COIN-OR::LEMON - Graph Library

source: lemon-0.x/lemon/grid_ugraph.h @ 1993:2115143eceea

Last change on this file since 1993:2115143eceea was 1993:2115143eceea, checked in by Balazs Dezso, 14 years ago

utility, invalid and traits moved to bits

File size: 14.0 KB
Line 
1/* -*- C++ -*-
2 *
3 * This file is a part of LEMON, a generic C++ optimization library
4 *
5 * Copyright (C) 2003-2006
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_UGRAPH_H
20#define GRID_UGRAPH_H
21
22#include <iostream>
23#include <lemon/bits/invalid.h>
24#include <lemon/bits/utility.h>
25
26#include <lemon/bits/graph_extender.h>
27
28#include <lemon/xy.h>
29
30///\ingroup graphs
31///\file
32///\brief GridUGraph class.
33
34namespace lemon {
35
36  /// \brief Base graph for GridUGraph.
37  ///
38  /// Base graph for grid graph. It describes some member functions
39  /// which can be used in the GridUGraph.
40  ///
41  /// \warning Always use the GridUGraph instead of this.
42  /// \see GridUGraph
43  class GridUGraphBase {
44
45  public:
46
47    typedef GridUGraphBase UGraph;
48
49    class Node;
50    class Edge;
51
52  public:
53
54    GridUGraphBase() {}
55
56  protected:
57
58    /// \brief Creates a grid graph with the given size.
59    ///
60    /// Creates a grid graph with the given size.
61    void construct(int width, int height) {
62      _height = height; _width = width;
63      _nodeNum = height * width; _edgeNum = 2 * _nodeNum - width - height;
64      _edgeLimit = _nodeNum - width;
65    }
66
67    /// \brief Gives back the edge goes down from the node.
68    ///
69    /// Gives back the edge goes down from the node. If there is not
70    /// outgoing edge then it gives back INVALID.
71    Edge _down(Node n) const {
72      if (n.id < _nodeNum - _width) {
73        return Edge(n.id);
74      } else {
75        return INVALID;
76      }
77    }
78
79    /// \brief Gives back the edge comes from up into the node.
80    ///
81    /// Gives back the edge comes from up into the node. If there is not
82    /// incoming edge then it gives back INVALID.
83    Edge _up(Node n) const {
84      if (n.id >= _width) {
85        return Edge(n.id - _width);
86      } else {
87        return INVALID;
88      }
89    }
90
91    /// \brief Gives back the edge goes right from the node.
92    ///
93    /// Gives back the edge goes right from the node. If there is not
94    /// outgoing edge then it gives back INVALID.
95    Edge _right(Node n) const {
96      if (n.id % _width < _width - 1) {
97        return _edgeLimit + n.id % _width + (n.id / _width) * (_width - 1);
98      } else {
99        return INVALID;
100      }
101    }
102
103    /// \brief Gives back the edge comes from left into the node.
104    ///
105    /// Gives back the edge comes left up into the node. If there is not
106    /// incoming edge then it gives back INVALID.
107    Edge _left(Node n) const {
108      if (n.id % _width > 0) {
109        return _edgeLimit + n.id % _width + (n.id / _width) * (_width - 1) - 1;
110      } else {
111        return INVALID;
112      }
113    }
114
115  public:
116
117    class IndexError : public RuntimeError {
118    public:
119      virtual const char* exceptionName() const {
120        return "lemon::GridUGraph::IndexError";
121      } 
122    };
123
124   
125    /// \brief The node on the given position.
126    ///
127    /// Gives back the node on the given position.
128    Node operator()(int i, int j) const {
129      LEMON_ASSERT(0 <= i && i < width() && 0 <= j  &&
130                   j < height(), IndexError());
131      return Node(i + j * _width);
132    }
133
134    /// \brief Gives back the row index of the node.
135    ///
136    /// Gives back the row index of the node.
137    int row(Node n) const {
138      return n.id / _width;
139    }
140   
141    /// \brief Gives back the coloumn index of the node.
142    ///
143    /// Gives back the coloumn index of the node.
144    int col(Node n) const {
145      return n.id % _width;   
146    }
147
148    /// \brief Gives back the width of the graph.
