| 1 | /* -*- mode: C++; indent-tabs-mode: nil; -*- |
| 2 | * |
| 3 | * This file is a part of LEMON, a generic C++ optimization library. |
| 4 | * |
| 5 | * Copyright (C) 2003-2008 |
| 6 | * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
| 7 | * (Egervary Research Group on Combinatorial Optimization, EGRES). |
| 8 | * |
| 9 | * Permission to use, modify and distribute this software is granted |
| 10 | * provided that this copyright notice appears in all copies. For |
| 11 | * precise terms see the accompanying LICENSE file. |
| 12 | * |
| 13 | * This software is provided "AS IS" with no warranty of any kind, |
| 14 | * express or implied, and with no claim as to its suitability for any |
| 15 | * purpose. |
| 16 | * |
| 17 | */ |
| 18 | |
| 19 | #ifndef GRID_GRAPH_H |
| 20 | #define GRID_GRAPH_H |
| 21 | |
| 22 | #include <iostream> |
| 23 | #include <lemon/core.h> |
| 24 | #include <lemon/assert.h> |
| 25 | |
| 26 | #include <lemon/bits/base_extender.h> |
| 27 | #include <lemon/bits/graph_extender.h> |
| 28 | |
| 29 | #include <lemon/dim2.h> |
| 30 | |
| 31 | ///\ingroup graphs |
| 32 | ///\file |
| 33 | ///\brief GridGraph class. |
| 34 | |
| 35 | namespace lemon { |
| 36 | |
| 37 | class GridGraphBase { |
| 38 | |
| 39 | public: |
| 40 | |
| 41 | typedef GridGraphBase Graph; |
| 42 | |
| 43 | class Node; |
| 44 | class Arc; |
| 45 | |
| 46 | public: |
| 47 | |
| 48 | GridGraphBase() {} |
| 49 | |
| 50 | protected: |
| 51 | |
| 52 | void construct(int w, int h) { |
| 53 | _height = h; _width = w; |
| 54 | _nodeNum = h * w; _arcNum = 2 * _nodeNum - w - h; |
| 55 | _arcLimit = _nodeNum - w; |
| 56 | } |
| 57 | |
| 58 | Arc _down(Node n) const { |
| 59 | if (n.id < _nodeNum - _width) { |
| 60 | return Arc(n.id); |
| 61 | } else { |
| 62 | return INVALID; |
| 63 | } |
| 64 | } |
| 65 | |
| 66 | Arc _up(Node n) const { |
| 67 | if (n.id >= _width) { |
| 68 | return Arc(n.id - _width); |
| 69 | } else { |
| 70 | return INVALID; |
| 71 | } |
| 72 | } |
| 73 | |
| 74 | Arc _right(Node n) const { |
| 75 | if (n.id % _width < _width - 1) { |
| 76 | return _arcLimit + n.id % _width + (n.id / _width) * (_width - 1); |
| 77 | } else { |
| 78 | return INVALID; |
| 79 | } |
| 80 | } |
| 81 | |
| 82 | Arc _left(Node n) const { |
| 83 | if (n.id % _width > 0) { |
| 84 | return _arcLimit + n.id % _width + (n.id / _width) * (_width - 1) - 1; |
| 85 | } else { |
| 86 | return INVALID; |
| 87 | } |
| 88 | } |
| 89 | |
| 90 | public: |
| 91 | |
| 92 | Node operator()(int i, int j) const { |
| 93 | LEMON_ASSERT(0 <= i && i < width() && |
| 94 | 0 <= j && j < height(), "lemon::GridGraph::IndexError"); |
| 95 | return Node(i + j * _width); |
| 96 | } |
| 97 | |
| 98 | int row(Node n) const { |
| 99 | return n.id / _width; |
| 100 | } |
| 101 | |
| 102 | int col(Node n) const { |
| 103 | return n.id % _width; |
| 104 | } |
| 105 | |
| 106 | int width() const { |
| 107 | return _width; |
| 108 | } |
| 109 | |
| 110 | int height() const { |
| 111 | return _height; |
| 112 | } |
| 113 | |
| 114 | typedef True NodeNumTag; |
| 115 | typedef True ArcNumTag; |
| 116 | |
| 117 | int nodeNum() const { return _nodeNum; } |
| 118 | int arcNum() const { return _arcNum; } |
| 119 | |
| 120 | int maxNodeId() const { return nodeNum() - 1; } |
| 121 | int maxArcId() const { return arcNum() - 1; } |
| 122 | |
| 123 | Node source(Arc e) const { |
| 124 | if (e.id < _arcLimit) { |
| 125 | return e.id; |
| 126 | } else { |
| 127 | return (e.id - _arcLimit) % (_width - 1) + |
| 128 | (e.id - _arcLimit) / (_width - 1) * _width; |
| 129 | } |
| 130 | } |
| 131 | |
| 132 | Node target(Arc e) const { |
| 133 | if (e.id < _arcLimit) { |
| 134 | return e.id + _width; |
| 135 | } else { |
