COIN-OR::LEMON - Graph Library

source: lemon-0.x/lemon/smart_graph.h @ 1999:2ff283124dfc

Last change on this file since 1999:2ff283124dfc was 1999:2ff283124dfc, checked in by Balazs Dezso, 14 years ago

Clarifing alteration observing system
It is directly connected now to a container

File size: 14.9 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 LEMON_SMART_GRAPH_H
20#define LEMON_SMART_GRAPH_H
21
22///\ingroup graphs
23///\file
24///\brief SmartGraph and SmartUGraph classes.
25
26#include <vector>
27
28#include <lemon/bits/invalid.h>
29
30#include <lemon/bits/base_extender.h>
31#include <lemon/bits/graph_extender.h>
32
33#include <lemon/bits/utility.h>
34#include <lemon/error.h>
35
36#include <lemon/bits/graph_extender.h>
37
38namespace lemon {
39
40  class SmartGraph;
41  ///Base of SmartGraph
42
43  ///Base of SmartGraph
44  ///
45  class SmartGraphBase {
46
47    friend class SmatGraph;
48
49  protected:
50    struct NodeT
51    {
52      int first_in,first_out;     
53      NodeT() : first_in(-1), first_out(-1) {}
54    };
55    struct EdgeT
56    {
57      int target, source, next_in, next_out;     
58      //FIXME: is this necessary?
59      EdgeT() : next_in(-1), next_out(-1) {} 
60    };
61
62    std::vector<NodeT> nodes;
63
64    std::vector<EdgeT> edges;
65   
66   
67  public:
68
69    typedef SmartGraphBase Graph;
70
71    class Node;
72    class Edge;
73
74   
75  public:
76
77    SmartGraphBase() : nodes(), edges() { }
78    SmartGraphBase(const SmartGraphBase &_g)
79      : nodes(_g.nodes), edges(_g.edges) { }
80   
81    typedef True NodeNumTag;
82    typedef True EdgeNumTag;
83
84    ///Number of nodes.
85    int nodeNum() const { return nodes.size(); }
86    ///Number of edges.
87    int edgeNum() const { return edges.size(); }
88
89    /// Maximum node ID.
90   
91    /// Maximum node ID.
92    ///\sa id(Node)
93    int maxNodeId() const { return nodes.size()-1; }
94    /// Maximum edge ID.
95   
96    /// Maximum edge ID.
97    ///\sa id(Edge)
98    int maxEdgeId() const { return edges.size()-1; }
99
100    Node source(Edge e) const { return edges[e.n].source; }
101    Node target(Edge e) const { return edges[e.n].target; }
102
103    /// Node ID.
104   
105    /// The ID of a valid Node is a nonnegative integer not greater than
106    /// \ref maxNodeId(). The range of the ID's is not surely continuous
107    /// and the greatest node ID can be actually less then \ref maxNodeId().
108    ///
109    /// The ID of the \ref INVALID node is -1.
110    ///\return The ID of the node \c v.
111    static int id(Node v) { return v.n; }
112    /// Edge ID.
113   
114    /// The ID of a valid Edge is a nonnegative integer not greater than
115    /// \ref maxEdgeId(). The range of the ID's is not surely continuous
116    /// and the greatest edge ID can be actually less then \ref maxEdgeId().
117    ///
118    /// The ID of the \ref INVALID edge is -1.
119    ///\return The ID of the edge \c e.
120    static int id(Edge e) { return e.n; }
121
122    static Node nodeFromId(int id) { return Node(id);}
123
124    static Edge edgeFromId(int id) { return Edge(id);}
125
126    Node addNode() {
127      Node n; n.n=nodes.size();
128      nodes.push_back(NodeT()); //FIXME: Hmmm...
129      return n;
