COIN-OR::LEMON - Graph Library

source: lemon-0.x/src/lemon/smart_graph.h @ 921:818510fa3d99

Last change on this file since 921:818510fa3d99 was 921:818510fa3d99, checked in by Alpar Juttner, 20 years ago

hugo -> lemon

File size: 10.1 KB
RevLine 
[906]1/* -*- C++ -*-
[921]2 * src/lemon/smart_graph.h - Part of LEMON, a generic C++ optimization library
[906]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 */
[105]16
[921]17#ifndef LEMON_SMART_GRAPH_H
18#define LEMON_SMART_GRAPH_H
[104]19
[491]20///\ingroup graphs
[242]21///\file
22///\brief SmartGraph and SymSmartGraph classes.
23
[104]24#include <vector>
[782]25#include <climits>
[104]26
[921]27#include <lemon/invalid.h>
[157]28
[921]29#include <lemon/array_map.h>
30#include <lemon/sym_map.h>
[919]31
[921]32#include <lemon/map_registry.h>
[782]33
[921]34#include <lemon/map_defines.h>
[782]35
[921]36namespace lemon {
[104]37
[407]38/// \addtogroup graphs
39/// @{
[782]40//  class SymSmartGraph;
[185]41
[186]42  ///A smart graph class.
43
44  ///This is a simple and fast graph implementation.
45  ///It is also quite memory efficient, but at the price
46  ///that <b> it does not support node and edge deletion</b>.
[880]47  ///It conforms to
48  ///the \ref skeleton::ExtendableGraph "ExtendableGraph" concept.
49  ///\sa skeleton::ExtendableGraph.
[402]50  ///
51  ///\todo Some member functions could be \c static.
[753]52  ///
53  ///\todo A possibly useful functionality: a function saveState() would
54  ///give back a data sturcture X and then the function restoreState(X)
55  ///would remove the nodes and edges added after the call of saveState().
56  ///Of course it should be used as a stack. (Maybe X is not necessary.)
57  ///
[456]58  ///\author Alpar Juttner
[104]59  class SmartGraph {
60
61    struct NodeT
62    {
63      int first_in,first_out;     
[157]64      NodeT() : first_in(-1), first_out(-1) {}
[104]65    };
66    struct EdgeT
67    {
68      int head, tail, next_in, next_out;     
69      //FIXME: is this necessary?
[157]70      EdgeT() : next_in(-1), next_out(-1) {} 
[104]71    };
72
73    std::vector<NodeT> nodes;
[129]74
[104]75    std::vector<EdgeT> edges;
76   
[185]77   
[104]78  public:
[782]79
80    typedef SmartGraph Graph;
[104]81
[164]82    class Node;
83    class Edge;
[108]84
[164]85    class NodeIt;
86    class EdgeIt;
[104]87    class OutEdgeIt;
88    class InEdgeIt;
89   
[904]90    // Create map registries.
[782]91    CREATE_MAP_REGISTRIES;
[904]92    // Create node and edge maps.
[897]93    CREATE_MAPS(ArrayMap);
[104]94   
95  public:
96
97    SmartGraph() : nodes(), edges() { }
[136]98    SmartGraph(const SmartGraph &_g) : nodes(_g.nodes), edges(_g.edges) { }
[104]99   
[813]100    ///Number of nodes.
101    int nodeNum() const { return nodes.size(); }
102    ///Number of edges.
103    int edgeNum() const { return edges.size(); }
[104]104
[813]105    /// Maximum node ID.
106   
107    /// Maximum node ID.
108    ///\sa id(Node)
109    int maxNodeId() const { return nodes.size()-1; }
110    /// Maximum edge ID.
111   
112    /// Maximum edge ID.
113    ///\sa id(Edge)
114    int maxEdgeId() const { return edges.size()-1; }
[108]115
[164]116    Node tail(Edge e) const { return edges[e.n].tail; }
117    Node head(Edge e) const { return edges[e.n].head; }
[104]118
[164]119    NodeIt& first(NodeIt& v) const {
120      v=NodeIt(*this); return v; }
121    EdgeIt& first(EdgeIt& e) const {
122      e=EdgeIt(*this); return e; }
123    OutEdgeIt& first(OutEdgeIt& e, const Node v) const {
[104]124      e=OutEdgeIt(*this,v); return e; }
[164]125    InEdgeIt& first(InEdgeIt& e, const Node v) const {
[104]126      e=InEdgeIt(*this,v); return e; }
127
[813]128    /// Node ID.
129   
130    /// The ID of a valid Node is a nonnegative integer not greater than
131    /// \ref maxNodeId(). The range of the ID's is not surely continuous
132    /// and the greatest node ID can be actually less then \ref maxNodeId().
