COIN-OR::LEMON - Graph Library

source: lemon-0.x/src/lemon/smart_graph.h @ 1035:f2a3426e64e6

Last change on this file since 1035:f2a3426e64e6 was 1035:f2a3426e64e6, checked in by Alpar Juttner, 16 years ago

Make UndirListGraph? and UndirSmartGraph? visible in the doc.

File size: 10.2 KB
Line 
1/* -*- C++ -*-
2 * src/lemon/smart_graph.h - Part of LEMON, a generic C++ optimization library
3 *
4 * Copyright (C) 2004 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
5 * (Egervary Combinatorial Optimization Research Group, 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/clearable_graph_extender.h>
29#include <lemon/extendable_graph_extender.h>
30#include <lemon/iterable_graph_extender.h>
31#include <lemon/alteration_observer_registry.h>
32#include <lemon/default_map.h>
33
34#include <lemon/undir_graph_extender.h>
35
36#include <lemon/utility.h>
37
38namespace lemon {
39
40  /// \addtogroup graphs
41  /// @{
42
43  class SmartGraph;
44  ///Base of SmartGraph
45
46  ///Base of SmartGraph
47  ///
48  class SmartGraphBase {
49
50    friend class SmatGraph;
51
52  protected:
53    struct NodeT
54    {
55      int first_in,first_out;     
56      NodeT() : first_in(-1), first_out(-1) {}
57    };
58    struct EdgeT
59    {
60      int target, source, next_in, next_out;     
61      //FIXME: is this necessary?
62      EdgeT() : next_in(-1), next_out(-1) {} 
63    };
64
65    std::vector<NodeT> nodes;
66
67    std::vector<EdgeT> edges;
68   
69   
70  public:
71
72    typedef SmartGraphBase Graph;
73
74    class Node;
75    class Edge;
76
77   
78  public:
79
80    SmartGraphBase() : nodes(), edges() { }
81    SmartGraphBase(const SmartGraphBase &_g) : nodes(_g.nodes), edges(_g.edges) { }
82   
83    typedef True NodeNumTag;
84    typedef True EdgeNumTag;
85
86    ///Number of nodes.
87    int nodeNum() const { return nodes.size(); }
88    ///Number of edges.
89    int edgeNum() const { return edges.size(); }
90
91    /// Maximum node ID.
92   
93    /// Maximum node ID.
94    ///\sa id(Node)
95    int maxId(Node = INVALID) const { return nodes.size()-1; }
96    /// Maximum edge ID.
97   
98    /// Maximum edge ID.
99    ///\sa id(Edge)
100    int maxId(Edge = INVALID) const { return edges.size()-1; }
101
102    Node source(Edge e) const { return edges[e.n].source; }
103    Node target(Edge e) const { return edges[e.n].target; }
104
105    /// Node ID.
106   
107    /// The ID of a valid Node is a nonnegative integer not greater than
108    /// \ref maxNodeId(). The range of the ID's is not surely continuous
109    /// and the greatest node ID can be actually less then \ref maxNodeId().
110    ///
111    /// The ID of the \ref INVALID node is -1.
112    ///\return The ID of the node \c v.
113    static int id(Node v) { return v.n; }
114    /// Edge ID.
115   
116    /// The ID of a valid Edge is a nonnegative integer not greater than
117    /// \ref maxEdgeId(). The range of the ID's is not surely continuous
118    /// and the greatest edge ID can be actually less then \ref maxEdgeId().
119    ///
120    /// The ID of the \ref INVALID edge is -1.
121    ///\return The ID of the edge \c e.
122    static int id(Edge e) { return e.n; }
123
124    Node addNode() {
125      Node n; n.n=nodes.size();
126      nodes.push_back(NodeT()); //FIXME: Hmmm...