130    }
131   
132    Edge addEdge(Node u, Node v) {
133      Edge e; e.n=edges.size(); edges.push_back(EdgeT()); //FIXME: Hmmm...
134      edges[e.n].source=u.n; edges[e.n].target=v.n;
135      edges[e.n].next_out=nodes[u.n].first_out;
136      edges[e.n].next_in=nodes[v.n].first_in;
137      nodes[u.n].first_out=nodes[v.n].first_in=e.n;
138
139      return e;
140    }
141
142    void clear() {
143      edges.clear();
144      nodes.clear();
145    }
146
147
148    class Node {
149      friend class SmartGraphBase;
150      friend class SmartGraph;
151
152    protected:
153      int n;
154      Node(int nn) {n=nn;}
155    public:
156      Node() {}
157      Node (Invalid) { n=-1; }
158      bool operator==(const Node i) const {return n==i.n;}
159      bool operator!=(const Node i) const {return n!=i.n;}
160      bool operator<(const Node i) const {return n<i.n;}
161    };
162   
163
164    class Edge {
165      friend class SmartGraphBase;
166      friend class SmartGraph;
167
168    protected:
169      int n;
170      Edge(int nn) {n=nn;}
171    public:
172      Edge() { }
173      Edge (Invalid) { n=-1; }
174      bool operator==(const Edge i) const {return n==i.n;}
175      bool operator!=(const Edge i) const {return n!=i.n;}
176      bool operator<(const Edge i) const {return n<i.n;}
177    };
178
179    void first(Node& node) const {
180      node.n = nodes.size() - 1;
181    }
182
183    static void next(Node& node) {
184      --node.n;
185    }
186
187    void first(Edge& edge) const {
188      edge.n = edges.size() - 1;
189    }
190
191    static void next(Edge& edge) {
192      --edge.n;
193    }
194
195    void firstOut(Edge& edge, const Node& node) const {
196      edge.n = nodes[node.n].first_out;
197    }
198
199    void nextOut(Edge& edge) const {
200      edge.n = edges[edge.n].next_out;
201    }
202
203    void firstIn(Edge& edge, const Node& node) const {
204      edge.n = nodes[node.n].first_in;
205    }
206   
207    void nextIn(Edge& edge) const {
208      edge.n = edges[edge.n].next_in;
209    }
210
211    Node _split(Node n, bool connect = true)
212    {
213      Node b = addNode();
214      nodes[b.n].first_out=nodes[n.n].first_out;
215      nodes[n.n].first_out=-1;
216      for(int i=nodes[b.n].first_out;i!=-1;i++) edges[i].source=b.n;
217      if(connect) addEdge(n,b);
218      return b;
219    }
220
221  };
222
223  typedef GraphExtender<SmartGraphBase> ExtendedSmartGraphBase;
224
225  /// \ingroup graphs
226
227  ///A smart graph class.
228
229  ///This is a simple and fast graph implementation.
230  ///It is also quite memory efficient, but at the price
231  ///that <b> it does support only limited (only stack-like)
232  ///node and edge deletions</b>.
233  ///It conforms to
234  ///the \ref concept::ExtendableGraph "ExtendableGraph" concept.
235  ///\sa concept::ExtendableGraph.
236  ///
237  ///\author Alpar Juttner
238  class SmartGraph : public ExtendedSmartGraphBase {
239  public:
240
241    typedef ExtendedSmartGraphBase Parent;
242
243    class Snapshot;
244    friend class Snapshot;
245
246  protected:
247    void restoreSnapshot(const Snapshot &s)
248    {
249      while(s.edge_num<edges.size()) {
250        Parent::getNotifier(Edge()).erase(Edge(edges.size()-1));
251        nodes[edges.back().target].first_in=edges.back().next_in;
252        nodes[edges.back().source].first_out=edges.back().next_out;
253        edges.pop_back();
254      }
255      //nodes.resize(s.nodes_num);
256      while(s.node_num<nodes.size()) {
257        Parent::getNotifier(Node()).erase(Node(nodes.size()-1));
258        nodes.pop_back();
259      }
260    }   
261
262  public:
263
264    ///Split a node.
265   
266    ///This function splits a node. First a new node is added to the graph,
267    ///then the source of each outgoing edge of \c n is moved to this new node.
268    ///If \c connect is \c true (this is the default value), then a new edge
269    ///from \c n to the newly created node is also added.
270    ///\return The newly created node.
271    ///
272    ///\note The <tt>Edge</tt>s
273    ///referencing a moved edge remain
274    ///valid. However <tt>InEdge</tt>'s and <tt>OutEdge</tt>'s
275    ///may be invalidated.
276    ///\warning This functionality cannot be used together with the Snapshot
277    ///feature.
278    ///\todo It could be implemented in a bit faster way.
279    Node split(Node n, bool connect = true)
280    {
281      Node b = _split(n,connect);
282      return b;
283    }
284 
285
286    ///Class to make a snapshot of the graph and to restrore to it later.
287
288    ///Class to make a snapshot of the graph and to restrore to it later.
289    ///
290    ///The newly added nodes and edges can be removed using the
291    ///restore() function.
292    ///\note After you restore a state, you cannot restore
293    ///a later state, in other word you cannot add again the edges deleted
294    ///by restore() using another Snapshot instance.
