COIN-OR::LEMON - Graph Library

source: lemon-0.x/src/lemon/list_graph.h @ 948:bc86b64f958e

Last change on this file since 948:bc86b64f958e was 948:bc86b64f958e, checked in by Alpar Juttner, 16 years ago
  • moveHead() and moveTail() added. Not tested.
File size: 8.3 KB
Line 
1/* -*- C++ -*-
2 * src/lemon/list_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_LIST_GRAPH_H
18#define LEMON_LIST_GRAPH_H
19
20///\ingroup graphs
21///\file
22///\brief ListGraph, SymListGraph, NodeSet and EdgeSet classes.
23
24#include <lemon/erasable_graph_extender.h>
25#include <lemon/clearable_graph_extender.h>
26#include <lemon/extendable_graph_extender.h>
27
28#include <lemon/idmappable_graph_extender.h>
29
30#include <lemon/iterable_graph_extender.h>
31
32#include <lemon/alteration_observer_registry.h>
33
34#include <lemon/default_map.h>
35
36
37namespace lemon {
38
39  class ListGraphBase {
40
41    struct NodeT {
42      int first_in,first_out;
43      int prev, next;
44    };
45 
46    struct EdgeT {
47      int head, tail;
48      int prev_in, prev_out;
49      int next_in, next_out;
50    };
51
52    std::vector<NodeT> nodes;
53
54    int first_node;
55
56    int first_free_node;
57
58    std::vector<EdgeT> edges;
59
60    int first_free_edge;
61   
62  public:
63   
64    typedef ListGraphBase Graph;
65   
66    class Node {
67      friend class Graph;
68    protected:
69
70      int id;
71      Node(int pid) { id = pid;}
72
73    public:
74      Node() {}
75      Node (Invalid) { id = -1; }
76      bool operator==(const Node& node) const {return id == node.id;}
77      bool operator!=(const Node& node) const {return id != node.id;}
78      bool operator<(const Node& node) const {return id < node.id;}
79    };
80
81    class Edge {
82      friend class Graph;
83    protected:
84
85      int id;
86      Edge(int pid) { id = pid;}
87
88    public:
89      Edge() {}
90      Edge (Invalid) { id = -1; }
91      bool operator==(const Edge& edge) const {return id == edge.id;}
92      bool operator!=(const Edge& edge) const {return id != edge.id;}
93      bool operator<(const Edge& edge) const {return id < edge.id;}
94    };
95
96
97
98    ListGraphBase()
99      : nodes(), first_node(-1),
100        first_free_node(-1), edges(), first_free_edge(-1) {}
101
102   
103    ///Using this it possible to avoid the superfluous memory allocation.
104    ///\todo more docs...
105    ///\todo It should be defined in ListGraph.
106    void reserveEdge(int n) { edges.reserve(n); };
107   
108    /// Maximum node ID.
109   
110    /// Maximum node ID.
111    ///\sa id(Node)
112    int maxNodeId() const { return nodes.size()-1; }
113
114    /// Maximum edge ID.
115   
116    /// Maximum edge ID.
117    ///\sa id(Edge)
118    int maxEdgeId() const { return edges.size()-1; }
119
120    Node tail(Edge e) const { return edges[e.id].tail; }
121    Node head(Edge e) const { return edges[e.id].head; }
122
123
124    void first(Node& node) const {
125      node.id = first_node;
126    }
127
128    void next(Node& node) const {
129      node.id = nodes[node.id].next;
130    }
131
132
133    void first(Edge& e) const {
134      int n;
135      for(n = first_node;
136          n!=-1 && nodes[n].first_in == -1;
137          n = nodes[n].next);
138      e.id = (n == -1) ? -1 : nodes[n].first_in;
139    }
140
141    void next(Edge& edge) const {
142      if (edges[edge.id].next_in != -1) {
143        edge.id = edges[edge.id].next_in;
144      } else {
145        int n;
146        for(n = nodes[edges[edge.id].head].next;
147          n!=-1 && nodes[n].first_in == -1;
148          n = nodes[n].next);
149        edge.id = (n == -1) ? -1 : nodes[n].first_in;
150      }     
151    }
152
153    void firstOut(Edge &e, const Node& v) const {
154      e.id = nodes[v.id].first_out;
155    }
156    void nextOut(Edge &e) const {
157      e.id=edges[e.id].next_out;
158    }
159
160    void firstIn(Edge &e, const Node& v) const {
161      e.id = nodes[v.id].first_in;
162    }
163    void nextIn(Edge &e) const {
164      e.id=edges[e.id].next_in;
165    }
166
167   
168    static int id(Node v) { return v.id; }
169    static int id(Edge e) { return e.id; }
170
171    /// Adds a new node to the graph.
172
173    /// \warning It adds the new node to the front of the list.
174    /// (i.e. the lastly added node becomes the first.)
