COIN-OR::LEMON - Graph Library

source: lemon-main/lemon/smart_graph.h

Last change on this file was 1210:da87dbdf3daf, checked in by Alpar Juttner <alpar@…>, 4 years ago

Resolve deprecation warnings of gcc 9 (#633)

File size: 36.9 KB
RevLine 
[209]1/* -*- mode: C++; indent-tabs-mode: nil; -*-
[109]2 *
[209]3 * This file is a part of LEMON, a generic C++ optimization library.
[109]4 *
[1092]5 * Copyright (C) 2003-2013
[109]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_SMART_GRAPH_H
20#define LEMON_SMART_GRAPH_H
21
22///\ingroup graphs
23///\file
24///\brief SmartDigraph and SmartGraph classes.
25
26#include <vector>
27
[220]28#include <lemon/core.h>
[109]29#include <lemon/error.h>
30#include <lemon/bits/graph_extender.h>
31
32namespace lemon {
33
34  class SmartDigraph;
35
36  class SmartDigraphBase {
37  protected:
38
[209]39    struct NodeT
[109]40    {
[209]41      int first_in, first_out;
[109]42      NodeT() {}
43    };
[209]44    struct ArcT
[109]45    {
[209]46      int target, source, next_in, next_out;
47      ArcT() {}
[109]48    };
49
[1130]50    std::vector<NodeT> _nodes;
51    std::vector<ArcT> _arcs;
[209]52
[109]53  public:
54
[617]55    typedef SmartDigraphBase Digraph;
[109]56
57    class Node;
58    class Arc;
59
60  public:
61
[1130]62    SmartDigraphBase() : _nodes(), _arcs() { }
[209]63    SmartDigraphBase(const SmartDigraphBase &_g)
[1130]64      : _nodes(_g._nodes), _arcs(_g._arcs) { }
[209]65
[109]66    typedef True NodeNumTag;
[360]67    typedef True ArcNumTag;
[109]68
[1130]69    int nodeNum() const { return _nodes.size(); }
70    int arcNum() const { return _arcs.size(); }
[109]71
[1130]72    int maxNodeId() const { return _nodes.size()-1; }
73    int maxArcId() const { return _arcs.size()-1; }
[109]74
75    Node addNode() {
[1130]76      int n = _nodes.size();
77      _nodes.push_back(NodeT());
78      _nodes[n].first_in = -1;
79      _nodes[n].first_out = -1;
[109]80      return Node(n);
81    }
[209]82
[109]83    Arc addArc(Node u, Node v) {
[1130]84      int n = _arcs.size();
85      _arcs.push_back(ArcT());
86      _arcs[n].source = u._id;
87      _arcs[n].target = v._id;
88      _arcs[n].next_out = _nodes[u._id].first_out;
89      _arcs[n].next_in = _nodes[v._id].first_in;
90      _nodes[u._id].first_out = _nodes[v._id].first_in = n;
[109]91
92      return Arc(n);
93    }
94
95    void clear() {
[1130]96      _arcs.clear();
97      _nodes.clear();
[109]98    }
99
[1130]100    Node source(Arc a) const { return Node(_arcs[a._id].source); }
101    Node target(Arc a) const { return Node(_arcs[a._id].target); }
[109]102
103    static int id(Node v) { return v._id; }
104    static int id(Arc a) { return a._id; }
105
106    static Node nodeFromId(int id) { return Node(id);}
107    static Arc arcFromId(int id) { return Arc(id);}
108
[209]109    bool valid(Node n) const {
[1130]110      return n._id >= 0 && n._id < static_cast<int>(_nodes.size());
[149]111    }
[209]112    bool valid(Arc a) const {
[1130]113      return a._id >= 0 && a._id < static_cast<int>(_arcs.size());
[149]114    }
115
[109]116    class Node {
117      friend class SmartDigraphBase;
118      friend class SmartDigraph;
119
120    protected:
121      int _id;
122      explicit Node(int id) : _id(id) {}
123    public:
124      Node() {}
125      Node (Invalid) : _id(-1) {}
126      bool operator==(const Node i) const {return _id == i._id;}
127      bool operator!=(const Node i) const {return _id != i._id;}
128      bool operator<(const Node i) const {return _id < i._id;}
129    };
[209]130
[109]131
132    class Arc {
133      friend class SmartDigraphBase;
134      friend class SmartDigraph;
135
136    protected:
137      int _id;
138      explicit Arc(int id) : _id(id) {}
139    public:
140      Arc() { }
141      Arc (Invalid) : _id(-1) {}
142      bool operator==(const Arc i) const {return _id == i._id;}
143      bool operator!=(const Arc i) const {return _id != i._id;}
144      bool operator<(const Arc i) const {return _id < i._id;}
145    };
146
147    void first(Node& node) const {
[1130]148      node._id = _nodes.size() - 1;
[109]149    }
150
151    static void next(Node& node) {
152      --node._id;
153    }
154
155    void first(Arc& arc) const {
[1130]156      arc._id = _arcs.size() - 1;
[109]157    }
158
159    static void next(Arc& arc) {
160      --arc._id;
161    }
162
163    void firstOut(Arc& arc, const Node& node) const {
[1130]164      arc._id = _nodes[node._id].first_out;
[109]165    }
166
167    void nextOut(Arc& arc) const {
[1130]168      arc._id = _arcs[arc._id].next_out;
[109]169    }
170
171    void firstIn(Arc& arc, const Node& node) const {
[1130]172      arc._id = _nodes[node._id].first_in;
[109]173    }
[209]174
[109]175    void nextIn(Arc& arc) const {
[1130]176      arc._id = _arcs[arc._id].next_in;
[109]177    }
178
179  };
180
181  typedef DigraphExtender<SmartDigraphBase> ExtendedSmartDigraphBase;
182
183  ///\ingroup graphs
184  ///
185  ///\brief A smart directed graph class.
186  ///
[735]187  ///\ref SmartDigraph is a simple and fast digraph implementation.
