constructor |
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| 220 | NodeIt() {} |
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| 221 | /// Invalid constructor |
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| 222 | NodeIt(Invalid) : idx(-1), p(0) {} |
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| 223 | /// Constructor with starting point |
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| 224 | NodeIt(const DirPath &_p, int _idx = 0) : |
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| 225 | idx(_idx), p(&_p) { validate(); } |
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| 226 | |
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| 227 | ///Validity check |
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| 228 | bool valid() const { return idx!=-1; } |
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| 229 | |
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| 230 | ///Conversion to Graph::Node |
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| 231 | operator const GraphNode& () const { |
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| 232 | if(idx >= p->length()) |
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[986] | 233 | return p->target(); |
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[819] | 234 | else if(idx >= 0) |
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[986] | 235 | return p->gr->source(p->edges[idx]); |
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[819] | 236 | else |
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| 237 | return INVALID; |
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| 238 | } |
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| 239 | /// Next node |
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| 240 | NodeIt& operator++() { ++idx; validate(); return *this; } |
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| 241 | |
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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 | /// Comparison operator |
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| 247 | bool operator<(const NodeIt& e) const { return idx<e.idx; } |
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| 248 | |
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| 249 | private: |
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[1282] | 250 | void validate() { if(idx > p->length() ) idx=-1; } |
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[819] | 251 | }; |
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| 252 | |
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[837] | 253 | friend class Builder; |
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[819] | 254 | |
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| 255 | /** |
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| 256 | * \brief Class to build paths |
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[837] | 257 | * |
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[819] | 258 | * This class is used to fill a path with edges. |
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| 259 | * |
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| 260 | * You can push new edges to the front and to the back of the path in |
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| 261 | * arbitrary order then you should commit these changes to the graph. |
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| 262 | * |
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| 263 | * Fundamentally, for most "Paths" (classes fulfilling the |
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| 264 | * PathConcept) while the builder is active (after the first modifying |
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| 265 | * operation and until the commit()) the original Path is in a |
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| 266 | * "transitional" state (operations on it have undefined result). But |
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| 267 | * in the case of DirPath the original path remains unchanged until the |
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| 268 | * commit. However we don't recomend that you use this feature. |
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| 269 | */ |
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| 270 | class Builder { |
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| 271 | DirPath &P; |
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| 272 | Container front, back; |
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| 273 | |
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| 274 | public: |
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[1228] | 275 | ///\param _p the path you want to fill in. |
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[819] | 276 | /// |
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[1228] | 277 | Builder(DirPath &_p) : P(_p) {} |
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[819] | 278 | |
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| 279 | /// Sets the starting node of the path. |
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[837] | 280 | |
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[819] | 281 | /// Sets the starting node of the path. Edge added to the path |
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| 282 | /// afterwards have to be incident to this node. |
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[900] | 283 | /// It should be called if and only if |
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| 284 | /// the path is empty and before any call to |
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[819] | 285 | /// \ref pushFront() or \ref pushBack() |
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| 286 | void setStartNode(const GraphNode &) {} |
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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 | |
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| 290 | ///Push a new edge to the front of the path. |
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| 291 | ///\sa setStartNode |
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| 292 | void pushFront(const GraphEdge& e) { |
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| 293 | front.push_back(e); |
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| 294 | } |
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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 | |
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| 298 | ///Push a new edge to the back of the path. |
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| 299 | ///\sa setStartNode |
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| 300 | void pushBack(const GraphEdge& e) { |
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| 301 | back.push_back(e); |
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| 302 | } |
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| 303 | |
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| 304 | ///Commit the changes to the path. |
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| 305 | void commit() { |
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[837] | 306 | if( !front.empty() || !back.empty() ) { |
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[819] | 307 | Container tmp; |
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| 308 | tmp.reserve(front.size()+back.size()+P.length()); |
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| 309 | tmp.insert(tmp.end(), front.rbegin(), front.rend()); |
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| 310 | tmp.insert(tmp.end(), P.edges.begin(), P.edges.end()); |
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| 311 | tmp.insert(tmp.end(), back.begin(), back.end()); |
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| 312 | P.edges.swap(tmp); |
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| 313 | front.clear(); |
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| 314 | back.clear(); |
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| 315 | } |
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| 316 | } |
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| 317 | |
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| 318 | ///Reserve storage for the builder in advance. |
