COIN-OR::LEMON - Graph Library

source: lemon-0.x/lemon/list_graph.h @ 1729:06f939455cb1

Last change on this file since 1729:06f939455cb1 was 1729:06f939455cb1, checked in by Balazs Dezso, 14 years ago

Removing signal/commit Change from alteration notifier

It makes slower the change Target/Source? functions
and used only by the In/Out? DegMap?

File size: 16.1 KB
Line 
1/* -*- C++ -*-
2 * lemon/list_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 LEMON_LIST_GRAPH_H
18#define LEMON_LIST_GRAPH_H
19
20///\ingroup graphs
21///\file
22///\brief ListGraph, UndirListGraph classes.
23
24#include <lemon/bits/erasable_graph_extender.h>
25#include <lemon/bits/clearable_graph_extender.h>
26#include <lemon/bits/extendable_graph_extender.h>
27#include <lemon/bits/iterable_graph_extender.h>
28#include <lemon/bits/alteration_notifier.h>
29#include <lemon/bits/default_map.h>
30
31#include <lemon/bits/undir_graph_extender.h>
32
33#include <list>
34
35namespace lemon {
36
37  class ListGraphBase {
38
39  protected:
40    struct NodeT {
41      int first_in, first_out;
42      int prev, next;
43    };
44 
45    struct EdgeT {
46      int target, source;
47      int prev_in, prev_out;
48      int next_in, next_out;
49    };
50
51    std::vector<NodeT> nodes;
52
53    int first_node;
54
55    int first_free_node;
56
57    std::vector<EdgeT> edges;
58
59    int first_free_edge;
60   
61  public:
62   
63    typedef ListGraphBase Graph;
64   
65    class Node {
66      friend class ListGraphBase;
67    protected:
68
69      int id;
70      Node(int pid) { id = pid;}
71
72    public:
73      Node() {}
74      Node (Invalid) { id = -1; }
75      bool operator==(const Node& node) const {return id == node.id;}
76      bool operator!=(const Node& node) const {return id != node.id;}
77      bool operator<(const Node& node) const {return id < node.id;}
78    };
79
80    class Edge {
81      friend class ListGraphBase;
82    protected:
83
84      int id;
85      Edge(int pid) { id = pid;}
86
87    public:
88      Edge() {}
89      Edge (Invalid) { id = -1; }
90      bool operator==(const Edge& edge) const {return id == edge.id;}
91      bool operator!=(const Edge& edge) const {return id != edge.id;}
92      bool operator<(const Edge& edge) const {return id < edge.id;}
93    };
94
95
96
97    ListGraphBase()
98      : nodes(), first_node(-1),
99        first_free_node(-1), edges(), first_free_edge(-1) {}
100
101   
102    /// Maximum node ID.
103   
104    /// Maximum node ID.
105    ///\sa id(Node)
106    int maxId(Node = INVALID) const { return nodes.size()-1; }
107
108    /// Maximum edge ID.
109   
110    /// Maximum edge ID.
111    ///\sa id(Edge)
112    int maxId(Edge = INVALID) const { return edges.size()-1; }
113
114    Node source(Edge e) const { return edges[e.id].source; }
115    Node target(Edge e) const { return edges[e.id].target; }
116
117
118    void first(Node& node) const {
119      node.id = first_node;
120    }
121
122    void next(Node& node) const {
123      node.id = nodes[node.id].next;
124    }
125
126
127    void first(Edge& e) const {
128      int n;
129      for(n = first_node;
130          n!=-1 && nodes[n].first_in == -1;
131          n = nodes[n].next);
132      e.id = (n == -1) ? -1 : nodes[n].first_in;
133    }
134
135    void next(Edge& edge) const {
136      if (edges[edge.id].next_in != -1) {
137        edge.id = edges[edge.id].next_in;
138      } else {
139        int n;
140        for(n = nodes[edges[edge.id].target].next;
141          n!=-1 && nodes[n].first_in == -1;
142          n = nodes[n].next);
143        edge.id = (n == -1) ? -1 : nodes[n].first_in;
144      }     
145    }
146
147    void firstOut(Edge &e, const Node& v) const {
148      e.id = nodes[v.id].first_out;
149    }
150    void nextOut(Edge &e) const {
151      e.id=edges[e.id].next_out;
152    }
153
154    void firstIn(Edge &e, const Node& v) const {
155      e.id = nodes[v.id].first_in;
156    }
157    void nextIn(Edge &e) const {
158      e.id=edges[e.id].next_in;
159    }
160
161   
162    static int id(Node v) { return v.id; }
163    static int id(Edge e) { return e.id; }
164
165    static Node fromId(int id, Node) { return Node(id);}
166    static Edge fromId(int id, Edge) { return Edge(id);}
167
168    /// Adds a new node to the graph.