149    ///
150    /// Gives back the width of the graph.
151    int width() const {
152      return _width;
153    }
154
155    /// \brief Gives back the height of the graph.
156    ///
157    /// Gives back the height of the graph.
158    int height() const {
159      return _height;
160    }
161
162    typedef True NodeNumTag;
163    typedef True EdgeNumTag;
164
165    ///Number of nodes.
166    int nodeNum() const { return _nodeNum; }
167    ///Number of edges.
168    int edgeNum() const { return _edgeNum; }
169
170    /// Maximum node ID.
171   
172    /// Maximum node ID.
173    ///\sa id(Node)
174    int maxNodeId() const { return nodeNum() - 1; }
175    /// Maximum edge ID.
176   
177    /// Maximum edge ID.
178    ///\sa id(Edge)
179    int maxEdgeId() const { return edgeNum() - 1; }
180
181    /// \brief Gives back the source node of an edge.
182    ///   
183    /// Gives back the source node of an edge.
184    Node source(Edge e) const {
185      if (e.id < _edgeLimit) {
186        return e.id;
187      } else {
188        return (e.id - _edgeLimit) % (_width - 1) +
189          (e.id - _edgeLimit) / (_width - 1) * _width;
190      }
191    }
192
193    /// \brief Gives back the target node of an edge.
194    ///   
195    /// Gives back the target node of an edge.
196    Node target(Edge e) const {
197      if (e.id < _edgeLimit) {
198        return e.id + _width;
199      } else {
200        return (e.id - _edgeLimit) % (_width - 1) +
201          (e.id - _edgeLimit) / (_width - 1) * _width + 1;
202      }
203    }
204
205    /// Node ID.
206   
207    /// The ID of a valid Node is a nonnegative integer not greater than
208    /// \ref maxNodeId(). The range of the ID's is not surely continuous
209    /// and the greatest node ID can be actually less then \ref maxNodeId().
210    ///
211    /// The ID of the \ref INVALID node is -1.
212    ///\return The ID of the node \c v.
213
214    static int id(Node v) { return v.id; }
215    /// Edge ID.
216   
217    /// The ID of a valid Edge is a nonnegative integer not greater than
218    /// \ref maxEdgeId(). The range of the ID's is not surely continuous
219    /// and the greatest edge ID can be actually less then \ref maxEdgeId().
220    ///
221    /// The ID of the \ref INVALID edge is -1.
222    ///\return The ID of the edge \c e.
223    static int id(Edge e) { return e.id; }
224
225    static Node nodeFromId(int id) { return Node(id);}
226   
227    static Edge edgeFromId(int id) { return Edge(id);}
228
229    typedef True FindEdgeTag;
230
231    /// Finds an edge between two nodes.
232   
233    /// Finds an edge from node \c u to node \c v.
234    ///
235    /// If \c prev is \ref INVALID (this is the default value), then
236    /// It finds the first edge from \c u to \c v. Otherwise it looks for
237    /// the next edge from \c u to \c v after \c prev.
238    /// \return The found edge or INVALID if there is no such an edge.