| 136 | return (e.id - _arcLimit) % (_width - 1) + |
| 137 | (e.id - _arcLimit) / (_width - 1) * _width + 1; |
| 138 | } |
| 139 | } |
| 140 | |
| 141 | static int id(Node v) { return v.id; } |
| 142 | static int id(Arc e) { return e.id; } |
| 143 | |
| 144 | static Node nodeFromId(int id) { return Node(id);} |
| 145 | |
| 146 | static Arc arcFromId(int id) { return Arc(id);} |
| 147 | |
| 148 | typedef True FindArcTag; |
| 149 | |
| 150 | Arc findArc(Node u, Node v, Arc prev = INVALID) const { |
| 151 | if (prev != INVALID) return INVALID; |
| 152 | if (v.id - u.id == _width) return Arc(u.id); |
| 153 | if (v.id - u.id == 1 && u.id % _width < _width - 1) { |
| 154 | return Arc(u.id / _width * (_width - 1) + |
| 155 | u.id % _width + _arcLimit); |
| 156 | } |
| 157 | return INVALID; |
| 158 | } |
| 159 | |
| 160 | class Node { |
| 161 | friend class GridGraphBase; |
| 162 | |
| 163 | protected: |
| 164 | int id; |
| 165 | Node(int _id) : id(_id) {} |
| 166 | public: |
| 167 | Node() {} |
| 168 | Node (Invalid) { id = -1; } |
| 169 | bool operator==(const Node node) const { return id == node.id; } |
| 170 | bool operator!=(const Node node) const { return id != node.id; } |
| 171 | bool operator<(const Node node) const { return id < node.id; } |
| 172 | }; |
| 173 | |
| 174 | class Arc { |
| 175 | friend class GridGraphBase; |
| 176 | |
| 177 | protected: |
| 178 | int id; |
| 179 | Arc(int _id) : id(_id) {} |
| 180 | public: |
| 181 | Arc() {} |
| 182 | Arc (Invalid) { id = -1; } |
| 183 | bool operator==(const Arc arc) const { return id == arc.id; } |
| 184 | bool operator!=(const Arc arc) const { return id != arc.id; } |
| 185 | bool operator<(const Arc arc) const { return id < arc.id; } |
| 186 | }; |
| 187 | |
| 188 | void first(Node& node) const { |
| 189 | node.id = nodeNum() - 1; |
| 190 | } |
| 191 | |
| 192 | static void next(Node& node) { |
| 193 | --node.id; |
| 194 | } |
| 195 | |
| 196 | void first(Arc& arc) const { |
| 197 | arc.id = arcNum() - 1; |
| 198 | } |
| 199 | |
| 200 | static void next(Arc& arc) { |
| 201 | --arc.id; |
| 202 | } |
| 203 | |
| 204 | void firstOut(Arc& arc, const Node& node) const { |
| 205 | if (node.id < _nodeNum - _width) { |
| 206 | arc.id = node.id; |
| 207 | } else if (node.id % _width < _width - 1) { |
| 208 | arc.id = _arcLimit + node.id % _width + |
| 209 | (node.id / _width) * (_width - 1); |
| 210 | } else { |
| 211 | arc.id = -1; |
| 212 | } |
| 213 | } |
| 214 | |
| 215 | void nextOut(Arc& arc) const { |
| 216 | if (arc.id >= _arcLimit) { |
| 217 | arc.id = -1; |
| 218 | } else if (arc.id % _width < _width - 1) { |
| 219 | arc.id = _arcLimit + arc.id % _width + |
| 220 | (arc.id / _width) * (_width - 1); |
| 221 | } else { |
| 222 | arc.id = -1; |
| 223 | } |
| 224 | } |
| 225 | |
| 226 | void firstIn(Arc& arc, const Node& node) const { |
| 227 | if (node.id >= _width) { |
| 228 | arc.id = node.id - _width; |
| 229 | } else if (node.id % _width > 0) { |
| 230 | arc.id = _arcLimit + node.id % _width + |
| 231 | (node.id / _width) * (_width - 1) - 1; |
| 232 | } else { |
| 233 | arc.id = -1; |
| 234 | } |
| 235 | } |
| 236 | |
| 237 | void nextIn(Arc& arc) const { |
| 238 | if (arc.id >= _arcLimit) { |
| 239 | arc.id = -1; |
| 240 | } else if (arc.id % _width > 0) { |
| 241 | arc.id = _arcLimit + arc.id % _width + |
| 242 | (arc.id / _width + 1) * (_width - 1) - 1; |
| 243 | } else { |
| 244 | arc.id = -1; |
| 245 | } |
| 246 | } |
| 247 | |
| 248 | private: |
| 249 | int _width, _height; |
| 250 | int _nodeNum, _arcNum; |
| 251 | int _arcLimit; |
| 252 | }; |
| 253 | |
| 254 | typedef GraphExtender<UndirDigraphExtender<GridGraphBase> > |
| 255 | ExtendedGridGraphBase; |
| 256 | |
| 257 | /// \ingroup graphs |