169
170    /// \warning It adds the new node to the front of the list.
171    /// (i.e. the lastly added node becomes the first.)
172    Node addNode() {     
173      int n;
174     
175      if(first_free_node==-1) {
176        n = nodes.size();
177        nodes.push_back(NodeT());
178      } else {
179        n = first_free_node;
180        first_free_node = nodes[n].next;
181      }
182     
183      nodes[n].next = first_node;
184      if(first_node != -1) nodes[first_node].prev = n;
185      first_node = n;
186      nodes[n].prev = -1;
187     
188      nodes[n].first_in = nodes[n].first_out = -1;
189     
190      return Node(n);
191    }
192   
193    Edge addEdge(Node u, Node v) {
194      int n;     
195
196      if (first_free_edge == -1) {
197        n = edges.size();
198        edges.push_back(EdgeT());
199      } else {
200        n = first_free_edge;
201        first_free_edge = edges[n].next_in;
202      }
203     
204      edges[n].source = u.id;
205      edges[n].target = v.id;
206
207      edges[n].next_out = nodes[u.id].first_out;
208      if(nodes[u.id].first_out != -1) {
209        edges[nodes[u.id].first_out].prev_out = n;
210      }
211     
212      edges[n].next_in = nodes[v.id].first_in;
213      if(nodes[v.id].first_in != -1) {
214        edges[nodes[v.id].first_in].prev_in = n;
215      }
216     
217      edges[n].prev_in = edges[n].prev_out = -1;
218       
219      nodes[u.id].first_out = nodes[v.id].first_in = n;
220
221      return Edge(n);
222    }
223   
224    void erase(const Node& node) {
225      int n = node.id;
226     
227      if(nodes[n].next != -1) {
228        nodes[nodes[n].next].prev = nodes[n].prev;
229      }
230     
231      if(nodes[n].prev != -1) {
232        nodes[nodes[n].prev].next = nodes[n].next;
233      } else {
234        first_node = nodes[n].next;
235      }
236     
237      nodes[n].next = first_free_node;
238      first_free_node = n;
239
240    }
241   
242    void erase(const Edge& edge) {
243      int n = edge.id;
244     
245      if(edges[n].next_in!=-1) {
246        edges[edges[n].next_in].prev_in = edges[n].prev_in;
247      }
248
249      if(edges[n].prev_in!=-1) {
250        edges[edges[n].prev_in].next_in = edges[n].next_in;
251      } else {
252        nodes[edges[n].target].first_in = edges[n].next_in;
253      }
254
255     
256      if(edges[n].next_out!=-1) {
257        edges[edges[n].next_out].prev_out = edges[n].prev_out;
258      }
259
260      if(edges[n].prev_out!=-1) {
261        edges[edges[n].prev_out].next_out = edges[n].next_out;
262      } else {
263        nodes[edges[n].source].first_out = edges[n].next_out;
264      }
265     
266      edges[n].next_in = first_free_edge;
267      first_free_edge = n;     
268
269    }
270
271    void clear() {
272      edges.clear();
273      nodes.clear();
274      first_node = first_free_node = first_free_edge = -1;
275    }
276
277  protected:
278    void _changeTarget(Edge e, Node n)
279    {
280      if(edges[e.id].next_in != -1)
281        edges[edges[e.id].next_in].prev_in = edges[e.id].prev_in;
282      if(edges[e.id].prev_in != -1)
283        edges[edges[e.id].prev_in].next_in = edges[e.id].next_in;
284      else nodes[edges[e.id].target].first_in = edges[e.id].next_in;