239    Edge findEdge(Node u, Node v, Edge prev = INVALID) const {
240      if (prev != INVALID) return INVALID;
241      if (v.id - u.id == _width) return Edge(u.id);
242      if (v.id - u.id == 1 && u.id % _width < _width - 1) {
243        return Edge(u.id / _width * (_width - 1) +
244                    u.id % _width + _edgeLimit);
245      }
246      return INVALID;
247    }
248   
249     
250    class Node {
251      friend class GridUGraphBase;
252
253    protected:
254      int id;
255      Node(int _id) { id = _id;}
256    public:
257      Node() {}
258      Node (Invalid) { id = -1; }
259      bool operator==(const Node node) const {return id == node.id;}
260      bool operator!=(const Node node) const {return id != node.id;}
261      bool operator<(const Node node) const {return id < node.id;}
262    };
263   
264
265
266    class Edge {
267      friend class GridUGraphBase;
268     
269    protected:
270      int id;
271
272      Edge(int _id) : id(_id) {}
273
274    public:
275      Edge() { }
276      Edge (Invalid) { id = -1; }
277      bool operator==(const Edge edge) const {return id == edge.id;}
278      bool operator!=(const Edge edge) const {return id != edge.id;}
279      bool operator<(const Edge edge) const {return id < edge.id;}
280    };
281
282    void first(Node& node) const {
283      node.id = nodeNum() - 1;
284    }
285
286    static void next(Node& node) {
287      --node.id;
288    }
289
290    void first(Edge& edge) const {
291      edge.id = edgeNum() - 1;
292    }
293
294    static void next(Edge& edge) {
295      --edge.id;
296    }
297
298    void firstOut(Edge& edge, const Node& node) const {
299      if (node.id < _nodeNum - _width) {
300        edge.id = node.id;
301      } else if (node.id % _width < _width - 1) {
302        edge.id = _edgeLimit + node.id % _width +
303          (node.id / _width) * (_width - 1);
304      } else {
305        edge.id = -1;
306      }
307    }
308
309    void nextOut(Edge& edge) const {
310      if (edge.id >= _edgeLimit) {
311        edge.id = -1;
312      } else if (edge.id % _width < _width - 1) {
313        edge.id = _edgeLimit + edge.id % _width +
314          (edge.id / _width) * (_width - 1);
315      } else {
316        edge.id = -1;
317      }
318    }
319
320    void firstIn(Edge& edge, const Node& node) const {
321      if (node.id >= _width) {
322        edge.id = node.id - _width;
323      } else if (node.id % _width > 0) {
324        edge.id = _edgeLimit + node.id % _width +
325          (node.id / _width) * (_width - 1) - 1;
326      } else {
327        edge.id = -1;
328      }
329    }
330   
331    void nextIn(Edge& edge) const {
332      if (edge.id >= _edgeLimit) {
333        edge.id = -1;
334      } else if (edge.id % _width > 0) {
335        edge.id = _edgeLimit + edge.id % _width +
336          (edge.id / _width + 1) * (_width - 1) - 1;
337      } else {
338        edge.id = -1;
339      }
340    }
341
342  private:
343    int _width, _height;
344    int _nodeNum, _edgeNum;
345    int _edgeLimit;
346  };
347
348
349  typedef UGraphExtender<UGraphBaseExtender<
350    GridUGraphBase> > ExtendedGridUGraphBase;
351
352  /// \ingroup graphs
353  ///
354  /// \brief Grid graph class
355  ///
356  /// This class implements a special graph type. The nodes of the
357  /// graph can be indiced by two integer \c (i,j) value where \c i
358  /// is in the \c [0,width) range and j is in the [0, height) range.
359  /// Two nodes are connected in the graph if the indices differ only
360  /// on one position and only one is the difference.
361  ///
362  /// The graph can be indiced in the following way:
363  ///\code
364  /// GridUGraph graph(w, h);
365  /// GridUGraph::NodeMap<int> val(graph);
366  /// for (int i = 0; i < graph.width(); ++i) {
367  ///   for (int j = 0; j < graph.height(); ++j) {
368  ///     val[graph(i, j)] = i + j;
369  ///   }
370  /// }
371  ///\endcode
372  ///
373  /// The graph type is fully conform to the \ref concept::UUGraph
374  /// "Undirected UGraph" concept.
375  ///
376  /// \author Balazs Dezso
377  /// \see GridUGraphBase
378  class GridUGraph : public ExtendedGridUGraphBase {
379  public:
380
381    typedef ExtendedGridUGraphBase Parent;
382
383    /// \brief Map to get the indices of the nodes as xy<int>.
384    ///
385    /// Map to get the indices of the nodes as xy<int>.
386    class IndexMap {
387    public:
388      /// \brief The key type of the map
389      typedef GridUGraph::Node Key;
390      /// \brief The value type of the map
391      typedef xy<int> Value;
392
393      /// \brief Constructor
394      ///
395      /// Constructor
396      IndexMap(const GridUGraph& _graph) : graph(_graph) {}
397
398      /// \brief The subscript operator
399      ///
400      /// The subscript operator.
