lemon/smart_graph.h
author Alpar Juttner <alpar@cs.elte.hu>
Thu, 11 Sep 2008 11:10:44 +0100
changeset 260 c691064dfd4f
parent 220 a5d8c039f218
child 280 e7f8647ce760
permissions -rw-r--r--
Merge
alpar@209
     1
/* -*- mode: C++; indent-tabs-mode: nil; -*-
deba@109
     2
 *
alpar@209
     3
 * This file is a part of LEMON, a generic C++ optimization library.
deba@109
     4
 *
deba@109
     5
 * Copyright (C) 2003-2008
deba@109
     6
 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
deba@109
     7
 * (Egervary Research Group on Combinatorial Optimization, EGRES).
deba@109
     8
 *
deba@109
     9
 * Permission to use, modify and distribute this software is granted
deba@109
    10
 * provided that this copyright notice appears in all copies. For
deba@109
    11
 * precise terms see the accompanying LICENSE file.
deba@109
    12
 *
deba@109
    13
 * This software is provided "AS IS" with no warranty of any kind,
deba@109
    14
 * express or implied, and with no claim as to its suitability for any
deba@109
    15
 * purpose.
deba@109
    16
 *
deba@109
    17
 */
deba@109
    18
deba@109
    19
#ifndef LEMON_SMART_GRAPH_H
deba@109
    20
#define LEMON_SMART_GRAPH_H
deba@109
    21
deba@109
    22
///\ingroup graphs
deba@109
    23
///\file
deba@109
    24
///\brief SmartDigraph and SmartGraph classes.
deba@109
    25
deba@109
    26
#include <vector>
deba@109
    27
deba@220
    28
#include <lemon/core.h>
deba@109
    29
#include <lemon/error.h>
deba@109
    30
#include <lemon/bits/graph_extender.h>
deba@109
    31
deba@109
    32
namespace lemon {
deba@109
    33
deba@109
    34
  class SmartDigraph;
deba@109
    35
  ///Base of SmartDigraph
deba@109
    36
deba@109
    37
  ///Base of SmartDigraph
deba@109
    38
  ///
deba@109
    39
  class SmartDigraphBase {
deba@109
    40
  protected:
deba@109
    41
alpar@209
    42
    struct NodeT
deba@109
    43
    {
alpar@209
    44
      int first_in, first_out;
deba@109
    45
      NodeT() {}
deba@109
    46
    };
alpar@209
    47
    struct ArcT
deba@109
    48
    {
alpar@209
    49
      int target, source, next_in, next_out;
alpar@209
    50
      ArcT() {}
deba@109
    51
    };
deba@109
    52
deba@109
    53
    std::vector<NodeT> nodes;
deba@109
    54
    std::vector<ArcT> arcs;
alpar@209
    55
deba@109
    56
  public:
deba@109
    57
deba@109
    58
    typedef SmartDigraphBase Graph;
deba@109
    59
deba@109
    60
    class Node;
deba@109
    61
    class Arc;
deba@109
    62
deba@109
    63
  public:
deba@109
    64
deba@109
    65
    SmartDigraphBase() : nodes(), arcs() { }
alpar@209
    66
    SmartDigraphBase(const SmartDigraphBase &_g)
deba@109
    67
      : nodes(_g.nodes), arcs(_g.arcs) { }
alpar@209
    68
deba@109
    69
    typedef True NodeNumTag;
deba@139
    70
    typedef True EdgeNumTag;
deba@109
    71
deba@109
    72
    int nodeNum() const { return nodes.size(); }
deba@109
    73
    int arcNum() const { return arcs.size(); }
deba@109
    74
deba@109
    75
    int maxNodeId() const { return nodes.size()-1; }
deba@109
    76
    int maxArcId() const { return arcs.size()-1; }
deba@109
    77
deba@109
    78
    Node addNode() {
alpar@209
    79
      int n = nodes.size();
deba@109
    80
      nodes.push_back(NodeT());
deba@109
    81
      nodes[n].first_in = -1;
deba@109
    82
      nodes[n].first_out = -1;
deba@109
    83
      return Node(n);
deba@109
    84
    }
alpar@209
    85
deba@109
    86
    Arc addArc(Node u, Node v) {
alpar@209
    87
      int n = arcs.size();
deba@109
    88
      arcs.push_back(ArcT());
alpar@209
    89
      arcs[n].source = u._id;
deba@109
    90
      arcs[n].target = v._id;
deba@109
    91
      arcs[n].next_out = nodes[u._id].first_out;
deba@109
    92
      arcs[n].next_in = nodes[v._id].first_in;
deba@109
    93
      nodes[u._id].first_out = nodes[v._id].first_in = n;
deba@109
    94
deba@109
    95
      return Arc(n);
deba@109
    96
    }
deba@109
    97
deba@109
    98
    void clear() {
deba@109
    99
      arcs.clear();
deba@109
   100
      nodes.clear();
deba@109
   101
    }
deba@109
   102
deba@109
   103
    Node source(Arc a) const { return Node(arcs[a._id].source); }
deba@109
   104
    Node target(Arc a) const { return Node(arcs[a._id].target); }
