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