COIN-OR::LEMON - Graph Library

source: lemon-0.x/lemon/concepts/ugraph.h

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[2260]1/* -*- C++ -*-
2 *
3 * This file is a part of LEMON, a generic C++ optimization library
4 *
[2553]5 * Copyright (C) 2003-2008
[2260]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///\ingroup graph_concepts
20///\file
[2474]21///\brief The concept of Undirected Graphs.
[2260]22
23#ifndef LEMON_CONCEPT_UGRAPH_H
24#define LEMON_CONCEPT_UGRAPH_H
25
26#include <lemon/concepts/graph_components.h>
27#include <lemon/concepts/graph.h>
28#include <lemon/bits/utility.h>
29
30namespace lemon {
31  namespace concepts {
32
[2485]33    /// \ingroup graph_concepts
[2474]34    ///
[2260]35    /// \brief Class describing the concept of Undirected Graphs.
36    ///
37    /// This class describes the common interface of all Undirected
38    /// Graphs.
39    ///
40    /// As all concept describing classes it provides only interface
41    /// without any sensible implementation. So any algorithm for
42    /// undirected graph should compile with this class, but it will not
43    /// run properly, of course.
44    ///
45    /// The LEMON undirected graphs also fulfill the concept of
46    /// directed graphs (\ref lemon::concepts::Graph "Graph
47    /// Concept"). Each undirected edges can be seen as two opposite
48    /// directed edge and consequently the undirected graph can be
49    /// seen as the direceted graph of these directed edges. The
50    /// UGraph has the UEdge inner class for the undirected edges and
51    /// the Edge type for the directed edges. The Edge type is
52    /// convertible to UEdge or inherited from it so from a directed
53    /// edge we can get the represented undirected edge.
54    ///
55    /// In the sense of the LEMON each undirected edge has a default
56    /// direction (it should be in every computer implementation,
57    /// because the order of undirected edge's nodes defines an
58    /// orientation). With the default orientation we can define that
59    /// the directed edge is forward or backward directed. With the \c
60    /// direction() and \c direct() function we can get the direction
61    /// of the directed edge and we can direct an undirected edge.
62    ///
63    /// The UEdgeIt is an iterator for the undirected edges. We can use
64    /// the UEdgeMap to map values for the undirected edges. The InEdgeIt and
65    /// OutEdgeIt iterates on the same undirected edges but with opposite
66    /// direction. The IncEdgeIt iterates also on the same undirected edges
67    /// as the OutEdgeIt and InEdgeIt but it is not convertible to Edge just
68    /// to UEdge. 
69    class UGraph {
70    public:
71      /// \brief The undirected graph should be tagged by the
72      /// UndirectedTag.
73      ///
74      /// The undirected graph should be tagged by the UndirectedTag. This
75      /// tag helps the enable_if technics to make compile time
76      /// specializations for undirected graphs. 
77      typedef True UndirectedTag;
78
79      /// \brief The base type of node iterators,
80      /// or in other words, the trivial node iterator.
81      ///
82      /// This is the base type of each node iterator,
83      /// thus each kind of node iterator converts to this.
84      /// More precisely each kind of node iterator should be inherited
85      /// from the trivial node iterator.
86      class Node {
87      public:
88        /// Default constructor
89
90        /// @warning The default constructor sets the iterator
91        /// to an undefined value.
92        Node() { }
93        /// Copy constructor.
94
95        /// Copy constructor.
96        ///
97        Node(const Node&) { }
98
99        /// Invalid constructor \& conversion.
100
101        /// This constructor initializes the iterator to be invalid.
102        /// \sa Invalid for more details.
103        Node(Invalid) { }
104        /// Equality operator
105
106        /// Two iterators are equal if and only if they point to the
107        /// same object or both are invalid.
108        bool operator==(Node) const { return true; }
109
110        /// Inequality operator
111       
112        /// \sa operator==(Node n)
113        ///
114        bool operator!=(Node) const { return true; }
115
116        /// Artificial ordering operator.
