COIN-OR::LEMON - Graph Library

source: lemon-0.x/src/lemon/smart_graph.h @ 950:d74557d1f100

Last change on this file since 950:d74557d1f100 was 950:d74557d1f100, checked in by Alpar Juttner, 16 years ago
  • Changes in doc (spell check).
  • SmallGraph? is a class instead of being a typedef. (For the sake of doxygen.)
File size: 7.0 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/erasable_graph_extender.h>
29#include <lemon/clearable_graph_extender.h>
30#include <lemon/extendable_graph_extender.h>
31
32#include <lemon/idmappable_graph_extender.h>
33
34#include <lemon/iterable_graph_extender.h>
35
36#include <lemon/alteration_observer_registry.h>
37#include <lemon/default_map.h>
38
39
40#include <lemon/graph_utils.h>
41
42
43namespace lemon {
44
45  /// \addtogroup graphs
46  /// @{
47
48  class SmartGraphBase {
49
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 head, tail, 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    ///Number of nodes.
81    int nodeNum() const { return nodes.size(); }
82    ///Number of edges.
83    int edgeNum() const { return edges.size(); }
84
85    /// Maximum node ID.
86   
87    /// Maximum node ID.
88    ///\sa id(Node)
89    int maxNodeId() const { return nodes.size()-1; }
90    /// Maximum edge ID.
91   
92    /// Maximum edge ID.
93    ///\sa id(Edge)
94    int maxEdgeId() const { return edges.size()-1; }
95
96    Node tail(Edge e) const { return edges[e.n].tail; }
97    Node head(Edge e) const { return edges[e.n].head; }
98
99    /// Node ID.
100   
101    /// The ID of a valid Node is a nonnegative integer not greater than
102    /// \ref maxNodeId(). The range of the ID's is not surely continuous
103    /// and the greatest node ID can be actually less then \ref maxNodeId().
104    ///
105    /// The ID of the \ref INVALID node is -1.
106    ///\return The ID of the node \c v.
107    static int id(Node v) { return v.n; }
108    /// Edge ID.
109   
110    /// The ID of a valid Edge is a nonnegative integer not greater than
111    /// \ref maxEdgeId(). The range of the ID's is not surely continuous
112    /// and the greatest edge ID can be actually less then \ref maxEdgeId().
113    ///
114    /// The ID of the \ref INVALID edge is -1.
115    ///\return The ID of the edge \c e.
116    static int id(Edge e) { return e.n; }
117
118    Node addNode() {
119      Node n; n.n=nodes.size();
120      nodes.push_back(NodeT()); //FIXME: Hmmm...
121      return n;
122    }
123   
124    Edge addEdge(Node u, Node v) {
125      Edge e; e.n=edges.size(); edges.push_back(EdgeT()); //FIXME: Hmmm...
126      edges[e.n].tail=u.n; edges[e.n].head=v.n;
127      edges[e.n].next_out=nodes[u.n].first_out;
128      edges[e.n].next_in=nodes[v.n].first_in;
129      nodes[u.n].first_out=nodes[v.n].first_in=e.n;
130
131      return e;
132    }
133
134    /// Finds an edge between two nodes.
135
136    /// Finds an edge from node \c u to node \c v.
137    ///
138    /// If \c prev is \ref INVALID (this is the default value), then
139    /// It finds the first edge from \c u to \c v. Otherwise it looks for
140    /// the next edge from \c u to \c v after \c prev.
141    /// \return The found edge or INVALID if there is no such an edge.
142    Edge findEdge(Node u,Node v, Edge prev = INVALID)
143    {
144      int e = (prev.n==-1)? nodes[u.n].first_out : edges[prev.n].next_out;
145      while(e!=-1 && edges[e].tail!=v.n) e = edges[e].next_out;
146      prev.n=e;
147      return prev;
148    }
149   
150    void clear() {
151      edges.clear();
152      nodes.clear();
153    }
154
155
156    class Node {
157      friend class SmartGraphBase;
158
159    protected:
160      int n;
161      Node(int nn) {n=nn;}
162    public:
163      Node() {}
164      Node (Invalid) { n=-1; }
165      bool operator==(const Node i) const {return n==i.n;}
166      bool operator!=(const Node i) const {return n!=i.n;}
167      bool operator<(const Node i) const {return n<i.n;}
168    };
169   
170
171    class Edge {
172      friend class SmartGraphBase;
173
174    protected:
175      int n;
176      Edge(int nn) {n=nn;}
177    public:
178      Edge() { }
179      Edge (Invalid) { n=-1; }
180      bool operator==(const Edge i) const {return n==i.n;}
181      bool operator!=(const Edge i) const {return n!=i.n;}
182      bool operator<(const Edge i) const {return n<i.n;}
183    };
184
185    void first(Node& node) const {
186      node.n = nodes.size() - 1;
187    }
188
189    static void next(Node& node) {
190      --node.n;
191    }
192
193    void first(Edge& edge) const {
194      edge.n = edges.size() - 1;
195    }
196
197    static void next(Edge& edge) {
198      --edge.n;
199    }
200
201    void firstOut(Edge& edge, const Node& node) const {
202      edge.n = nodes[node.n].first_out;
203    }
204
205    void nextOut(Edge& edge) const {
206      edge.n = edges[edge.n].next_out;
207    }
208
209    void firstIn(Edge& edge, const Node& node) const {
210      edge.n = nodes[node.n].first_in;
211    }
212   
213    void nextIn(Edge& edge) const {
214      edge.n = edges[edge.n].next_in;
215    }
216
217  };
218
219  typedef AlterableGraphExtender<SmartGraphBase> AlterableSmartGraphBase;
220  typedef IterableGraphExtender<AlterableSmartGraphBase> IterableSmartGraphBase;
221  typedef IdMappableGraphExtender<IterableSmartGraphBase> IdMappableSmartGraphBase;
222  typedef DefaultMappableGraphExtender<IdMappableSmartGraphBase> MappableSmartGraphBase;
223  typedef ExtendableGraphExtender<MappableSmartGraphBase> ExtendableSmartGraphBase;
224  typedef ClearableGraphExtender<ExtendableSmartGraphBase> ClearableSmartGraphBase;
225
226  ///A smart graph class.
227
228  ///This is a simple and fast graph implementation.
229  ///It is also quite memory efficient, but at the price
230  ///that <b> it does not support node and edge deletion</b>.
231  ///It conforms to
232  ///the \ref skeleton::ExtendableGraph "ExtendableGraph" concept.
233  ///\sa skeleton::ExtendableGraph.
234  ///
235  ///\todo Some member functions could be \c static.
236  ///
237  ///\todo A possibly useful functionality: a function saveState()
238  ///(or snapshot() ) would
239  ///give back a data sturcture X and then the function restoreState(X)
240  ///(or rollBack() )
241  ///would remove the nodes and edges added after the call of saveState().
242  ///Of course it should be used as a stack. (Maybe X is not necessary.)
243  ///
244  ///\author Alpar Juttner
245  class SmartGraph :public ClearableSmartGraphBase { };
246 
247  template <>
248  int countNodes<SmartGraph>(const SmartGraph& graph) {
249    return graph.nodeNum();
250  }
251
252  template <>
253  int countEdges<SmartGraph>(const SmartGraph& graph) {
254    return graph.edgeNum();
255  }
256
257  /// @} 
258} //namespace lemon
259
260
261
262
263#endif //LEMON_SMART_GRAPH_H
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