1 | /* -*- C++ -*- |
---|
2 | * lemon/grid_graph.h - Part of LEMON, a generic C++ optimization library |
---|
3 | * |
---|
4 | * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
---|
5 | * (Egervary Research Group on Combinatorial Optimization, 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 GRID_GRAPH_H |
---|
18 | #define GRID_GRAPH_H |
---|
19 | |
---|
20 | #include <iostream> |
---|
21 | #include <lemon/invalid.h> |
---|
22 | #include <lemon/utility.h> |
---|
23 | |
---|
24 | #include <lemon/bits/iterable_graph_extender.h> |
---|
25 | #include <lemon/bits/alteration_notifier.h> |
---|
26 | #include <lemon/bits/default_map.h> |
---|
27 | |
---|
28 | #include <lemon/bits/undir_graph_extender.h> |
---|
29 | |
---|
30 | namespace lemon { |
---|
31 | |
---|
32 | class GridGraphBase { |
---|
33 | |
---|
34 | public: |
---|
35 | |
---|
36 | typedef GridGraphBase Graph; |
---|
37 | |
---|
38 | class Node; |
---|
39 | class Edge; |
---|
40 | |
---|
41 | public: |
---|
42 | |
---|
43 | GridGraphBase() {} |
---|
44 | |
---|
45 | protected: |
---|
46 | |
---|
47 | /// \brief Creates a grid graph with the given size. |
---|
48 | /// |
---|
49 | /// Creates a grid graph with the given size. |
---|
50 | void construct(int height, int width) { |
---|
51 | _height = height; _width = width; |
---|
52 | _nodeNum = height * width; _edgeNum = 2 * _nodeNum - width - height; |
---|
53 | _edgeLimit = _nodeNum - width; |
---|
54 | } |
---|
55 | |
---|
56 | public: |
---|
57 | |
---|
58 | /// \brief The node on the given position. |
---|
59 | /// |
---|
60 | /// Gives back the node on the given position. |
---|
61 | Node operator()(int i, int j) const { |
---|
62 | return Node(i * _width + j); |
---|
63 | } |
---|
64 | |
---|
65 | /// \brief Gives back the row index of the node. |
---|
66 | /// |
---|
67 | /// Gives back the row index of the node. |
---|
68 | int row(Node n) const { |
---|
69 | return n.id / _width; |
---|
70 | } |
---|
71 | |
---|
72 | /// \brief Gives back the coloumn index of the node. |
---|
73 | /// |
---|
74 | /// Gives back the coloumn index of the node. |
---|
75 | int col(Node node) const { |
---|
76 | return n.id % _width; |
---|
77 | } |
---|
78 | |
---|
79 | /// \brief Gives back the width of the graph. |
---|
80 | /// |
---|
81 | /// Gives back the width of the graph. |
---|
82 | int width() const { |
---|
83 | return _width; |
---|
84 | } |
---|
85 | |
---|
86 | /// \brief Gives back the height of the graph. |
---|
87 | /// |
---|
88 | /// Gives back the height of the graph. |
---|
89 | int height() const { |
---|
90 | return _height; |
---|
91 | } |
---|
92 | |
---|
93 | typedef True NodeNumTag; |
---|
94 | typedef True EdgeNumTag; |
---|
95 | |
---|
96 | ///Number of nodes. |
---|
97 | int nodeNum() const { return _nodeNum; } |
---|
98 | ///Number of edges. |
---|
99 | int edgeNum() const { return _edgeNum; } |
---|
100 | |
---|
101 | /// Maximum node ID. |
---|
102 | |
---|
103 | /// Maximum node ID. |
---|
104 | ///\sa id(Node) |
---|
105 | int maxId(Node = INVALID) const { return nodeNum() - 1; } |
---|
106 | /// Maximum edge ID. |
---|
107 | |
---|
108 | /// Maximum edge ID. |
---|
109 | ///\sa id(Edge) |
---|
110 | int maxId(Edge = INVALID) const { return edgeNum() - 1; } |
---|
111 | |
---|
112 | /// \brief Gives back the source node of an edge. |
---|
113 | /// |
---|
114 | /// Gives back the source node of an edge. |
---|
115 | Node source(Edge e) const { |
---|
116 | if (e.id < _edgeLimit) { |
---|
117 | return e.id; |
---|
118 | } else { |
---|
119 | return (e.id - _edgeLimit) % (_width - 1) + |
---|
120 | (e.id - _edgeLimit) / (_width - 1) * _width; |
---|
121 | } |
---|
122 | } |
---|