117       
118        /// To allow the use of graph descriptors as key type in std::map or
119        /// similar associative container we require this.
120        ///
121        /// \note This operator only have to define some strict ordering of
122        /// the items; this order has nothing to do with the iteration
123        /// ordering of the items.
124        bool operator<(Node) const { return false; }
125
126      };
127   
128      /// This iterator goes through each node.
129
130      /// This iterator goes through each node.
131      /// Its usage is quite simple, for example you can count the number
132      /// of nodes in graph \c g of type \c Graph like this:
133      ///\code
134      /// int count=0;
135      /// for (Graph::NodeIt n(g); n!=INVALID; ++n) ++count;
136      ///\endcode
137      class NodeIt : public Node {
138      public:
139        /// Default constructor
140
141        /// @warning The default constructor sets the iterator
142        /// to an undefined value.
143        NodeIt() { }
144        /// Copy constructor.
145       
146        /// Copy constructor.
147        ///
148        NodeIt(const NodeIt& n) : Node(n) { }
149        /// Invalid constructor \& conversion.
150
151        /// Initialize the iterator to be invalid.
152        /// \sa Invalid for more details.
153        NodeIt(Invalid) { }
154        /// Sets the iterator to the first node.
155
156        /// Sets the iterator to the first node of \c g.
157        ///
158        NodeIt(const UGraph&) { }
159        /// Node -> NodeIt conversion.
160
161        /// Sets the iterator to the node of \c the graph pointed by
162        /// the trivial iterator.
163        /// This feature necessitates that each time we
164        /// iterate the edge-set, the iteration order is the same.
165        NodeIt(const UGraph&, const Node&) { }
166        /// Next node.
167
168        /// Assign the iterator to the next node.
169        ///
170        NodeIt& operator++() { return *this; }
171      };
172   
173   
174      /// The base type of the undirected edge iterators.
175
176      /// The base type of the undirected edge iterators.
177      ///
178      class UEdge {
179      public:
180        /// Default constructor
181
182        /// @warning The default constructor sets the iterator
183        /// to an undefined value.
184        UEdge() { }
185        /// Copy constructor.
186
187        /// Copy constructor.
188        ///
189        UEdge(const UEdge&) { }
190        /// Initialize the iterator to be invalid.
191
192        /// Initialize the iterator to be invalid.
193        ///
194        UEdge(Invalid) { }
195        /// Equality operator
196
197        /// Two iterators are equal if and only if they point to the
198        /// same object or both are invalid.
199        bool operator==(UEdge) const { return true; }
200        /// Inequality operator
201
202        /// \sa operator==(UEdge n)
203        ///
204        bool operator!=(UEdge) const { return true; }
205
206        /// Artificial ordering operator.
207       
208        /// To allow the use of graph descriptors as key type in std::map or
209        /// similar associative container we require this.
210        ///
211        /// \note This operator only have to define some strict ordering of
212        /// the items; this order has nothing to do with the iteration
213        /// ordering of the items.
214        bool operator<(UEdge) const { return false; }
215      };
216
217      /// This iterator goes through each undirected edge.
218
219      /// This iterator goes through each undirected edge of a graph.
220      /// Its usage is quite simple, for example you can count the number
221      /// of undirected edges in a graph \c g of type \c Graph as follows:
222      ///\code
223      /// int count=0;
224      /// for(Graph::UEdgeIt e(g); e!=INVALID; ++e) ++count;
225      ///\endcode
226      class UEdgeIt : public UEdge {
227      public:
228        /// Default constructor
229
230        /// @warning The default constructor sets the iterator
231        /// to an undefined value.
232        UEdgeIt() { }
233        /// Copy constructor.
234
235        /// Copy constructor.
236        ///
237        UEdgeIt(const UEdgeIt& e) : UEdge(e) { }
238        /// Initialize the iterator to be invalid.
