COIN-OR::LEMON - Graph Library

source: lemon-0.x/lemon/smart_graph.h @ 1791:62e7d237e1fb

Last change on this file since 1791:62e7d237e1fb was 1791:62e7d237e1fb, checked in by Balazs Dezso, 14 years ago

Modification on the base graph concept
The extended interface does not changed

File size: 10.0 KB
Line 
1/* -*- C++ -*-
2 * lemon/smart_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_SMART_GRAPH_H
18#define LEMON_SMART_GRAPH_H
19
20///\ingroup graphs
21///\file
22///\brief SmartGraph and UndirSmartGraph classes.
23
24#include <vector>
25
26#include <lemon/invalid.h>
27
28#include <lemon/bits/clearable_graph_extender.h>
29#include <lemon/bits/extendable_graph_extender.h>
30#include <lemon/bits/iterable_graph_extender.h>
31#include <lemon/bits/alteration_notifier.h>
32#include <lemon/bits/default_map.h>
33#include <lemon/bits/graph_extender.h>
34
35#include <lemon/utility.h>
36
37namespace lemon {
38
39  class SmartGraph;
40  ///Base of SmartGraph
41
42  ///Base of SmartGraph
43  ///
44  class SmartGraphBase {
45
46    friend class SmatGraph;
47
48  protected:
49    struct NodeT
50    {
51      int first_in,first_out;     
52      NodeT() : first_in(-1), first_out(-1) {}
53    };
54    struct EdgeT
55    {
56      int target, source, next_in, next_out;     
57      //FIXME: is this necessary?
58      EdgeT() : next_in(-1), next_out(-1) {} 
59    };
60
61    std::vector<NodeT> nodes;
62
63    std::vector<EdgeT> edges;
64   
65   
66  public:
67
68    typedef SmartGraphBase Graph;
69
70    class Node;
71    class Edge;
72
73   
74  public:
75
76    SmartGraphBase() : nodes(), edges() { }
77    SmartGraphBase(const SmartGraphBase &_g)
78      : nodes(_g.nodes), edges(_g.edges) { }
79   
80    typedef True NodeNumTag;
81    typedef True EdgeNumTag;
82
83    ///Number of nodes.
84    int nodeNum() const { return nodes.size(); }
85    ///Number of edges.
86    int edgeNum() const { return edges.size(); }
87
88    /// Maximum node ID.
89   
90    /// Maximum node ID.
91    ///\sa id(Node)
92    int maxNodeId() const { return nodes.size()-1; }
93    /// Maximum edge ID.
94   
95    /// Maximum edge ID.
96    ///\sa id(Edge)
97    int maxEdgeId() const { return edges.size()-1; }
98
99    Node source(Edge e) const { return edges[e.n].source; }
100    Node target(Edge e) const { return edges[e.n].target; }
101
102    /// Node ID.
103   
104    /// The ID of a valid Node is a nonnegative integer not greater than
105    /// \ref maxNodeId(). The range of the ID's is not surely continuous
106    /// and the greatest node ID can be actually less then \ref maxNodeId().
107    ///
108    /// The ID of the \ref INVALID node is -1.
109    ///\return The ID of the node \c v.
110    static int id(Node v) { return v.n; }
111    /// Edge ID.
112   
113    /// The ID of a valid Edge is a nonnegative integer not greater than
114    /// \ref maxEdgeId(). The range of the ID's is not surely continuous
115    /// and the greatest edge ID can be actually less then \ref maxEdgeId().
116    ///
117    /// The ID of the \ref INVALID edge is -1.
118    ///\return The ID of the edge \c e.
119    static int id(Edge e) { return e.n; }
120
121    static Node nodeFromId(int id) { return Node(id);}
122
123    static Edge edgeFromId(int id) { return Edge(id);}
124
125    Node addNode() {
126      Node n; n.n=nodes.size();
127      nodes.push_back(NodeT()); //FIXME: Hmmm...