123 | |
---|
124 | /// \brief Gives back the target node of an edge. |
---|
125 | /// |
---|
126 | /// Gives back the target node of an edge. |
---|
127 | Node target(Edge e) const { |
---|
128 | if (e.id < _edgeLimit) { |
---|
129 | return e.id + _width; |
---|
130 | } else { |
---|
131 | return (e.id - _edgeLimit) % (_width - 1) + |
---|
132 | (e.id - _edgeLimit) / (_width - 1) * _width + 1; |
---|
133 | } |
---|
134 | } |
---|
135 | |
---|
136 | /// Node ID. |
---|
137 | |
---|
138 | /// The ID of a valid Node is a nonnegative integer not greater than |
---|
139 | /// \ref maxNodeId(). The range of the ID's is not surely continuous |
---|
140 | /// and the greatest node ID can be actually less then \ref maxNodeId(). |
---|
141 | /// |
---|
142 | /// The ID of the \ref INVALID node is -1. |
---|
143 | ///\return The ID of the node \c v. |
---|
144 | |
---|
145 | static int id(Node v) { return v.id; } |
---|
146 | /// Edge ID. |
---|
147 | |
---|
148 | /// The ID of a valid Edge is a nonnegative integer not greater than |
---|
149 | /// \ref maxEdgeId(). The range of the ID's is not surely continuous |
---|
150 | /// and the greatest edge ID can be actually less then \ref maxEdgeId(). |
---|
151 | /// |
---|
152 | /// The ID of the \ref INVALID edge is -1. |
---|
153 | ///\return The ID of the edge \c e. |
---|
154 | static int id(Edge e) { return e.id; } |
---|
155 | |
---|
156 | static Node fromId(int id, Node) { return Node(id);} |
---|
157 | |
---|
158 | static Edge fromId(int id, Edge) { return Edge(id);} |
---|
159 | |
---|
160 | typedef True FindEdgeTag; |
---|
161 | |
---|
162 | /// Finds an edge between two nodes. |
---|
163 | |
---|
164 | /// Finds an edge from node \c u to node \c v. |
---|
165 | /// |
---|
166 | /// If \c prev is \ref INVALID (this is the default value), then |
---|
167 | /// It finds the first edge from \c u to \c v. Otherwise it looks for |
---|
168 | /// the next edge from \c u to \c v after \c prev. |
---|
169 | /// \return The found edge or INVALID if there is no such an edge. |
---|
170 | Edge findEdge(Node u, Node v, Edge prev = INVALID) { |
---|
171 | if (prev != INVALID) return INVALID; |
---|
172 | if (v.id - u.id == _width) return Edge(u.id); |
---|
173 | if (v.id - u.id == 1 && u.id % _width < _width - 1) { |
---|
174 | return Edge(u.id / _width * (_width - 1) + |
---|
175 | u.id % _width + _edgeLimit); |
---|
176 | } |
---|
177 | return INVALID; |
---|
178 | } |
---|
179 | |
---|
180 | |
---|
181 | class Node { |
---|
182 | friend class GridGraphBase; |
---|
183 | |
---|
184 | protected: |
---|
185 | int id; |
---|
186 | Node(int _id) { id = _id;} |
---|
187 | public: |
---|
188 | Node() {} |
---|
189 | Node (Invalid) { id = -1; } |
---|
190 | bool operator==(const Node node) const {return id == node.id;} |
---|
191 | bool operator!=(const Node node) const {return id != node.id;} |
---|
192 | bool operator<(const Node node) const {return id < node.id;} |
---|
193 | }; |
---|
194 | |
---|
195 | |
---|
196 | |
---|
197 | class Edge { |
---|
198 | friend class GridGraphBase; |
---|
199 | |
---|
200 | protected: |
---|
201 | int id; |
---|
202 | |
---|
203 | Edge(int _id) : id(_id) {} |
---|
204 | |
---|
205 | public: |
---|
206 | Edge() { } |
---|
207 | Edge (Invalid) { id = -1; } |
---|
208 | bool operator==(const Edge edge) const {return id == edge.id;} |
---|
209 | bool operator!=(const Edge edge) const {return id != edge.id;} |
---|
210 | bool operator<(const Edge edge) const {return id < edge.id;} |
---|
211 | }; |
---|
212 | |
---|
213 | void first(Node& node) const { |
---|
214 | node.id = nodeNum() - 1; |
---|
215 | } |
---|
216 | |
---|
217 | static void next(Node& node) { |
