[962] | 1 | /* -*- C++ -*- |
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| 2 | * |
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| 3 | * src/lemon/undir_graph_extender.h - Part of LEMON, a generic C++ |
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| 4 | * optimization library |
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| 5 | * |
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| 6 | * Copyright (C) 2004 Egervary Jeno Kombinatorikus Optimalizalasi |
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| 7 | * Kutatocsoport (Egervary Combinatorial Optimization Research Group, |
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| 8 | * EGRES). |
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| 9 | * |
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| 10 | * Permission to use, modify and distribute this software is granted |
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| 11 | * provided that this copyright notice appears in all copies. For |
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| 12 | * precise terms see the accompanying LICENSE file. |
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| 13 | * |
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| 14 | * This software is provided "AS IS" with no warranty of any kind, |
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| 15 | * express or implied, and with no claim as to its suitability for any |
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| 16 | * purpose. |
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| 17 | * |
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| 18 | */ |
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| 19 | |
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| 20 | #ifndef LEMON_UNDIR_GRAPH_EXTENDER_H |
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| 21 | #define LEMON_UNDIR_GRAPH_EXTENDER_H |
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| 22 | |
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| 23 | #include <lemon/invalid.h> |
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| 24 | |
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| 25 | namespace lemon { |
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| 26 | |
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| 27 | template <typename _Base> |
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| 28 | class UndirGraphExtender : public _Base { |
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| 29 | typedef _Base Parent; |
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| 30 | typedef UndirGraphExtender Graph; |
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| 31 | |
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| 32 | public: |
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| 33 | |
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| 34 | typedef typename Parent::Edge UndirEdge; |
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| 35 | typedef typename Parent::Node Node; |
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| 36 | |
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| 37 | class Edge : public UndirEdge { |
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[978] | 38 | friend class UndirGraphExtender; |
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[962] | 39 | |
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| 40 | protected: |
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| 41 | // FIXME: Marci use opposite logic in his graph wrappers. It would |
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| 42 | // be reasonable to syncronize... |
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| 43 | bool forward; |
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| 44 | |
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| 45 | public: |
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| 46 | Edge() {} |
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| 47 | /// Construct a direct edge from undirect edge and a direction. |
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| 48 | Edge(const UndirEdge &ue, bool _forward) : |
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| 49 | UndirEdge(ue), forward(_forward) {} |
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| 50 | /// Invalid edge constructor |
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| 51 | Edge(Invalid i) : UndirEdge(i), forward(false) {} |
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| 52 | |
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| 53 | bool operator==(const Edge &that) const { |
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| 54 | return forward==that.forward && UndirEdge(*this)==UndirEdge(that); |
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| 55 | } |
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| 56 | bool operator!=(const Edge &that) const { |
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| 57 | return forward!=that.forward || UndirEdge(*this)!=UndirEdge(that); |
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| 58 | } |
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| 59 | bool operator<(const Edge &that) const { |
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| 60 | return forward<that.forward || |
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| 61 | (!(that.forward<forward) && UndirEdge(*this)<UndirEdge(that)); |
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| 62 | } |
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| 63 | }; |
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| 64 | |
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| 65 | |
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| 66 | /// \brief Returns the Edge of opposite direction. |
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| 67 | /// |
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| 68 | /// \bug Is this a good name for this? Or "reverse" is better? |
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| 69 | Edge opposite(const Edge &e) const { |
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| 70 | return Edge(e,!e.forward); |
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| 71 | } |
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| 72 | |
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| 73 | /// Tail of the given Edge. |
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| 74 | Node tail(const Edge &e) const { |
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| 75 | return e.forward ? Parent::tail(e) : Parent::head(e); |
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| 76 | } |
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| 77 | |
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| 78 | /// \todo Shouldn't the "tail" of an undirected edge be called "aNode" |
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| 79 | /// or something??? |
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| 80 | using Parent::tail; |
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| 81 | |
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| 82 | /// Head of the given Edge. |
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| 83 | Node head(const Edge &e) const { |
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| 84 | return e.forward ? Parent::head(e) : Parent::tail(e); |
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| 85 | } |
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| 86 | |
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| 87 | /// \todo Shouldn't the "head" of an undirected edge be called "bNode" |
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| 88 | /// or something??? |
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| 89 | using Parent::head; |
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| 90 | |
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| 91 | /// Returns whether the given directed edge is same orientation as the |
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| 92 | /// corresponding undirected edge. |
