COIN-OR::LEMON - Graph Library

source: lemon-0.x/src/work/deba/list_graph.h @ 702:4207f82a1778

Last change on this file since 702:4207f82a1778 was 702:4207f82a1778, checked in by Balazs Dezso, 16 years ago
File size: 10.6 KB
Line 
1// -*- mode:C++ -*-
2
3#ifndef HUGO_LIST_GRAPH_H
4#define HUGO_LIST_GRAPH_H
5
6///\ingroup graphs
7///\file
8///\brief ListGraph, SymListGraph, NodeSet and EdgeSet classes.
9
10#include <vector>
11#include <climits>
12
13#include "invalid.h"
14
15#include "vector_map_factory.h"
16#include "map_registry.h"
17
18#include "map_defines.h"
19
20namespace hugo {
21
22/// \addtogroup graphs
23/// @{
24
25  ///A list graph class.
26
27  ///This is a simple and fast erasable graph implementation.
28  ///
29  ///It conforms to the graph interface documented under
30  ///the description of \ref GraphSkeleton.
31  ///\sa \ref GraphSkeleton.
32  class ListGraph {
33
34    //Nodes are double linked.
35    //The free nodes are only single linked using the "next" field.
36    struct NodeT
37    {
38      int first_in,first_out;
39      int prev, next;
40      //      NodeT() {}
41    };
42    //Edges are double linked.
43    //The free edges are only single linked using the "next_in" field.
44    struct EdgeT
45    {
46      int head, tail;
47      int prev_in, prev_out;
48      int next_in, next_out;
49      //FIXME: is this necessary?
50      //      EdgeT() : next_in(-1), next_out(-1) prev_in(-1), prev_out(-1) {} 
51    };
52
53    std::vector<NodeT> nodes;
54    //The first node
55    int first_node;
56    //The first free node
57    int first_free_node;
58    std::vector<EdgeT> edges;
59    //The first free edge
60    int first_free_edge;
61   
62  protected:
63   
64  public:
65   
66    class Node;
67    class Edge;
68
69    typedef ListGraph Graph;
70
71  public:
72
73    class NodeIt;
74    class EdgeIt;
75    class OutEdgeIt;
76    class InEdgeIt;
77   
78    CREATE_MAP_REGISTRIES;
79    CREATE_MAPS(VectorMapFactory);
80  public:
81
82    ListGraph() : nodes(), first_node(-1),
83                  first_free_node(-1), edges(), first_free_edge(-1) {}
84    ListGraph(const ListGraph &_g) : nodes(_g.nodes), first_node(_g.first_node),
85                                     first_free_node(_g.first_free_node),
86                                     edges(_g.edges),
87                                     first_free_edge(_g.first_free_edge) {}
88   
89
90    int nodeNum() const { return nodes.size(); }  //FIXME: What is this?
91    int edgeNum() const { return edges.size(); }  //FIXME: What is this?
92
93    ///Set the expected number of edges
94
95    ///With this function, it is possible to set the expected number of edges.
96    ///The use of this fasten the building of the graph and makes
97    ///it possible to avoid the superfluous memory allocation.
98    void reserveEdge(int n) { edges.reserve(n); };
99   
100    ///\bug This function does something different than
101    ///its name would suggests...
102    int maxNodeId() const { return nodes.size(); }  //FIXME: What is this?
103    ///\bug This function does something different than
104    ///its name would suggests...
105    int maxEdgeId() const { return edges.size(); }  //FIXME: What is this?