| 258 | /// |
| 259 | /// \brief Grid graph class |
| 260 | /// |
| 261 | /// This class implements a special graph type. The nodes of the |
| 262 | /// graph can be indiced by two integer \c (i,j) value where \c i |
| 263 | /// is in the \c [0,width) range and j is in the [0, height) range. |
| 264 | /// Two nodes are connected in the graph if the indices differ only |
| 265 | /// on one position and only one is the difference. |
| 266 | /// |
| 267 | /// \image html grid_graph.png |
| 268 | /// \image latex grid_graph.eps "Grid graph" width=\textwidth |
| 269 | /// |
| 270 | /// The graph can be indiced in the following way: |
| 271 | ///\code |
| 272 | /// GridGraph gr(w, h); |
| 273 | /// GridGraph::NodeMap<int> val(gr); |
| 274 | /// for (int i = 0; i < gr.width(); ++i) { |
| 275 | /// for (int j = 0; j < gr.height(); ++j) { |
| 276 | /// val[gr(i, j)] = i + j; |
| 277 | /// } |
| 278 | /// } |
| 279 | ///\endcode |
| 280 | /// |
| 281 | /// This graph type is fully conform to the \ref concepts::Graph |
| 282 | /// "Undirected Graph" concept, and it also has an important extra |
| 283 | /// feature that its maps are real \ref concepts::ReferenceMap |
| 284 | /// "reference map"s. |
| 285 | class GridGraph : public ExtendedGridGraphBase { |
| 286 | public: |
| 287 | |
| 288 | typedef ExtendedGridGraphBase Parent; |
| 289 | |
| 290 | /// \brief Map to get the indices of the nodes as dim2::Point<int>. |
| 291 | /// |
| 292 | /// Map to get the indices of the nodes as dim2::Point<int>. |
| 293 | class IndexMap { |
| 294 | public: |
| 295 | /// The key type of the map |
| 296 | typedef GridGraph::Node Key; |
| 297 | /// The value type of the map |
| 298 | typedef dim2::Point<int> Value; |
| 299 | |
| 300 | /// Constructor |
| 301 | IndexMap(const GridGraph& graph) : _graph(graph) {} |
| 302 | |
| 303 | /// The subscript operator |
| 304 | Value operator[](const Key& key) const { |
| 305 | return dim2::Point<int>(_graph.row(key), _graph.col(key)); |
| 306 | } |
| 307 | |
| 308 | private: |
| 309 | const GridGraph& _graph; |
| 310 | }; |
| 311 | |
| 312 | /// \brief Map to get the row of the nodes. |
| 313 | /// |
| 314 | /// Map to get the row of the nodes. |
| 315 | class RowMap { |
| 316 | public: |
| 317 | /// The key type of the map |
| 318 | typedef GridGraph::Node Key; |
| 319 | /// The value type of the map |
| 320 | typedef int Value; |
| 321 | |
| 322 | /// Constructor |
| 323 | RowMap(const GridGraph& graph) : _graph(graph) {} |
| 324 | |
| 325 | /// The subscript operator |
| 326 | Value operator[](const Key& key) const { |
| 327 | return _graph.row(key); |
| 328 | } |
| 329 | |
| 330 | private: |
| 331 | const GridGraph& _graph; |
| 332 | }; |
| 333 | |
| 334 | /// \brief Map to get the column of the nodes. |
| 335 | /// |
| 336 | /// Map to get the column of the nodes. |
| 337 | class ColMap { |
| 338 | public: |
| 339 | /// The key type of the map |
| 340 | typedef GridGraph::Node Key; |
| 341 | /// The value type of the map |
| 342 | typedef int Value; |
| 343 | |
| 344 | /// Constructor |
| 345 | ColMap(const GridGraph& graph) : _graph(graph) {} |
| 346 | |
| 347 | /// The subscript operator |
| 348 | Value operator[](const Key& key) const { |
| 349 | return _graph.col(key); |
| 350 | } |
| 351 | |
| 352 | private: |
| 353 | const GridGraph& _graph; |
| 354 | }; |
| 355 | |
| 356 | /// \brief Constructor |
| 357 | /// |
| 358 | /// Constructor. |
| 359 | /// \param width The width of the grid. |
| 360 | /// \param height The height of the grid. |
| 361 | GridGraph(int width, int height) { construct(width, height); } |
| 362 | |
| 363 | /// \brief Resize the graph |
| 364 | /// |
| 365 | /// Resize the grid. |