295    ///
296    class Snapshot
297    {
298      SmartGraph *g;
299    protected:
300      friend class SmartGraph;
301      unsigned int node_num;
302      unsigned int edge_num;
303    public:
304      ///Default constructor.
305     
306      ///Default constructor.
307      ///To actually make a snapshot you must call save().
308      ///
309      Snapshot() : g(0) {}
310      ///Constructor that immediately makes a snapshot
311     
312      ///This constructor immediately makes a snapshot of the graph.
313      ///\param _g The graph we make a snapshot of.
314      Snapshot(SmartGraph &_g) :g(&_g) {
315        node_num=g->nodes.size();
316        edge_num=g->edges.size();
317      }
318
319      ///Make a snapshot.
320
321      ///Make a snapshot of the graph.
322      ///
323      ///This function can be called more than once. In case of a repeated
324      ///call, the previous snapshot gets lost.
325      ///\param _g The graph we make the snapshot of.
326      void save(SmartGraph &_g)
327      {
328        g=&_g;
329        node_num=g->nodes.size();
330        edge_num=g->edges.size();
331      }
332
333      ///Undo the changes until a snapshot.
334     
335      ///Undo the changes until a snapshot created by save().
336      ///
337      ///\note After you restored a state, you cannot restore
338      ///a later state, in other word you cannot add again the edges deleted
339      ///by restore().
340      ///
341      ///\todo This function might be called undo().
342     
343      void restore()
344      {
345        g->restoreSnapshot(*this);
346      }
347    };
348  };
349
350
351  /**************** Undirected List Graph ****************/
352
353  typedef UGraphExtender<UGraphBaseExtender<SmartGraphBase> >
354  ExtendedSmartUGraphBase;
355
356  /// \ingroup graphs
357  ///
358  /// \brief A smart undirected graph class.
359  ///
360  /// This is a simple and fast undirected graph implementation.
361  /// It is also quite memory efficient, but at the price
362  /// that <b> it does support only limited (only stack-like)
363  /// node and edge deletions</b>.
364  /// Except from this it conforms to
365  /// the \ref concept::UGraph "UGraph" concept.
366  /// \sa concept::UGraph.
367  ///
368  /// \todo Snapshot hasn't been implemented yet.
369  ///
370  class SmartUGraph : public ExtendedSmartUGraphBase {
371  };
372
373
374  class SmartBpUGraphBase {
375  public:
376
377    class NodeSetError : public LogicError {
378      virtual const char* exceptionName() const {
379        return "lemon::SmartBpUGraph::NodeSetError";
380      }
381    };
382
383  protected:
384
385    struct NodeT {
386      int first;
387      NodeT() {}
388      NodeT(int _first) : first(_first) {}
389    };
390
391    struct EdgeT {
392      int aNode, next_out;
393      int bNode, next_in;
394    };
395
396    std::vector<NodeT> aNodes;
397    std::vector<NodeT> bNodes;
398
399    std::vector<EdgeT> edges;
400
401  public:
402 
403    class Node {
404      friend class SmartBpUGraphBase;
405    protected:
406      int id;
407
408      Node(int _id) : id(_id) {}
409    public:
410      Node() {}
411      Node(Invalid) { id = -1; }
412      bool operator==(const Node i) const {return id==i.id;}
413      bool operator!=(const Node i) const {return id!=i.id;}
414      bool operator<(const Node i) const {return id<i.id;}
415    };
416
417    class Edge {
418      friend class SmartBpUGraphBase;
419    protected:
420      int id;
421
422      Edge(int _id) { id = _id;}
423    public:
424      Edge() {}
425      Edge (Invalid) { id = -1; }
426      bool operator==(const Edge i) const {return id==i.id;}
427      bool operator!=(const Edge i) const {return id!=i.id;}
428      bool operator<(const Edge i) const {return id<i.id;}
429    };
430
431    void firstANode(Node& node) const {
432      node.id = 2 * aNodes.size() - 2;
433      if (node.id < 0) node.id = -1;
434    }
435    void nextANode(Node& node) const {
436      node.id -= 2;
437      if (node.id < 0) node.id = -1;
438    }
439
440    void firstBNode(Node& node) const {
441      node.id = 2 * bNodes.size() - 1;
442    }
443    void nextBNode(Node& node) const {
444      node.id -= 2;
445    }
446
447    void first(Node& node) const {
448      if (aNodes.size() > 0) {
449        node.id = 2 * aNodes.size() - 2;
450      } else {
451        node.id = 2 * bNodes.size() - 1;
452      }
453    }
454    void next(Node& node) const {
455      node.id -= 2;
456      if (node.id == -2) {
457        node.id = 2 * bNodes.size() - 1;
458      }
459    }
460 
461    void first(Edge& edge) const {
462      edge.id = edges.size() - 1;
463    }
464    void next(Edge& edge) const {
465      --edge.id;
466    }
467
468    void firstOut(Edge& edge, const Node& node) const {
469      LEMON_ASSERT((node.id & 1) == 0, NodeSetError());
470      edge.id = aNodes[node.id >> 1].first;
471    }
472    void nextOut(Edge& edge) const {
473      edge.id = edges[edge.id].next_out;
474    }
475
476    void firstIn(Edge& edge, const Node& node) const {
477      LEMON_ASSERT((node.id & 1) == 1, NodeSetError());
478      edge.id = bNodes[node.id >> 1].first;
479    }
480    void nextIn(Edge& edge) const {
481      edge.id = edges[edge.id].next_in;
482    }
483
484    static int id(const Node& node) {
485      return node.id;
486    }
487    static Node nodeFromId(int id) {
488      return Node(id);
489    }
490    int maxNodeId() const {
491      return aNodes.size() > bNodes.size() ?