239
240        /// Initialize the iterator to be invalid.
241        ///
242        UEdgeIt(Invalid) { }
243        /// This constructor sets the iterator to the first undirected edge.
244   
245        /// This constructor sets the iterator to the first undirected edge.
246        UEdgeIt(const UGraph&) { }
247        /// UEdge -> UEdgeIt conversion
248
249        /// Sets the iterator to the value of the trivial iterator.
250        /// This feature necessitates that each time we
251        /// iterate the undirected edge-set, the iteration order is the
252        /// same.
253        UEdgeIt(const UGraph&, const UEdge&) { }
254        /// Next undirected edge
255       
256        /// Assign the iterator to the next undirected edge.
257        UEdgeIt& operator++() { return *this; }
258      };
259
260      /// \brief This iterator goes trough the incident undirected
261      /// edges of a node.
262      ///
263      /// This iterator goes trough the incident undirected edges
264      /// of a certain node of a graph. You should assume that the
265      /// loop edges will be iterated twice.
266      ///
267      /// Its usage is quite simple, for example you can compute the
268      /// degree (i.e. count the number of incident edges of a node \c n
269      /// in graph \c g of type \c Graph as follows.
270      ///
271      ///\code
272      /// int count=0;
273      /// for(Graph::IncEdgeIt e(g, n); e!=INVALID; ++e) ++count;
274      ///\endcode
275      class IncEdgeIt : public UEdge {
276      public:
277        /// Default constructor
278
279        /// @warning The default constructor sets the iterator
280        /// to an undefined value.
281        IncEdgeIt() { }
282        /// Copy constructor.
283
284        /// Copy constructor.
285        ///
286        IncEdgeIt(const IncEdgeIt& e) : UEdge(e) { }
287        /// Initialize the iterator to be invalid.
288
289        /// Initialize the iterator to be invalid.
290        ///
291        IncEdgeIt(Invalid) { }
292        /// This constructor sets the iterator to first incident edge.
293   
294        /// This constructor set the iterator to the first incident edge of
295        /// the node.
296        IncEdgeIt(const UGraph&, const Node&) { }
297        /// UEdge -> IncEdgeIt conversion
298
299        /// Sets the iterator to the value of the trivial iterator \c e.
300        /// This feature necessitates that each time we
301        /// iterate the edge-set, the iteration order is the same.
302        IncEdgeIt(const UGraph&, const UEdge&) { }
303        /// Next incident edge
304
305        /// Assign the iterator to the next incident edge
306        /// of the corresponding node.
307        IncEdgeIt& operator++() { return *this; }
308      };
309
310      /// The directed edge type.
311
312      /// The directed edge type. It can be converted to the
313      /// undirected edge or it should be inherited from the undirected
314      /// edge.
315      class Edge : public UEdge {
316      public:
317        /// Default constructor
318
319        /// @warning The default constructor sets the iterator
320        /// to an undefined value.
321        Edge() { }
322        /// Copy constructor.
323
324        /// Copy constructor.
325        ///
326        Edge(const Edge& e) : UEdge(e) { }
327        /// Initialize the iterator to be invalid.
328
329        /// Initialize the iterator to be invalid.
330        ///
331        Edge(Invalid) { }
332        /// Equality operator
333
334        /// Two iterators are equal if and only if they point to the
335        /// same object or both are invalid.
336        bool operator==(Edge) const { return true; }
337        /// Inequality operator
338
339        /// \sa operator==(Edge n)
340        ///
341        bool operator!=(Edge) const { return true; }
342
343        /// Artificial ordering operator.
344       
345        /// To allow the use of graph descriptors as key type in std::map or
346        /// similar associative container we require this.
347        ///
348        /// \note This operator only have to define some strict ordering of
349        /// the items; this order has nothing to do with the iteration
350        /// ordering of the items.