188  ///It is also quite memory efficient but at the price
[877]189  ///that it does not support node and arc deletion
[735]190  ///(except for the Snapshot feature).
[109]191  ///
[735]192  ///This type fully conforms to the \ref concepts::Digraph "Digraph concept"
193  ///and it also provides some additional functionalities.
194  ///Most of its member functions and nested classes are documented
195  ///only in the concept class.
196  ///
[787]197  ///This class provides constant time counting for nodes and arcs.
198  ///
[735]199  ///\sa concepts::Digraph
200  ///\sa SmartGraph
[109]201  class SmartDigraph : public ExtendedSmartDigraphBase {
202    typedef ExtendedSmartDigraphBase Parent;
203
204  private:
[735]205    /// Digraphs are \e not copy constructible. Use DigraphCopy instead.
[109]206    SmartDigraph(const SmartDigraph &) : ExtendedSmartDigraphBase() {};
[735]207    /// \brief Assignment of a digraph to another one is \e not allowed.
208    /// Use DigraphCopy instead.
[109]209    void operator=(const SmartDigraph &) {}
210
211  public:
[209]212
[109]213    /// Constructor
[209]214
[109]215    /// Constructor.
216    ///
217    SmartDigraph() {};
[209]218
[109]219    ///Add a new node to the digraph.
[209]220
[735]221    ///This function adds a new node to the digraph.
222    ///\return The new node.
[109]223    Node addNode() { return Parent::addNode(); }
[209]224
[109]225    ///Add a new arc to the digraph.
[209]226
[735]227    ///This function adds a new arc to the digraph with source node \c s
[109]228    ///and target node \c t.
[559]229    ///\return The new arc.
[735]230    Arc addArc(Node s, Node t) {
[209]231      return Parent::addArc(s, t);
[109]232    }
233
[149]234    /// \brief Node validity check
235    ///
[735]236    /// This function gives back \c true if the given node is valid,
237    /// i.e. it is a real node of the digraph.
[149]238    ///
239    /// \warning A removed node (using Snapshot) could become valid again
[735]240    /// if new nodes are added to the digraph.
[149]241    bool valid(Node n) const { return Parent::valid(n); }
242
243    /// \brief Arc validity check
244    ///
[735]245    /// This function gives back \c true if the given arc is valid,
246    /// i.e. it is a real arc of the digraph.
[149]247    ///
248    /// \warning A removed arc (using Snapshot) could become valid again
[735]249    /// if new arcs are added to the graph.
[149]250    bool valid(Arc a) const { return Parent::valid(a); }
251
[109]252    ///Split a node.
[209]253
[735]254    ///This function splits the given node. First, a new node is added
255    ///to the digraph, then the source of each outgoing arc of node \c n
256    ///is moved to this new node.
257    ///If the second parameter \c connect is \c true (this is the default
258    ///value), then a new arc from node \c n to the newly created node
259    ///is also added.
[109]260    ///\return The newly created node.
261    ///
[735]262    ///\note All iterators remain valid.
263    ///
[109]264    ///\warning This functionality cannot be used together with the Snapshot
265    ///feature.
266    Node split(Node n, bool connect = true)
267    {
268      Node b = addNode();
[1130]269      _nodes[b._id].first_out=_nodes[n._id].first_out;
270      _nodes[n._id].first_out=-1;
271      for(int i=_nodes[b._id].first_out; i!=-1; i=_arcs[i].next_out) {
272        _arcs[i].source=b._id;
[370]273      }
[109]274      if(connect) addArc(n,b);
275      return b;
276    }
277
[735]278    ///Clear the digraph.
279
280    ///This function erases all nodes and arcs from the digraph.
281    ///
282    void clear() {
283      Parent::clear();
284    }
285
286    /// Reserve memory for nodes.
287
288    /// Using this function, it is possible to avoid superfluous memory
289    /// allocation: if you know that the digraph you want to build will
290    /// be large (e.g. it will contain millions of nodes and/or arcs),
291    /// then it is worth reserving space for this amount before starting
292    /// to build the digraph.
293    /// \sa reserveArc()
[1130]294    void reserveNode(int n) { _nodes.reserve(n); };
[735]295
296    /// Reserve memory for arcs.
297
298    /// Using this function, it is possible to avoid superfluous memory
299    /// allocation: if you know that the digraph you want to build will
300    /// be large (e.g. it will contain millions of nodes and/or arcs),
301    /// then it is worth reserving space for this amount before starting
302    /// to build the digraph.
303    /// \sa reserveNode()
[1130]304    void reserveArc(int m) { _arcs.reserve(m); };
[735]305
[109]306  public:
[209]307
[109]308    class Snapshot;
309
310  protected:
311
312    void restoreSnapshot(const Snapshot &s)
313    {
[1130]314      while(s.arc_num<_arcs.size()) {
315        Arc arc = arcFromId(_arcs.size()-1);
[209]316        Parent::notifier(Arc()).erase(arc);
[1130]317        _nodes[_arcs.back().source].first_out=_arcs.back().next_out;
318        _nodes[_arcs.back().target].first_in=_arcs.back().next_in;
319        _arcs.pop_back();
[109]320      }
[1130]321      while(s.node_num<_nodes.size()) {
322        Node node = nodeFromId(_nodes.size()-1);
[209]323        Parent::notifier(Node()).erase(node);
[1130]324        _nodes.pop_back();
[109]325      }
[209]326    }
[109]327
328  public:
329
[735]330    ///Class to make a snapshot of the digraph and to restore it later.
[109]331
[735]332    ///Class to make a snapshot of the digraph and to restore it later.
[109]333    ///
334    ///The newly added nodes and arcs can be removed using the
[735]335    ///restore() function. This is the only way for deleting nodes and/or
336    ///arcs from a SmartDigraph structure.
[109]337    ///
[877]338    ///\note After a state is restored, you cannot restore a later state,
[735]339    ///i.e. you cannot add the removed nodes and arcs again using
340    ///another Snapshot instance.
341    ///
342    ///\warning Node splitting cannot be restored.