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| 93 | /// |
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| 94 | /// \todo reference to the corresponding point of the undirected graph |
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| 95 | /// concept. "What does the direction of an undirected edge mean?" |
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| 96 | bool forward(const Edge &e) const { return e.forward; } |
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| 97 | |
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| 98 | Node oppsiteNode(const Node &n, const Edge &e) const { |
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| 99 | if( n == Parent::tail(e)) |
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| 100 | return Parent::head(e); |
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| 101 | else if( n == Parent::head(e)) |
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| 102 | return Parent::tail(e); |
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| 103 | else |
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| 104 | return INVALID; |
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| 105 | } |
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| 106 | |
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| 107 | |
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| 108 | using Parent::first; |
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| 109 | void first(Edge &e) const { |
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| 110 | Parent::first(e); |
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| 111 | e.forward=true; |
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| 112 | } |
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| 113 | |
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| 114 | using Parent::next; |
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| 115 | void next(Edge &e) const { |
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| 116 | if( e.forward ) { |
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| 117 | e.forward = false; |
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| 118 | } |
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| 119 | else { |
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| 120 | Parent::next(e); |
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| 121 | e.forward = true; |
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| 122 | } |
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| 123 | } |
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| 124 | |
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| 125 | void firstOut(Edge &e, const Node &n) const { |
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| 126 | Parent::firstOut(e,n); |
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| 127 | if( UndirEdge(e) != INVALID ) { |
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| 128 | e.forward = true; |
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| 129 | } |
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| 130 | else { |
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| 131 | Parent::firstIn(e,n); |
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| 132 | e.forward = false; |
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| 133 | } |
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| 134 | } |
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| 135 | void firstIn(Edge &e, const Node &n) const { |
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| 136 | Parent::firstIn(e,n); |
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| 137 | if( UndirEdge(e) != INVALID ) { |
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| 138 | e.forward = true; |
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| 139 | } |
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| 140 | else { |
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| 141 | Parent::firstOut(e,n); |
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| 142 | e.forward = false; |
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| 143 | } |
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| 144 | } |
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| 145 | |
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| 146 | void nextOut(Edge &e) const { |
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| 147 | if( e.forward ) { |
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| 148 | Parent::nextOut(e); |
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| 149 | if( UndirEdge(e) == INVALID ) { |
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| 150 | Parent::firstIn(e, Parent::tail(e)); |
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| 151 | e.forward = false; |
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| 152 | } |
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| 153 | } |
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| 154 | else { |
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| 155 | Parent::nextIn(e); |
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| 156 | } |
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| 157 | } |
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| 158 | void nextIn(Edge &e) const { |
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| 159 | if( e.forward ) { |
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| 160 | Parent::nextIn(e); |
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| 161 | if( UndirEdge(e) == INVALID ) { |
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| 162 | Parent::firstOut(e, Parent::head(e)); |
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| 163 | e.forward = false; |
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| 164 | } |
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| 165 | } |
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| 166 | else { |
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| 167 | Parent::nextOut(e); |
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| 168 | } |
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| 169 | } |
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| 170 | |
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| 171 | // Miscellaneous stuff: |
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| 172 | |
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| 173 | /// \todo these methods (id, maxEdgeId) should be moved into separate |
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| 174 | /// Extender |
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| 175 | |
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| 176 | using Parent::id; |
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| 177 | |
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| 178 | int id(const Edge &e) const { |
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| 179 | return 2*Parent::id(e) + int(e.forward); |
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| 180 | } |
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| 181 | |
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| 182 | int maxEdgeId() const { |
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| 183 | return 2*Parent::maxEdgeId() + 1; |
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| 184 | } |
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| 185 | int maxUndirEdgeId() const { |
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| 186 | return Parent::maxEdgeId(); |
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| 187 | } |
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| 188 | |
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| 189 | }; |
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| 190 | |
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| 191 | } |
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| 192 | |
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| 193 | #endif // LEMON_UNDIR_GRAPH_EXTENDER_H |
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