128      return n;
129    }
130   
131    Edge addEdge(Node u, Node v) {
132      Edge e; e.n=edges.size(); edges.push_back(EdgeT()); //FIXME: Hmmm...
133      edges[e.n].source=u.n; edges[e.n].target=v.n;
134      edges[e.n].next_out=nodes[u.n].first_out;
135      edges[e.n].next_in=nodes[v.n].first_in;
136      nodes[u.n].first_out=nodes[v.n].first_in=e.n;
137
138      return e;
139    }
140
141    void clear() {
142      edges.clear();
143      nodes.clear();
144    }
145
146
147    class Node {
148      friend class SmartGraphBase;
149      friend class SmartGraph;
150
151    protected:
152      int n;
153      Node(int nn) {n=nn;}
154    public:
155      Node() {}
156      Node (Invalid) { n=-1; }
157      bool operator==(const Node i) const {return n==i.n;}
158      bool operator!=(const Node i) const {return n!=i.n;}
159      bool operator<(const Node i) const {return n<i.n;}
160    };
161   
162
163    class Edge {
164      friend class SmartGraphBase;
165      friend class SmartGraph;
166
167    protected:
168      int n;
169      Edge(int nn) {n=nn;}
170    public:
171      Edge() { }
172      Edge (Invalid) { n=-1; }
173      bool operator==(const Edge i) const {return n==i.n;}
174      bool operator!=(const Edge i) const {return n!=i.n;}
175      bool operator<(const Edge i) const {return n<i.n;}
176    };
177
178    void first(Node& node) const {
179      node.n = nodes.size() - 1;
180    }
181
182    static void next(Node& node) {
183      --node.n;
184    }
185
186    void first(Edge& edge) const {
187      edge.n = edges.size() - 1;
188    }
189
190    static void next(Edge& edge) {
191      --edge.n;
192    }
193
194    void firstOut(Edge& edge, const Node& node) const {
195      edge.n = nodes[node.n].first_out;
196    }
197
198    void nextOut(Edge& edge) const {
199      edge.n = edges[edge.n].next_out;
200    }
201
202    void firstIn(Edge& edge, const Node& node) const {
203      edge.n = nodes[node.n].first_in;
204    }
205   
206    void nextIn(Edge& edge) const {
207      edge.n = edges[edge.n].next_in;
208    }
209
210    Node _split(Node n, bool connect = true)
211    {
212      Node b = addNode();
213      nodes[b.n].first_out=nodes[n.n].first_out;
214      nodes[n.n].first_out=-1;
215      for(int i=nodes[b.n].first_out;i!=-1;i++) edges[i].source=b.n;
216      if(connect) addEdge(n,b);
217      return b;
218    }
219
220  };
221
222  typedef ClearableGraphExtender<
223    ExtendableGraphExtender<
224    MappableGraphExtender<
225    IterableGraphExtender<
226    AlterableGraphExtender<
227    GraphExtender<SmartGraphBase> > > > > > ExtendedSmartGraphBase;
228
229  /// \ingroup graphs
230
231  ///A smart graph class.
232
233  ///This is a simple and fast graph implementation.
234  ///It is also quite memory efficient, but at the price
235  ///that <b> it does support only limited (only stack-like)
236  ///node and edge deletions</b>.
237  ///It conforms to
238  ///the \ref concept::ExtendableGraph "ExtendableGraph" concept.
239  ///\sa concept::ExtendableGraph.
240  ///
241  ///\author Alpar Juttner
242  class SmartGraph : public ExtendedSmartGraphBase {
243  public:
244   
245    class Snapshot;
246    friend class Snapshot;
247
248  protected:
249    void restoreSnapshot(const Snapshot &s)
250    {
251      while(s.edge_num<edges.size()) {
252        Parent::getNotifier(Edge()).erase(Edge(edges.size()-1));
253        nodes[edges.back().target].first_in=edges.back().next_in;
254        nodes[edges.back().source].first_out=edges.back().next_out;
255        edges.pop_back();
256      }
257      //nodes.resize(s.nodes_num);
258      while(s.node_num<nodes.size()) {
259        Parent::getNotifier(Node()).erase(Node(nodes.size()-1));
260        nodes.pop_back();
261      }
262    }   
263
264  public:
265
266    ///Split a node.