285      if (nodes[n.id].first_in != -1) {
286        edges[nodes[n.id].first_in].prev_in = e.id;
287      }
288      edges[e.id].target = n.id;
289      edges[e.id].prev_in = -1;
290      edges[e.id].next_in = nodes[n.id].first_in;
291      nodes[n.id].first_in = e.id;
292    }
293    void _changeSource(Edge e, Node n)
294    {
295      if(edges[e.id].next_out != -1)
296        edges[edges[e.id].next_out].prev_out = edges[e.id].prev_out;
297      if(edges[e.id].prev_out != -1)
298        edges[edges[e.id].prev_out].next_out = edges[e.id].next_out;
299      else nodes[edges[e.id].source].first_out = edges[e.id].next_out;
300      if (nodes[n.id].first_out != -1) {
301        edges[nodes[n.id].first_out].prev_out = e.id;
302      }
303      edges[e.id].source = n.id;
304      edges[e.id].prev_out = -1;
305      edges[e.id].next_out = nodes[n.id].first_out;
306      nodes[n.id].first_out = e.id;
307    }
308
309  };
310
311  typedef ErasableGraphExtender<
312    ClearableGraphExtender<
313    ExtendableGraphExtender<
314    MappableGraphExtender<
315    IterableGraphExtender<
316    AlterableGraphExtender<ListGraphBase> > > > > > ExtendedListGraphBase;
317
318  /// \addtogroup graphs
319  /// @{
320
321  ///A list graph class.
322
323  ///This is a simple and fast erasable graph implementation.
324  ///
325  ///It addition that it conforms to the
326  ///\ref concept::ErasableGraph "ErasableGraph" concept,
327  ///it also provides several additional useful extra functionalities.
328  ///\sa concept::ErasableGraph.
329
330  class ListGraph : public ExtendedListGraphBase
331  {
332  public:
333    /// Changes the target of \c e to \c n
334
335    /// Changes the target of \c e to \c n
336    ///
337    ///\note The <tt>Edge</tt>'s and <tt>OutEdge</tt>'s
338    ///referencing the changed edge remain
339    ///valid. However <tt>InEdge</tt>'s are invalidated.
340    void changeTarget(Edge e, Node n) {
341      _changeTarget(e,n);
342    }
343    /// Changes the source of \c e to \c n
344
345    /// Changes the source of \c e to \c n
346    ///
347    ///\note The <tt>Edge</tt>'s and <tt>InEdge</tt>'s
348    ///referencing the changed edge remain
349    ///valid. However <tt>OutEdge</tt>'s are invalidated.
350    void changeSource(Edge e, Node n) {
351      _changeSource(e,n);
352    }
353
354    /// Invert the direction of an edge.
355
356    ///\note The <tt>Edge</tt>'s
357    ///referencing the changed edge remain
358    ///valid. However <tt>OutEdge</tt>'s  and <tt>InEdge</tt>'s are invalidated.
359    void reverseEdge(Edge e) {
360      Node t=target(e);
361      _changeTarget(e,source(e));
362      _changeSource(e,t);
363    }
364
365    ///Using this it possible to avoid the superfluous memory allocation.
366
367    ///Using this it possible to avoid the superfluous memory allocation.
368    ///\todo more docs...
369    void reserveEdge(int n) { edges.reserve(n); };
370
371    ///Contract two nodes.
372
373    ///This function contracts two nodes.
374    ///
375    ///Node \p b will be removed but instead of deleting
376    ///its neighboring edges, they will be joined to \p a.
377    ///The last parameter \p r controls whether to remove loops. \c true
378    ///means that loops will be removed.