492        aNodes.size() * 2 - 2 : bNodes.size() * 2 - 1;
493    }
494 
495    static int id(const Edge& edge) {
496      return edge.id;
497    }
498    static Edge edgeFromId(int id) {
499      return Edge(id);
500    }
501    int maxEdgeId() const {
502      return edges.size();
503    }
504 
505    static int aNodeId(const Node& node) {
506      return node.id >> 1;
507    }
508    static Node fromANodeId(int id) {
509      return Node(id << 1);
510    }
511    int maxANodeId() const {
512      return aNodes.size();
513    }
514
515    static int bNodeId(const Node& node) {
516      return node.id >> 1;
517    }
518    static Node fromBNodeId(int id) {
519      return Node((id << 1) + 1);
520    }
521    int maxBNodeId() const {
522      return bNodes.size();
523    }
524
525    Node aNode(const Edge& edge) const {
526      return Node(edges[edge.id].aNode);
527    }
528    Node bNode(const Edge& edge) const {
529      return Node(edges[edge.id].bNode);
530    }
531
532    static bool aNode(const Node& node) {
533      return (node.id & 1) == 0;
534    }
535
536    static bool bNode(const Node& node) {
537      return (node.id & 1) == 1;
538    }
539
540    Node addANode() {
541      NodeT nodeT;
542      nodeT.first = -1;
543      aNodes.push_back(nodeT);
544      return Node(aNodes.size() * 2 - 2);
545    }
546
547    Node addBNode() {
548      NodeT nodeT;
549      nodeT.first = -1;
550      bNodes.push_back(nodeT);
551      return Node(bNodes.size() * 2 - 1);
552    }
553
554    Edge addEdge(const Node& source, const Node& target) {
555      LEMON_ASSERT(((source.id ^ target.id) & 1) == 1, NodeSetError());
556      EdgeT edgeT;
557      if ((source.id & 1) == 0) {
558        edgeT.aNode = source.id;
559        edgeT.bNode = target.id;
560      } else {
561        edgeT.aNode = target.id;
562        edgeT.bNode = source.id;
563      }
564      edgeT.next_out = aNodes[edgeT.aNode >> 1].first;
565      aNodes[edgeT.aNode >> 1].first = edges.size();
566      edgeT.next_in = bNodes[edgeT.bNode >> 1].first;
567      bNodes[edgeT.bNode >> 1].first = edges.size();
568      edges.push_back(edgeT);
569      return Edge(edges.size() - 1);
570    }
571
572    void clear() {
573      aNodes.clear();
574      bNodes.clear();
575      edges.clear();
576    }
577
578  };
579
580
581  typedef BpUGraphExtender< BpUGraphBaseExtender<
582    SmartBpUGraphBase> > ExtendedSmartBpUGraphBase;
583
584  /// \ingroup graphs
585  ///
586  /// \brief A smart bipartite undirected graph class.
587  ///
588  /// This is a simple and fast bipartite undirected graph implementation.
589  /// It is also quite memory efficient, but at the price
590  /// that <b> it does not support node and edge deletions</b>.
591  /// Except from this it conforms to
592  /// the \ref concept::BpUGraph "BpUGraph" concept.
593  /// \sa concept::BpUGraph.
594  ///
595  class SmartBpUGraph : public ExtendedSmartBpUGraphBase {};
596
597 
598  /// @} 
599} //namespace lemon
600
601
602#endif //LEMON_SMART_GRAPH_H
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