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| 319 | |
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[837] | 320 | ///If you know a reasonable upper bound of the number of the edges |
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| 321 | ///to add to the front, using this function you can speed up the building. |
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[819] | 322 | |
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[837] | 323 | void reserveFront(size_t r) {front.reserve(r);} |
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| 324 | |
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| 325 | ///Reserve storage for the builder in advance. |
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| 326 | |
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| 327 | ///If you know a reasonable upper bound of the number of the edges |
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| 328 | ///to add to the back, using this function you can speed up the building. |
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| 329 | |
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| 330 | void reserveBack(size_t r) {back.reserve(r);} |
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[831] | 331 | |
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[819] | 332 | private: |
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| 333 | bool empty() { |
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| 334 | return front.empty() && back.empty() && P.empty(); |
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| 335 | } |
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| 336 | |
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[986] | 337 | GraphNode source() const { |
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[819] | 338 | if( ! front.empty() ) |
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[986] | 339 | return P.gr->source(front[front.size()-1]); |
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[819] | 340 | else if( ! P.empty() ) |
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[986] | 341 | return P.gr->source(P.edges[0]); |
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[819] | 342 | else if( ! back.empty() ) |
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[986] | 343 | return P.gr->source(back[0]); |
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[819] | 344 | else |
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| 345 | return INVALID; |
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| 346 | } |
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[986] | 347 | GraphNode target() const { |
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[819] | 348 | if( ! back.empty() ) |
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[986] | 349 | return P.gr->target(back[back.size()-1]); |
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[819] | 350 | else if( ! P.empty() ) |
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[986] | 351 | return P.gr->target(P.edges[P.length()-1]); |
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[819] | 352 | else if( ! front.empty() ) |
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[986] | 353 | return P.gr->target(front[0]); |
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[819] | 354 | else |
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| 355 | return INVALID; |
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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 | |
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| 373 | |
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| 374 | //! \brief A structure for representing undirected path in a graph. |
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| 375 | //! |
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| 376 | //! A structure for representing undirected path in a graph. Ie. this is |
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| 377 | //! a path in a \e directed graph but the edges should not be directed |
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| 378 | //! forward. |
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| 379 | //! |
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| 380 | //! \param Graph The graph type in which the path is. |
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| 381 | //! \param DM DebugMode, defaults to DefaultDebugMode. |
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[837] | 382 | //! |
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[819] | 383 | //! In a sense, the path can be treated as a graph, for is has \c NodeIt |
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| 384 | //! and \c EdgeIt with the same usage. These types converts to the \c Node |
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| 385 | //! and \c Edge of the original graph. |
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| 386 | //! |
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| 387 | //! \todo Thoroughfully check all the range and consistency tests. |
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[1730] | 388 | /// \todo May we need just path for undirected graph instead of this. |
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[831] | 389 | template<typename Graph> |
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[1909] | 390 | class UPath { |
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[819] | 391 | public: |
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| 392 | /// Edge type of the underlying graph. |
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| 393 | typedef typename Graph::Edge GraphEdge; |
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| 394 | /// Node type of the underlying graph. |
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| 395 | typedef typename Graph::Node GraphNode; |
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| 396 | class NodeIt; |
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| 397 | class EdgeIt; |
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| 398 | |
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| 399 | protected: |
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| 400 | const Graph *gr; |
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| 401 | typedef std::vector<GraphEdge> Container; |
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| 402 | Container edges; |
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| 403 | |
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| 404 | public: |
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| 405 | |
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| 406 | /// \param _G The graph in which the path is. |
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| 407 | /// |
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[1909] | 408 | UPath(const Graph &_G) : gr(&_G) {} |
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[819] | 409 | |
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| 410 | /// \brief Subpath constructor. |
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| 411 | /// |
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| 412 | /// Subpath defined by two nodes. |
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| 413 | /// \warning It is an error if the two edges are not in order! |
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[1909] | 414 | UPath(const UPath &P, const NodeIt &a, const NodeIt &b) { |
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[819] | 415 | gr = P.gr; |
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| 416 | edges.insert(edges.end(), P.edges.begin()+a.idx, P.edges.begin()+b.idx); |
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| 417 | } |
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| 418 | |
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| 419 | /// \brief Subpath constructor. |
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| 420 | /// |
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| 421 | /// Subpath defined by two edges. Contains edges in [a,b) |
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| 422 | /// \warning It is an error if the two edges are not in order! |
