COIN-OR::LEMON - Graph Library

source: lemon-0.x/src/lemon/smart_graph.h @ 1274:5676e48ca026

Last change on this file since 1274:5676e48ca026 was 1274:5676e48ca026, checked in by zsuzska, 15 years ago

some small corrections in docs

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1/* -*- C++ -*-
2 * src/lemon/smart_graph.h - Part of LEMON, a generic C++ optimization library
3 *
4 * Copyright (C) 2005 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_notifier.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  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 = INVALID) const { return nodes.size()-1; }
93    /// Maximum edge ID.
94   
95    /// Maximum edge ID.
96    ///\sa id(Edge)
97    int maxId(Edge = INVALID) 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 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      ///\todo It should be removed (or at least define a setToId() instead).
154      ///
155      Node(int nn) {n=nn;}
156    public:
157      Node() {}
158      Node (Invalid) { n=-1; }
159      bool operator==(const Node i) const {return n==i.n;}
160      bool operator!=(const Node i) const {return n!=i.n;}
161      bool operator<(const Node i) const {return n<i.n;}
162    };
163   
164
165    class Edge {
166      friend class SmartGraphBase;
167      friend class SmartGraph;
168
169    protected:
170      int n;
171      ///\todo It should be removed (or at least define a setToId() instead).
172      ///
173      Edge(int nn) {n=nn;}
174    public:
175      Edge() { }
176      Edge (Invalid) { n=-1; }
177      bool operator==(const Edge i) const {return n==i.n;}
178      bool operator!=(const Edge i) const {return n!=i.n;}
179      bool operator<(const Edge i) const {return n<i.n;}
180    };
181
182    void first(Node& node) const {
183      node.n = nodes.size() - 1;
184    }
185
186    static void next(Node& node) {
187      --node.n;
188    }
189
190    void first(Edge& edge) const {
191      edge.n = edges.size() - 1;
192    }
193
194    static void next(Edge& edge) {
195      --edge.n;
196    }
197
198    void firstOut(Edge& edge, const Node& node) const {
199      edge.n = nodes[node.n].first_out;
200    }
201
202    void nextOut(Edge& edge) const {
203      edge.n = edges[edge.n].next_out;
204    }
205
206    void firstIn(Edge& edge, const Node& node) const {
207      edge.n = nodes[node.n].first_in;
208    }
209   
210    void nextIn(Edge& edge) const {
211      edge.n = edges[edge.n].next_in;
212    }
213
214    Edge _findEdge(Node u,Node v, Edge prev = INVALID)
215    {
216      int e = (prev.n==-1)? nodes[u.n].first_out : edges[prev.n].next_out;
217      while(e!=-1 && edges[e].target!=v.n) e = edges[e].next_out;
218      prev.n=e;
219      return prev;
220    }
221
222  };
223
224  typedef AlterableGraphExtender<SmartGraphBase> AlterableSmartGraphBase;
225  typedef IterableGraphExtender<AlterableSmartGraphBase> IterableSmartGraphBase;
226  typedef DefaultMappableGraphExtender<IterableSmartGraphBase> MappableSmartGraphBase;
227  typedef ExtendableGraphExtender<MappableSmartGraphBase> ExtendableSmartGraphBase;
228  typedef ClearableGraphExtender<ExtendableSmartGraphBase> ClearableSmartGraphBase;
229
230  /// \addtogroup graphs
231  /// @{
232
233  ///A smart graph class.
234
235  ///This is a simple and fast graph implementation.
236  ///It is also quite memory efficient, but at the price
237  ///that <b> it does support only limited (only stack-like)
238  ///node and edge deletions</b>.
239  ///It conforms to
240  ///the \ref concept::ExtendableGraph "ExtendableGraph" concept.
241  ///\sa concept::ExtendableGraph.
242  ///
243  ///\author Alpar Juttner
244  class SmartGraph : public ClearableSmartGraphBase {
245  public:
246    /// Finds an edge between two nodes.
247   
248    /// Finds an edge from node \c u to node \c v.
249    ///
250    /// If \c prev is \ref INVALID (this is the default value), then
251    /// it finds the first edge from \c u to \c v. Otherwise it looks for
252    /// the next edge from \c u to \c v after \c prev.
253    /// \return The found edge or \ref INVALID if there is no such an edge.
254    ///
255    /// Thus you can iterate through each edge from \c u to \c v as it follows.
256    /// \code
257    /// for(Edge e=G.findEdge(u,v);e!=INVALID;e=G.findEdge(u,v,e)) {
258    ///   ...
259    /// }
260    /// \endcode
261    /// \todo Possibly it should be a global function.
262    Edge findEdge(Node u,Node v, Edge prev = INVALID)
263    {
264      return _findEdge(u,v,prev);
265    }
266   
267    class SnapShot;
268    friend class SnapShot;
269
270  protected:
271    void restoreSnapShot(const SnapShot &s)
272    {
273      while(s.edge_num>edges.size()) {
274        Parent::getNotifier(Edge()).erase(Edge(edges.size()-1));
275        nodes[edges.back().target].first_in=edges.back().next_in;
276        nodes[edges.back().source].first_out=edges.back().next_out;
277        edges.pop_back();
278      }
279      //nodes.resize(s.nodes_num);
280      while(s.node_num>nodes.size()) {
281        Parent::getNotifier(Node()).erase(Node(nodes.size()-1));
282        nodes.pop_back();
283      }
284    }   
285
286  public:
287    ///Class to make a snapshot of the graph and to restrore to it later.
288
289    ///Class to make a snapshot of the graph and to restrore to it later.
290    ///
291    ///The newly added nodes and edges can be removed using the
292    ///restore() function.
293    ///\note After you restore a state, you cannot restore
294    ///a later state, in other word you cannot add again the edges deleted
295    ///by restore() using another SnapShot instance.
296    ///
297    class SnapShot
298    {
299      SmartGraph *g;
300    protected:
301      friend class SmartGraph;
302      unsigned int node_num;
303      unsigned int edge_num;
304    public:
305      ///Default constructor.
306     
307      ///Default constructor.
308      ///To actually make a snapshot you must call save().
309      ///
310      SnapShot() : g(0) {}
311      ///Constructor that immediately makes a snapshot
312     
313      ///This constructor immediately makes a snapshot of the graph.
314      ///\param _g The graph we make a snapshot of.
315      SnapShot(SmartGraph &_g) :g(&_g) {
316        node_num=g->nodes.size();
317        edge_num=g->edges.size();
318      }
319
320      ///Make a snapshot.
321
322      ///Make a snapshot of the graph.
323      ///
324      ///This function can be called more than once. In case of a repeated
325      ///call, the previous snapshot gets lost.
326      ///\param _g The graph we make the snapshot of.
327      void save(SmartGraph &_g)
328      {
329        g=&_g;
330        node_num=g->nodes.size();
331        edge_num=g->edges.size();
332      }
333
334      ///Undo the changes until a snapshot.
335     
336      ///Undo the changes until a snapshot created by save().
337      ///
338      ///\param s an internal stucture given back by save()
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> > > > > > UndirSmartGraphBase;
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 UndirSmartGraphBase {
375  };
376
377 
378  /// @} 
379} //namespace lemon
380
381
382#endif //LEMON_SMART_GRAPH_H
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