343    ///\warning The validity of the snapshot is not stored due to
344    ///performance reasons. If you do not use the snapshot correctly,
345    ///it can cause broken program, invalid or not restored state of
346    ///the digraph or no change.
[209]347    class Snapshot
[109]348    {
349      SmartDigraph *_graph;
350    protected:
351      friend class SmartDigraph;
352      unsigned int node_num;
353      unsigned int arc_num;
354    public:
355      ///Default constructor.
[209]356
[109]357      ///Default constructor.
[735]358      ///You have to call save() to actually make a snapshot.
[109]359      Snapshot() : _graph(0) {}
360      ///Constructor that immediately makes a snapshot
[209]361
[735]362      ///This constructor immediately makes a snapshot of the given digraph.
363      ///
364      Snapshot(SmartDigraph &gr) : _graph(&gr) {
[1130]365        node_num=_graph->_nodes.size();
366        arc_num=_graph->_arcs.size();
[109]367      }
368
369      ///Make a snapshot.
370
[735]371      ///This function makes a snapshot of the given digraph.
372      ///It can be called more than once. In case of a repeated
[109]373      ///call, the previous snapshot gets lost.
[735]374      void save(SmartDigraph &gr) {
375        _graph=&gr;
[1130]376        node_num=_graph->_nodes.size();
377        arc_num=_graph->_arcs.size();
[109]378      }
379
380      ///Undo the changes until a snapshot.
[209]381
[735]382      ///This function undos the changes until the last snapshot
383      ///created by save() or Snapshot(SmartDigraph&).
[109]384      void restore()
385      {
[209]386        _graph->restoreSnapshot(*this);
[109]387      }
388    };
389  };
390
391
392  class SmartGraphBase {
393
394  protected:
395
396    struct NodeT {
397      int first_out;
398    };
[209]399
[109]400    struct ArcT {
401      int target;
402      int next_out;
403    };
404
[1130]405    std::vector<NodeT> _nodes;
406    std::vector<ArcT> _arcs;
[109]407
408  public:
[209]409
[617]410    typedef SmartGraphBase Graph;
[109]411
412    class Node;
413    class Arc;
414    class Edge;
[209]415
[109]416    class Node {
417      friend class SmartGraphBase;
418    protected:
419
420      int _id;
421      explicit Node(int id) { _id = id;}
422
423    public:
424      Node() {}
425      Node (Invalid) { _id = -1; }
426      bool operator==(const Node& node) const {return _id == node._id;}
427      bool operator!=(const Node& node) const {return _id != node._id;}
428      bool operator<(const Node& node) const {return _id < node._id;}
429    };
430
431    class Edge {
432      friend class SmartGraphBase;
433    protected:
434
435      int _id;
436      explicit Edge(int id) { _id = id;}
437
438    public:
439      Edge() {}
440      Edge (Invalid) { _id = -1; }
441      bool operator==(const Edge& arc) const {return _id == arc._id;}
442      bool operator!=(const Edge& arc) const {return _id != arc._id;}
443      bool operator<(const Edge& arc) const {return _id < arc._id;}
444    };
445
446    class Arc {
447      friend class SmartGraphBase;
448    protected:
449
450      int _id;
451      explicit Arc(int id) { _id = id;}
452
453    public:
[329]454      operator Edge() const {
455        return _id != -1 ? edgeFromId(_id / 2) : INVALID;
[238]456      }
[109]457
458      Arc() {}
459      Arc (Invalid) { _id = -1; }
460      bool operator==(const Arc& arc) const {return _id == arc._id;}
461      bool operator!=(const Arc& arc) const {return _id != arc._id;}
462      bool operator<(const Arc& arc) const {return _id < arc._id;}
463    };
464
465
466
467    SmartGraphBase()
[1130]468      : _nodes(), _arcs() {}
[109]469
[368]470    typedef True NodeNumTag;
471    typedef True EdgeNumTag;
472    typedef True ArcNumTag;
473
[1130]474    int nodeNum() const { return _nodes.size(); }
475    int edgeNum() const { return _arcs.size() / 2; }
476    int arcNum() const { return _arcs.size(); }
[209]477
[1130]478    int maxNodeId() const { return _nodes.size()-1; }
479    int maxEdgeId() const { return _arcs.size() / 2 - 1; }
480    int maxArcId() const { return _arcs.size()-1; }
[109]481
[1130]482    Node source(Arc e) const { return Node(_arcs[e._id ^ 1].target); }
483    Node target(Arc e) const { return Node(_arcs[e._id].target); }
[109]484
[1130]485    Node u(Edge e) const { return Node(_arcs[2 * e._id].target); }
486    Node v(Edge e) const { return Node(_arcs[2 * e._id + 1].target); }
[109]487
488    static bool direction(Arc e) {
489      return (e._id & 1) == 1;
490    }
491
492    static Arc direct(Edge e, bool d) {
493      return Arc(e._id * 2 + (d ? 1 : 0));
494    }
495
[209]496    void first(Node& node) const {
[1130]497      node._id = _nodes.size() - 1;
[109]498    }
499
[778]500    static void next(Node& node) {
[109]501      --node._id;
502    }
503
[209]504    void first(Arc& arc) const {
[1130]505      arc._id = _arcs.size() - 1;
[109]506    }
507
[778]508    static void next(Arc& arc) {
[109]509      --arc._id;
510    }
511
[209]512    void first(Edge& arc) const {
[1130]513      arc._id = _arcs.size() / 2 - 1;
[109]514    }
515
[778]516    static void next(Edge& arc) {
[109]517      --arc._id;
518    }
519
520    void firstOut(Arc &arc, const Node& v) const {
[1130]521      arc._id = _nodes[v._id].first_out;
[109]522    }
523    void nextOut(Arc &arc) const {
[1130]524      arc._id = _arcs[arc._id].next_out;
[109]525    }
526
527    void firstIn(Arc &arc, const Node& v) const {
[1130]528      arc._id = ((_nodes[v._id].first_out) ^ 1);
[109]529      if (arc._id == -2) arc._id = -1;
