COIN-OR::LEMON - Graph Library

source: lemon-0.x/lemon/bits/base_extender.h @ 2187:a54a2dd03f03

Last change on this file since 2187:a54a2dd03f03 was 2187:a54a2dd03f03, checked in by Balazs Dezso, 13 years ago

Bug fix in UndirGraphAdaptor?

File size: 6.6 KB
Line 
1/* -*- C++ -*-
2 *
3 * This file is a part of LEMON, a generic C++ optimization library
4 *
5 * Copyright (C) 2003-2006
6 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
7 * (Egervary Research Group on Combinatorial Optimization, EGRES).
8 *
9 * Permission to use, modify and distribute this software is granted
10 * provided that this copyright notice appears in all copies. For
11 * precise terms see the accompanying LICENSE file.
12 *
13 * This software is provided "AS IS" with no warranty of any kind,
14 * express or implied, and with no claim as to its suitability for any
15 * purpose.
16 *
17 */
18
19#ifndef LEMON_BITS_BASE_EXTENDER_H
20#define LEMON_BITS_BASE_EXTENDER_H
21
22#include <lemon/bits/invalid.h>
23#include <lemon/error.h>
24
25#include <lemon/bits/map_extender.h>
26#include <lemon/bits/default_map.h>
27
28#include <lemon/concept_check.h>
29#include <lemon/concept/maps.h>
30
31///\ingroup graphbits
32///\file
33///\brief Extenders for the graph types
34namespace lemon {
35
36  /// \ingroup graphbits
37  ///
38  /// \brief BaseExtender for the UGraphs
39  template <typename Base>
40  class UndirGraphExtender : public Base {
41
42  public:
43
44    typedef Base Parent;
45    typedef typename Parent::Edge UEdge;
46    typedef typename Parent::Node Node;
47
48    typedef True UndirectedTag;
49
50    class Edge : public UEdge {
51      friend class UndirGraphExtender;
52
53    protected:
54      bool forward;
55
56      Edge(const UEdge &ue, bool _forward) :
57        UEdge(ue), forward(_forward) {}
58
59    public:
60      Edge() {}
61
62      /// Invalid edge constructor
63      Edge(Invalid i) : UEdge(i), forward(true) {}
64
65      bool operator==(const Edge &that) const {
66        return forward==that.forward && UEdge(*this)==UEdge(that);
67      }
68      bool operator!=(const Edge &that) const {
69        return forward!=that.forward || UEdge(*this)!=UEdge(that);
70      }
71      bool operator<(const Edge &that) const {
72        return forward<that.forward ||
73          (!(that.forward<forward) && UEdge(*this)<UEdge(that));
74      }
75    };
76
77
78
79    using Parent::source;
80
81    /// Source of the given Edge.
82    Node source(const Edge &e) const {
83      return e.forward ? Parent::source(e) : Parent::target(e);
84    }
85
86    using Parent::target;
87
88    /// Target of the given Edge.
89    Node target(const Edge &e) const {
90      return e.forward ? Parent::target(e) : Parent::source(e);
91    }
92
93    /// \brief Directed edge from an undirected edge.
94    ///
95    /// Returns a directed edge corresponding to the specified UEdge.
96    /// If the given bool is true the given undirected edge and the
97    /// returned edge have the same source node.
98    static Edge direct(const UEdge &ue, bool d) {
99      return Edge(ue, d);
100    }
101
102    /// Returns whether the given directed edge is same orientation as the
103    /// corresponding undirected edge.
104    ///
105    /// \todo reference to the corresponding point of the undirected graph
106    /// concept. "What does the direction of an undirected edge mean?"
107    static bool direction(const Edge &e) { return e.forward; }
108
109
110    using Parent::first;
111    using Parent::next;
112
113    void first(Edge &e) const {
114      Parent::first(e);
115      e.forward=true;
116    }
117
118    void next(Edge &e) const {
119      if( e.forward ) {
120        e.forward = false;
121      }
122      else {
123        Parent::next(e);
124        e.forward = true;
125      }
126    }
127
128    void firstOut(Edge &e, const Node &n) const {
129      Parent::firstIn(e,n);
130      if( UEdge(e) != INVALID ) {
131        e.forward = false;
132      }
133      else {
134        Parent::firstOut(e,n);
135        e.forward = true;
136      }
137    }