133    ///
134    /// The ID of the \ref INVALID node is -1.
135    ///\return The ID of the node \c v.
[713]136    static int id(Node v) { return v.n; }
[813]137    /// Edge ID.
138   
139    /// The ID of a valid Edge is a nonnegative integer not greater than
140    /// \ref maxEdgeId(). The range of the ID's is not surely continuous
141    /// and the greatest edge ID can be actually less then \ref maxEdgeId().
142    ///
143    /// The ID of the \ref INVALID edge is -1.
144    ///\return The ID of the edge \c e.
[713]145    static int id(Edge e) { return e.n; }
[104]146
[164]147    Node addNode() {
148      Node n; n.n=nodes.size();
[104]149      nodes.push_back(NodeT()); //FIXME: Hmmm...
[108]150
[782]151     
152      node_maps.add(n);
[104]153      return n;
154    }
[108]155   
[164]156    Edge addEdge(Node u, Node v) {
157      Edge e; e.n=edges.size(); edges.push_back(EdgeT()); //FIXME: Hmmm...
[104]158      edges[e.n].tail=u.n; edges[e.n].head=v.n;
159      edges[e.n].next_out=nodes[u.n].first_out;
160      edges[e.n].next_in=nodes[v.n].first_in;
161      nodes[u.n].first_out=nodes[v.n].first_in=e.n;
[108]162
[782]163      edge_maps.add(e);
[108]164
[104]165      return e;
166    }
167
[774]168    /// Finds an edge between two nodes.
169
170    /// Finds an edge from node \c u to node \c v.
171    ///
172    /// If \c prev is \ref INVALID (this is the default value), then
173    /// It finds the first edge from \c u to \c v. Otherwise it looks for
174    /// the next edge from \c u to \c v after \c prev.
175    /// \return The found edge or INVALID if there is no such an edge.
176    Edge findEdge(Node u,Node v, Edge prev = INVALID)
177    {
178      int e = (prev.n==-1)? nodes[u.n].first_out : edges[prev.n].next_out;
179      while(e!=-1 && edges[e].tail!=v.n) e = edges[e].next_out;
180      prev.n=e;
181      return prev;
182    }
183   
[782]184    void clear() {
185      edge_maps.clear();
186      edges.clear();
187      node_maps.clear();
188      nodes.clear();
189    }
[104]190
[164]191    class Node {
[104]192      friend class SmartGraph;
193      template <typename T> friend class NodeMap;
194     
[164]195      friend class Edge;
[104]196      friend class OutEdgeIt;
197      friend class InEdgeIt;
[164]198      friend class SymEdge;
[104]199
200    protected:
201      int n;
[722]202      friend int SmartGraph::id(Node v);
[164]203      Node(int nn) {n=nn;}
[104]204    public:
[164]205      Node() {}
[503]206      Node (Invalid) { n=-1; }
[164]207      bool operator==(const Node i) const {return n==i.n;}
208      bool operator!=(const Node i) const {return n!=i.n;}
209      bool operator<(const Node i) const {return n<i.n;}
[774]210      //      ///Validity check
211      //      operator bool() { return n!=-1; }
[104]212    };
213   
[164]214    class NodeIt : public Node {
[774]215      const SmartGraph *G;
[104]216      friend class SmartGraph;
217    public:
[402]218      NodeIt() : Node() { }
[774]219      NodeIt(const SmartGraph& _G,Node n) : Node(n), G(&_G) { }
[402]220      NodeIt(Invalid i) : Node(i) { }
[774]221      NodeIt(const SmartGraph& _G) : Node(_G.nodes.size()?0:-1), G(&_G) { }
222      NodeIt &operator++() {
223        n=(n+2)%(G->nodes.size()+1)-1;
224        return *this;
225      }
226//       ///Validity check
227//       operator bool() { return Node::operator bool(); }     
[104]228    };
229
[164]230    class Edge {
[104]231      friend class SmartGraph;
232      template <typename T> friend class EdgeMap;
[185]233
[905]234      friend class SymSmartGraph;
[104]235     
[164]236      friend class Node;
[104]237      friend class NodeIt;
238    protected:
239      int n;
[722]240      friend int SmartGraph::id(Edge e);
[905]241      Edge(int nn) {n=nn;}
[706]242    public:
243      /// An Edge with id \c n.
244
[164]245      Edge() { }
[174]246      Edge (Invalid) { n=-1; }
[164]247      bool operator==(const Edge i) const {return n==i.n;}
248      bool operator!=(const Edge i) const {return n!=i.n;}
249      bool operator<(const Edge i) const {return n<i.n;}
[774]250//       ///Validity check
251//       operator bool() { return n!=-1; }
[905]252
253      ///Set the edge to that have ID \c ID.