530    }
531    void nextIn(Arc &arc) const {
[1130]532      arc._id = ((_arcs[arc._id ^ 1].next_out) ^ 1);
[109]533      if (arc._id == -2) arc._id = -1;
534    }
535
536    void firstInc(Edge &arc, bool& d, const Node& v) const {
[1130]537      int de = _nodes[v._id].first_out;
[109]538      if (de != -1) {
539        arc._id = de / 2;
540        d = ((de & 1) == 1);
541      } else {
542        arc._id = -1;
543        d = true;
544      }
545    }
546    void nextInc(Edge &arc, bool& d) const {
[1130]547      int de = (_arcs[(arc._id * 2) | (d ? 1 : 0)].next_out);
[109]548      if (de != -1) {
549        arc._id = de / 2;
550        d = ((de & 1) == 1);
551      } else {
552        arc._id = -1;
[209]553        d = true;
[109]554      }
555    }
[209]556
[109]557    static int id(Node v) { return v._id; }
558    static int id(Arc e) { return e._id; }
559    static int id(Edge e) { return e._id; }
560
561    static Node nodeFromId(int id) { return Node(id);}
562    static Arc arcFromId(int id) { return Arc(id);}
563    static Edge edgeFromId(int id) { return Edge(id);}
564
[209]565    bool valid(Node n) const {
[1130]566      return n._id >= 0 && n._id < static_cast<int>(_nodes.size());
[149]567    }
[209]568    bool valid(Arc a) const {
[1130]569      return a._id >= 0 && a._id < static_cast<int>(_arcs.size());
[149]570    }
[209]571    bool valid(Edge e) const {
[1130]572      return e._id >= 0 && 2 * e._id < static_cast<int>(_arcs.size());
[149]573    }
574
[209]575    Node addNode() {
[1130]576      int n = _nodes.size();
577      _nodes.push_back(NodeT());
578      _nodes[n].first_out = -1;
[209]579
[109]580      return Node(n);
581    }
[209]582
[138]583    Edge addEdge(Node u, Node v) {
[1130]584      int n = _arcs.size();
585      _arcs.push_back(ArcT());
586      _arcs.push_back(ArcT());
[209]587
[1130]588      _arcs[n].target = u._id;
589      _arcs[n | 1].target = v._id;
[109]590
[1130]591      _arcs[n].next_out = _nodes[v._id].first_out;
592      _nodes[v._id].first_out = n;
[109]593
[1130]594      _arcs[n | 1].next_out = _nodes[u._id].first_out;
595      _nodes[u._id].first_out = (n | 1);
[109]596
597      return Edge(n / 2);
598    }
[209]599
[109]600    void clear() {
[1130]601      _arcs.clear();
602      _nodes.clear();
[109]603    }
604
605  };
606
607  typedef GraphExtender<SmartGraphBase> ExtendedSmartGraphBase;
608
609  /// \ingroup graphs
610  ///
611  /// \brief A smart undirected graph class.
612  ///
[735]613  /// \ref SmartGraph is a simple and fast graph implementation.
614  /// It is also quite memory efficient but at the price
[877]615  /// that it does not support node and edge deletion
[735]616  /// (except for the Snapshot feature).
[109]617  ///
[735]618  /// This type fully conforms to the \ref concepts::Graph "Graph concept"
619  /// and it also provides some additional functionalities.
620  /// Most of its member functions and nested classes are documented
621  /// only in the concept class.
622  ///
[787]623  /// This class provides constant time counting for nodes, edges and arcs.
624  ///
[735]625  /// \sa concepts::Graph
626  /// \sa SmartDigraph
[109]627  class SmartGraph : public ExtendedSmartGraphBase {
[617]628    typedef ExtendedSmartGraphBase Parent;
629
[109]630  private:
[735]631    /// Graphs are \e not copy constructible. Use GraphCopy instead.
[109]632    SmartGraph(const SmartGraph &) : ExtendedSmartGraphBase() {};
[735]633    /// \brief Assignment of a graph to another one is \e not allowed.
634    /// Use GraphCopy instead.
[109]635    void operator=(const SmartGraph &) {}
636
637  public:
638
639    /// Constructor
[209]640
[109]641    /// Constructor.
642    ///
643    SmartGraph() {}
644
[735]645    /// \brief Add a new node to the graph.
646    ///
647    /// This function adds a new node to the graph.
[559]648    /// \return The new node.
[109]649    Node addNode() { return Parent::addNode(); }
[209]650
[735]651    /// \brief Add a new edge to the graph.
652    ///
653    /// This function adds a new edge to the graph between nodes
654    /// \c u and \c v with inherent orientation from node \c u to
655    /// node \c v.
656    /// \return The new edge.
657    Edge addEdge(Node u, Node v) {
658      return Parent::addEdge(u, v);
[109]659    }
660
[149]661    /// \brief Node validity check
662    ///
[735]663    /// This function gives back \c true if the given node is valid,
664    /// i.e. it is a real node of the graph.
[149]665    ///
666    /// \warning A removed node (using Snapshot) could become valid again
[735]667    /// if new nodes are added to the graph.
[149]668    bool valid(Node n) const { return Parent::valid(n); }
669
[735]670    /// \brief Edge validity check
671    ///
672    /// This function gives back \c true if the given edge is valid,
673    /// i.e. it is a real edge of the graph.
674    ///
675    /// \warning A removed edge (using Snapshot) could become valid again
676    /// if new edges are added to the graph.
677    bool valid(Edge e) const { return Parent::valid(e); }
678
[149]679    /// \brief Arc validity check
680    ///
[735]681    /// This function gives back \c true if the given arc is valid,
682    /// i.e. it is a real arc of the graph.
[149]683    ///
684    /// \warning A removed arc (using Snapshot) could become valid again
[735]685    /// if new edges are added to the graph.
[149]686    bool valid(Arc a) const { return Parent::valid(a); }
687
[109]688    ///Clear the graph.
[209]689
[735]690    ///This function erases all nodes and arcs from the graph.