deba@109
   105
deba@109
   106
    static int id(Node v) { return v._id; }
deba@109
   107
    static int id(Arc a) { return a._id; }
deba@109
   108
deba@109
   109
    static Node nodeFromId(int id) { return Node(id);}
deba@109
   110
    static Arc arcFromId(int id) { return Arc(id);}
deba@109
   111
alpar@209
   112
    bool valid(Node n) const {
alpar@209
   113
      return n._id >= 0 && n._id < static_cast<int>(nodes.size());
deba@149
   114
    }
alpar@209
   115
    bool valid(Arc a) const {
alpar@209
   116
      return a._id >= 0 && a._id < static_cast<int>(arcs.size());
deba@149
   117
    }
deba@149
   118
deba@109
   119
    class Node {
deba@109
   120
      friend class SmartDigraphBase;
deba@109
   121
      friend class SmartDigraph;
deba@109
   122
deba@109
   123
    protected:
deba@109
   124
      int _id;
deba@109
   125
      explicit Node(int id) : _id(id) {}
deba@109
   126
    public:
deba@109
   127
      Node() {}
deba@109
   128
      Node (Invalid) : _id(-1) {}
deba@109
   129
      bool operator==(const Node i) const {return _id == i._id;}
deba@109
   130
      bool operator!=(const Node i) const {return _id != i._id;}
deba@109
   131
      bool operator<(const Node i) const {return _id < i._id;}
deba@109
   132
    };
alpar@209
   133
deba@109
   134
deba@109
   135
    class Arc {
deba@109
   136
      friend class SmartDigraphBase;
deba@109
   137
      friend class SmartDigraph;
deba@109
   138
deba@109
   139
    protected:
deba@109
   140
      int _id;
deba@109
   141
      explicit Arc(int id) : _id(id) {}
deba@109
   142
    public:
deba@109
   143
      Arc() { }
deba@109
   144
      Arc (Invalid) : _id(-1) {}
deba@109
   145
      bool operator==(const Arc i) const {return _id == i._id;}
deba@109
   146
      bool operator!=(const Arc i) const {return _id != i._id;}
deba@109
   147
      bool operator<(const Arc i) const {return _id < i._id;}
deba@109
   148
    };
deba@109
   149
deba@109
   150
    void first(Node& node) const {
deba@109
   151
      node._id = nodes.size() - 1;
deba@109
   152
    }
deba@109
   153
deba@109
   154
    static void next(Node& node) {
deba@109
   155
      --node._id;
deba@109
   156
    }
deba@109
   157
deba@109
   158
    void first(Arc& arc) const {
deba@109
   159
      arc._id = arcs.size() - 1;
deba@109
   160
    }
deba@109
   161
deba@109
   162
    static void next(Arc& arc) {
deba@109
   163
      --arc._id;
deba@109
   164
    }
deba@109
   165
deba@109
   166
    void firstOut(Arc& arc, const Node& node) const {
deba@109
   167
      arc._id = nodes[node._id].first_out;
deba@109
   168
    }
deba@109
   169
deba@109
   170
    void nextOut(Arc& arc) const {
deba@109
   171
      arc._id = arcs[arc._id].next_out;
deba@109
   172
    }
deba@109
   173
deba@109
   174
    void firstIn(Arc& arc, const Node& node) const {
deba@109
   175
      arc._id = nodes[node._id].first_in;
deba@109
   176
    }
alpar@209
   177
deba@109
   178
    void nextIn(Arc& arc) const {
deba@109
   179
      arc._id = arcs[arc._id].next_in;
deba@109
   180
    }
deba@109
   181
deba@109
   182
  };
deba@109
   183
deba@109
   184
  typedef DigraphExtender<SmartDigraphBase> ExtendedSmartDigraphBase;
deba@109
   185
deba@109
   186
  ///\ingroup graphs
deba@109
   187
  ///
deba@109
   188
  ///\brief A smart directed graph class.
deba@109
   189
  ///
deba@109
   190
  ///This is a simple and fast digraph implementation.
deba@109
   191
  ///It is also quite memory efficient, but at the price
deba@109
   192
  ///that <b> it does support only limited (only stack-like)
deba@109
   193
  ///node and arc deletions</b>.
deba@109
   194
  ///It conforms to the \ref concepts::Digraph "Digraph concept" with
deba@109
   195
  ///an important extra feature that its maps are real \ref
deba@109
   196
  ///concepts::ReferenceMap "reference map"s.
deba@109
   197
  ///
deba@109
   198
  ///\sa concepts::Digraph.
deba@109
   199
  class SmartDigraph : public ExtendedSmartDigraphBase {
deba@109
   200
  public:
deba@109
   201
deba@109
   202
    typedef ExtendedSmartDigraphBase Parent;
deba@109
   203
deba@109
   204
  private:
deba@109
   205
deba@109
   206
    ///SmartDigraph is \e not copy constructible. Use DigraphCopy() instead.
