COIN-OR::LEMON - Graph Library

source: lemon-0.x/src/lemon/smart_graph.h @ 977:48962802d168

Last change on this file since 977:48962802d168 was 977:48962802d168, checked in by Mihaly Barasz, 15 years ago
  • enable_if imported from BOOST
  • count{Nodes,Edges} implemented via graph tags
  • some #include bugs fixed
File size: 8.9 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/idmappable_graph_extender.h>
31#include <lemon/iterable_graph_extender.h>
32#include <lemon/alteration_observer_registry.h>
33#include <lemon/default_map.h>
34
35#include <lemon/utility.h>
36
37namespace lemon {
38
39  /// \addtogroup graphs
40  /// @{
41
42  class SmartGraph;
43  ///Base of SmartGraph
44
45  ///Base of SmartGraph
46  ///
47  class SmartGraphBase {
48
49    friend class SmatGraph;
50
51  protected:
52    struct NodeT
53    {
54      int first_in,first_out;     
55      NodeT() : first_in(-1), first_out(-1) {}
56    };
57    struct EdgeT
58    {
59      int head, tail, next_in, next_out;     
60      //FIXME: is this necessary?
61      EdgeT() : next_in(-1), next_out(-1) {} 
62    };
63
64    std::vector<NodeT> nodes;
65
66    std::vector<EdgeT> edges;
67   
68   
69  public:
70
71    typedef SmartGraphBase Graph;
72
73    class Node;
74    class Edge;
75
76   
77  public:
78
79    SmartGraphBase() : nodes(), edges() { }
80    SmartGraphBase(const SmartGraphBase &_g) : nodes(_g.nodes), edges(_g.edges) { }
81   
82    typedef True NodeNumTag;
83    typedef True EdgeNumTag;
84
85    ///Number of nodes.
86    int nodeNum() const { return nodes.size(); }
87    ///Number of edges.
88    int edgeNum() const { return edges.size(); }
89
90    /// Maximum node ID.
91   
92    /// Maximum node ID.
93    ///\sa id(Node)
94    int maxNodeId() const { return nodes.size()-1; }
95    /// Maximum edge ID.
96   
97    /// Maximum edge ID.
98    ///\sa id(Edge)
99    int maxEdgeId() const { return edges.size()-1; }
100
101    Node tail(Edge e) const { return edges[e.n].tail; }
102    Node head(Edge e) const { return edges[e.n].head; }
103
104    /// Node ID.
105   
106    /// The ID of a valid Node is a nonnegative integer not greater than
107    /// \ref maxNodeId(). The range of the ID's is not surely continuous
108    /// and the greatest node ID can be actually less then \ref maxNodeId().
109    ///
110    /// The ID of the \ref INVALID node is -1.
111    ///\return The ID of the node \c v.
112    static int id(Node v) { return v.n; }
113    /// Edge ID.
114   
115    /// The ID of a valid Edge is a nonnegative integer not greater than
116    /// \ref maxEdgeId(). The range of the ID's is not surely continuous
117    /// and the greatest edge ID can be actually less then \ref maxEdgeId().
118    ///
119    /// The ID of the \ref INVALID edge is -1.
120    ///\return The ID of the edge \c e.
121    static int id(Edge e) { return e.n; }
122
123    Node addNode() {
124      Node n; n.n=nodes.size();
125      nodes.push_back(NodeT()); //FIXME: Hmmm...
126      return n;
127    }
128   
129    Edge addEdge(Node u, Node v) {
130      Edge e; e.n=edges.size(); edges.push_back(EdgeT()); //FIXME: Hmmm...
131      edges[e.n].tail=u.n; edges[e.n].head=v.n;
132      edges[e.n].next_out=nodes[u.n].first_out;
133      edges[e.n].next_in=nodes[v.n].first_in;
134      nodes[u.n].first_out=nodes[v.n].first_in=e.n;
135
136      return e;
137    }
138
139    void clear() {
140      edges.clear();
141      nodes.clear();
142    }
143
144
145    class Node {
146      friend class SmartGraphBase;
147      friend class SmartGraph;
148
149    protected:
150      int n;
151      ///\todo It should be removed (or at least define a setToId() instead).