| 366 | void resize(int width, int height) { |
| 367 | Parent::notifier(Arc()).clear(); |
| 368 | Parent::notifier(Edge()).clear(); |
| 369 | Parent::notifier(Node()).clear(); |
| 370 | construct(width, height); |
| 371 | Parent::notifier(Node()).build(); |
| 372 | Parent::notifier(Edge()).build(); |
| 373 | Parent::notifier(Arc()).build(); |
| 374 | } |
| 375 | |
| 376 | /// \brief The node on the given position. |
| 377 | /// |
| 378 | /// Gives back the node on the given position. |
| 379 | Node operator()(int i, int j) const { |
| 380 | return Parent::operator()(i, j); |
| 381 | } |
| 382 | |
| 383 | /// \brief Gives back the row index of the node. |
| 384 | /// |
| 385 | /// Gives back the row index of the node. |
| 386 | int row(Node n) const { |
| 387 | return Parent::row(n); |
| 388 | } |
| 389 | |
| 390 | /// \brief Gives back the column index of the node. |
| 391 | /// |
| 392 | /// Gives back the column index of the node. |
| 393 | int col(Node n) const { |
| 394 | return Parent::col(n); |
| 395 | } |
| 396 | |
| 397 | /// \brief Gives back the width of the grid. |
| 398 | /// |
| 399 | /// Gives back the width of the grid. |
| 400 | int width() const { |
| 401 | return Parent::width(); |
| 402 | } |
| 403 | |
| 404 | /// \brief Gives back the height of the grid. |
| 405 | /// |
| 406 | /// Gives back the height of the grid. |
| 407 | int height() const { |
| 408 | return Parent::height(); |
| 409 | } |
| 410 | |
| 411 | /// \brief Gives back the arc goes down from the node. |
| 412 | /// |
| 413 | /// Gives back the arc goes down from the node. If there is not |
| 414 | /// outgoing arc then it gives back \c INVALID. |
| 415 | Arc down(Node n) const { |
| 416 | Edge e = _down(n); |
| 417 | return e != INVALID ? direct(e, true) : INVALID; |
| 418 | } |
| 419 | |
| 420 | /// \brief Gives back the arc goes up from the node. |
| 421 | /// |
| 422 | /// Gives back the arc goes up from the node. If there is not |
| 423 | /// outgoing arc then it gives back \c INVALID. |
| 424 | Arc up(Node n) const { |
| 425 | Edge e = _up(n); |
| 426 | return e != INVALID ? direct(e, false) : INVALID; |
| 427 | } |
| 428 | |
| 429 | /// \brief Gives back the arc goes right from the node. |
| 430 | /// |
| 431 | /// Gives back the arc goes right from the node. If there is not |
| 432 | /// outgoing arc then it gives back \c INVALID. |
| 433 | Arc right(Node n) const { |
| 434 | Edge e = _right(n); |
| 435 | return e != INVALID ? direct(e, true) : INVALID; |
| 436 | } |
| 437 | |
| 438 | /// \brief Gives back the arc goes left from the node. |
| 439 | /// |
| 440 | /// Gives back the arc goes left from the node. If there is not |
| 441 | /// outgoing arc then it gives back \c INVALID. |
| 442 | Arc left(Node n) const { |
| 443 | Edge e = _left(n); |
| 444 | return e != INVALID ? direct(e, false) : INVALID; |
| 445 | } |
| 446 | |
| 447 | }; // class GridGraph |
| 448 | |
| 449 | /// \brief Index map of the grid graph |
| 450 | /// |
| 451 | /// Just returns an IndexMap for the grid graph. |
| 452 | inline GridGraph::IndexMap indexMap(const GridGraph& graph) { |
| 453 | return GridGraph::IndexMap(graph); |
| 454 | } |
| 455 | |
| 456 | /// \brief Row map of the grid graph |
| 457 | /// |
| 458 | /// Just returns a RowMap for the grid graph. |
| 459 | inline GridGraph::RowMap rowMap(const GridGraph& graph) { |
| 460 | return GridGraph::RowMap(graph); |
| 461 | } |
| 462 | |
| 463 | /// \brief Column map of the grid graph |
| 464 | /// |
| 465 | /// Just returns a ColMap for the grid graph. |
| 466 | inline GridGraph::ColMap colMap(const GridGraph& graph) { |
| 467 | return GridGraph::ColMap(graph); |
| 468 | } |
| 469 | } |
| 470 | |
| 471 | #endif // GRID_GRAPH_H |