deba@109
   207
deba@109
   208
    ///SmartDigraph is \e not copy constructible. Use DigraphCopy() instead.
deba@109
   209
    ///
deba@109
   210
    SmartDigraph(const SmartDigraph &) : ExtendedSmartDigraphBase() {};
deba@109
   211
    ///\brief Assignment of SmartDigraph to another one is \e not allowed.
deba@109
   212
    ///Use DigraphCopy() instead.
deba@109
   213
deba@109
   214
    ///Assignment of SmartDigraph to another one is \e not allowed.
deba@109
   215
    ///Use DigraphCopy() instead.
deba@109
   216
    void operator=(const SmartDigraph &) {}
deba@109
   217
deba@109
   218
  public:
alpar@209
   219
deba@109
   220
    /// Constructor
alpar@209
   221
deba@109
   222
    /// Constructor.
deba@109
   223
    ///
deba@109
   224
    SmartDigraph() {};
alpar@209
   225
deba@109
   226
    ///Add a new node to the digraph.
alpar@209
   227
deba@109
   228
    /// \return the new node.
deba@109
   229
    ///
deba@109
   230
    Node addNode() { return Parent::addNode(); }
alpar@209
   231
deba@109
   232
    ///Add a new arc to the digraph.
alpar@209
   233
deba@109
   234
    ///Add a new arc to the digraph with source node \c s
deba@109
   235
    ///and target node \c t.
deba@109
   236
    ///\return the new arc.
alpar@209
   237
    Arc addArc(const Node& s, const Node& t) {
alpar@209
   238
      return Parent::addArc(s, t);
deba@109
   239
    }
deba@109
   240
deba@109
   241
    /// \brief Using this it is possible to avoid the superfluous memory
deba@109
   242
    /// allocation.
deba@109
   243
deba@109
   244
    /// Using this it is possible to avoid the superfluous memory
deba@109
   245
    /// allocation: if you know that the digraph you want to build will
deba@109
   246
    /// be very large (e.g. it will contain millions of nodes and/or arcs)
deba@109
   247
    /// then it is worth reserving space for this amount before starting
deba@109
   248
    /// to build the digraph.
deba@109
   249
    /// \sa reserveArc
deba@109
   250
    void reserveNode(int n) { nodes.reserve(n); };
deba@109
   251
deba@109
   252
    /// \brief Using this it is possible to avoid the superfluous memory
deba@109
   253
    /// allocation.
deba@109
   254
deba@109
   255
    /// Using this it is possible to avoid the superfluous memory
deba@109
   256
    /// allocation: if you know that the digraph you want to build will
deba@109
   257
    /// be very large (e.g. it will contain millions of nodes and/or arcs)
deba@109
   258
    /// then it is worth reserving space for this amount before starting
deba@109
   259
    /// to build the digraph.
deba@109
   260
    /// \sa reserveNode
deba@109
   261
    void reserveArc(int m) { arcs.reserve(m); };
deba@109
   262
deba@149
   263
    /// \brief Node validity check
deba@149
   264
    ///
deba@149
   265
    /// This function gives back true if the given node is valid,
alpar@209
   266
    /// ie. it is a real node of the graph.
deba@149
   267
    ///
deba@149
   268
    /// \warning A removed node (using Snapshot) could become valid again
deba@149
   269
    /// when new nodes are added to the graph.
deba@149
   270
    bool valid(Node n) const { return Parent::valid(n); }
deba@149
   271
deba@149
   272
    /// \brief Arc validity check
deba@149
   273
    ///
deba@149
   274
    /// This function gives back true if the given arc is valid,
alpar@209
   275
    /// ie. it is a real arc of the graph.
deba@149
   276
    ///
deba@149
   277
    /// \warning A removed arc (using Snapshot) could become valid again
deba@149
   278
    /// when new arcs are added to the graph.
deba@149
   279
    bool valid(Arc a) const { return Parent::valid(a); }
deba@149
   280
deba@109
   281
    ///Clear the digraph.
alpar@209
   282
deba@109
   283
    ///Erase all the nodes and arcs from the digraph.
deba@109
   284
    ///
deba@109
   285
    void clear() {
deba@109
   286
      Parent::clear();
deba@109
   287
    }
deba@109
   288
deba@109
   289
    ///Split a node.
alpar@209
   290
deba@109
   291
    ///This function splits a node. First a new node is added to the digraph,
deba@109
   292
    ///then the source of each outgoing arc of \c n is moved to this new node.
deba@109
   293
    ///If \c connect is \c true (this is the default value), then a new arc
deba@109
   294
    ///from \c n to the newly created node is also added.
deba@109
   295
    ///\return The newly created node.
deba@109
   296
    ///
deba@109
   297
    ///\note The <tt>Arc</tt>s
deba@109
   298
    ///referencing a moved arc remain
deba@109
   299
    ///valid. However <tt>InArc</tt>'s and <tt>OutArc</tt>'s
deba@109
   300
    ///may be invalidated.