[109]691    ///
692    void clear() {
693      Parent::clear();
694    }
695
[736]696    /// Reserve memory for nodes.
697
698    /// Using this function, it is possible to avoid superfluous memory
699    /// allocation: if you know that the graph you want to build will
700    /// be large (e.g. it will contain millions of nodes and/or edges),
701    /// then it is worth reserving space for this amount before starting
702    /// to build the graph.
703    /// \sa reserveEdge()
[1130]704    void reserveNode(int n) { _nodes.reserve(n); };
[736]705
706    /// Reserve memory for edges.
707
708    /// Using this function, it is possible to avoid superfluous memory
709    /// allocation: if you know that the graph you want to build will
710    /// be large (e.g. it will contain millions of nodes and/or edges),
711    /// then it is worth reserving space for this amount before starting
712    /// to build the graph.
713    /// \sa reserveNode()
[1130]714    void reserveEdge(int m) { _arcs.reserve(2 * m); };
[736]715
[109]716  public:
[209]717
[109]718    class Snapshot;
719
720  protected:
721
722    void saveSnapshot(Snapshot &s)
723    {
724      s._graph = this;
[1130]725      s.node_num = _nodes.size();
726      s.arc_num = _arcs.size();
[109]727    }
728
729    void restoreSnapshot(const Snapshot &s)
730    {
[1130]731      while(s.arc_num<_arcs.size()) {
732        int n=_arcs.size()-1;
[109]733        Edge arc=edgeFromId(n/2);
[209]734        Parent::notifier(Edge()).erase(arc);
[109]735        std::vector<Arc> dir;
736        dir.push_back(arcFromId(n));
737        dir.push_back(arcFromId(n-1));
[209]738        Parent::notifier(Arc()).erase(dir);
[1130]739        _nodes[_arcs[n-1].target].first_out=_arcs[n].next_out;
740        _nodes[_arcs[n].target].first_out=_arcs[n-1].next_out;
741        _arcs.pop_back();
742        _arcs.pop_back();
[109]743      }
[1130]744      while(s.node_num<_nodes.size()) {
745        int n=_nodes.size()-1;
[109]746        Node node = nodeFromId(n);
[209]747        Parent::notifier(Node()).erase(node);
[1130]748        _nodes.pop_back();
[109]749      }
[209]750    }
[109]751
752  public:
753
[735]754    ///Class to make a snapshot of the graph and to restore it later.
[109]755
[735]756    ///Class to make a snapshot of the graph and to restore it later.
[109]757    ///
[735]758    ///The newly added nodes and edges can be removed using the
759    ///restore() function. This is the only way for deleting nodes and/or
760    ///edges from a SmartGraph structure.
[109]761    ///
[877]762    ///\note After a state is restored, you cannot restore a later state,
[735]763    ///i.e. you cannot add the removed nodes and edges again using
764    ///another Snapshot instance.
[109]765    ///
[735]766    ///\warning The validity of the snapshot is not stored due to
767    ///performance reasons. If you do not use the snapshot correctly,
768    ///it can cause broken program, invalid or not restored state of
769    ///the graph or no change.
[209]770    class Snapshot
[109]771    {
772      SmartGraph *_graph;
773    protected:
774      friend class SmartGraph;
775      unsigned int node_num;
776      unsigned int arc_num;
777    public:
778      ///Default constructor.
[209]779
[109]780      ///Default constructor.
[735]781      ///You have to call save() to actually make a snapshot.
[109]782      Snapshot() : _graph(0) {}
783      ///Constructor that immediately makes a snapshot
[209]784
[735]785      /// This constructor immediately makes a snapshot of the given graph.
786      ///
787      Snapshot(SmartGraph &gr) {
788        gr.saveSnapshot(*this);
[109]789      }
790
791      ///Make a snapshot.
792
[735]793      ///This function makes a snapshot of the given graph.
794      ///It can be called more than once. In case of a repeated
[109]795      ///call, the previous snapshot gets lost.
[735]796      void save(SmartGraph &gr)
[109]797      {
[735]798        gr.saveSnapshot(*this);
[109]799      }
800
[735]801      ///Undo the changes until the last snapshot.
[209]802
[735]803      ///This function undos the changes until the last snapshot
804      ///created by save() or Snapshot(SmartGraph&).
