[946] | 1 | /* -*- C++ -*- |
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| 2 | * src/lemon/graph_utils.h - Part of LEMON, a generic C++ optimization library |
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| 3 | * |
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| 4 | * Copyright (C) 2004 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
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| 5 | * (Egervary Combinatorial Optimization Research Group, EGRES). |
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| 6 | * |
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| 7 | * Permission to use, modify and distribute this software is granted |
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| 8 | * provided that this copyright notice appears in all copies. For |
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| 9 | * precise terms see the accompanying LICENSE file. |
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| 10 | * |
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| 11 | * This software is provided "AS IS" with no warranty of any kind, |
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| 12 | * express or implied, and with no claim as to its suitability for any |
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| 13 | * purpose. |
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| 14 | * |
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| 15 | */ |
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| 16 | |
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| 17 | #ifndef LEMON_GRAPH_UTILS_H |
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| 18 | #define LEMON_GRAPH_UTILS_H |
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| 19 | |
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| 20 | #include <iterator> |
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| 21 | |
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| 22 | #include <lemon/invalid.h> |
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[977] | 23 | #include <lemon/utility.h> |
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[946] | 24 | |
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[947] | 25 | ///\ingroup gutils |
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[946] | 26 | ///\file |
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[947] | 27 | ///\brief Graph utilities. |
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[946] | 28 | /// |
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[964] | 29 | ///\todo Please |
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| 30 | ///revise the documentation. |
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| 31 | /// |
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[946] | 32 | |
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| 33 | |
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| 34 | namespace lemon { |
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| 35 | |
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[947] | 36 | /// \addtogroup gutils |
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| 37 | /// @{ |
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| 38 | |
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[946] | 39 | /// \brief Function to count the items in the graph. |
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| 40 | /// |
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| 41 | /// This function counts the items in the graph. |
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| 42 | /// The complexity of the function is O(n) because |
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| 43 | /// it iterates on all of the items. |
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| 44 | |
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| 45 | template <typename Graph, typename ItemIt> |
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[977] | 46 | inline int countItems(const Graph& g) { |
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[946] | 47 | int num = 0; |
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[977] | 48 | for (ItemIt it(g); it != INVALID; ++it) { |
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[946] | 49 | ++num; |
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| 50 | } |
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| 51 | return num; |
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| 52 | } |
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| 53 | |
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[977] | 54 | // Node counting: |
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| 55 | |
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| 56 | template <typename Graph> |
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| 57 | inline |
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| 58 | typename enable_if<typename Graph::NodeNumTag, int>::type |
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| 59 | _countNodes(const Graph &g) { |
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| 60 | return g.nodeNum(); |
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| 61 | } |
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| 62 | |
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| 63 | template <typename Graph> |
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| 64 | inline int _countNodes(Wrap<Graph> w) { |
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| 65 | return countItems<Graph, typename Graph::NodeIt>(w.value); |
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| 66 | } |
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| 67 | |
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[946] | 68 | /// \brief Function to count the nodes in the graph. |
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| 69 | /// |
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| 70 | /// This function counts the nodes in the graph. |
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| 71 | /// The complexity of the function is O(n) but for some |
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[964] | 72 | /// graph structure it is specialized to run in O(1). |
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[977] | 73 | /// |
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| 74 | /// \todo refer how to specialize it |
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[946] | 75 | |
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| 76 | template <typename Graph> |
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[977] | 77 | inline int countNodes(const Graph& g) { |
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| 78 | return _countNodes<Graph>(g); |
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| 79 | } |
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| 80 | |
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| 81 | // Edge counting: |
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| 82 | |
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| 83 | template <typename Graph> |
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| 84 | inline |
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| 85 | typename enable_if<typename Graph::EdgeNumTag, int>::type |
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| 86 | _countEdges(const Graph &g) { |
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| 87 | return g.edgeNum(); |
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| 88 | } |
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| 89 | |
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| 90 | template <typename Graph> |
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| 91 | inline int _countEdges(Wrap<Graph> w) { |
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| 92 | return countItems<Graph, typename Graph::EdgeIt>(w.value); |