379    ///
380    ///\note The <tt>Edge</tt>s
381    ///referencing a moved edge remain
382    ///valid. However <tt>InEdge</tt>'s and <tt>OutEdge</tt>'s
383    ///may be invalidated.
384    void contract(Node a, Node b, bool r = true)
385    {
386      for(OutEdgeIt e(*this,b);e!=INVALID;) {
387        OutEdgeIt f=e;
388        ++f;
389        if(r && target(e)==a) erase(e);
390        else changeSource(e,a);
391        e=f;
392      }
393      for(InEdgeIt e(*this,b);e!=INVALID;) {
394        InEdgeIt f=e;
395        ++f;
396        if(r && source(e)==a) erase(e);
397        else changeTarget(e,a);
398        e=f;
399      }
400      erase(b);
401    }
402
403    ///Split a node.
404
405    ///This function splits a node. First a new node is added to the graph,
406    ///then the source of each outgoing edge of \c n is moved to this new node.
407    ///If \c connect is \c true (this is the default value), then a new edge
408    ///from \c n to the newly created node is also added.
409    ///\return The newly created node.
410    ///
411    ///\note The <tt>Edge</tt>s
412    ///referencing a moved edge remain
413    ///valid. However <tt>InEdge</tt>'s and <tt>OutEdge</tt>'s
414    ///may be invalidated.
415    ///\warning This functionality cannot be used together with the SnapShot
416    ///feature.
417    ///\todo It could be implemented in a bit faster way.
418    Node split(Node n, bool connect = true)
419    {
420      Node b = addNode();
421      for(OutEdgeIt e(*this,n);e!=INVALID;) {
422        OutEdgeIt f=e;
423        ++f;
424        changeSource(e,b);
425        e=f;
426      }
427      if(connect) addEdge(n,b);
428      return b;
429    }
430     
431    ///Class to make a snapshot of the graph and to restrore to it later.
432
433    ///Class to make a snapshot of the graph and to restrore to it later.
434    ///
435    ///The newly added nodes and edges can be removed using the
436    ///restore() function.
437    ///
438    ///\warning Edge and node deletions cannot be restored.
439    ///\warning SnapShots cannot be nested.
440    ///\todo \c SnapShot or \c Snapshot?
441    class SnapShot : protected AlterationNotifier<Node>::ObserverBase,
442                     protected AlterationNotifier<Edge>::ObserverBase
443    {
444      protected:
445     
446      ListGraph *g;
447      std::list<Node> added_nodes;
448      std::list<Edge> added_edges;
449     
450      bool active;
451      virtual void add(const Node& n) {
452        added_nodes.push_back(n);
453      };
454      ///\bug Exception...
455      ///
456      virtual void erase(const Node&)
457      {
458        exit(1);
459      }
460      virtual void add(const Edge& n) {
461        added_edges.push_back(n);
462      };
463      ///\bug Exception...
464      ///
465      virtual void erase(const Edge&)
466      {
467        exit(1);
468      }
469
470      ///\bug What is this used for?
471      ///
472      virtual void build() {}
473      ///\bug What is this used for?
474      ///
475      virtual void clear() {}
476
477      void regist(ListGraph &_g) {
478        g=&_g;
479        AlterationNotifier<Node>::ObserverBase::
480          attach(g->getNotifier(Node()));
481        AlterationNotifier<Edge>::ObserverBase::
482          attach(g->getNotifier(Edge()));
483      }
484           
485      void deregist() {
486        AlterationNotifier<Node>::ObserverBase::
487          detach();
488        AlterationNotifier<Edge>::ObserverBase::
489          detach();
490        g=0;
491      }
492           
493    public:
494      ///Default constructur.
495     
496      ///Default constructur.
497      ///To actually make a snapshot you must call save().
498      ///
499      SnapShot() : g(0) {}
500      ///Constructor that immediately makes a snapshot.
501     
502      ///This constructor immediately makes a snapshot of the graph.
503      ///\param _g The graph we make a snapshot of.
504      SnapShot(ListGraph &_g) {
505        regist(_g);
506      }
507      ///\bug Is it necessary?