---|
218 | --node.id; |
---|
219 | } |
---|
220 | |
---|
221 | void first(Edge& edge) const { |
---|
222 | edge.id = edgeNum() - 1; |
---|
223 | } |
---|
224 | |
---|
225 | static void next(Edge& edge) { |
---|
226 | --edge.id; |
---|
227 | } |
---|
228 | |
---|
229 | void firstOut(Edge& edge, const Node& node) const { |
---|
230 | if (node.id < _nodeNum - _width) { |
---|
231 | edge.id = node.id; |
---|
232 | } else if (node.id % _width < _width - 1) { |
---|
233 | edge.id = _edgeLimit + node.id % _width + |
---|
234 | (node.id / _width) * (_width - 1); |
---|
235 | } else { |
---|
236 | edge.id = -1; |
---|
237 | } |
---|
238 | } |
---|
239 | |
---|
240 | void nextOut(Edge& edge) const { |
---|
241 | if (edge.id >= _edgeLimit) { |
---|
242 | edge.id = -1; |
---|
243 | } else if (edge.id % _width < _width - 1) { |
---|
244 | edge.id = _edgeLimit + edge.id % _width + |
---|
245 | (edge.id / _width) * (_width - 1); |
---|
246 | } else { |
---|
247 | edge.id = -1; |
---|
248 | } |
---|
249 | } |
---|
250 | |
---|
251 | void firstIn(Edge& edge, const Node& node) const { |
---|
252 | if (node.id >= _width) { |
---|
253 | edge.id = node.id - _width; |
---|
254 | } else if (node.id % _width > 0) { |
---|
255 | edge.id = _edgeLimit + node.id % _width + |
---|
256 | (node.id / _width) * (_width - 1) - 1; |
---|
257 | } else { |
---|
258 | edge.id = -1; |
---|
259 | } |
---|
260 | } |
---|
261 | |
---|
262 | void nextIn(Edge& edge) const { |
---|
263 | if (edge.id >= _edgeLimit) { |
---|
264 | edge.id = -1; |
---|
265 | } else if (edge.id % _width > 0) { |
---|
266 | edge.id = _edgeLimit + edge.id % _width + |
---|
267 | (edge.id / _width + 1) * (_width - 1) - 1; |
---|
268 | } else { |
---|
269 | edge.id = -1; |
---|
270 | } |
---|
271 | } |
---|
272 | |
---|
273 | private: |
---|
274 | int _width, _height; |
---|
275 | int _nodeNum, _edgeNum; |
---|
276 | int _edgeLimit; |
---|
277 | }; |
---|
278 | |
---|
279 | |
---|
280 | typedef UndirGraphExtender<GridGraphBase> |
---|
281 | UndirGridGraphBase; |
---|
282 | typedef AlterableUndirGraphExtender<UndirGridGraphBase> |
---|
283 | AlterableGridGraphBase; |
---|
284 | typedef IterableUndirGraphExtender<AlterableGridGraphBase> |
---|
285 | IterableGridGraphBase; |
---|
286 | typedef MappableUndirGraphExtender<IterableGridGraphBase> |
---|
287 | MappableGridGraphBase; |
---|
288 | |
---|
289 | /// \ingroup graphs |
---|
290 | /// |
---|
291 | /// \brief Grid graph class |
---|
292 | /// |
---|
293 | /// This class implements a special graph type. The nodes of the |
---|
294 | /// graph can be indiced by two integer \c (i,j) value where \c i |
---|
295 | /// is in the \c [0,height) range and j is in the [0, width) range. |
---|
296 | /// Two nodes are connected in the graph if the indices differ only |
---|
297 | /// on one position and only one is the difference. |
---|
298 | /// |
---|
299 | /// The graph can be indiced in the following way: |
---|
300 | /// \code |
---|
301 | /// GridGraph graph(h, w); |
---|
302 | /// GridGraph::NodeMap<int> val(graph); |
---|
303 | /// for (int i = 0; i < graph.height(); ++i) { |
---|
304 | /// for (int j = 0; j < graph.width(); ++j) { |
---|
305 | /// val[graph(i, j)] = i + j; |
---|
306 | /// } |
---|
307 | /// } |
---|
308 | /// \endcode |
---|
309 | /// |
---|
310 | /// The graph type is fully conform to the \ref concept::UndirGraph |
---|
311 | /// "Undirected Graph" concept. |
---|
312 | /// |
---|
313 | /// \author Balazs Dezso |
---|
314 | class GridGraph : public MappableGridGraphBase { |
---|
315 | public: |
---|
316 | |
---|
317 | GridGraph(int m, int n) { construct(m, n); } |
---|
318 | }; |
---|
319 | } |
---|
320 | #endif |
---|