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[946] | 93 | } |
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| 94 | |
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| 95 | /// \brief Function to count the edges in the graph. |
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| 96 | /// |
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| 97 | /// This function counts the edges in the graph. |
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| 98 | /// The complexity of the function is O(e) but for some |
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[964] | 99 | /// graph structure it is specialized to run in O(1). |
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[977] | 100 | |
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[946] | 101 | template <typename Graph> |
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[977] | 102 | inline int countEdges(const Graph& g) { |
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| 103 | return _countEdges<Graph>(g); |
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[946] | 104 | } |
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| 105 | |
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[1053] | 106 | // Undirected edge counting: |
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| 107 | |
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| 108 | template <typename Graph> |
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| 109 | inline |
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| 110 | typename enable_if<typename Graph::EdgeNumTag, int>::type |
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| 111 | _countUndirEdges(const Graph &g) { |
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| 112 | return g.undirEdgeNum(); |
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| 113 | } |
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| 114 | |
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| 115 | template <typename Graph> |
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| 116 | inline int _countUndirEdges(Wrap<Graph> w) { |
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| 117 | return countItems<Graph, typename Graph::UndirEdgeIt>(w.value); |
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| 118 | } |
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| 119 | |
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| 120 | /// \brief Function to count the edges in the graph. |
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[946] | 121 | /// |
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[1053] | 122 | /// This function counts the edges in the graph. |
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[946] | 123 | /// The complexity of the function is O(e) but for some |
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[964] | 124 | /// graph structure it is specialized to run in O(1). |
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[1053] | 125 | |
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[946] | 126 | template <typename Graph> |
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[1053] | 127 | inline int countUndirEdges(const Graph& g) { |
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| 128 | return _countUndirEdges<Graph>(g); |
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[946] | 129 | } |
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| 130 | |
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[977] | 131 | |
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[1053] | 132 | |
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[946] | 133 | template <typename Graph, typename DegIt> |
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| 134 | inline int countNodeDegree(const Graph& _g, const typename Graph::Node& _n) { |
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| 135 | int num = 0; |
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| 136 | for (DegIt it(_g, _n); it != INVALID; ++it) { |
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| 137 | ++num; |
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| 138 | } |
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| 139 | return num; |
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| 140 | } |
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[967] | 141 | |
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| 142 | /// Finds an edge between two nodes of a graph. |
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| 143 | |
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| 144 | /// Finds an edge from node \c u to node \c v in graph \c g. |
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| 145 | /// |
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| 146 | /// If \c prev is \ref INVALID (this is the default value), then |
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| 147 | /// it finds the first edge from \c u to \c v. Otherwise it looks for |
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| 148 | /// the next edge from \c u to \c v after \c prev. |
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| 149 | /// \return The found edge or \ref INVALID if there is no such an edge. |
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| 150 | /// |
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| 151 | /// Thus you can iterate through each edge from \c u to \c v as it follows. |
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| 152 | /// \code |
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| 153 | /// for(Edge e=findEdge(g,u,v);e!=INVALID;e=findEdge(g,u,v,e)) { |
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| 154 | /// ... |
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| 155 | /// } |
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| 156 | /// \endcode |
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| 157 | /// \todo We may want to use the \ref concept::GraphBase "GraphBase" |
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| 158 | /// interface here... |
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| 159 | /// \bug Untested ... |
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| 160 | template <typename Graph> |
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| 161 | typename Graph::Edge findEdge(const Graph &g, |
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| 162 | typename Graph::Node u, typename Graph::Node v, |
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| 163 | typename Graph::Edge prev = INVALID) |
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| 164 | { |
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| 165 | typename Graph::OutEdgeIt e(g,prev); |
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[1079] | 166 | // if(prev==INVALID) g.first(e,u); |
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| 167 | if(prev==INVALID) e=typename Graph::OutEdgeIt(g,u); |
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[967] | 168 | else ++e; |
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[1079] | 169 | while(e!=INVALID && g.target(e)!=v) ++e; |
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[967] | 170 | return e; |
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| 171 | } |
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[964] | 172 | |
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| 173 | ///\e |
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[946] | 174 | |
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[964] | 175 | ///\todo Please document. |
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| 176 | /// |
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[946] | 177 | template <typename Graph> |
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| 178 | inline int countOutEdges(const Graph& _g, const typename Graph::Node& _n) { |