351        bool operator<(Edge) const { return false; }
352       
353      };
354      /// This iterator goes through each directed edge.
355
356      /// This iterator goes through each edge of a graph.
357      /// Its usage is quite simple, for example you can count the number
358      /// of edges in a graph \c g of type \c Graph as follows:
359      ///\code
360      /// int count=0;
361      /// for(Graph::EdgeIt e(g); e!=INVALID; ++e) ++count;
362      ///\endcode
363      class EdgeIt : public Edge {
364      public:
365        /// Default constructor
366
367        /// @warning The default constructor sets the iterator
368        /// to an undefined value.
369        EdgeIt() { }
370        /// Copy constructor.
371
372        /// Copy constructor.
373        ///
374        EdgeIt(const EdgeIt& e) : Edge(e) { }
375        /// Initialize the iterator to be invalid.
376
377        /// Initialize the iterator to be invalid.
378        ///
379        EdgeIt(Invalid) { }
380        /// This constructor sets the iterator to the first edge.
381   
382        /// This constructor sets the iterator to the first edge of \c g.
383        ///@param g the graph
384        EdgeIt(const UGraph &g) { ignore_unused_variable_warning(g); }
385        /// Edge -> EdgeIt conversion
386
387        /// Sets the iterator to the value of the trivial iterator \c e.
388        /// This feature necessitates that each time we
389        /// iterate the edge-set, the iteration order is the same.
390        EdgeIt(const UGraph&, const Edge&) { }
391        ///Next edge
392       
393        /// Assign the iterator to the next edge.
394        EdgeIt& operator++() { return *this; }
395      };
396   
397      /// This iterator goes trough the outgoing directed edges of a node.
398
399      /// This iterator goes trough the \e outgoing edges of a certain node
400      /// of a graph.
401      /// Its usage is quite simple, for example you can count the number
402      /// of outgoing edges of a node \c n
403      /// in graph \c g of type \c Graph as follows.
404      ///\code
405      /// int count=0;
406      /// for (Graph::OutEdgeIt e(g, n); e!=INVALID; ++e) ++count;
407      ///\endcode
408   
409      class OutEdgeIt : public Edge {
410      public:
411        /// Default constructor
412
413        /// @warning The default constructor sets the iterator
414        /// to an undefined value.
415        OutEdgeIt() { }
416        /// Copy constructor.
417
418        /// Copy constructor.
419        ///
420        OutEdgeIt(const OutEdgeIt& e) : Edge(e) { }
421        /// Initialize the iterator to be invalid.
422
423        /// Initialize the iterator to be invalid.
424        ///
425        OutEdgeIt(Invalid) { }
426        /// This constructor sets the iterator to the first outgoing edge.
427   
428        /// This constructor sets the iterator to the first outgoing edge of
429        /// the node.
430        ///@param n the node
431        ///@param g the graph
432        OutEdgeIt(const UGraph& n, const Node& g) {
433          ignore_unused_variable_warning(n);
434          ignore_unused_variable_warning(g);
435        }
436        /// Edge -> OutEdgeIt conversion
437
438        /// Sets the iterator to the value of the trivial iterator.
439        /// This feature necessitates that each time we
440        /// iterate the edge-set, the iteration order is the same.
441        OutEdgeIt(const UGraph&, const Edge&) { }
442        ///Next outgoing edge
443       
444        /// Assign the iterator to the next
445        /// outgoing edge of the corresponding node.
446        OutEdgeIt& operator++() { return *this; }
447      };
448
449      /// This iterator goes trough the incoming directed edges of a node.
450
451      /// This iterator goes trough the \e incoming edges of a certain node
452      /// of a graph.
453      /// Its usage is quite simple, for example you can count the number
454      /// of outgoing edges of a node \c n
455      /// in graph \c g of type \c Graph as follows.