267   
268    ///This function splits a node. First a new node is added to the graph,
269    ///then the source of each outgoing edge of \c n is moved to this new node.
270    ///If \c connect is \c true (this is the default value), then a new edge
271    ///from \c n to the newly created node is also added.
272    ///\return The newly created node.
273    ///
274    ///\note The <tt>Edge</tt>s
275    ///referencing a moved edge remain
276    ///valid. However <tt>InEdge</tt>'s and <tt>OutEdge</tt>'s
277    ///may be invalidated.
278    ///\warning This functionality cannot be used together with the Snapshot
279    ///feature.
280    ///\todo It could be implemented in a bit faster way.
281    Node split(Node n, bool connect = true)
282    {
283      Node b = _split(n,connect);
284      return b;
285    }
286 
287
288    ///Class to make a snapshot of the graph and to restrore to it later.
289
290    ///Class to make a snapshot of the graph and to restrore to it later.
291    ///
292    ///The newly added nodes and edges can be removed using the
293    ///restore() function.
294    ///\note After you restore a state, you cannot restore
295    ///a later state, in other word you cannot add again the edges deleted
296    ///by restore() using another Snapshot instance.
297    ///
298    class Snapshot
299    {
300      SmartGraph *g;
301    protected:
302      friend class SmartGraph;
303      unsigned int node_num;
304      unsigned int edge_num;
305    public:
306      ///Default constructor.
307     
308      ///Default constructor.
309      ///To actually make a snapshot you must call save().
310      ///
311      Snapshot() : g(0) {}
312      ///Constructor that immediately makes a snapshot
313     
314      ///This constructor immediately makes a snapshot of the graph.
315      ///\param _g The graph we make a snapshot of.
316      Snapshot(SmartGraph &_g) :g(&_g) {
317        node_num=g->nodes.size();
318        edge_num=g->edges.size();
319      }
320
321      ///Make a snapshot.
322
323      ///Make a snapshot of the graph.
324      ///
325      ///This function can be called more than once. In case of a repeated
326      ///call, the previous snapshot gets lost.
327      ///\param _g The graph we make the snapshot of.
328      void save(SmartGraph &_g)
329      {
330        g=&_g;
331        node_num=g->nodes.size();
332        edge_num=g->edges.size();
333      }
334
335      ///Undo the changes until a snapshot.
336     
337      ///Undo the changes until a snapshot created by save().
338      ///
339      ///\note After you restored a state, you cannot restore
340      ///a later state, in other word you cannot add again the edges deleted
341      ///by restore().
342      ///
343      ///\todo This function might be called undo().
344     
345      void restore()
346      {
347        g->restoreSnapshot(*this);
348      }
349    };
350  };
351
352
353  /**************** Undirected List Graph ****************/
354
355  typedef ClearableUndirGraphExtender<
356    ExtendableUndirGraphExtender<
357    MappableUndirGraphExtender<
358    IterableUndirGraphExtender<
359    AlterableUndirGraphExtender<
360    UndirGraphExtender<SmartGraphBase> > > > > > ExtendedUndirSmartGraphBase;
361
362  ///A smart undirected graph class.
363
364  ///This is a simple and fast undirected graph implementation.
365  ///It is also quite memory efficient, but at the price
366  ///that <b> it does support only limited (only stack-like)
367  ///node and edge deletions</b>.
368  ///Except from this it conforms to
369  ///the \ref concept::UndirGraph "UndirGraph" concept.
370  ///\sa concept::UndirGraph.
371  ///
372  ///\todo Snapshot hasn't been implemented yet.
373  ///
374  class UndirSmartGraph : public ExtendedUndirSmartGraphBase {
375  };
376
377 
378  /// @} 
379} //namespace lemon
380
381
382#endif //LEMON_SMART_GRAPH_H
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