deba@109
   301
    ///\warning This functionality cannot be used together with the Snapshot
deba@109
   302
    ///feature.
deba@109
   303
    ///\todo It could be implemented in a bit faster way.
deba@109
   304
    Node split(Node n, bool connect = true)
deba@109
   305
    {
deba@109
   306
      Node b = addNode();
deba@109
   307
      nodes[b._id].first_out=nodes[n._id].first_out;
deba@109
   308
      nodes[n._id].first_out=-1;
deba@109
   309
      for(int i=nodes[b._id].first_out;i!=-1;i++) arcs[i].source=b._id;
deba@109
   310
      if(connect) addArc(n,b);
deba@109
   311
      return b;
deba@109
   312
    }
deba@109
   313
deba@109
   314
  public:
alpar@209
   315
deba@109
   316
    class Snapshot;
deba@109
   317
deba@109
   318
  protected:
deba@109
   319
deba@109
   320
    void restoreSnapshot(const Snapshot &s)
deba@109
   321
    {
deba@109
   322
      while(s.arc_num<arcs.size()) {
deba@109
   323
        Arc arc = arcFromId(arcs.size()-1);
alpar@209
   324
        Parent::notifier(Arc()).erase(arc);
alpar@209
   325
        nodes[arcs.back().source].first_out=arcs.back().next_out;
alpar@209
   326
        nodes[arcs.back().target].first_in=arcs.back().next_in;
alpar@209
   327
        arcs.pop_back();
deba@109
   328
      }
deba@109
   329
      while(s.node_num<nodes.size()) {
deba@109
   330
        Node node = nodeFromId(nodes.size()-1);
alpar@209
   331
        Parent::notifier(Node()).erase(node);
alpar@209
   332
        nodes.pop_back();
deba@109
   333
      }
alpar@209
   334
    }
deba@109
   335
deba@109
   336
  public:
deba@109
   337
deba@109
   338
    ///Class to make a snapshot of the digraph and to restrore to it later.
deba@109
   339
deba@109
   340
    ///Class to make a snapshot of the digraph and to restrore to it later.
deba@109
   341
    ///
deba@109
   342
    ///The newly added nodes and arcs can be removed using the
deba@109
   343
    ///restore() function.
deba@109
   344
    ///\note After you restore a state, you cannot restore
deba@109
   345
    ///a later state, in other word you cannot add again the arcs deleted
deba@109
   346
    ///by restore() using another one Snapshot instance.
deba@109
   347
    ///
deba@109
   348
    ///\warning If you do not use correctly the snapshot that can cause
deba@109
   349
    ///either broken program, invalid state of the digraph, valid but
deba@109
   350
    ///not the restored digraph or no change. Because the runtime performance
deba@109
   351
    ///the validity of the snapshot is not stored.
alpar@209
   352
    class Snapshot
deba@109
   353
    {
deba@109
   354
      SmartDigraph *_graph;
deba@109
   355
    protected:
deba@109
   356
      friend class SmartDigraph;
deba@109
   357
      unsigned int node_num;
deba@109
   358
      unsigned int arc_num;
deba@109
   359
    public:
deba@109
   360
      ///Default constructor.
alpar@209
   361
deba@109
   362
      ///Default constructor.
deba@109
   363
      ///To actually make a snapshot you must call save().
deba@109
   364
      ///
deba@109
   365
      Snapshot() : _graph(0) {}
deba@109
   366
      ///Constructor that immediately makes a snapshot
alpar@209
   367
deba@109
   368
      ///This constructor immediately makes a snapshot of the digraph.
deba@109
   369
      ///\param _g The digraph we make a snapshot of.
deba@109
   370
      Snapshot(SmartDigraph &graph) : _graph(&graph) {
alpar@209
   371
        node_num=_graph->nodes.size();
alpar@209
   372
        arc_num=_graph->arcs.size();
deba@109
   373
      }
deba@109
   374
deba@109
   375
      ///Make a snapshot.
deba@109
   376
deba@109
   377
      ///Make a snapshot of the digraph.
deba@109
   378
      ///
deba@109
   379
      ///This function can be called more than once. In case of a repeated
deba@109
   380
      ///call, the previous snapshot gets lost.
deba@109
   381
      ///\param _g The digraph we make the snapshot of.
alpar@209
   382
      void save(SmartDigraph &graph)
deba@109
   383
      {
alpar@209
   384
        _graph=&graph;
alpar@209
   385
        node_num=_graph->nodes.size();
alpar@209
   386
        arc_num=_graph->arcs.size();
deba@109
   387
      }
deba@109
   388
deba@109
   389
      ///Undo the changes until a snapshot.
alpar@209
   390
deba@109
   391
      ///Undo the changes until a snapshot created by save().
deba@109
   392
      ///
deba@109
   393
      ///\note After you restored a state, you cannot restore
deba@109
   394
      ///a later state, in other word you cannot add again the arcs deleted
deba@109
   395
      ///by restore().