[109]805      void restore()
806      {
807        _graph->restoreSnapshot(*this);
808      }
809    };
810  };
[209]811
[1019]812  class SmartBpGraphBase {
813
814  protected:
815
816    struct NodeT {
817      int first_out;
818      int partition_next;
819      int partition_index;
820      bool red;
821    };
822
823    struct ArcT {
824      int target;
825      int next_out;
826    };
827
[1130]828    std::vector<NodeT> _nodes;
829    std::vector<ArcT> _arcs;
[1019]830
831    int first_red, first_blue;
[1023]832    int max_red, max_blue;
[1019]833
834  public:
835
836    typedef SmartBpGraphBase Graph;
837
838    class Node;
839    class Arc;
840    class Edge;
841
842    class Node {
843      friend class SmartBpGraphBase;
844    protected:
845
846      int _id;
847      explicit Node(int id) { _id = id;}
848
849    public:
850      Node() {}
851      Node (Invalid) { _id = -1; }
852      bool operator==(const Node& node) const {return _id == node._id;}
853      bool operator!=(const Node& node) const {return _id != node._id;}
854      bool operator<(const Node& node) const {return _id < node._id;}
855    };
856
[1025]857    class RedNode : public Node {
858      friend class SmartBpGraphBase;
859    protected:
860
861      explicit RedNode(int pid) : Node(pid) {}
862
863    public:
864      RedNode() {}
865      RedNode(const RedNode& node) : Node(node) {}
[1210]866      RedNode(Invalid) : Node(INVALID) {}
867      const RedNode& operator=(const RedNode& node) { Node::operator=(node); return *this;}
[1025]868    };
869
870    class BlueNode : public Node {
871      friend class SmartBpGraphBase;
872    protected:
873
874      explicit BlueNode(int pid) : Node(pid) {}
875
876    public:
877      BlueNode() {}
878      BlueNode(const BlueNode& node) : Node(node) {}
879      BlueNode(Invalid) : Node(INVALID){}
[1210]880      const BlueNode& operator=(const BlueNode& node) { Node::operator=(node); return *this;}
[1025]881    };
882
[1019]883    class Edge {
884      friend class SmartBpGraphBase;
885    protected:
886
887      int _id;
888      explicit Edge(int id) { _id = id;}
889
890    public:
891      Edge() {}
892      Edge (Invalid) { _id = -1; }
893      bool operator==(const Edge& arc) const {return _id == arc._id;}
894      bool operator!=(const Edge& arc) const {return _id != arc._id;}
895      bool operator<(const Edge& arc) const {return _id < arc._id;}
896    };
897
898    class Arc {
899      friend class SmartBpGraphBase;
900    protected:
901
902      int _id;
903      explicit Arc(int id) { _id = id;}
904
905    public:
906      operator Edge() const {
907        return _id != -1 ? edgeFromId(_id / 2) : INVALID;
908      }
909
910      Arc() {}
911      Arc (Invalid) { _id = -1; }
912      bool operator==(const Arc& arc) const {return _id == arc._id;}
913      bool operator!=(const Arc& arc) const {return _id != arc._id;}
914      bool operator<(const Arc& arc) const {return _id < arc._id;}
915    };
916
917
918
919    SmartBpGraphBase()
[1130]920      : _nodes(), _arcs(), first_red(-1), first_blue(-1),
[1023]921        max_red(-1), max_blue(-1) {}
[1019]922
923    typedef True NodeNumTag;
924    typedef True EdgeNumTag;
925    typedef True ArcNumTag;
926
[1130]927    int nodeNum() const { return _nodes.size(); }
[1023]928    int redNum() const { return max_red + 1; }
929    int blueNum() const { return max_blue + 1; }
[1130]930    int edgeNum() const { return _arcs.size() / 2; }
931    int arcNum() const { return _arcs.size(); }
[1019]932
[1130]933    int maxNodeId() const { return _nodes.size()-1; }
[1023]934    int maxRedId() const { return max_red; }
935    int maxBlueId() const { return max_blue; }
[1130]936    int maxEdgeId() const { return _arcs.size() / 2 - 1; }
937    int maxArcId() const { return _arcs.size()-1; }
[1019]938
[1130]939    bool red(Node n) const { return _nodes[n._id].red; }
940    bool blue(Node n) const { return !_nodes[n._id].red; }
[1019]941
[1025]942    static RedNode asRedNodeUnsafe(Node n) { return RedNode(n._id); }
943    static BlueNode asBlueNodeUnsafe(Node n) { return BlueNode(n._id); }
944
[1130]945    Node source(Arc a) const { return Node(_arcs[a._id ^ 1].target); }
946    Node target(Arc a) const { return Node(_arcs[a._id].target); }
[1019]947
[1025]948    RedNode redNode(Edge e) const {
[1130]949      return RedNode(_arcs[2 * e._id].target);
[1025]950    }
951    BlueNode blueNode(Edge e) const {
[1130]952      return BlueNode(_arcs[2 * e._id + 1].target);
[1025]953    }
[1019]954
955    static bool direction(Arc a) {
956      return (a._id & 1) == 1;
957    }
958
959    static Arc direct(Edge e, bool d) {
960      return Arc(e._id * 2 + (d ? 1 : 0));
961    }
962
963    void first(Node& node) const {
[1130]964      node._id = _nodes.size() - 1;
[1019]965    }
966
967    static void next(Node& node) {
968      --node._id;
969    }
970
[1025]971    void first(RedNode& node) const {
[1019]972      node._id = first_red;
973    }
974
[1025]975    void next(RedNode& node) const {
[1130]976      node._id = _nodes[node._id].partition_next;
[1019]977    }
978
[1025]979    void first(BlueNode& node) const {
[1019]980      node._id = first_blue;
981    }
982
[1025]983    void next(BlueNode& node) const {
[1130]984      node._id = _nodes[node._id].partition_next;
[1019]985    }
986
987    void first(Arc& arc) const {
[1130]988      arc._id = _arcs.size() - 1;
[1019]989    }
990
991    static void next(Arc& arc) {
992      --arc._id;
993    }
994
995    void first(Edge& arc) const {
[1130]996      arc._id = _arcs.size() / 2 - 1;
[1019]997    }
998
999    static void next(Edge& arc) {
1000      --arc._id;
1001    }
1002
1003    void firstOut(Arc &arc, const Node& v) const {
[1130]1004      arc._id = _nodes[v._id].first_out;
[1019]1005    }
1006    void nextOut(Arc &arc) const {
[1130]1007      arc._id = _arcs[arc._id].next_out;
[1019]1008    }
1009
1010    void firstIn(Arc &arc, const Node& v) const {
[1130]1011      arc._id = ((_nodes[v._id].first_out) ^ 1);
[1019]1012      if (arc._id == -2) arc._id = -1;
1013    }
1014    void nextIn(Arc &arc) const {