106
107    Node tail(Edge e) const { return edges[e.n].tail; }
108    Node head(Edge e) const { return edges[e.n].head; }
109
110    Node aNode(OutEdgeIt e) const { return edges[e.n].tail; }
111    Node aNode(InEdgeIt e) const { return edges[e.n].head; }
112
113    Node bNode(OutEdgeIt e) const { return edges[e.n].head; }
114    Node bNode(InEdgeIt e) const { return edges[e.n].tail; }
115
116    NodeIt& first(NodeIt& v) const {
117      v=NodeIt(*this); return v; }
118    EdgeIt& first(EdgeIt& e) const {
119      e=EdgeIt(*this); return e; }
120    OutEdgeIt& first(OutEdgeIt& e, const Node v) const {
121      e=OutEdgeIt(*this,v); return e; }
122    InEdgeIt& first(InEdgeIt& e, const Node v) const {
123      e=InEdgeIt(*this,v); return e; }
124
125//     template< typename It >
126//     It first() const { It e; first(e); return e; }
127
128//     template< typename It >
129//     It first(Node v) const { It e; first(e,v); return e; }
130
131    bool valid(Edge e) const { return e.n!=-1; }
132    bool valid(Node n) const { return n.n!=-1; }
133   
134    void setInvalid(Edge &e) { e.n=-1; }
135    void setInvalid(Node &n) { n.n=-1; }
136   
137    template <typename It> It getNext(It it) const
138    { It tmp(it); return next(tmp); }
139
140    NodeIt& next(NodeIt& it) const {
141      it.n=nodes[it.n].next;
142      return it;
143    }
144    OutEdgeIt& next(OutEdgeIt& it) const
145    { it.n=edges[it.n].next_out; return it; }
146    InEdgeIt& next(InEdgeIt& it) const
147    { it.n=edges[it.n].next_in; return it; }
148    EdgeIt& next(EdgeIt& it) const {
149      if(edges[it.n].next_in!=-1) {
150        it.n=edges[it.n].next_in;
151      }
152      else {
153        int n;
154        for(n=nodes[edges[it.n].head].next;
155            n!=-1 && nodes[n].first_in == -1;
156            n = nodes[n].next) ;
157        it.n = (n==-1)?-1:nodes[n].first_in;
158      }
159      return it;
160    }
161
162    int id(Node v) const { return v.n; }
163    int id(Edge e) const { return e.n; }
164
165    /// Adds a new node to the graph.
166
167    /// \todo It adds the nodes in a reversed order.
168    /// (i.e. the lastly added node becomes the first.)
169    Node addNode() {
170      int n;
171     
172      if(first_free_node==-1)
173        {
174          n = nodes.size();
175          nodes.push_back(NodeT());
176        }
177      else {
178        n = first_free_node;
179        first_free_node = nodes[n].next;
180      }
181     
182      nodes[n].next = first_node;
183      if(first_node != -1) nodes[first_node].prev = n;
184      first_node = n;
185      nodes[n].prev = -1;
186     
187      nodes[n].first_in = nodes[n].first_out = -1;
188     
189      Node nn; nn.n=n;
190
191      //Update dynamic maps
192      node_maps.add(nn);
193
194      return nn;
195    }
196   
197    Edge addEdge(Node u, Node v) {
198      int n;
199     
200      if(first_free_edge==-1)
201        {
202          n = edges.size();
203          edges.push_back(EdgeT());
204        }
205      else {
206        n = first_free_edge;
207        first_free_edge = edges[n].next_in;
208      }
209     
210      edges[n].tail = u.n; edges[n].head = v.n;
211
212      edges[n].next_out = nodes[u.n].first_out;
213      if(nodes[u.n].first_out != -1) edges[nodes[u.n].first_out].prev_out = n;
214      edges[n].next_in = nodes[v.n].first_in;
215      if(nodes[v.n].first_in != -1) edges[nodes[v.n].first_in].prev_in = n;
216      edges[n].prev_in = edges[n].prev_out = -1;
217       
218      nodes[u.n].first_out = nodes[v.n].first_in = n;
219
220      Edge e; e.n=n;
221
222      //Update dynamic maps
223      edge_maps.add(e);
224
225      return e;
226    }
227
228  private:
229    void eraseEdge(int n) {
230     
231      if(edges[n].next_in!=-1)
232        edges[edges[n].next_in].prev_in = edges[n].prev_in;
233      if(edges[n].prev_in!=-1)
234        edges[edges[n].prev_in].next_in = edges[n].next_in;
235      else nodes[edges[n].head].first_in = edges[n].next_in;
236     
237      if(edges[n].next_out!=-1)
238        edges[edges[n].next_out].prev_out = edges[n].prev_out;
239      if(edges[n].prev_out!=-1)
240        edges[edges[n].prev_out].next_out = edges[n].next_out;
241      else nodes[edges[n].tail].first_out = edges[n].next_out;
242     
243      edges[n].next_in = first_free_edge;
244      first_free_edge = n;     
245
246      //Update dynamic maps
247      Edge e; e.n=n;
248    }
249     
250  public:
251
252    void erase(Node nn) {
253      int n=nn.n;
254     
255      int m;
256      while((m=nodes[n].first_in)!=-1) eraseEdge(m);
257      while((m=nodes[n].first_out)!=-1) eraseEdge(m);
258
259      if(nodes[n].next != -1) nodes[nodes[n].next].prev = nodes[n].prev;
260      if(nodes[n].prev != -1) nodes[nodes[n].prev].next = nodes[n].next;
261      else first_node = nodes[n].next;
262     
263      nodes[n].next = first_free_node;
264      first_free_node = n;
265
266      //Update dynamic maps
267      node_maps.erase(nn);
268     }
269   
270    void erase(Edge e) {
271      edge_maps.erase(e);
272      eraseEdge(e.n);
273    }
274
275    ///\bug Dynamic maps must be updated!