deba@109
   396
      void restore()
deba@109
   397
      {
alpar@209
   398
        _graph->restoreSnapshot(*this);
deba@109
   399
      }
deba@109
   400
    };
deba@109
   401
  };
deba@109
   402
deba@109
   403
deba@109
   404
  class SmartGraphBase {
deba@109
   405
deba@109
   406
  protected:
deba@109
   407
deba@109
   408
    struct NodeT {
deba@109
   409
      int first_out;
deba@109
   410
    };
alpar@209
   411
deba@109
   412
    struct ArcT {
deba@109
   413
      int target;
deba@109
   414
      int next_out;
deba@109
   415
    };
deba@109
   416
deba@109
   417
    std::vector<NodeT> nodes;
deba@109
   418
    std::vector<ArcT> arcs;
deba@109
   419
deba@109
   420
    int first_free_arc;
alpar@209
   421
deba@109
   422
  public:
alpar@209
   423
deba@109
   424
    typedef SmartGraphBase Digraph;
deba@109
   425
deba@109
   426
    class Node;
deba@109
   427
    class Arc;
deba@109
   428
    class Edge;
alpar@209
   429
deba@109
   430
    class Node {
deba@109
   431
      friend class SmartGraphBase;
deba@109
   432
    protected:
deba@109
   433
deba@109
   434
      int _id;
deba@109
   435
      explicit Node(int id) { _id = id;}
deba@109
   436
deba@109
   437
    public:
deba@109
   438
      Node() {}
deba@109
   439
      Node (Invalid) { _id = -1; }
deba@109
   440
      bool operator==(const Node& node) const {return _id == node._id;}
deba@109
   441
      bool operator!=(const Node& node) const {return _id != node._id;}
deba@109
   442
      bool operator<(const Node& node) const {return _id < node._id;}
deba@109
   443
    };
deba@109
   444
deba@109
   445
    class Edge {
deba@109
   446
      friend class SmartGraphBase;
deba@109
   447
    protected:
deba@109
   448
deba@109
   449
      int _id;
deba@109
   450
      explicit Edge(int id) { _id = id;}
deba@109
   451
deba@109
   452
    public:
deba@109
   453
      Edge() {}
deba@109
   454
      Edge (Invalid) { _id = -1; }
deba@109
   455
      bool operator==(const Edge& arc) const {return _id == arc._id;}
deba@109
   456
      bool operator!=(const Edge& arc) const {return _id != arc._id;}
deba@109
   457
      bool operator<(const Edge& arc) const {return _id < arc._id;}
deba@109
   458
    };
deba@109
   459
deba@109
   460
    class Arc {
deba@109
   461
      friend class SmartGraphBase;
deba@109
   462
    protected:
deba@109
   463
deba@109
   464
      int _id;
deba@109
   465
      explicit Arc(int id) { _id = id;}
deba@109
   466
deba@109
   467
    public:
deba@238
   468
      operator Edge() const { 
deba@238
   469
        return _id != -1 ? edgeFromId(_id / 2) : INVALID; 
deba@238
   470
      }
deba@109
   471
deba@109
   472
      Arc() {}
deba@109
   473
      Arc (Invalid) { _id = -1; }
deba@109
   474
      bool operator==(const Arc& arc) const {return _id == arc._id;}
deba@109
   475
      bool operator!=(const Arc& arc) const {return _id != arc._id;}
deba@109
   476
      bool operator<(const Arc& arc) const {return _id < arc._id;}
deba@109
   477
    };
deba@109
   478
deba@109
   479
deba@109
   480
deba@109
   481
    SmartGraphBase()
deba@109
   482
      : nodes(), arcs() {}
deba@109
   483
alpar@209
   484
alpar@209
   485
    int maxNodeId() const { return nodes.size()-1; }
deba@109
   486
    int maxEdgeId() const { return arcs.size() / 2 - 1; }
deba@109
   487
    int maxArcId() const { return arcs.size()-1; }
deba@109
   488
deba@109
   489
    Node source(Arc e) const { return Node(arcs[e._id ^ 1].target); }
deba@109
   490
    Node target(Arc e) const { return Node(arcs[e._id].target); }
deba@109
   491
deba@125
   492
    Node u(Edge e) const { return Node(arcs[2 * e._id].target); }
deba@125
   493
    Node v(Edge e) const { return Node(arcs[2 * e._id + 1].target); }
deba@109
   494
deba@109
   495
    static bool direction(Arc e) {
deba@109
   496
      return (e._id & 1) == 1;
deba@109
   497
    }
deba@109
   498
deba@109
   499
    static Arc direct(Edge e, bool d) {
deba@109
   500
      return Arc(e._id * 2 + (d ? 1 : 0));
deba@109
   501
    }
deba@109
   502
alpar@209
   503
    void first(Node& node) const {
deba@109
   504
      node._id = nodes.size() - 1;
deba@109
   505
    }
deba@109
   506
deba@109
   507
    void next(Node& node) const {
deba@109
   508
      --node._id;
deba@109
   509
    }