127      return n;
128    }
129   
130    Edge addEdge(Node u, Node v) {
131      Edge e; e.n=edges.size(); edges.push_back(EdgeT()); //FIXME: Hmmm...
132      edges[e.n].source=u.n; edges[e.n].target=v.n;
133      edges[e.n].next_out=nodes[u.n].first_out;
134      edges[e.n].next_in=nodes[v.n].first_in;
135      nodes[u.n].first_out=nodes[v.n].first_in=e.n;
136
137      return e;
138    }
139
140    void clear() {
141      edges.clear();
142      nodes.clear();
143    }
144
145
146    class Node {
147      friend class SmartGraphBase;
148      friend class SmartGraph;
149
150    protected:
151      int n;
152      ///\todo It should be removed (or at least define a setToId() instead).
153      ///
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      ///\todo It should be removed (or at least define a setToId() instead).
171      ///
172      Edge(int nn) {n=nn;}
173    public:
174      Edge() { }
175      Edge (Invalid) { n=-1; }
176      bool operator==(const Edge i) const {return n==i.n;}
177      bool operator!=(const Edge i) const {return n!=i.n;}
178      bool operator<(const Edge i) const {return n<i.n;}
179    };
180
181    void first(Node& node) const {
182      node.n = nodes.size() - 1;
183    }
184
185    static void next(Node& node) {
186      --node.n;
187    }
188
189    void first(Edge& edge) const {
190      edge.n = edges.size() - 1;
191    }
192
193    static void next(Edge& edge) {
194      --edge.n;
195    }
196
197    void firstOut(Edge& edge, const Node& node) const {
198      edge.n = nodes[node.n].first_out;
199    }
200
201    void nextOut(Edge& edge) const {
202      edge.n = edges[edge.n].next_out;
203    }
204
205    void firstIn(Edge& edge, const Node& node) const {
206      edge.n = nodes[node.n].first_in;
207    }
208   
209    void nextIn(Edge& edge) const {
210      edge.n = edges[edge.n].next_in;
211    }
212
213    Edge _findEdge(Node u,Node v, Edge prev = INVALID)
214    {
215      int e = (prev.n==-1)? nodes[u.n].first_out : edges[prev.n].next_out;
216      while(e!=-1 && edges[e].source!=v.n) e = edges[e].next_out;
217      prev.n=e;
218      return prev;
219    }
220
221  };
222
223  typedef AlterableGraphExtender<SmartGraphBase> AlterableSmartGraphBase;
224  typedef IterableGraphExtender<AlterableSmartGraphBase> IterableSmartGraphBase;
225  typedef DefaultMappableGraphExtender<IterableSmartGraphBase> MappableSmartGraphBase;
226  typedef ExtendableGraphExtender<MappableSmartGraphBase> ExtendableSmartGraphBase;
227  typedef ClearableGraphExtender<ExtendableSmartGraphBase> ClearableSmartGraphBase;
228
229  ///A smart graph class.
230
231  ///This is a simple and fast graph implementation.
232  ///It is also quite memory efficient, but at the price
233  ///that <b> it does support only limited (only stack-like)
234  ///node and edge deletions</b>.
235  ///It conforms to
236  ///the \ref concept::ExtendableGraph "ExtendableGraph" concept.
237  ///\sa concept::ExtendableGraph.
238  ///
239  ///\author Alpar Juttner
240  class SmartGraph : public ClearableSmartGraphBase {
241  public:
242    /// Finds an edge between two nodes.
243   
244    /// Finds an edge from node \c u to node \c v.
245    ///
246    /// If \c prev is \ref INVALID (this is the default value), then
247    /// it finds the first edge from \c u to \c v. Otherwise it looks for
248    /// the next edge from \c u to \c v after \c prev.
249    /// \return The found edge or \ref INVALID if there is no such an edge.
250    ///
251    /// Thus you can iterate through each edge from \c u to \c v as it follows.
252    /// \code
253    /// for(Edge e=G.findEdge(u,v);e!=INVALID;e=G.findEdge(u,v,e)) {
254    ///   ...
