COIN-OR::LEMON - Graph Library

source: lemon-0.x/src/lemon/smart_graph.h @ 1034:be6ee857b72d

Last change on this file since 1034:be6ee857b72d was 1034:be6ee857b72d, checked in by Mihaly Barasz, 16 years ago

Undir list and smart graph

File size: 9.9 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  ///\todo Some member functions could be \c static.
240  ///
241  ///\author Alpar Juttner
242  class SmartGraph : public ClearableSmartGraphBase {
243  public:
244    /// Finds an edge between two nodes.
245   
246    /// Finds an edge from node \c u to node \c v.
247    ///
248    /// If \c prev is \ref INVALID (this is the default value), then
249    /// it finds the first edge from \c u to \c v. Otherwise it looks for
250    /// the next edge from \c u to \c v after \c prev.
251    /// \return The found edge or \ref INVALID if there is no such an edge.
252    ///
253    /// Thus you can iterate through each edge from \c u to \c v as it follows.
254    /// \code
255    /// for(Edge e=G.findEdge(u,v);e!=INVALID;e=G.findEdge(u,v,e)) {
256    ///   ...
257    /// }
258    /// \endcode
259    /// \todo Possibly it should be a global function.
260    Edge findEdge(Node u,Node v, Edge prev = INVALID)
261    {
262      return _findEdge(u,v,prev);
263    }
264   
265    class SnapShot;
266    friend class SnapShot;
267
268  protected:
269    void restoreSnapShot(const SnapShot &s)
270    {
271      while(s.edge_num>edges.size()) {
272        edge_observers.erase(Edge(edges.size()-1));
273        nodes[edges.back().target].first_in=edges.back().next_in;
274        nodes[edges.back().source].first_out=edges.back().next_out;
275        edges.pop_back();
276      }
277      //nodes.resize(s.nodes_num);
278      while(s.node_num>nodes.size()) {
279        node_observers.erase(Node(nodes.size()-1));
280        nodes.pop_back();
281      }
282    }   
283
284  public:
285    ///Class to make a snapshot of the graph and to restrore to it later.
286
287    ///Class to make a snapshot of the graph and to restrore to it later.
288    ///
289    ///The newly added nodes and edges can be removed using the
290    ///restore() function.
291    ///\note After you restore a state, you cannot restore
292    ///a later state, in other word you cannot add again the edges deleted
293    ///by restore() using another SnapShot instance.
294    ///
295    ///\ingroup graphs
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 constructur.
305     
306      ///Default constructur.
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      ///\param s an internal stucture given back by save()
338      ///\note After you restored a state, you cannot restore
339      ///a later state, in other word you cannot add again the edges deleted
340      ///by restore().
341      ///
342      ///\todo This function might be called undo().
343     
344      void restore()
345      {
346        g->restoreSnapShot(*this);
347      }
348    };
349  };
350
351
352  /**************** Undirected List Graph ****************/
353
354  typedef ClearableUndirGraphExtender<
355    ExtendableUndirGraphExtender<
356    MappableUndirGraphExtender<
357    IterableUndirGraphExtender<
358    AlterableUndirGraphExtender<
359    UndirGraphExtender<SmartGraphBase> > > > > > UndirSmartGraphBase;
360
361  class UndirSmartGraph : public UndirSmartGraphBase {
362  };
363
364 
365  /// @} 
366} //namespace lemon
367
368
369#endif //LEMON_SMART_GRAPH_H
Note: See TracBrowser for help on using the repository browser.