deba@109
   510
alpar@209
   511
    void first(Arc& arc) const {
deba@109
   512
      arc._id = arcs.size() - 1;
deba@109
   513
    }
deba@109
   514
deba@109
   515
    void next(Arc& arc) const {
deba@109
   516
      --arc._id;
deba@109
   517
    }
deba@109
   518
alpar@209
   519
    void first(Edge& arc) const {
deba@109
   520
      arc._id = arcs.size() / 2 - 1;
deba@109
   521
    }
deba@109
   522
deba@109
   523
    void next(Edge& arc) const {
deba@109
   524
      --arc._id;
deba@109
   525
    }
deba@109
   526
deba@109
   527
    void firstOut(Arc &arc, const Node& v) const {
deba@109
   528
      arc._id = nodes[v._id].first_out;
deba@109
   529
    }
deba@109
   530
    void nextOut(Arc &arc) const {
deba@109
   531
      arc._id = arcs[arc._id].next_out;
deba@109
   532
    }
deba@109
   533
deba@109
   534
    void firstIn(Arc &arc, const Node& v) const {
deba@109
   535
      arc._id = ((nodes[v._id].first_out) ^ 1);
deba@109
   536
      if (arc._id == -2) arc._id = -1;
deba@109
   537
    }
deba@109
   538
    void nextIn(Arc &arc) const {
deba@109
   539
      arc._id = ((arcs[arc._id ^ 1].next_out) ^ 1);
deba@109
   540
      if (arc._id == -2) arc._id = -1;
deba@109
   541
    }
deba@109
   542
deba@109
   543
    void firstInc(Edge &arc, bool& d, const Node& v) const {
deba@109
   544
      int de = nodes[v._id].first_out;
deba@109
   545
      if (de != -1) {
deba@109
   546
        arc._id = de / 2;
deba@109
   547
        d = ((de & 1) == 1);
deba@109
   548
      } else {
deba@109
   549
        arc._id = -1;
deba@109
   550
        d = true;
deba@109
   551
      }
deba@109
   552
    }
deba@109
   553
    void nextInc(Edge &arc, bool& d) const {
deba@109
   554
      int de = (arcs[(arc._id * 2) | (d ? 1 : 0)].next_out);
deba@109
   555
      if (de != -1) {
deba@109
   556
        arc._id = de / 2;
deba@109
   557
        d = ((de & 1) == 1);
deba@109
   558
      } else {
deba@109
   559
        arc._id = -1;
alpar@209
   560
        d = true;
deba@109
   561
      }
deba@109
   562
    }
alpar@209
   563
deba@109
   564
    static int id(Node v) { return v._id; }
deba@109
   565
    static int id(Arc e) { return e._id; }
deba@109
   566
    static int id(Edge e) { return e._id; }
deba@109
   567
deba@109
   568
    static Node nodeFromId(int id) { return Node(id);}
deba@109
   569
    static Arc arcFromId(int id) { return Arc(id);}
deba@109
   570
    static Edge edgeFromId(int id) { return Edge(id);}
deba@109
   571
alpar@209
   572
    bool valid(Node n) const {
alpar@209
   573
      return n._id >= 0 && n._id < static_cast<int>(nodes.size());
deba@149
   574
    }
alpar@209
   575
    bool valid(Arc a) const {
deba@149
   576
      return a._id >= 0 && a._id < static_cast<int>(arcs.size());
deba@149
   577
    }
alpar@209
   578
    bool valid(Edge e) const {
alpar@209
   579
      return e._id >= 0 && 2 * e._id < static_cast<int>(arcs.size());
deba@149
   580
    }
deba@149
   581
alpar@209
   582
    Node addNode() {
deba@109
   583
      int n = nodes.size();
deba@109
   584
      nodes.push_back(NodeT());
deba@109
   585
      nodes[n].first_out = -1;
alpar@209
   586
deba@109
   587
      return Node(n);
deba@109
   588
    }
alpar@209
   589
deba@138
   590
    Edge addEdge(Node u, Node v) {
deba@109
   591
      int n = arcs.size();
deba@109
   592
      arcs.push_back(ArcT());
deba@109
   593
      arcs.push_back(ArcT());
alpar@209
   594
deba@109
   595
      arcs[n].target = u._id;
deba@109
   596
      arcs[n | 1].target = v._id;
deba@109
   597
deba@109
   598
      arcs[n].next_out = nodes[v._id].first_out;
deba@109
   599
      nodes[v._id].first_out = n;
deba@109
   600
alpar@209
   601
      arcs[n | 1].next_out = nodes[u._id].first_out;
deba@109
   602
      nodes[u._id].first_out = (n | 1);
deba@109
   603
deba@109
   604
      return Edge(n / 2);
deba@109
   605
    }
alpar@209
   606
deba@109
   607
    void clear() {
deba@109
   608
      arcs.clear();
deba@109
   609
      nodes.clear();
deba@109
   610
    }
deba@109
   611
deba@109
   612
  };
deba@109
   613
deba@109
   614
  typedef GraphExtender<SmartGraphBase> ExtendedSmartGraphBase;
deba@109
   615
deba@109
   616
  /// \ingroup graphs
deba@109
   617
  ///
deba@109
   618
  /// \brief A smart undirected graph class.