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[1909] | 423 | UPath(const UPath &P, const EdgeIt &a, const EdgeIt &b) { |
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[819] | 424 | gr = P.gr; |
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| 425 | edges.insert(edges.end(), P.edges.begin()+a.idx, P.edges.begin()+b.idx); |
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| 426 | } |
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| 427 | |
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| 428 | /// Length of the path. |
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| 429 | size_t length() const { return edges.size(); } |
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| 430 | /// Returns whether the path is empty. |
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| 431 | bool empty() const { return edges.empty(); } |
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| 432 | |
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| 433 | /// Resets the path to an empty path. |
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| 434 | void clear() { edges.clear(); } |
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| 435 | |
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| 436 | /// \brief Starting point of the path. |
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| 437 | /// |
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| 438 | /// Starting point of the path. |
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| 439 | /// Returns INVALID if the path is empty. |
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[986] | 440 | GraphNode source() const { |
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| 441 | return empty() ? INVALID : gr->source(edges[0]); |
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[819] | 442 | } |
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| 443 | /// \brief End point of the path. |
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| 444 | /// |
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| 445 | /// End point of the path. |
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| 446 | /// Returns INVALID if the path is empty. |
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[986] | 447 | GraphNode target() const { |
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| 448 | return empty() ? INVALID : gr->target(edges[length()-1]); |
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[819] | 449 | } |
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| 450 | |
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| 451 | /// \brief Initializes node or edge iterator to point to the first |
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| 452 | /// node or edge. |
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| 453 | /// |
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| 454 | /// \sa nth |
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| 455 | template<typename It> |
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| 456 | It& first(It &i) const { return i=It(*this); } |
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| 457 | |
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| 458 | /// \brief Initializes node iterator to point to the node of a given index. |
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| 459 | NodeIt& nth(NodeIt &i, int n) const { |
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| 460 | return i=NodeIt(*this, n); |
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| 461 | } |
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| 462 | |
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| 463 | /// \brief Initializes edge iterator to point to the edge of a given index. |
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| 464 | EdgeIt& nth(EdgeIt &i, int n) const { |
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| 465 | return i=EdgeIt(*this, n); |
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| 466 | } |
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| 467 | |
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| 468 | /// Checks validity of a node or edge iterator. |
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| 469 | template<typename It> |
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| 470 | static |
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| 471 | bool valid(const It &i) { return i.valid(); } |
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| 472 | |
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| 473 | /// Steps the given node or edge iterator. |
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| 474 | template<typename It> |
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| 475 | static |
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| 476 | It& next(It &e) { |
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| 477 | return ++e; |
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| 478 | } |
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| 479 | |
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[986] | 480 | /// \brief Returns node iterator pointing to the target node of the |
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[819] | 481 | /// given edge iterator. |
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[986] | 482 | NodeIt target(const EdgeIt& e) const { |
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[819] | 483 | return NodeIt(*this, e.idx+1); |
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| 484 | } |
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| 485 | |
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[986] | 486 | /// \brief Returns node iterator pointing to the source node of the |
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[819] | 487 | /// given edge iterator. |
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[986] | 488 | NodeIt source(const EdgeIt& e) const { |
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[819] | 489 | return NodeIt(*this, e.idx); |
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| 490 | } |
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| 491 | |
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| 492 | |
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| 493 | |
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| 494 | /** |
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| 495 | * \brief Iterator class to iterate on the edges of the paths |
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[837] | 496 | * |
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[819] | 497 | * This class is used to iterate on the edges of the paths |
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| 498 | * |
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| 499 | * Of course it converts to Graph::Edge |
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[837] | 500 | * |
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[819] | 501 | * \todo Its interface differs from the standard edge iterator. |
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| 502 | * Yes, it shouldn't. |
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| 503 | */ |
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| 504 | class EdgeIt { |
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[1909] | 505 | friend class UPath; |
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[819] | 506 | |
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| 507 | int idx; |
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[1909] | 508 | const UPath *p; |
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[819] | 509 | public: |
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| 510 | /// Default constructor |
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| 511 | EdgeIt() {} |
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| 512 | /// Invalid constructor |
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| 513 | EdgeIt(Invalid) : idx(-1), p(0) {} |
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| 514 | /// Constructor with starting point |
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[1909] | 515 | EdgeIt(const UPath &_p, int _idx = 0) : |
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[819] | 516 | idx(_idx), p(&_p) { validate(); } |
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| 517 | |
