[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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| 23 | |
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[947] | 24 | ///\ingroup gutils |
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[946] | 25 | ///\file |
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[947] | 26 | ///\brief Graph utilities. |
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[946] | 27 | /// |
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[964] | 28 | ///\todo Please |
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| 29 | ///revise the documentation. |
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| 30 | /// |
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[946] | 31 | |
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| 32 | |
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| 33 | namespace lemon { |
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| 34 | |
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[947] | 35 | /// \addtogroup gutils |
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| 36 | /// @{ |
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| 37 | |
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[946] | 38 | // counters in the graph |
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| 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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| 46 | inline int countItems(const Graph& _g) { |
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| 47 | int num = 0; |
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| 48 | for (ItemIt it(_g); it != INVALID; ++it) { |
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| 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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| 54 | /// \brief Function to count the nodes in the graph. |
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| 55 | /// |
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| 56 | /// This function counts the nodes in the graph. |
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| 57 | /// The complexity of the function is O(n) but for some |
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[964] | 58 | /// graph structure it is specialized to run in O(1). |
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[946] | 59 | |
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| 60 | template <typename Graph> |
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| 61 | inline int countNodes(const Graph& _g) { |
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| 62 | return countItems<Graph, typename Graph::NodeIt>(_g); |
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| 63 | } |
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| 64 | |
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| 65 | /// \brief Function to count the edges in the graph. |
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| 66 | /// |
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| 67 | /// This function counts the edges in the graph. |
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| 68 | /// The complexity of the function is O(e) but for some |
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[964] | 69 | /// graph structure it is specialized to run in O(1). |
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[946] | 70 | template <typename Graph> |
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| 71 | inline int countEdges(const Graph& _g) { |
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| 72 | return countItems<Graph, typename Graph::EdgeIt>(_g); |
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| 73 | } |
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| 74 | |
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| 75 | /// \brief Function to count the symmetric edges in the graph. |
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| 76 | /// |
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| 77 | /// This function counts the symmetric edges in the graph. |
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| 78 | /// The complexity of the function is O(e) but for some |
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[964] | 79 | /// graph structure it is specialized to run in O(1). |
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[946] | 80 | template <typename Graph> |
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| 81 | inline int countSymEdges(const Graph& _g) { |
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| 82 | return countItems<Graph, typename Graph::SymEdgeIt>(_g); |
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| 83 | } |
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| 84 | |
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| 85 | template <typename Graph, typename DegIt> |
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| 86 | inline int countNodeDegree(const Graph& _g, const typename Graph::Node& _n) { |
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| 87 | int num = 0; |
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| 88 | for (DegIt it(_g, _n); it != INVALID; ++it) { |
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| 89 | ++num; |
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| 90 | } |
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| 91 | return num; |
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| 92 | } |
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[967] | 93 | |
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| 94 | /// Finds an edge between two nodes of a graph. |
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| 95 | |
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| 96 | /// Finds an edge from node \c u to node \c v in graph \c g. |
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| 97 | /// |
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| 98 | /// If \c prev is \ref INVALID (this is the default value), then |
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| 99 | /// it finds the first edge from \c u to \c v. Otherwise it looks for |
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| 100 | /// the next edge from \c u to \c v after \c prev. |
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| 101 | /// \return The found edge or \ref INVALID if there is no such an edge. |
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| 102 | /// |
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| 103 | /// Thus you can iterate through each edge from \c u to \c v as it follows. |
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| 104 | /// \code |
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| 105 | /// for(Edge e=findEdge(g,u,v);e!=INVALID;e=findEdge(g,u,v,e)) { |
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| 106 | /// ... |
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| 107 | /// } |
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| 108 | /// \endcode |
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| 109 | /// \todo We may want to use the \ref concept::GraphBase "GraphBase" |
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| 110 | /// interface here... |
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| 111 | /// \bug Untested ... |
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| 112 | template <typename Graph> |
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| 113 | typename Graph::Edge findEdge(const Graph &g, |
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| 114 | typename Graph::Node u, typename Graph::Node v, |
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| 115 | typename Graph::Edge prev = INVALID) |
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| 116 | { |
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| 117 | typename Graph::OutEdgeIt e(g,prev); |
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| 118 | if(prev==INVALID) g.first(e,u); |
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| 119 | else ++e; |
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| 120 | while(e!=INVALID && g.tail(e)!=v) ++e; |
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| 121 | return e; |
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| 122 | } |