deba@109
   619
  ///
deba@109
   620
  /// This is a simple and fast graph implementation.
deba@109
   621
  /// It is also quite memory efficient, but at the price
deba@109
   622
  /// that <b> it does support only limited (only stack-like)
deba@109
   623
  /// node and arc deletions</b>.
alpar@209
   624
  /// Except from this it conforms to
deba@109
   625
  /// the \ref concepts::Graph "Graph concept".
deba@109
   626
  ///
deba@109
   627
  /// It also has an
deba@109
   628
  /// important extra feature that
deba@109
   629
  /// its maps are real \ref concepts::ReferenceMap "reference map"s.
deba@109
   630
  ///
deba@109
   631
  /// \sa concepts::Graph.
deba@109
   632
  ///
deba@109
   633
  class SmartGraph : public ExtendedSmartGraphBase {
deba@109
   634
  private:
deba@109
   635
deba@109
   636
    ///SmartGraph is \e not copy constructible. Use GraphCopy() instead.
deba@109
   637
deba@109
   638
    ///SmartGraph is \e not copy constructible. Use GraphCopy() instead.
deba@109
   639
    ///
deba@109
   640
    SmartGraph(const SmartGraph &) : ExtendedSmartGraphBase() {};
deba@109
   641
deba@109
   642
    ///\brief Assignment of SmartGraph to another one is \e not allowed.
deba@109
   643
    ///Use GraphCopy() instead.
deba@109
   644
deba@109
   645
    ///Assignment of SmartGraph to another one is \e not allowed.
deba@109
   646
    ///Use GraphCopy() instead.
deba@109
   647
    void operator=(const SmartGraph &) {}
deba@109
   648
deba@109
   649
  public:
deba@109
   650
deba@109
   651
    typedef ExtendedSmartGraphBase Parent;
deba@109
   652
deba@109
   653
    /// Constructor
alpar@209
   654
deba@109
   655
    /// Constructor.
deba@109
   656
    ///
deba@109
   657
    SmartGraph() {}
deba@109
   658
deba@109
   659
    ///Add a new node to the graph.
alpar@209
   660
deba@109
   661
    /// \return the new node.
deba@109
   662
    ///
deba@109
   663
    Node addNode() { return Parent::addNode(); }
alpar@209
   664
deba@109
   665
    ///Add a new edge to the graph.
alpar@209
   666
deba@109
   667
    ///Add a new edge to the graph with node \c s
deba@109
   668
    ///and \c t.
deba@109
   669
    ///\return the new edge.
alpar@209
   670
    Edge addEdge(const Node& s, const Node& t) {
alpar@209
   671
      return Parent::addEdge(s, t);
deba@109
   672
    }
deba@109
   673
deba@149
   674
    /// \brief Node validity check
deba@149
   675
    ///
deba@149
   676
    /// This function gives back true if the given node is valid,
alpar@209
   677
    /// ie. it is a real node of the graph.
deba@149
   678
    ///
deba@149
   679
    /// \warning A removed node (using Snapshot) could become valid again
deba@149
   680
    /// when new nodes are added to the graph.
deba@149
   681
    bool valid(Node n) const { return Parent::valid(n); }
deba@149
   682
deba@149
   683
    /// \brief Arc validity check
deba@149
   684
    ///
deba@149
   685
    /// This function gives back true if the given arc is valid,
alpar@209
   686
    /// ie. it is a real arc of the graph.
deba@149
   687
    ///
deba@149
   688
    /// \warning A removed arc (using Snapshot) could become valid again
deba@149
   689
    /// when new edges are added to the graph.
deba@149
   690
    bool valid(Arc a) const { return Parent::valid(a); }
deba@149
   691
deba@149
   692
    /// \brief Edge validity check
deba@149
   693
    ///
deba@149
   694
    /// This function gives back true if the given edge is valid,
alpar@209
   695
    /// ie. it is a real edge of the graph.
deba@149
   696
    ///
deba@149
   697
    /// \warning A removed edge (using Snapshot) could become valid again
deba@149
   698
    /// when new edges are added to the graph.
deba@149
   699
    bool valid(Edge e) const { return Parent::valid(e); }
deba@149
   700
deba@109
   701
    ///Clear the graph.
alpar@209
   702
deba@109
   703
    ///Erase all the nodes and edges from the graph.