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| 179 | return countNodeDegree<Graph, typename Graph::OutEdgeIt>(_g, _n); |
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| 180 | } |
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| 181 | |
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[964] | 182 | ///\e |
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| 183 | |
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| 184 | ///\todo Please document. |
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| 185 | /// |
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[946] | 186 | template <typename Graph> |
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| 187 | inline int countInEdges(const Graph& _g, const typename Graph::Node& _n) { |
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| 188 | return countNodeDegree<Graph, typename Graph::InEdgeIt>(_g, _n); |
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| 189 | } |
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| 190 | |
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| 191 | // graph copy |
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| 192 | |
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| 193 | template < |
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| 194 | typename DestinationGraph, |
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| 195 | typename SourceGraph, |
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| 196 | typename NodeBijection> |
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| 197 | void copyNodes(DestinationGraph& _d, const SourceGraph& _s, |
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| 198 | NodeBijection& _nb) { |
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| 199 | for (typename SourceGraph::NodeIt it(_s); it != INVALID; ++it) { |
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| 200 | _nb[it] = _d.addNode(); |
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| 201 | } |
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| 202 | } |
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| 203 | |
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| 204 | template < |
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| 205 | typename DestinationGraph, |
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| 206 | typename SourceGraph, |
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| 207 | typename NodeBijection, |
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| 208 | typename EdgeBijection> |
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| 209 | void copyEdges(DestinationGraph& _d, const SourceGraph& _s, |
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| 210 | const NodeBijection& _nb, EdgeBijection& _eb) { |
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| 211 | for (typename SourceGraph::EdgeIt it(_s); it != INVALID; ++it) { |
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[986] | 212 | _eb[it] = _d.addEdge(_nb[_s.source(it)], _nb[_s.target(it)]); |
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[946] | 213 | } |
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| 214 | } |
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| 215 | |
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| 216 | template < |
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| 217 | typename DestinationGraph, |
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| 218 | typename SourceGraph, |
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| 219 | typename NodeBijection, |
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| 220 | typename EdgeBijection> |
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| 221 | void copyGraph(DestinationGraph& _d, const SourceGraph& _s, |
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| 222 | NodeBijection& _nb, EdgeBijection& _eb) { |
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| 223 | nodeCopy(_d, _s, _nb); |
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| 224 | edgeCopy(_d, _s, _nb, _eb); |
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| 225 | } |
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| 226 | |
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| 227 | template < |
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| 228 | typename _DestinationGraph, |
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| 229 | typename _SourceGraph, |
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| 230 | typename _NodeBijection |
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| 231 | =typename _SourceGraph::template NodeMap<typename _DestinationGraph::Node>, |
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| 232 | typename _EdgeBijection |
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| 233 | =typename _SourceGraph::template EdgeMap<typename _DestinationGraph::Edge> |
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| 234 | > |
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| 235 | class GraphCopy { |
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| 236 | public: |
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| 237 | |
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| 238 | typedef _DestinationGraph DestinationGraph; |
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| 239 | typedef _SourceGraph SourceGraph; |
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| 240 | |
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| 241 | typedef _NodeBijection NodeBijection; |
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| 242 | typedef _EdgeBijection EdgeBijection; |
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| 243 | |
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| 244 | protected: |
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| 245 | |
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| 246 | NodeBijection node_bijection; |
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| 247 | EdgeBijection edge_bijection; |
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| 248 | |
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| 249 | public: |
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| 250 | |
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| 251 | GraphCopy(DestinationGraph& _d, const SourceGraph& _s) { |
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| 252 | copyGraph(_d, _s, node_bijection, edge_bijection); |
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| 253 | } |
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| 254 | |
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| 255 | const NodeBijection& getNodeBijection() const { |
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| 256 | return node_bijection; |
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| 257 | } |
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| 258 | |
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| 259 | const EdgeBijection& getEdgeBijection() const { |
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| 260 | return edge_bijection; |
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| 261 | } |
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| 262 | |
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| 263 | }; |
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[947] | 264 | |
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| 265 | /// @} |
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| 266 | |
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| 267 | } //END OF NAMESPACE LEMON |
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[946] | 268 | |
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| 269 | #endif |
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