401      Value operator[](Key key) const {
402        return xy<int>(graph.row(key), graph.col(key));
403      }
404
405    private:
406      const GridUGraph& graph;
407    };
408
409    /// \brief Map to get the row of the nodes.
410    ///
411    /// Map to get the row of the nodes.
412    class RowMap {
413    public:
414      /// \brief The key type of the map
415      typedef GridUGraph::Node Key;
416      /// \brief The value type of the map
417      typedef int Value;
418
419      /// \brief Constructor
420      ///
421      /// Constructor
422      RowMap(const GridUGraph& _graph) : graph(_graph) {}
423
424      /// \brief The subscript operator
425      ///
426      /// The subscript operator.
427      Value operator[](Key key) const {
428        return graph.row(key);
429      }
430
431    private:
432      const GridUGraph& graph;
433    };
434
435    /// \brief Map to get the column of the nodes.
436    ///
437    /// Map to get the column of the nodes.
438    class ColMap {
439    public:
440      /// \brief The key type of the map
441      typedef GridUGraph::Node Key;
442      /// \brief The value type of the map
443      typedef int Value;
444
445      /// \brief Constructor
446      ///
447      /// Constructor
448      ColMap(const GridUGraph& _graph) : graph(_graph) {}
449
450      /// \brief The subscript operator
451      ///
452      /// The subscript operator.
453      Value operator[](Key key) const {
454        return graph.col(key);
455      }
456
457    private:
458      const GridUGraph& graph;
459    };
460
461    /// \brief Constructor
462    ///
463    ///
464    GridUGraph(int n, int m) { construct(n, m); }
465
466    /// \brief Resize the graph
467    ///
468    void resize(int n, int m) {
469      Parent::getNotifier(Edge()).clear();
470      Parent::getNotifier(UEdge()).clear();
471      Parent::getNotifier(Node()).clear();
472      construct(n, m);
473      Parent::getNotifier(Node()).build();
474      Parent::getNotifier(UEdge()).build();
475      Parent::getNotifier(Edge()).build();
476    }
477   
478    /// \brief Gives back the edge goes down from the node.
479    ///
480    /// Gives back the edge goes down from the node. If there is not
481    /// outgoing edge then it gives back INVALID.
482    Edge down(Node n) const {
483      UEdge ue = _down(n);
484      return ue != INVALID ? direct(ue, true) : INVALID;
485    }
486   
487    /// \brief Gives back the edge goes up from the node.
488    ///
489    /// Gives back the edge goes up from the node. If there is not
490    /// outgoing edge then it gives back INVALID.
491    Edge up(Node n) const {
492      UEdge ue = _up(n);
493      return ue != INVALID ? direct(ue, false) : INVALID;
494    }
495
496    /// \brief Gives back the edge goes right from the node.
497    ///
498    /// Gives back the edge goes right from the node. If there is not
499    /// outgoing edge then it gives back INVALID.
500    Edge right(Node n) const {
501      UEdge ue = _right(n);
502      return ue != INVALID ? direct(ue, true) : INVALID;
503    }
504
505    /// \brief Gives back the edge goes left from the node.
506    ///
507    /// Gives back the edge goes left from the node. If there is not
508    /// outgoing edge then it gives back INVALID.
509    Edge left(Node n) const {
510      UEdge ue = _left(n);
511      return ue != INVALID ? direct(ue, false) : INVALID;
512    }
513   
514  };
515
516  /// \brief Index map of the grid graph
517  ///
518  /// Just returns an IndexMap for the grid graph.
519  GridUGraph::IndexMap indexMap(const GridUGraph& graph) {
520    return GridUGraph::IndexMap(graph);
521  }
522
523  /// \brief Row map of the grid graph
524  ///
525  /// Just returns a RowMap for the grid graph.
526  GridUGraph::RowMap rowMap(const GridUGraph& graph) {
527    return GridUGraph::RowMap(graph);
528  }
529
530  /// \brief Column map of the grid graph
531  ///
532  /// Just returns a ColMap for the grid graph.
533  GridUGraph::ColMap colMap(const GridUGraph& graph) {
534    return GridUGraph::ColMap(graph);
535  }
536}
537#endif
Note: See TracBrowser for help on using the repository browser.