deba@109
   704
    ///
deba@109
   705
    void clear() {
deba@109
   706
      Parent::clear();
deba@109
   707
    }
deba@109
   708
deba@109
   709
  public:
alpar@209
   710
deba@109
   711
    class Snapshot;
deba@109
   712
deba@109
   713
  protected:
deba@109
   714
deba@109
   715
    void saveSnapshot(Snapshot &s)
deba@109
   716
    {
deba@109
   717
      s._graph = this;
deba@109
   718
      s.node_num = nodes.size();
deba@109
   719
      s.arc_num = arcs.size();
deba@109
   720
    }
deba@109
   721
deba@109
   722
    void restoreSnapshot(const Snapshot &s)
deba@109
   723
    {
deba@109
   724
      while(s.arc_num<arcs.size()) {
deba@109
   725
        int n=arcs.size()-1;
deba@109
   726
        Edge arc=edgeFromId(n/2);
alpar@209
   727
        Parent::notifier(Edge()).erase(arc);
deba@109
   728
        std::vector<Arc> dir;
deba@109
   729
        dir.push_back(arcFromId(n));
deba@109
   730
        dir.push_back(arcFromId(n-1));
alpar@209
   731
        Parent::notifier(Arc()).erase(dir);
alpar@209
   732
        nodes[arcs[n].target].first_out=arcs[n].next_out;
alpar@209
   733
        nodes[arcs[n-1].target].first_out=arcs[n-1].next_out;
alpar@209
   734
        arcs.pop_back();
alpar@209
   735
        arcs.pop_back();
deba@109
   736
      }
deba@109
   737
      while(s.node_num<nodes.size()) {
deba@109
   738
        int n=nodes.size()-1;
deba@109
   739
        Node node = nodeFromId(n);
alpar@209
   740
        Parent::notifier(Node()).erase(node);
alpar@209
   741
        nodes.pop_back();
deba@109
   742
      }
alpar@209
   743
    }
deba@109
   744
deba@109
   745
  public:
deba@109
   746
deba@109
   747
    ///Class to make a snapshot of the digraph and to restrore to it later.
deba@109
   748
deba@109
   749
    ///Class to make a snapshot of the digraph and to restrore to it later.
deba@109
   750
    ///
deba@109
   751
    ///The newly added nodes and arcs can be removed using the
deba@109
   752
    ///restore() function.
deba@109
   753
    ///
deba@109
   754
    ///\note After you restore a state, you cannot restore
deba@109
   755
    ///a later state, in other word you cannot add again the arcs deleted
deba@109
   756
    ///by restore() using another one Snapshot instance.
deba@109
   757
    ///
deba@109
   758
    ///\warning If you do not use correctly the snapshot that can cause
deba@109
   759
    ///either broken program, invalid state of the digraph, valid but
deba@109
   760
    ///not the restored digraph or no change. Because the runtime performance
deba@109
   761
    ///the validity of the snapshot is not stored.
alpar@209
   762
    class Snapshot
deba@109
   763
    {
deba@109
   764
      SmartGraph *_graph;
deba@109
   765
    protected:
deba@109
   766
      friend class SmartGraph;
deba@109
   767
      unsigned int node_num;
deba@109
   768
      unsigned int arc_num;
deba@109
   769
    public:
deba@109
   770
      ///Default constructor.
alpar@209
   771
deba@109
   772
      ///Default constructor.
deba@109
   773
      ///To actually make a snapshot you must call save().
deba@109
   774
      ///
deba@109
   775
      Snapshot() : _graph(0) {}
deba@109
   776
      ///Constructor that immediately makes a snapshot
alpar@209
   777
deba@109
   778
      ///This constructor immediately makes a snapshot of the digraph.
deba@109
   779
      ///\param g The digraph we make a snapshot of.
deba@109
   780
      Snapshot(SmartGraph &graph) {
deba@109
   781
        graph.saveSnapshot(*this);
deba@109
   782
      }
deba@109
   783
deba@109
   784
      ///Make a snapshot.
deba@109
   785
deba@109
   786
      ///Make a snapshot of the graph.
deba@109
   787
      ///
deba@109
   788
      ///This function can be called more than once. In case of a repeated
deba@109
   789
      ///call, the previous snapshot gets lost.
deba@109
   790
      ///\param g The digraph we make the snapshot of.
alpar@209
   791
      void save(SmartGraph &graph)
deba@109
   792
      {
deba@109
   793
        graph.saveSnapshot(*this);
deba@109
   794
      }
deba@109
   795
deba@109
   796
      ///Undo the changes until a snapshot.
alpar@209
   797
deba@109
   798
      ///Undo the changes until a snapshot created by save().
deba@109
   799
      ///
deba@109
   800
      ///\note After you restored a state, you cannot restore
deba@109
   801
      ///a later state, in other word you cannot add again the arcs deleted
deba@109
   802
      ///by restore().
deba@109
   803
      void restore()
deba@109
   804
      {
deba@109
   805
        _graph->restoreSnapshot(*this);
deba@109
   806
      }
deba@109
   807
    };
deba@109
   808
  };
alpar@209
   809
deba@109
   810
} //namespace lemon
deba@109
   811
deba@109
   812
deba@109
   813
#endif //LEMON_SMART_GRAPH_H