276    ///
277    void clear() {
278      nodes.clear();edges.clear();
279      first_node=first_free_node=first_free_edge=-1;
280    }
281
282    class Node {
283      friend class ListGraph;
284      template <typename T> friend class NodeMap;
285       
286      friend class Edge;
287      friend class OutEdgeIt;
288      friend class InEdgeIt;
289      friend class SymEdge;
290
291    protected:
292      int n;
293      friend int ListGraph::id(Node v) const;
294      Node(int nn) {n=nn;}
295    public:
296      Node() {}
297      Node (Invalid) { n=-1; }
298      bool operator==(const Node i) const {return n==i.n;}
299      bool operator!=(const Node i) const {return n!=i.n;}
300      bool operator<(const Node i) const {return n<i.n;}
301    };
302   
303    class NodeIt : public Node {
304      friend class ListGraph;
305    public:
306      NodeIt() : Node() { }
307      NodeIt(Invalid i) : Node(i) { }
308      NodeIt(const ListGraph& G) : Node(G.first_node) { }
309      ///\todo Undocumented conversion Node -\> NodeIt.
310      NodeIt(const ListGraph& G, const Node &n) : Node(n) { }
311    };
312
313    class Edge {
314      friend class ListGraph;
315      template <typename T> friend class EdgeMap;
316
317      //template <typename T> friend class SymListGraph::SymEdgeMap;     
318      //friend Edge SymListGraph::opposite(Edge) const;
319     
320      friend class Node;
321      friend class NodeIt;
322    protected:
323      int n;
324      friend int ListGraph::id(Edge e) const;
325
326      Edge(int nn) {n=nn;}
327    public:
328      Edge() { }
329      Edge (Invalid) { n=-1; }
330      bool operator==(const Edge i) const {return n==i.n;}
331      bool operator!=(const Edge i) const {return n!=i.n;}
332      bool operator<(const Edge i) const {return n<i.n;}
333      ///\bug This is a workaround until somebody tells me how to
334      ///make class \c SymListGraph::SymEdgeMap friend of Edge
335      int &idref() {return n;}
336      const int &idref() const {return n;}
337    };
338   
339    class EdgeIt : public Edge {
340      friend class ListGraph;
341    public:
342      EdgeIt(const ListGraph& G) : Edge() {
343        int m;
344        for(m=G.first_node;
345            m!=-1 && G.nodes[m].first_in == -1; m = G.nodes[m].next);
346        n = (m==-1)?-1:G.nodes[m].first_in;
347      }
348      EdgeIt (Invalid i) : Edge(i) { }
349      EdgeIt() : Edge() { }
350      ///\bug This is a workaround until somebody tells me how to
351      ///make class \c SymListGraph::SymEdgeMap friend of Edge
352      int &idref() {return n;}
353    };
354   
355    class OutEdgeIt : public Edge {
356      friend class ListGraph;
357    public:
358      OutEdgeIt() : Edge() { }
359      OutEdgeIt (Invalid i) : Edge(i) { }
360
361      OutEdgeIt(const ListGraph& G,const Node v)
362        : Edge(G.nodes[v.n].first_out) {}
363    };
364   
365    class InEdgeIt : public Edge {
366      friend class ListGraph;
367    public:
368      InEdgeIt() : Edge() { }
369      InEdgeIt (Invalid i) : Edge(i) { }
370      InEdgeIt(const ListGraph& G,Node v) :Edge(G.nodes[v.n].first_in) {}
371    };
372
373  };
374
375  ///Graph for bidirectional edges.
376
377  ///The purpose of this graph structure is to handle graphs
378  ///having bidirectional edges. Here the function \c addEdge(u,v) adds a pair
379  ///of oppositely directed edges.
380  ///There is a new edge map type called
381  ///\ref SymListGraph::SymEdgeMap "SymEdgeMap"
382  ///that complements this
383  ///feature by
384  ///storing shared values for the edge pairs. The usual
385  ///\ref GraphSkeleton::EdgeMap "EdgeMap"
386  ///can be used
387  ///as well.
388  ///
389  ///The oppositely directed edge can also be obtained easily
390  ///using \ref opposite.
391  ///
392  ///Here erase(Edge) deletes a pair of edges.
393  ///
394  ///\todo this date structure need some reconsiderations. Maybe it
395  ///should be implemented independently from ListGraph.
396
397}
398
399#endif //HUGO_LIST_GRAPH_H
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