COIN-OR::LEMON - Graph Library

source: lemon-0.x/src/lemon/smart_graph.h @ 946:c94ef40a22ce

Last change on this file since 946:c94ef40a22ce was 946:c94ef40a22ce, checked in by Mihaly Barasz, 16 years ago

The graph_factory branch (@ 1321) has been merged to trunk.

File size: 6.9 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/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  ///A smart graph class.
49
50  ///This is a simple and fast graph implementation.
51  ///It is also quite memory efficient, but at the price
52  ///that <b> it does not support node and edge deletion</b>.
53  ///It conforms to
54  ///the \ref skeleton::ExtendableGraph "ExtendableGraph" concept.
55  ///\sa skeleton::ExtendableGraph.
56  ///
57  ///\todo Some member functions could be \c static.
58  ///
59  ///\todo A possibly useful functionality: a function saveState() would
60  ///give back a data sturcture X and then the function restoreState(X)
61  ///would remove the nodes and edges added after the call of saveState().
62  ///Of course it should be used as a stack. (Maybe X is not necessary.)
63  ///
64  ///\author Alpar Juttner
65  class SmartGraphBase {
66
67    struct NodeT
68    {
69      int first_in,first_out;     
70      NodeT() : first_in(-1), first_out(-1) {}
71    };
72    struct EdgeT
73    {
74      int head, tail, next_in, next_out;     
75      //FIXME: is this necessary?
76      EdgeT() : next_in(-1), next_out(-1) {} 
77    };
78
79    std::vector<NodeT> nodes;
80
81    std::vector<EdgeT> edges;
82   
83   
84  public:
85
86    typedef SmartGraphBase Graph;
87
88    class Node;
89    class Edge;
90
91   
92  public:
93
94    SmartGraphBase() : nodes(), edges() { }
95    SmartGraphBase(const SmartGraphBase &_g) : nodes(_g.nodes), edges(_g.edges) { }
96   
97    ///Number of nodes.
98    int nodeNum() const { return nodes.size(); }
99    ///Number of edges.
100    int edgeNum() const { return edges.size(); }
101
102    /// Maximum node ID.
103   
104    /// Maximum node ID.
105    ///\sa id(Node)
106    int maxNodeId() const { return nodes.size()-1; }
107    /// Maximum edge ID.
108   
109    /// Maximum edge ID.
110    ///\sa id(Edge)
111    int maxEdgeId() const { return edges.size()-1; }
112
113    Node tail(Edge e) const { return edges[e.n].tail; }
114    Node head(Edge e) const { return edges[e.n].head; }
115
116    /// Node ID.
117   
118    /// The ID of a valid Node is a nonnegative integer not greater than
119    /// \ref maxNodeId(). The range of the ID's is not surely continuous
120    /// and the greatest node ID can be actually less then \ref maxNodeId().
121    ///
122    /// The ID of the \ref INVALID node is -1.
123    ///\return The ID of the node \c v.
124    static int id(Node v) { return v.n; }
125    /// Edge ID.
126   
127    /// The ID of a valid Edge is a nonnegative integer not greater than
128    /// \ref maxEdgeId(). The range of the ID's is not surely continuous
129    /// and the greatest edge ID can be actually less then \ref maxEdgeId().
130    ///
131    /// The ID of the \ref INVALID edge is -1.
132    ///\return The ID of the edge \c e.
133    static int id(Edge e) { return e.n; }
134
135    Node addNode() {
136      Node n; n.n=nodes.size();
137      nodes.push_back(NodeT()); //FIXME: Hmmm...
138      return n;
139    }
140   
141    Edge addEdge(Node u, Node v) {
142      Edge e; e.n=edges.size(); edges.push_back(EdgeT()); //FIXME: Hmmm...
143      edges[e.n].tail=u.n; edges[e.n].head=v.n;
144      edges[e.n].next_out=nodes[u.n].first_out;
145      edges[e.n].next_in=nodes[v.n].first_in;
146      nodes[u.n].first_out=nodes[v.n].first_in=e.n;
147
148      return e;
149    }
150
151    /// Finds an edge between two nodes.
152
153    /// Finds an edge from node \c u to node \c v.
154    ///
155    /// If \c prev is \ref INVALID (this is the default value), then
156    /// It finds the first edge from \c u to \c v. Otherwise it looks for
157    /// the next edge from \c u to \c v after \c prev.
158    /// \return The found edge or INVALID if there is no such an edge.
159    Edge findEdge(Node u,Node v, Edge prev = INVALID)
160    {
161      int e = (prev.n==-1)? nodes[u.n].first_out : edges[prev.n].next_out;
162      while(e!=-1 && edges[e].tail!=v.n) e = edges[e].next_out;
163      prev.n=e;
164      return prev;
165    }
166   
167    void clear() {
168      edges.clear();
169      nodes.clear();
170    }
171
172
173    class Node {
174      friend class SmartGraphBase;
175
176    protected:
177      int n;
178      Node(int nn) {n=nn;}
179    public:
180      Node() {}
181      Node (Invalid) { n=-1; }
182      bool operator==(const Node i) const {return n==i.n;}
183      bool operator!=(const Node i) const {return n!=i.n;}
184      bool operator<(const Node i) const {return n<i.n;}
185    };
186   
187
188    class Edge {
189      friend class SmartGraphBase;
190
191    protected:
192      int n;
193      Edge(int nn) {n=nn;}
194    public:
195      Edge() { }
196      Edge (Invalid) { n=-1; }
197      bool operator==(const Edge i) const {return n==i.n;}
198      bool operator!=(const Edge i) const {return n!=i.n;}
199      bool operator<(const Edge i) const {return n<i.n;}
200    };
201
202    void first(Node& node) const {
203      node.n = nodes.size() - 1;
204    }
205
206    static void next(Node& node) {
207      --node.n;
208    }
209
210    void first(Edge& edge) const {
211      edge.n = edges.size() - 1;
212    }
213
214    static void next(Edge& edge) {
215      --edge.n;
216    }
217
218    void firstOut(Edge& edge, const Node& node) const {
219      edge.n = nodes[node.n].first_out;
220    }
221
222    void nextOut(Edge& edge) const {
223      edge.n = edges[edge.n].next_out;
224    }
225
226    void firstIn(Edge& edge, const Node& node) const {
227      edge.n = nodes[node.n].first_in;
228    }
229   
230    void nextIn(Edge& edge) const {
231      edge.n = edges[edge.n].next_in;
232    }
233
234  };
235
236  typedef AlterableGraphExtender<SmartGraphBase> AlterableSmartGraphBase;
237  typedef IterableGraphExtender<AlterableSmartGraphBase> IterableSmartGraphBase;
238  typedef IdMappableGraphExtender<IterableSmartGraphBase> IdMappableSmartGraphBase;
239  typedef DefaultMappableGraphExtender<IdMappableSmartGraphBase> MappableSmartGraphBase;
240  typedef ExtendableGraphExtender<MappableSmartGraphBase> ExtendableSmartGraphBase;
241  typedef ClearableGraphExtender<ExtendableSmartGraphBase> ClearableSmartGraphBase;
242
243  typedef ClearableSmartGraphBase SmartGraph;
244
245
246  template <>
247  int countNodes<SmartGraph>(const SmartGraph& graph) {
248    return graph.nodeNum();
249  }
250
251  template <>
252  int countEdges<SmartGraph>(const SmartGraph& graph) {
253    return graph.edgeNum();
254  }
255
256  /// @} 
257} //namespace lemon
258
259
260
261
262#endif //LEMON_SMART_GRAPH_H
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