[1130]1015      arc._id = ((_arcs[arc._id ^ 1].next_out) ^ 1);
[1019]1016      if (arc._id == -2) arc._id = -1;
1017    }
1018
1019    void firstInc(Edge &arc, bool& d, const Node& v) const {
[1130]1020      int de = _nodes[v._id].first_out;
[1019]1021      if (de != -1) {
1022        arc._id = de / 2;
1023        d = ((de & 1) == 1);
1024      } else {
1025        arc._id = -1;
1026        d = true;
1027      }
1028    }
1029    void nextInc(Edge &arc, bool& d) const {
[1130]1030      int de = (_arcs[(arc._id * 2) | (d ? 1 : 0)].next_out);
[1019]1031      if (de != -1) {
1032        arc._id = de / 2;
1033        d = ((de & 1) == 1);
1034      } else {
1035        arc._id = -1;
1036        d = true;
1037      }
1038    }
1039
1040    static int id(Node v) { return v._id; }
[1130]1041    int id(RedNode v) const { return _nodes[v._id].partition_index; }
1042    int id(BlueNode v) const { return _nodes[v._id].partition_index; }
[1019]1043    static int id(Arc e) { return e._id; }
1044    static int id(Edge e) { return e._id; }
1045
1046    static Node nodeFromId(int id) { return Node(id);}
1047    static Arc arcFromId(int id) { return Arc(id);}
1048    static Edge edgeFromId(int id) { return Edge(id);}
1049
1050    bool valid(Node n) const {
[1130]1051      return n._id >= 0 && n._id < static_cast<int>(_nodes.size());
[1019]1052    }
1053    bool valid(Arc a) const {
[1130]1054      return a._id >= 0 && a._id < static_cast<int>(_arcs.size());
[1019]1055    }
1056    bool valid(Edge e) const {
[1130]1057      return e._id >= 0 && 2 * e._id < static_cast<int>(_arcs.size());
[1019]1058    }
1059
[1025]1060    RedNode addRedNode() {
[1130]1061      int n = _nodes.size();
1062      _nodes.push_back(NodeT());
1063      _nodes[n].first_out = -1;
1064      _nodes[n].red = true;
1065      _nodes[n].partition_index = ++max_red;
1066      _nodes[n].partition_next = first_red;
[1019]1067      first_red = n;
1068
[1025]1069      return RedNode(n);
[1019]1070    }
1071
[1025]1072    BlueNode addBlueNode() {
[1130]1073      int n = _nodes.size();
1074      _nodes.push_back(NodeT());
1075      _nodes[n].first_out = -1;
1076      _nodes[n].red = false;
1077      _nodes[n].partition_index = ++max_blue;
1078      _nodes[n].partition_next = first_blue;
[1019]1079      first_blue = n;
1080
[1025]1081      return BlueNode(n);
[1019]1082    }
1083
[1025]1084    Edge addEdge(RedNode u, BlueNode v) {
[1130]1085      int n = _arcs.size();
1086      _arcs.push_back(ArcT());
1087      _arcs.push_back(ArcT());
[1019]1088
[1130]1089      _arcs[n].target = u._id;
1090      _arcs[n | 1].target = v._id;
[1019]1091
[1130]1092      _arcs[n].next_out = _nodes[v._id].first_out;
1093      _nodes[v._id].first_out = n;
[1019]1094
[1130]1095      _arcs[n | 1].next_out = _nodes[u._id].first_out;
1096      _nodes[u._id].first_out = (n | 1);
[1019]1097
1098      return Edge(n / 2);
1099    }
1100
1101    void clear() {
[1130]1102      _arcs.clear();
1103      _nodes.clear();
[1019]1104      first_red = -1;
1105      first_blue = -1;
[1023]1106      max_blue = -1;
1107      max_red = -1;
[1019]1108    }
1109
1110  };
1111
1112  typedef BpGraphExtender<SmartBpGraphBase> ExtendedSmartBpGraphBase;
1113
1114  /// \ingroup graphs
1115  ///
[1020]1116  /// \brief A smart undirected bipartite graph class.
[1019]1117  ///
[1020]1118  /// \ref SmartBpGraph is a simple and fast bipartite graph implementation.
[1019]1119  /// It is also quite memory efficient but at the price
1120  /// that it does not support node and edge deletion
1121  /// (except for the Snapshot feature).
1122  ///
[1020]1123  /// This type fully conforms to the \ref concepts::BpGraph "BpGraph concept"
[1019]1124  /// and it also provides some additional functionalities.
1125  /// Most of its member functions and nested classes are documented
1126  /// only in the concept class.
1127  ///
1128  /// This class provides constant time counting for nodes, edges and arcs.
1129  ///
[1020]1130  /// \sa concepts::BpGraph
1131  /// \sa SmartGraph
[1019]1132  class SmartBpGraph : public ExtendedSmartBpGraphBase {
1133    typedef ExtendedSmartBpGraphBase Parent;
1134
1135  private:
1136    /// Graphs are \e not copy constructible. Use GraphCopy instead.
1137    SmartBpGraph(const SmartBpGraph &) : ExtendedSmartBpGraphBase() {};
1138    /// \brief Assignment of a graph to another one is \e not allowed.
1139    /// Use GraphCopy instead.
1140    void operator=(const SmartBpGraph &) {}
1141
1142  public:
1143
1144    /// Constructor
1145
1146    /// Constructor.
1147    ///
1148    SmartBpGraph() {}
1149
1150    /// \brief Add a new red node to the graph.
1151    ///
1152    /// This function adds a red new node to the graph.
1153    /// \return The new node.
[1025]1154    RedNode addRedNode() { return Parent::addRedNode(); }
[1019]1155
1156    /// \brief Add a new blue node to the graph.
1157    ///
1158    /// This function adds a blue new node to the graph.
1159    /// \return The new node.
[1025]1160    BlueNode addBlueNode() { return Parent::addBlueNode(); }
[1019]1161
1162    /// \brief Add a new edge to the graph.
1163    ///
1164    /// This function adds a new edge to the graph between nodes
1165    /// \c u and \c v with inherent orientation from node \c u to
1166    /// node \c v.
1167    /// \return The new edge.
[1025]1168    Edge addEdge(RedNode u, BlueNode v) {
1169      return Parent::addEdge(u, v);
1170    }
1171    Edge addEdge(BlueNode v, RedNode u) {
1172      return Parent::addEdge(u, v);
[1019]1173    }
1174
1175    /// \brief Node validity check
1176    ///
1177    /// This function gives back \c true if the given node is valid,
1178    /// i.e. it is a real node of the graph.
1179    ///
1180    /// \warning A removed node (using Snapshot) could become valid again
1181    /// if new nodes are added to the graph.
1182    bool valid(Node n) const { return Parent::valid(n); }
1183
1184    /// \brief Edge validity check
1185    ///
1186    /// This function gives back \c true if the given edge is valid,
1187    /// i.e. it is a real edge of the graph.
