COIN-OR::LEMON - Graph Library

source: lemon-0.x/lemon/smart_graph.h @ 1669:66ae78d29f1e

Last change on this file since 1669:66ae78d29f1e was 1669:66ae78d29f1e, checked in by Balazs Dezso, 14 years ago

Template assign operator for graph maps.

Some naming and coding conventions.

File size: 11.1 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 SymSmartGraph 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
34#include <lemon/bits/undir_graph_extender.h>
35
36#include <lemon/utility.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) : 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 maxId(Node) const { return nodes.size()-1; }
93    /// Maximum edge ID.
94   
95    /// Maximum edge ID.
96    ///\sa id(Edge)
97    int maxId(Edge) 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 maxId(Node). The range of the ID's is not surely continuous
106    /// and the greatest node ID can be actually less then \ref maxId(Node).
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 maxId(Edge). The range of the ID's is not surely continuous
115    /// and the greatest edge ID can be actually less then \ref maxId(Edge).
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 fromId(int id, Node) { return Node(id);}
122
123    static Edge fromId(int id, Edge) { 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      ///\e
154
155      ///\todo It should be removed (or at least define a setToId() instead).
156      ///
157      Node(int nn) {n=nn;}
158    public:
159      Node() {}
160      Node (Invalid) { n=-1; }
161      bool operator==(const Node i) const {return n==i.n;}
162      bool operator!=(const Node i) const {return n!=i.n;}
163      bool operator<(const Node i) const {return n<i.n;}
164    };
165   
166
167    class Edge {
168      friend class SmartGraphBase;
169      friend class SmartGraph;
170
171    protected:
172      int n;
173      ///\todo It should be removed (or at least define a setToId() instead).
174      ///
175      Edge(int nn) {n=nn;}
176    public:
177      Edge() { }
178      Edge (Invalid) { n=-1; }
179      bool operator==(const Edge i) const {return n==i.n;}
180      bool operator!=(const Edge i) const {return n!=i.n;}
181      bool operator<(const Edge i) const {return n<i.n;}
182    };
183
184    void first(Node& node) const {
185      node.n = nodes.size() - 1;
186    }
187
188    static void next(Node& node) {
189      --node.n;
190    }
191
192    void first(Edge& edge) const {
193      edge.n = edges.size() - 1;
194    }
195
196    static void next(Edge& edge) {
197      --edge.n;
198    }
199
200    void firstOut(Edge& edge, const Node& node) const {
201      edge.n = nodes[node.n].first_out;
202    }
203
204    void nextOut(Edge& edge) const {
205      edge.n = edges[edge.n].next_out;
206    }
207
208    void firstIn(Edge& edge, const Node& node) const {
209      edge.n = nodes[node.n].first_in;
210    }
211   
212    void nextIn(Edge& edge) const {
213      edge.n = edges[edge.n].next_in;
214    }
215
216    Edge _findEdge(Node u,Node v, Edge prev = INVALID)
217    {
218      int e = (prev.n==-1)? nodes[u.n].first_out : edges[prev.n].next_out;
219      while(e!=-1 && edges[e].target!=v.n) e = edges[e].next_out;
220      prev.n=e;
221      return prev;
222    }
223
224    Node _split(Node n, bool connect = true)
225    {
226      Node b = addNode();
227      nodes[b.n].first_out=nodes[n.n].first_out;
228      nodes[n.n].first_out=-1;
229      for(int i=nodes[b.n].first_out;i!=-1;i++) edges[i].source=b.n;
230      if(connect) addEdge(n,b);
231      return b;
232    }
233
234  };
235
236  typedef ClearableGraphExtender<
237    ExtendableGraphExtender<
238    MappableGraphExtender<
239    IterableGraphExtender<
240    AlterableGraphExtender<SmartGraphBase> > > > > ExtendedSmartGraphBase;
241
242  /// \addtogroup graphs
243  /// @{
244
245  ///A smart graph class.
246
247  ///This is a simple and fast graph implementation.
248  ///It is also quite memory efficient, but at the price
249  ///that <b> it does support only limited (only stack-like)
250  ///node and edge deletions</b>.
251  ///It conforms to
252  ///the \ref concept::ExtendableGraph "ExtendableGraph" concept.
253  ///\sa concept::ExtendableGraph.
254  ///
255  ///\author Alpar Juttner
256  class SmartGraph : public ExtendedSmartGraphBase {
257  public:
258    /// Finds an edge between two nodes.
259   
260    /// Finds an edge from node \c u to node \c v.
261    ///
262    /// If \c prev is \ref INVALID (this is the default value), then
263    /// it finds the first edge from \c u to \c v. Otherwise it looks for
264    /// the next edge from \c u to \c v after \c prev.
265    /// \return The found edge or \ref INVALID if there is no such an edge.
266    ///
267    /// Thus you can iterate through each edge from \c u to \c v as it follows.
268    /// \code