255    /// }
256    /// \endcode
257    /// \todo Possibly it should be a global function.
258    Edge findEdge(Node u,Node v, Edge prev = INVALID)
259    {
260      return _findEdge(u,v,prev);
261    }
262   
263    class SnapShot;
264    friend class SnapShot;
265
266  protected:
267    void restoreSnapShot(const SnapShot &s)
268    {
269      while(s.edge_num>edges.size()) {
270        edge_observers.erase(Edge(edges.size()-1));
271        nodes[edges.back().target].first_in=edges.back().next_in;
272        nodes[edges.back().source].first_out=edges.back().next_out;
273        edges.pop_back();
274      }
275      //nodes.resize(s.nodes_num);
276      while(s.node_num>nodes.size()) {
277        node_observers.erase(Node(nodes.size()-1));
278        nodes.pop_back();
279      }
280    }   
281
282  public:
283    ///Class to make a snapshot of the graph and to restrore to it later.
284
285    ///Class to make a snapshot of the graph and to restrore to it later.
286    ///
287    ///The newly added nodes and edges can be removed using the
288    ///restore() function.
289    ///\note After you restore a state, you cannot restore
290    ///a later state, in other word you cannot add again the edges deleted
291    ///by restore() using another SnapShot instance.
292    ///
293    ///\ingroup graphs
294    class SnapShot
295    {
296      SmartGraph *g;
297    protected:
298      friend class SmartGraph;
299      unsigned int node_num;
300      unsigned int edge_num;
301    public:
302      ///Default constructur.
303     
304      ///Default constructur.
305      ///To actually make a snapshot you must call save().
306      ///
307      SnapShot() : g(0) {}
308      ///Constructor that immediately makes a snapshot
309     
310      ///This constructor immediately makes a snapshot of the graph.
311      ///\param _g The graph we make a snapshot of.
312      SnapShot(SmartGraph &_g) :g(&_g) {
313        node_num=g->nodes.size();
314        edge_num=g->edges.size();
315      }
316
317      ///Make a snapshot.
318
319      ///Make a snapshot of the graph.
320      ///
321      ///This function can be called more than once. In case of a repeated
322      ///call, the previous snapshot gets lost.
323      ///\param _g The graph we make the snapshot of.
324      void save(SmartGraph &_g)
325      {
326        g=&_g;
327        node_num=g->nodes.size();
328        edge_num=g->edges.size();
329      }
330
331      ///Undo the changes until a snapshot.
332     
333      ///Undo the changes until a snapshot created by save().
334      ///
335      ///\param s an internal stucture given back by save()
336      ///\note After you restored a state, you cannot restore
337      ///a later state, in other word you cannot add again the edges deleted
338      ///by restore().
339      ///
340      ///\todo This function might be called undo().
341     
342      void restore()
343      {
344        g->restoreSnapShot(*this);
345      }
346    };
347  };
348
349
350  /**************** Undirected List Graph ****************/
351
352  typedef ClearableUndirGraphExtender<
353    ExtendableUndirGraphExtender<
354    MappableUndirGraphExtender<
355    IterableUndirGraphExtender<
356    AlterableUndirGraphExtender<
357    UndirGraphExtender<SmartGraphBase> > > > > > UndirSmartGraphBase;
358
359  ///A smart undirected graph class.
360
361  ///This is a simple and fast undirected graph implementation.
362  ///It is also quite memory efficient, but at the price
363  ///that <b> it does support only limited (only stack-like)
364  ///node and edge deletions</b>.
365  ///Except from this it conforms to
366  ///the \ref concept::UndirGraph "UndirGraph" concept.
367  ///\sa concept::UndirGraph.
368  ///
369  ///\todo SnapShot hasn't been implemented yet.
370  ///
371  class UndirSmartGraph : public UndirSmartGraphBase {
372  };
373
374 
375  /// @} 
376} //namespace lemon
377
378
379#endif //LEMON_SMART_GRAPH_H
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