1188    ///
1189    /// \warning A removed edge (using Snapshot) could become valid again
1190    /// if new edges are added to the graph.
1191    bool valid(Edge e) const { return Parent::valid(e); }
1192
1193    /// \brief Arc validity check
1194    ///
1195    /// This function gives back \c true if the given arc is valid,
1196    /// i.e. it is a real arc of the graph.
1197    ///
1198    /// \warning A removed arc (using Snapshot) could become valid again
1199    /// if new edges are added to the graph.
1200    bool valid(Arc a) const { return Parent::valid(a); }
1201
1202    ///Clear the graph.
1203
1204    ///This function erases all nodes and arcs from the graph.
1205    ///
1206    void clear() {
1207      Parent::clear();
1208    }
1209
1210    /// Reserve memory for nodes.
1211
1212    /// Using this function, it is possible to avoid superfluous memory
1213    /// allocation: if you know that the graph you want to build will
1214    /// be large (e.g. it will contain millions of nodes and/or edges),
1215    /// then it is worth reserving space for this amount before starting
1216    /// to build the graph.
1217    /// \sa reserveEdge()
[1130]1218    void reserveNode(int n) { _nodes.reserve(n); };
[1019]1219
1220    /// Reserve memory for edges.
1221
1222    /// Using this function, it is possible to avoid superfluous memory
1223    /// allocation: if you know that the graph you want to build will
1224    /// be large (e.g. it will contain millions of nodes and/or edges),
1225    /// then it is worth reserving space for this amount before starting
1226    /// to build the graph.
1227    /// \sa reserveNode()
[1130]1228    void reserveEdge(int m) { _arcs.reserve(2 * m); };
[1019]1229
1230  public:
1231
1232    class Snapshot;
1233
1234  protected:
1235
1236    void saveSnapshot(Snapshot &s)
1237    {
1238      s._graph = this;
[1130]1239      s.node_num = _nodes.size();
1240      s.arc_num = _arcs.size();
[1019]1241    }
1242
1243    void restoreSnapshot(const Snapshot &s)
1244    {
[1130]1245      while(s.arc_num<_arcs.size()) {
1246        int n=_arcs.size()-1;
[1019]1247        Edge arc=edgeFromId(n/2);
1248        Parent::notifier(Edge()).erase(arc);
1249        std::vector<Arc> dir;
1250        dir.push_back(arcFromId(n));
1251        dir.push_back(arcFromId(n-1));
1252        Parent::notifier(Arc()).erase(dir);
[1130]1253        _nodes[_arcs[n-1].target].first_out=_arcs[n].next_out;
1254        _nodes[_arcs[n].target].first_out=_arcs[n-1].next_out;
1255        _arcs.pop_back();
1256        _arcs.pop_back();
[1019]1257      }
[1130]1258      while(s.node_num<_nodes.size()) {
1259        int n=_nodes.size()-1;
[1019]1260        Node node = nodeFromId(n);
1261        if (Parent::red(node)) {
[1130]1262          first_red = _nodes[n].partition_next;
[1023]1263          if (first_red != -1) {
[1130]1264            max_red = _nodes[first_red].partition_index;
[1023]1265          } else {
1266            max_red = -1;
1267          }
[1092]1268          Parent::notifier(RedNode()).erase(asRedNodeUnsafe(node));
[1019]1269        } else {
[1130]1270          first_blue = _nodes[n].partition_next;
[1023]1271          if (first_blue != -1) {
[1130]1272            max_blue = _nodes[first_blue].partition_index;
[1023]1273          } else {
1274            max_blue = -1;
1275          }
[1025]1276          Parent::notifier(BlueNode()).erase(asBlueNodeUnsafe(node));
[1019]1277        }
1278        Parent::notifier(Node()).erase(node);
[1130]1279        _nodes.pop_back();
[1019]1280      }
1281    }
1282
1283  public:
1284
1285    ///Class to make a snapshot of the graph and to restore it later.
1286
1287    ///Class to make a snapshot of the graph and to restore it later.
1288    ///
1289    ///The newly added nodes and edges can be removed using the
1290    ///restore() function. This is the only way for deleting nodes and/or
1291    ///edges from a SmartBpGraph structure.
1292    ///
1293    ///\note After a state is restored, you cannot restore a later state,
1294    ///i.e. you cannot add the removed nodes and edges again using
1295    ///another Snapshot instance.
1296    ///
1297    ///\warning The validity of the snapshot is not stored due to
1298    ///performance reasons. If you do not use the snapshot correctly,
1299    ///it can cause broken program, invalid or not restored state of
1300    ///the graph or no change.
1301    class Snapshot
1302    {
1303      SmartBpGraph *_graph;
1304    protected:
1305      friend class SmartBpGraph;
1306      unsigned int node_num;
1307      unsigned int arc_num;
1308    public:
1309      ///Default constructor.
1310
1311      ///Default constructor.
1312      ///You have to call save() to actually make a snapshot.
1313      Snapshot() : _graph(0) {}
1314      ///Constructor that immediately makes a snapshot
1315
1316      /// This constructor immediately makes a snapshot of the given graph.
1317      ///
1318      Snapshot(SmartBpGraph &gr) {
1319        gr.saveSnapshot(*this);
1320      }
1321
1322      ///Make a snapshot.
1323
1324      ///This function makes a snapshot of the given graph.
1325      ///It can be called more than once. In case of a repeated
1326      ///call, the previous snapshot gets lost.
1327      void save(SmartBpGraph &gr)
1328      {
1329        gr.saveSnapshot(*this);
1330      }
1331
1332      ///Undo the changes until the last snapshot.
1333
1334      ///This function undos the changes until the last snapshot
1335      ///created by save() or Snapshot(SmartBpGraph&).
1336      void restore()
1337      {
1338        _graph->restoreSnapshot(*this);
1339      }
1340    };
1341  };
1342
[109]1343} //namespace lemon
1344
1345
1346#endif //LEMON_SMART_GRAPH_H
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