254      void setToId(int id) { n=id; }
[774]255   };
[104]256   
[164]257    class EdgeIt : public Edge {
[774]258      const SmartGraph *G;
[104]259      friend class SmartGraph;
260    public:
[774]261      EdgeIt(const SmartGraph& _G) : Edge(_G.edges.size()-1), G(&_G) { }
262      EdgeIt(const SmartGraph& _G, Edge e) : Edge(e), G(&_G) { }
[164]263      EdgeIt (Invalid i) : Edge(i) { }
264      EdgeIt() : Edge() { }
[774]265      EdgeIt &operator++() { --n; return *this; }
266//       ///Validity check
267//       operator bool() { return Edge::operator bool(); }     
[104]268    };
269   
[164]270    class OutEdgeIt : public Edge {
[774]271      const SmartGraph *G;
[104]272      friend class SmartGraph;
273    public:
[164]274      OutEdgeIt() : Edge() { }
[774]275      OutEdgeIt(const SmartGraph& _G, Edge e) : Edge(e), G(&_G) { }
[164]276      OutEdgeIt (Invalid i) : Edge(i) { }
[157]277
[774]278      OutEdgeIt(const SmartGraph& _G,const Node v)
279        : Edge(_G.nodes[v.n].first_out), G(&_G) {}
280      OutEdgeIt &operator++() { n=G->edges[n].next_out; return *this; }
281//       ///Validity check
282//       operator bool() { return Edge::operator bool(); }     
[104]283    };
284   
[164]285    class InEdgeIt : public Edge {
[774]286      const SmartGraph *G;
[104]287      friend class SmartGraph;
288    public:
[164]289      InEdgeIt() : Edge() { }
[774]290      InEdgeIt(const SmartGraph& _G, Edge e) : Edge(e), G(&_G) { }
[164]291      InEdgeIt (Invalid i) : Edge(i) { }
[774]292      InEdgeIt(const SmartGraph& _G,Node v)
293        : Edge(_G.nodes[v.n].first_in), G(&_G) { }
294      InEdgeIt &operator++() { n=G->edges[n].next_in; return *this; }
295//       ///Validity check
296//       operator bool() { return Edge::operator bool(); }     
[104]297    };
[105]298
[104]299  };
[185]300
301  ///Graph for bidirectional edges.
302
303  ///The purpose of this graph structure is to handle graphs
304  ///having bidirectional edges. Here the function \c addEdge(u,v) adds a pair
[186]305  ///of oppositely directed edges.
306  ///There is a new edge map type called
307  ///\ref SymSmartGraph::SymEdgeMap "SymEdgeMap"
308  ///that complements this
309  ///feature by
310  ///storing shared values for the edge pairs. The usual
[880]311  ///\ref Graph::EdgeMap "EdgeMap"
[186]312  ///can be used
[185]313  ///as well.
314  ///
[186]315  ///The oppositely directed edge can also be obtained easily
316  ///using \ref opposite.
317  ///\warning It shares the similarity with \ref SmartGraph that
318  ///it is not possible to delete edges or nodes from the graph.
[880]319  //\sa SmartGraph.
[185]320
[919]321  class SymSmartGraph : public SmartGraph
[185]322  {
323  public:
[782]324    typedef SymSmartGraph Graph;
325
[904]326    // Create symmetric map registry.
[782]327    CREATE_SYM_EDGE_MAP_REGISTRY;
[904]328    // Create symmetric edge map.
[897]329    CREATE_SYM_EDGE_MAP(ArrayMap);
[822]330
[186]331
[185]332    SymSmartGraph() : SmartGraph() { }
333    SymSmartGraph(const SmartGraph &_g) : SmartGraph(_g) { }
[398]334    ///Adds a pair of oppositely directed edges to the graph.
[185]335    Edge addEdge(Node u, Node v)
336    {
337      Edge e = SmartGraph::addEdge(u,v);
[798]338      Edge f = SmartGraph::addEdge(v,u);
339      sym_edge_maps.add(e);
340      sym_edge_maps.add(f);
[185]341      return e;
342    }
343
[186]344    ///The oppositely directed edge.
345
346    ///Returns the oppositely directed
347    ///pair of the edge \c e.
[713]348    static Edge opposite(Edge e)
[185]349    {
350      Edge f;
[905]351      f.n = e.n - 2*(e.n%2) + 1;
[185]352      return f;
353    }
354   
355
[919]356  };
[185]357 
[407]358  /// @} 
[921]359} //namespace lemon
[104]360
[157]361
362
363
[921]364#endif //LEMON_SMART_GRAPH_H
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