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| 518 | ///Validity check |
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| 519 | bool valid() const { return idx!=-1; } |
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| 520 | |
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| 521 | ///Conversion to Graph::Edge |
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| 522 | operator GraphEdge () const { |
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| 523 | return valid() ? p->edges[idx] : INVALID; |
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| 524 | } |
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| 525 | /// Next edge |
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| 526 | EdgeIt& operator++() { ++idx; validate(); return *this; } |
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| 527 | |
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| 528 | /// Comparison operator |
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| 529 | bool operator==(const EdgeIt& e) const { return idx==e.idx; } |
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| 530 | /// Comparison operator |
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| 531 | bool operator!=(const EdgeIt& e) const { return idx!=e.idx; } |
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| 532 | /// Comparison operator |
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| 533 | bool operator<(const EdgeIt& e) const { return idx<e.idx; } |
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| 534 | |
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| 535 | private: |
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| 536 | // FIXME: comparison between signed and unsigned... |
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| 537 | // Jo ez igy? Vagy esetleg legyen a length() int? |
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| 538 | void validate() { if( size_t(idx) >= p->length() ) idx=-1; } |
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| 539 | }; |
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| 540 | |
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| 541 | /** |
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| 542 | * \brief Iterator class to iterate on the nodes of the paths |
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[837] | 543 | * |
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[819] | 544 | * This class is used to iterate on the nodes of the paths |
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| 545 | * |
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| 546 | * Of course it converts to Graph::Node |
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[837] | 547 | * |
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[819] | 548 | * \todo Its interface differs from the standard node iterator. |
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| 549 | * Yes, it shouldn't. |
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| 550 | */ |
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| 551 | class NodeIt { |
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[1909] | 552 | friend class UPath; |
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[819] | 553 | |
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| 554 | int idx; |
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[1909] | 555 | const UPath *p; |
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[819] | 556 | public: |
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| 557 | /// Default constructor |
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| 558 | NodeIt() {} |
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| 559 | /// Invalid constructor |
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| 560 | NodeIt(Invalid) : idx(-1), p(0) {} |
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| 561 | /// Constructor with starting point |
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[1909] | 562 | NodeIt(const UPath &_p, int _idx = 0) : |
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[819] | 563 | idx(_idx), p(&_p) { validate(); } |
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| 564 | |
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| 565 | ///Validity check |
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| 566 | bool valid() const { return idx!=-1; } |
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| 567 | |
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| 568 | ///Conversion to Graph::Node |
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| 569 | operator const GraphNode& () const { |
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| 570 | if(idx >= p->length()) |
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[986] | 571 | return p->target(); |
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[819] | 572 | else if(idx >= 0) |
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[986] | 573 | return p->gr->source(p->edges[idx]); |
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[819] | 574 | else |
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| 575 | return INVALID; |
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| 576 | } |
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| 577 | /// Next node |
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| 578 | NodeIt& operator++() { ++idx; validate(); return *this; } |
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| 579 | |
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| 580 | /// Comparison operator |
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| 581 | bool operator==(const NodeIt& e) const { return idx==e.idx; } |
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| 582 | /// Comparison operator |
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| 583 | bool operator!=(const NodeIt& e) const { return idx!=e.idx; } |
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| 584 | /// Comparison operator |
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| 585 | bool operator<(const NodeIt& e) const { return idx<e.idx; } |
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| 586 | |
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| 587 | private: |
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| 588 | void validate() { if( size_t(idx) > p->length() ) idx=-1; } |
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| 589 | }; |
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| 590 | |
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[837] | 591 | friend class Builder; |
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[819] | 592 | |
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| 593 | /** |
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| 594 | * \brief Class to build paths |
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[837] | 595 | * |
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[819] | 596 | * This class is used to fill a path with edges. |
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| 597 | * |
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| 598 | * You can push new edges to the front and to the back of the path in |
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| 599 | * arbitrary order then you should commit these changes to the graph. |
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| 600 | * |
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| 601 | * Fundamentally, for most "Paths" (classes fulfilling the |
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| 602 | * PathConcept) while the builder is active (after the first modifying |
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| 603 | * operation and until the commit()) the original Path is in a |
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| 604 | * "transitional" state (operations ot it have undefined result). But |
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[1909] | 605 | * in the case of UPath the original path is unchanged until the |
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[819] | 606 | * commit. However we don't recomend that you use this feature. |
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| 607 | */ |
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| 608 | class Builder { |