456      ///\code
457      /// int count=0;
458      /// for(Graph::InEdgeIt e(g, n); e!=INVALID; ++e) ++count;
459      ///\endcode
460
461      class InEdgeIt : public Edge {
462      public:
463        /// Default constructor
464
465        /// @warning The default constructor sets the iterator
466        /// to an undefined value.
467        InEdgeIt() { }
468        /// Copy constructor.
469
470        /// Copy constructor.
471        ///
472        InEdgeIt(const InEdgeIt& e) : Edge(e) { }
473        /// Initialize the iterator to be invalid.
474
475        /// Initialize the iterator to be invalid.
476        ///
477        InEdgeIt(Invalid) { }
478        /// This constructor sets the iterator to first incoming edge.
479   
480        /// This constructor set the iterator to the first incoming edge of
481        /// the node.
482        ///@param n the node
483        ///@param g the graph
484        InEdgeIt(const UGraph& g, const Node& n) {
485          ignore_unused_variable_warning(n);
486          ignore_unused_variable_warning(g);
487        }
488        /// Edge -> InEdgeIt conversion
489
490        /// Sets the iterator to the value of the trivial iterator \c e.
491        /// This feature necessitates that each time we
492        /// iterate the edge-set, the iteration order is the same.
493        InEdgeIt(const UGraph&, const Edge&) { }
494        /// Next incoming edge
495
496        /// Assign the iterator to the next inedge of the corresponding node.
497        ///
498        InEdgeIt& operator++() { return *this; }
499      };
500
501      /// \brief Read write map of the nodes to type \c T.
502      ///
503      /// ReadWrite map of the nodes to type \c T.
504      /// \sa Reference
505      template<class T>
506      class NodeMap : public ReadWriteMap< Node, T >
507      {
508      public:
509
510        ///\e
511        NodeMap(const UGraph&) { }
512        ///\e
513        NodeMap(const UGraph&, T) { }
514
515        ///Copy constructor
516        NodeMap(const NodeMap& nm) : ReadWriteMap< Node, T >(nm) { }
517        ///Assignment operator
518        template <typename CMap>
519        NodeMap& operator=(const CMap&) {
520          checkConcept<ReadMap<Node, T>, CMap>();
521          return *this;
522        }
523      };
524
525      /// \brief Read write map of the directed edges to type \c T.
526      ///
527      /// Reference map of the directed edges to type \c T.
528      /// \sa Reference
529      template<class T>
530      class EdgeMap : public ReadWriteMap<Edge,T>
531      {
532      public:
533
534        ///\e
535        EdgeMap(const UGraph&) { }
536        ///\e
537        EdgeMap(const UGraph&, T) { }
538        ///Copy constructor
539        EdgeMap(const EdgeMap& em) : ReadWriteMap<Edge,T>(em) { }
540        ///Assignment operator
541        template <typename CMap>
542        EdgeMap& operator=(const CMap&) {
543          checkConcept<ReadMap<Edge, T>, CMap>();
544          return *this;
545        }
546      };
547
548      /// Read write map of the undirected edges to type \c T.
549
550      /// Reference map of the edges to type \c T.
551      /// \sa Reference
552      template<class T>
553      class UEdgeMap : public ReadWriteMap<UEdge,T>
554      {
555      public:
556
557        ///\e
558        UEdgeMap(const UGraph&) { }
559        ///\e
560        UEdgeMap(const UGraph&, T) { }
561        ///Copy constructor
562        UEdgeMap(const UEdgeMap& em) : ReadWriteMap<UEdge,T>(em) {}
563        ///Assignment operator
564        template <typename CMap>
565        UEdgeMap& operator=(const CMap&) {
566          checkConcept<ReadMap<UEdge, T>, CMap>();
567          return *this;
568        }
569      };
570
571      /// \brief Direct the given undirected edge.
572      ///
573      /// Direct the given undirected edge. The returned edge source
574      /// will be the given node.