138    void nextOut(Edge &e) const {
139      if( ! e.forward ) {
140        Node n = Parent::target(e);
141        Parent::nextIn(e);
142        if( UEdge(e) == INVALID ) {
143          Parent::firstOut(e, n);
144          e.forward = true;
145        }
146      }
147      else {
148        Parent::nextOut(e);
149      }
150    }
151
152    void firstIn(Edge &e, const Node &n) const {
153      Parent::firstOut(e,n);
154      if( UEdge(e) != INVALID ) {
155        e.forward = false;
156      }
157      else {
158        Parent::firstIn(e,n);
159        e.forward = true;
160      }
161    }
162    void nextIn(Edge &e) const {
163      if( ! e.forward ) {
164        Node n = Parent::source(e);
165        Parent::nextOut(e);
166        if( UEdge(e) == INVALID ) {
167          Parent::firstIn(e, n);
168          e.forward = true;
169        }
170      }
171      else {
172        Parent::nextIn(e);
173      }
174    }
175
176    void firstInc(UEdge &e, bool &d, const Node &n) const {
177      d = true;
178      Parent::firstOut(e, n);
179      if (e != INVALID) return;
180      d = false;
181      Parent::firstIn(e, n);
182    }
183
184    void nextInc(UEdge &e, bool &d) const {
185      if (d) {
186        Node s = Parent::source(e);
187        Parent::nextOut(e);
188        if (e != INVALID) return;
189        d = false;
190        Parent::firstIn(e, s);
191      } else {
192        Parent::nextIn(e);
193      }
194    }
195
196    Node nodeFromId(int id) const {
197      return Parent::nodeFromId(id);
198    }
199
200    Edge edgeFromId(int id) const {
201      return direct(Parent::edgeFromId(id >> 1), bool(id & 1));
202    }
203
204    UEdge uEdgeFromId(int id) const {
205      return Parent::edgeFromId(id);
206    }
207
208    int id(const Node &n) const {
209      return Parent::id(n);
210    }
211
212    int id(const UEdge &e) const {
213      return Parent::id(e);
214    }
215
216    int id(const Edge &e) const {
217      return 2 * Parent::id(e) + int(e.forward);
218    }
219
220    int maxNodeId() const {
221      return Parent::maxNodeId();
222    }
223
224    int maxEdgeId() const {
225      return 2 * Parent::maxEdgeId() + 1;
226    }
227
228    int maxUEdgeId() const {
229      return Parent::maxEdgeId();
230    }
231
232
233    int edgeNum() const {
234      return 2 * Parent::edgeNum();
235    }
236
237    int uEdgeNum() const {
238      return Parent::edgeNum();
239    }
240
241    Edge findEdge(Node source, Node target, Edge prev) const {
242      if (prev == INVALID) {
243        UEdge edge = Parent::findEdge(source, target);
244        if (edge != INVALID) return direct(edge, true);
245        edge = Parent::findEdge(target, source);
246        if (edge != INVALID) return direct(edge, false);
247      } else if (direction(prev)) {
248        UEdge edge = Parent::findEdge(source, target, prev);
249        if (edge != INVALID) return direct(edge, true);
250        edge = Parent::findEdge(target, source);
251        if (edge != INVALID) return direct(edge, false);       
252      } else {
253        UEdge edge = Parent::findEdge(target, source, prev);
254        if (edge != INVALID) return direct(edge, false);             
255      }
256      return INVALID;
257    }
258
259    UEdge findUEdge(Node source, Node target, UEdge prev) const {
260      if (prev == INVALID) {
261        UEdge edge = Parent::findEdge(source, target);
262        if (edge != INVALID) return edge;
263        edge = Parent::findEdge(target, source);
264        if (edge != INVALID) return edge;
265      } else if (Parent::source(prev) == source) {
266        UEdge edge = Parent::findEdge(source, target, prev);
267        if (edge != INVALID) return edge;
268        edge = Parent::findEdge(target, source);
269        if (edge != INVALID) return edge;       
270      } else {
271        UEdge edge = Parent::findEdge(target, source, prev);
272        if (edge != INVALID) return edge;             
273      }
274      return INVALID;
275    }
276  };
277
278}
279
280#endif
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