152      ///
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      ///\todo It should be removed (or at least define a setToId() instead).
170      ///
171      Edge(int nn) {n=nn;}
172    public:
173      Edge() { }
174      Edge (Invalid) { n=-1; }
175      bool operator==(const Edge i) const {return n==i.n;}
176      bool operator!=(const Edge i) const {return n!=i.n;}
177      bool operator<(const Edge i) const {return n<i.n;}
178    };
179
180    void first(Node& node) const {
181      node.n = nodes.size() - 1;
182    }
183
184    static void next(Node& node) {
185      --node.n;
186    }
187
188    void first(Edge& edge) const {
189      edge.n = edges.size() - 1;
190    }
191
192    static void next(Edge& edge) {
193      --edge.n;
194    }
195
196    void firstOut(Edge& edge, const Node& node) const {
197      edge.n = nodes[node.n].first_out;
198    }
199
200    void nextOut(Edge& edge) const {
201      edge.n = edges[edge.n].next_out;
202    }
203
204    void firstIn(Edge& edge, const Node& node) const {
205      edge.n = nodes[node.n].first_in;
206    }
207   
208    void nextIn(Edge& edge) const {
209      edge.n = edges[edge.n].next_in;
210    }
211
212    Edge _findEdge(Node u,Node v, Edge prev = INVALID)
213    {
214      int e = (prev.n==-1)? nodes[u.n].first_out : edges[prev.n].next_out;
215      while(e!=-1 && edges[e].tail!=v.n) e = edges[e].next_out;
216      prev.n=e;
217      return prev;
218    }
219
220  };
221
222  typedef AlterableGraphExtender<SmartGraphBase> AlterableSmartGraphBase;
223  typedef IterableGraphExtender<AlterableSmartGraphBase> IterableSmartGraphBase;
224  typedef IdMappableGraphExtender<IterableSmartGraphBase> IdMappableSmartGraphBase;
225  typedef DefaultMappableGraphExtender<IdMappableSmartGraphBase> 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    ///Internal data structure to store snapshots
266   
267    ///\ingroup graphs
268    ///\sa makeSnapShot()
269    ///\sa rollBack()
270    struct SnapShot
271    {
272      unsigned int node_num;
273      unsigned int edge_num;
274    };
275   
276    ///Make a snapshot of the graph.
277
278    ///Make a snapshot of the graph.
279    ///
280    ///The newly added nodes and edges can be removed using the
281    ///rollBack() function.
282    ///
283    ///\return An stucture SnapShot describing the pesent state of the
284    ///graph.
285    ///\note After you rolled back to a state, you cannot roll "back" to
286    ///a later state, in other word you cannot add again the edges deleted
287    ///by rollBack().
288    ///\todo This function might be called saveState() or getState().
289    SnapShot makeSnapShot()
290    {
291      SnapShot s;
292      s.node_num=nodes.size();
293      s.edge_num=edges.size();
294      return s;
295    }
296   
297    ///Undo the changes until a snapshot.
298
299    ///Undo the changes until a snapshot created by makeSnapShot().
300    ///
301    ///\param s an internal stucture given back by makeSnapShot()
302    ///\note After you rolled back to a state, you cannot "roll forward" to
303    ///a later state, in other word you cannot add again the edges deleted
304    ///by rollBack().
305    ///
306    ///\todo This function might be called undo().
307   
308    void rollBack(const SnapShot &s)
309    {
310      while(s.edge_num>edges.size()) {
311        edge_observers.erase(Edge(edges.size()-1));
312        nodes[edges.back().head].first_in=edges.back().next_in;
313        nodes[edges.back().tail].first_out=edges.back().next_out;
314        edges.pop_back();
315      }
316      //nodes.resize(s.nodes_num);
317      while(s.node_num>nodes.size()) {
318        node_observers.erase(Node(nodes.size()-1));
319        nodes.pop_back();
320      }
321    }
322  };
323 
324  /// @} 
325} //namespace lemon
326
327
328#endif //LEMON_SMART_GRAPH_H
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