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[1909] | 609 | UPath &P; |
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[819] | 610 | Container front, back; |
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| 611 | |
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| 612 | public: |
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[1228] | 613 | ///\param _p the path you want to fill in. |
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[819] | 614 | /// |
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[1909] | 615 | Builder(UPath &_p) : P(_p) {} |
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[819] | 616 | |
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| 617 | /// Sets the starting node of the path. |
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[837] | 618 | |
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[819] | 619 | /// Sets the starting node of the path. Edge added to the path |
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| 620 | /// afterwards have to be incident to this node. |
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[900] | 621 | /// It should be called if and only if |
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| 622 | /// the path is empty and before any call to |
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[819] | 623 | /// \ref pushFront() or \ref pushBack() |
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| 624 | void setStartNode(const GraphNode &) {} |
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| 625 | |
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| 626 | ///Push a new edge to the front of the path |
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| 627 | |
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| 628 | ///Push a new edge to the front of the path. |
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| 629 | ///\sa setStartNode |
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| 630 | void pushFront(const GraphEdge& e) { |
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| 631 | front.push_back(e); |
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| 632 | } |
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| 633 | |
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| 634 | ///Push a new edge to the back of the path |
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| 635 | |
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| 636 | ///Push a new edge to the back of the path. |
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| 637 | ///\sa setStartNode |
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| 638 | void pushBack(const GraphEdge& e) { |
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| 639 | back.push_back(e); |
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| 640 | } |
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| 641 | |
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| 642 | ///Commit the changes to the path. |
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| 643 | void commit() { |
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| 644 | if( !(front.empty() && back.empty()) ) { |
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| 645 | Container tmp; |
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| 646 | tmp.reserve(front.size()+back.size()+P.length()); |
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| 647 | tmp.insert(tmp.end(), front.rbegin(), front.rend()); |
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| 648 | tmp.insert(tmp.end(), P.edges.begin(), P.edges.end()); |
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| 649 | tmp.insert(tmp.end(), back.begin(), back.end()); |
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| 650 | P.edges.swap(tmp); |
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| 651 | front.clear(); |
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| 652 | back.clear(); |
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| 653 | } |
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| 654 | } |
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| 655 | |
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| 656 | |
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| 657 | ///Reserve storage for the builder in advance. |
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| 658 | |
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[837] | 659 | ///If you know a reasonable upper bound of the number of the edges |
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| 660 | ///to add to the front, using this function you can speed up the building. |
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[819] | 661 | |
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[837] | 662 | void reserveFront(size_t r) {front.reserve(r);} |
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| 663 | |
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| 664 | ///Reserve storage for the builder in advance. |
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| 665 | |
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| 666 | ///If you know a reasonable upper bound of the number of the edges |
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| 667 | ///to add to the back, using this function you can speed up the building. |
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| 668 | |
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| 669 | void reserveBack(size_t r) {back.reserve(r);} |
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[831] | 670 | |
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[819] | 671 | private: |
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| 672 | bool empty() { |
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| 673 | return front.empty() && back.empty() && P.empty(); |
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| 674 | } |
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| 675 | |
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[986] | 676 | GraphNode source() const { |
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[819] | 677 | if( ! front.empty() ) |
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[986] | 678 | return P.gr->source(front[front.size()-1]); |
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[819] | 679 | else if( ! P.empty() ) |
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[986] | 680 | return P.gr->source(P.edges[0]); |
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[819] | 681 | else if( ! back.empty() ) |
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[986] | 682 | return P.gr->source(back[0]); |
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[819] | 683 | else |
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| 684 | return INVALID; |
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| 685 | } |
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[986] | 686 | GraphNode target() const { |
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[819] | 687 | if( ! back.empty() ) |
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[986] | 688 | return P.gr->target(back[back.size()-1]); |
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[819] | 689 | else if( ! P.empty() ) |
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[986] | 690 | return P.gr->target(P.edges[P.length()-1]); |
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[819] | 691 | else if( ! front.empty() ) |
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[986] | 692 | return P.gr->target(front[0]); |
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[819] | 693 | else |
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| 694 | return INVALID; |
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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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| 701 | |
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| 702 | ///@} |
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| 703 | |
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[921] | 704 | } // namespace lemon |
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[819] | 705 | |
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[921] | 706 | #endif // LEMON_PATH_H |
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