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[964] | 123 | |
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| 124 | ///\e |
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[946] | 125 | |
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[964] | 126 | ///\todo Please document. |
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| 127 | /// |
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[946] | 128 | template <typename Graph> |
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| 129 | inline int countOutEdges(const Graph& _g, const typename Graph::Node& _n) { |
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| 130 | return countNodeDegree<Graph, typename Graph::OutEdgeIt>(_g, _n); |
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| 131 | } |
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| 132 | |
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[964] | 133 | ///\e |
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| 134 | |
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| 135 | ///\todo Please document. |
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| 136 | /// |
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[946] | 137 | template <typename Graph> |
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| 138 | inline int countInEdges(const Graph& _g, const typename Graph::Node& _n) { |
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| 139 | return countNodeDegree<Graph, typename Graph::InEdgeIt>(_g, _n); |
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| 140 | } |
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| 141 | |
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| 142 | // graph copy |
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| 143 | |
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| 144 | template < |
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| 145 | typename DestinationGraph, |
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| 146 | typename SourceGraph, |
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| 147 | typename NodeBijection> |
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| 148 | void copyNodes(DestinationGraph& _d, const SourceGraph& _s, |
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| 149 | NodeBijection& _nb) { |
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| 150 | for (typename SourceGraph::NodeIt it(_s); it != INVALID; ++it) { |
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| 151 | _nb[it] = _d.addNode(); |
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| 152 | } |
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| 153 | } |
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| 154 | |
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| 155 | template < |
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| 156 | typename DestinationGraph, |
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| 157 | typename SourceGraph, |
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| 158 | typename NodeBijection, |
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| 159 | typename EdgeBijection> |
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| 160 | void copyEdges(DestinationGraph& _d, const SourceGraph& _s, |
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| 161 | const NodeBijection& _nb, EdgeBijection& _eb) { |
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| 162 | for (typename SourceGraph::EdgeIt it(_s); it != INVALID; ++it) { |
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| 163 | _eb[it] = _d.addEdge(_nb[_s.tail(it)], _nb[_s.head(it)]); |
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| 164 | } |
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| 165 | } |
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| 166 | |
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| 167 | template < |
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| 168 | typename DestinationGraph, |
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| 169 | typename SourceGraph, |
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| 170 | typename NodeBijection, |
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| 171 | typename EdgeBijection> |
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| 172 | void copyGraph(DestinationGraph& _d, const SourceGraph& _s, |
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| 173 | NodeBijection& _nb, EdgeBijection& _eb) { |
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| 174 | nodeCopy(_d, _s, _nb); |
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| 175 | edgeCopy(_d, _s, _nb, _eb); |
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| 176 | } |
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| 177 | |
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| 178 | template < |
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| 179 | typename _DestinationGraph, |
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| 180 | typename _SourceGraph, |
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| 181 | typename _NodeBijection |
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| 182 | =typename _SourceGraph::template NodeMap<typename _DestinationGraph::Node>, |
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| 183 | typename _EdgeBijection |
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| 184 | =typename _SourceGraph::template EdgeMap<typename _DestinationGraph::Edge> |
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| 185 | > |
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| 186 | class GraphCopy { |
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| 187 | public: |
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| 188 | |
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| 189 | typedef _DestinationGraph DestinationGraph; |
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| 190 | typedef _SourceGraph SourceGraph; |
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| 191 | |
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| 192 | typedef _NodeBijection NodeBijection; |
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| 193 | typedef _EdgeBijection EdgeBijection; |
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| 194 | |
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| 195 | protected: |
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| 196 | |
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| 197 | NodeBijection node_bijection; |
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| 198 | EdgeBijection edge_bijection; |
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| 199 | |
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| 200 | public: |
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| 201 | |
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| 202 | GraphCopy(DestinationGraph& _d, const SourceGraph& _s) { |
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| 203 | copyGraph(_d, _s, node_bijection, edge_bijection); |
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| 204 | } |
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| 205 | |
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| 206 | const NodeBijection& getNodeBijection() const { |
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| 207 | return node_bijection; |
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| 208 | } |
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| 209 | |
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| 210 | const EdgeBijection& getEdgeBijection() const { |
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| 211 | return edge_bijection; |
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| 212 | } |
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| 213 | |
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| 214 | }; |
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[947] | 215 | |
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| 216 | /// @} |
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| 217 | |
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| 218 | } //END OF NAMESPACE LEMON |
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[946] | 219 | |
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| 220 | #endif |
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