175    Node addNode() {     
176      int n;
177     
178      if(first_free_node==-1) {
179        n = nodes.size();
180        nodes.push_back(NodeT());
181      } else {
182        n = first_free_node;
183        first_free_node = nodes[n].next;
184      }
185     
186      nodes[n].next = first_node;
187      if(first_node != -1) nodes[first_node].prev = n;
188      first_node = n;
189      nodes[n].prev = -1;
190     
191      nodes[n].first_in = nodes[n].first_out = -1;
192     
193      return Node(n);
194    }
195   
196    Edge addEdge(Node u, Node v) {
197      int n;     
198
199      if (first_free_edge == -1) {
200        n = edges.size();
201        edges.push_back(EdgeT());
202      } else {
203        n = first_free_edge;
204        first_free_edge = edges[n].next_in;
205      }
206     
207      edges[n].tail = u.id;
208      edges[n].head = v.id;
209
210      edges[n].next_out = nodes[u.id].first_out;
211      if(nodes[u.id].first_out != -1) {
212        edges[nodes[u.id].first_out].prev_out = n;
213      }
214     
215      edges[n].next_in = nodes[v.id].first_in;
216      if(nodes[v.id].first_in != -1) {
217        edges[nodes[v.id].first_in].prev_in = n;
218      }
219     
220      edges[n].prev_in = edges[n].prev_out = -1;
221       
222      nodes[u.id].first_out = nodes[v.id].first_in = n;
223
224      return Edge(n);
225    }
226   
227    void erase(const Node& node) {
228      int n = node.id;
229     
230      if(nodes[n].next != -1) {
231        nodes[nodes[n].next].prev = nodes[n].prev;
232      }
233     
234      if(nodes[n].prev != -1) {
235        nodes[nodes[n].prev].next = nodes[n].next;
236      } else {
237        first_node = nodes[n].next;
238      }
239     
240      nodes[n].next = first_free_node;
241      first_free_node = n;
242
243    }
244   
245    void erase(const Edge& edge) {
246      int n = edge.id;
247     
248      if(edges[n].next_in!=-1) {
249        edges[edges[n].next_in].prev_in = edges[n].prev_in;
250      }
251
252      if(edges[n].prev_in!=-1) {
253        edges[edges[n].prev_in].next_in = edges[n].next_in;
254      } else {
255        nodes[edges[n].head].first_in = edges[n].next_in;
256      }
257
258     
259      if(edges[n].next_out!=-1) {
260        edges[edges[n].next_out].prev_out = edges[n].prev_out;
261      }
262
263      if(edges[n].prev_out!=-1) {
264        edges[edges[n].prev_out].next_out = edges[n].next_out;
265      } else {
266        nodes[edges[n].tail].first_out = edges[n].next_out;
267      }
268     
269      edges[n].next_in = first_free_edge;
270      first_free_edge = n;     
271
272    }
273
274    void clear() {
275      edges.clear();
276      nodes.clear();
277      first_node = first_free_node = first_free_edge = -1;
278    }
279
280  };
281
282  typedef AlterableGraphExtender<ListGraphBase> AlterableListGraphBase;
283  typedef IterableGraphExtender<AlterableListGraphBase> IterableListGraphBase;
284  typedef IdMappableGraphExtender<IterableListGraphBase> IdMappableListGraphBase;
285  typedef DefaultMappableGraphExtender<IdMappableListGraphBase> MappableListGraphBase;
286  typedef ExtendableGraphExtender<MappableListGraphBase> ExtendableListGraphBase;
287  typedef ClearableGraphExtender<ExtendableListGraphBase> ClearableListGraphBase;
288  typedef ErasableGraphExtender<ClearableListGraphBase> ErasableListGraphBase;
289
290/// \addtogroup graphs
291/// @{
292
293  ///A list graph class.
294
295  ///This is a simple and fast erasable graph implementation.
296  ///
297  ///It conforms to the
298  ///\ref skeleton::ErasableGraph "ErasableGraph" concept.
299  ///\sa skeleton::ErasableGraph.
300
301  class ListGraph : public ErasableListGraphBase
302  {
303  public:
304    /// Moves the head of \c e to \c n
305
306    /// Moves the head of \c e to \c n
307    ///
308    void moveHead(Edge e, Node n)
309    {
310      if(edges[e.n].next_in != -1)
311        edges[edges[e.n].next_in].prev_in = edges[e.n].prev_in;
312      if(edges[e.n].prev_in != -1)
313        edges[edges[e.n].prev_in].next_in = edges[e.n].next_in;
314      else nodes[edges[e.n].head].first_in = edges[e.n].next_in;
315      edges[e.n].head = n.n;
316      edges[e.n].prev_in = -1;
317      edges[e.n].next_in = nodes[n.n].first_in;
318      nodes[n.n].first_in = e.n;
319    }
320    /// Moves the tail of \c e to \c n
321
322    /// Moves the tail of \c e to \c n
323    ///
324    void moveTail(Edge e, Node n)
325    {
326      if(edges[e.n].next_out != -1)
327        edges[edges[e.n].next_out].prev_out = edges[e.n].prev_out;
328      if(edges[e.n].prev_out != -1)
329        edges[edges[e.n].prev_out].next_out = edges[e.n].next_out;
330      else nodes[edges[e.n].tail].first_out = edges[e.n].next_out;
331      edges[e.n].tail = n.n;
332      edges[e.n].prev_out = -1;
333      edges[e.n].next_out = nodes[n.n].first_out;
334      nodes[n.n].first_out = e.n;
335    }
336  }
337  /// @} 
338} //namespace lemon
339 
340
341#endif
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