269    /// for(Edge e=G.findEdge(u,v);e!=INVALID;e=G.findEdge(u,v,e)) {
270    ///   ...
271    /// }
272    /// \endcode
273    /// \todo Possibly it should be a global function.
274    Edge findEdge(Node u,Node v, Edge prev = INVALID)
275    {
276      return _findEdge(u,v,prev);
277    }
278   
279    class SnapShot;
280    friend class SnapShot;
281
282  protected:
283    void restoreSnapShot(const SnapShot &s)
284    {
285      while(s.edge_num<edges.size()) {
286        Parent::getNotifier(Edge()).erase(Edge(edges.size()-1));
287        nodes[edges.back().target].first_in=edges.back().next_in;
288        nodes[edges.back().source].first_out=edges.back().next_out;
289        edges.pop_back();
290      }
291      //nodes.resize(s.nodes_num);
292      while(s.node_num<nodes.size()) {
293        Parent::getNotifier(Node()).erase(Node(nodes.size()-1));
294        nodes.pop_back();
295      }
296    }   
297
298  public:
299
300    ///Split a node.
301   
302    ///This function splits a node. First a new node is added to the graph,
303    ///then the source of each outgoing edge of \c n is moved to this new node.
304    ///If \c connect is \c true (this is the default value), then a new edge
305    ///from \c n to the newly created node is also added.
306    ///\return The newly created node.
307    ///
308    ///\note The <tt>Edge</tt>s
309    ///referencing a moved edge remain
310    ///valid. However <tt>InEdge</tt>'s and <tt>OutEdge</tt>'s
311    ///may be invalidated.
312    ///\warning This functionality cannot be used together with the SnapShot
313    ///feature.
314    ///\todo It could be implemented in a bit faster way.
315    Node split(Node n, bool connect = true)
316    {
317      return _split(n,connect);
318    }
319 
320
321    ///Class to make a snapshot of the graph and to restrore to it later.
322
323    ///Class to make a snapshot of the graph and to restrore to it later.
324    ///
325    ///The newly added nodes and edges can be removed using the
326    ///restore() function.
327    ///\note After you restore a state, you cannot restore
328    ///a later state, in other word you cannot add again the edges deleted
329    ///by restore() using another SnapShot instance.
330    ///
331    class SnapShot
332    {
333      SmartGraph *g;
334    protected:
335      friend class SmartGraph;
336      unsigned int node_num;
337      unsigned int edge_num;
338    public:
339      ///Default constructor.
340     
341      ///Default constructor.
342      ///To actually make a snapshot you must call save().
343      ///
344      SnapShot() : g(0) {}
345      ///Constructor that immediately makes a snapshot
346     
347      ///This constructor immediately makes a snapshot of the graph.
348      ///\param _g The graph we make a snapshot of.
349      SnapShot(SmartGraph &_g) :g(&_g) {
350        node_num=g->nodes.size();
351        edge_num=g->edges.size();
352      }
353
354      ///Make a snapshot.
355
356      ///Make a snapshot of the graph.
357      ///
358      ///This function can be called more than once. In case of a repeated
359      ///call, the previous snapshot gets lost.
360      ///\param _g The graph we make the snapshot of.
361      void save(SmartGraph &_g)
362      {
363        g=&_g;
364        node_num=g->nodes.size();
365        edge_num=g->edges.size();
366      }
367
368      ///Undo the changes until a snapshot.
369     
370      ///Undo the changes until a snapshot created by save().
371      ///
372      ///\note After you restored a state, you cannot restore
373      ///a later state, in other word you cannot add again the edges deleted
374      ///by restore().
375      ///
376      ///\todo This function might be called undo().
377     
378      void restore()
379      {
380        g->restoreSnapShot(*this);
381      }
382    };
383  };
384
385
386  /**************** Undirected List Graph ****************/
387
388  typedef ClearableUndirGraphExtender<
389    ExtendableUndirGraphExtender<
390    MappableUndirGraphExtender<
391    IterableUndirGraphExtender<
392    AlterableUndirGraphExtender<
393    UndirGraphExtender<SmartGraphBase> > > > > > ExtendedUndirSmartGraphBase;
394
395  ///A smart undirected graph class.
396
397  ///This is a simple and fast undirected graph implementation.
398  ///It is also quite memory efficient, but at the price
399  ///that <b> it does support only limited (only stack-like)
400  ///node and edge deletions</b>.
401  ///Except from this it conforms to
402  ///the \ref concept::UndirGraph "UndirGraph" concept.
403  ///\sa concept::UndirGraph.
404  ///
405  ///\todo SnapShot hasn't been implemented yet.
406  ///
407  class UndirSmartGraph : public ExtendedUndirSmartGraphBase {
408  };
409
410 
411  /// @} 
412} //namespace lemon
413
414
415#endif //LEMON_SMART_GRAPH_H
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