575      Edge direct(const UEdge&, const Node&) const {
576        return INVALID;
577      }
578
579      /// \brief Direct the given undirected edge.
580      ///
581      /// Direct the given undirected edge. The returned edge
[2291]582      /// represents the given undirected edge and the direction comes
[2260]583      /// from the given bool.  The source of the undirected edge and
584      /// the directed edge is the same when the given bool is true.
585      Edge direct(const UEdge&, bool) const {
586        return INVALID;
587      }
588
589      /// \brief Returns true if the edge has default orientation.
590      ///
591      /// Returns whether the given directed edge is same orientation as
592      /// the corresponding undirected edge's default orientation.
593      bool direction(Edge) const { return true; }
594
595      /// \brief Returns the opposite directed edge.
596      ///
597      /// Returns the opposite directed edge.
598      Edge oppositeEdge(Edge) const { return INVALID; }
599
600      /// \brief Opposite node on an edge
601      ///
602      /// \return the opposite of the given Node on the given UEdge
603      Node oppositeNode(Node, UEdge) const { return INVALID; }
604
605      /// \brief First node of the undirected edge.
606      ///
607      /// \return the first node of the given UEdge.
608      ///
609      /// Naturally undirected edges don't have direction and thus
610      /// don't have source and target node. But we use these two methods
611      /// to query the two nodes of the edge. The direction of the edge
612      /// which arises this way is called the inherent direction of the
613      /// undirected edge, and is used to define the "default" direction
614      /// of the directed versions of the edges.
615      /// \sa direction
616      Node source(UEdge) const { return INVALID; }
617
618      /// \brief Second node of the undirected edge.
619      Node target(UEdge) const { return INVALID; }
620
621      /// \brief Source node of the directed edge.
622      Node source(Edge) const { return INVALID; }
623
624      /// \brief Target node of the directed edge.
625      Node target(Edge) const { return INVALID; }
626
627      void first(Node&) const {}
628      void next(Node&) const {}
629
630      void first(UEdge&) const {}
631      void next(UEdge&) const {}
632
633      void first(Edge&) const {}
634      void next(Edge&) const {}
635
636      void firstOut(Edge&, Node) const {}
637      void nextOut(Edge&) const {}
638
639      void firstIn(Edge&, Node) const {}
640      void nextIn(Edge&) const {}
641
642
643      void firstInc(UEdge &, bool &, const Node &) const {}
644      void nextInc(UEdge &, bool &) const {}
645
646      /// \brief Base node of the iterator
647      ///
648      /// Returns the base node (the source in this case) of the iterator
649      Node baseNode(OutEdgeIt e) const {
650        return source(e);
651      }
652      /// \brief Running node of the iterator
653      ///
654      /// Returns the running node (the target in this case) of the
655      /// iterator
656      Node runningNode(OutEdgeIt e) const {
657        return target(e);
658      }
659
660      /// \brief Base node of the iterator
661      ///
662      /// Returns the base node (the target in this case) of the iterator
663      Node baseNode(InEdgeIt e) const {
664        return target(e);
665      }
666      /// \brief Running node of the iterator
667      ///
668      /// Returns the running node (the source in this case) of the
669      /// iterator
670      Node runningNode(InEdgeIt e) const {
671        return source(e);
672      }
673
674      /// \brief Base node of the iterator
675      ///
676      /// Returns the base node of the iterator
677      Node baseNode(IncEdgeIt) const {
678        return INVALID;
679      }
680     
681      /// \brief Running node of the iterator
682      ///
683      /// Returns the running node of the iterator
684      Node runningNode(IncEdgeIt) const {
685        return INVALID;
686      }
687
688      template <typename Graph>
689      struct Constraints {
690        void constraints() {
691          checkConcept<IterableUGraphComponent<>, Graph>();
692          checkConcept<MappableUGraphComponent<>, Graph>();
693        }
694      };
695
696    };
697
698  }
699
700}
701
702#endif
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