508      ///
509      ~SnapShot()
510      {
511        if(g) deregist();
512      }
513     
514      ///Make a snapshot.
515
516      ///Make a snapshot of the graph.
517      ///
518      ///This function can be called more than once. In case of a repeated
519      ///call, the previous snapshot gets lost.
520      ///\param _g The graph we make the snapshot of.
521      void save(ListGraph &_g)
522      {
523        if(g!=&_g) {
524          if(g) deregist();
525          regist(_g);
526        }
527        added_nodes.clear();
528        added_edges.clear();
529      }
530     
531    ///Undo the changes until the last snapshot.
532
533    ///Undo the changes until last snapshot created by save().
534    ///
535    ///\todo This function might be called undo().
536      void restore() {
537        ListGraph &old_g=*g;
538        deregist();
539        while(!added_edges.empty()) {
540          old_g.erase(added_edges.front());
541          added_edges.pop_front();
542        }
543        while(!added_nodes.empty()) {
544          old_g.erase(added_nodes.front());
545          added_nodes.pop_front();
546        }
547      }
548    };
549   
550  };
551
552  ///@}
553
554  /**************** Undirected List Graph ****************/
555
556  typedef ErasableUndirGraphExtender<
557    ClearableUndirGraphExtender<
558    ExtendableUndirGraphExtender<
559    MappableUndirGraphExtender<
560    IterableUndirGraphExtender<
561    AlterableUndirGraphExtender<
562    UndirGraphExtender<ListGraphBase> > > > > > > ExtendedUndirListGraphBase;
563
564  /// \addtogroup graphs
565  /// @{
566
567  ///An undirected list graph class.
568
569  ///This is a simple and fast erasable undirected graph implementation.
570  ///
571  ///It conforms to the
572  ///\ref concept::UndirGraph "UndirGraph" concept.
573  ///
574  ///\sa concept::UndirGraph.
575  ///
576  ///\todo SnapShot, reverseEdge(), changeTarget(), changeSource(), contract()
577  ///haven't been implemented yet.
578  ///
579  class UndirListGraph : public ExtendedUndirListGraphBase {
580  public:
581    typedef ExtendedUndirListGraphBase Parent;
582    /// \brief Changes the target of \c e to \c n
583    ///
584    /// Changes the target of \c e to \c n
585    ///
586    /// \note The <tt>Edge</tt>'s and <tt>OutEdge</tt>'s
587    /// referencing the changed edge remain
588    /// valid. However <tt>InEdge</tt>'s are invalidated.
589    void changeTarget(UndirEdge e, Node n) {
590      _changeTarget(e,n);
591    }
592    /// Changes the source of \c e to \c n
593    ///
594    /// Changes the source of \c e to \c n
595    ///
596    ///\note The <tt>Edge</tt>'s and <tt>InEdge</tt>'s
597    ///referencing the changed edge remain
598    ///valid. However <tt>OutEdge</tt>'s are invalidated.
599    void changeSource(UndirEdge e, Node n) {
600      _changeSource(e,n);
601    }
602    /// \brief Contract two nodes.
603    ///
604    /// This function contracts two nodes.
605    ///
606    /// Node \p b will be removed but instead of deleting
607    /// its neighboring edges, they will be joined to \p a.
608    /// The last parameter \p r controls whether to remove loops. \c true
609    /// means that loops will be removed.
610    ///
611    /// \note The <tt>Edge</tt>s
612    /// referencing a moved edge remain
613    /// valid.
614    void contract(Node a, Node b, bool r = true) {
615      for(IncEdgeIt e(*this, b); e!=INVALID;) {
616        IncEdgeIt f = e; ++f;
617        if (r && runningNode(e) == a) {
618          erase(e);
619        } else if (source(e) == b) {
620          changeSource(e, a);
621        } else {
622          changeTarget(e, a);
623        }
624        e = f;
625      }
626      erase(b);
627    }
628  };
629
630 
631  /// @} 
632} //namespace lemon
633 
634
635#endif
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