Porting SmartGraph from svn -r 3481
authorBalazs Dezso <deba@inf.elte.hu>
Wed, 26 Mar 2008 17:28:28 +0100
changeset 109abddaa08b507
parent 108 889d0c289d19
child 110 f2d66d810c88
Porting SmartGraph from svn -r 3481
lemon/Makefile.am
lemon/smart_graph.h
test/graph_test.cc
     1.1 --- a/lemon/Makefile.am	Tue Mar 25 16:36:44 2008 +0100
     1.2 +++ b/lemon/Makefile.am	Wed Mar 26 17:28:28 2008 +0100
     1.3 @@ -31,6 +31,7 @@
     1.4  	lemon/math.h \
     1.5  	lemon/path.h \
     1.6          lemon/random.h \
     1.7 +	lemon/smart_graph.h \
     1.8          lemon/tolerance.h \
     1.9  	lemon/unionfind.h
    1.10  
     2.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     2.2 +++ b/lemon/smart_graph.h	Wed Mar 26 17:28:28 2008 +0100
     2.3 @@ -0,0 +1,757 @@
     2.4 +/* -*- C++ -*-
     2.5 + *
     2.6 + * This file is a part of LEMON, a generic C++ optimization library
     2.7 + *
     2.8 + * Copyright (C) 2003-2008
     2.9 + * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
    2.10 + * (Egervary Research Group on Combinatorial Optimization, EGRES).
    2.11 + *
    2.12 + * Permission to use, modify and distribute this software is granted
    2.13 + * provided that this copyright notice appears in all copies. For
    2.14 + * precise terms see the accompanying LICENSE file.
    2.15 + *
    2.16 + * This software is provided "AS IS" with no warranty of any kind,
    2.17 + * express or implied, and with no claim as to its suitability for any
    2.18 + * purpose.
    2.19 + *
    2.20 + */
    2.21 +
    2.22 +#ifndef LEMON_SMART_GRAPH_H
    2.23 +#define LEMON_SMART_GRAPH_H
    2.24 +
    2.25 +///\ingroup graphs
    2.26 +///\file
    2.27 +///\brief SmartDigraph and SmartGraph classes.
    2.28 +
    2.29 +#include <vector>
    2.30 +
    2.31 +#include <lemon/bits/invalid.h>
    2.32 +
    2.33 +#include <lemon/bits/base_extender.h>
    2.34 +#include <lemon/bits/graph_extender.h>
    2.35 +
    2.36 +#include <lemon/bits/utility.h>
    2.37 +#include <lemon/error.h>
    2.38 +
    2.39 +#include <lemon/bits/graph_extender.h>
    2.40 +
    2.41 +namespace lemon {
    2.42 +
    2.43 +  class SmartDigraph;
    2.44 +  ///Base of SmartDigraph
    2.45 +
    2.46 +  ///Base of SmartDigraph
    2.47 +  ///
    2.48 +  class SmartDigraphBase {
    2.49 +  protected:
    2.50 +
    2.51 +    struct NodeT 
    2.52 +    {
    2.53 +      int first_in, first_out;      
    2.54 +      NodeT() {}
    2.55 +    };
    2.56 +    struct ArcT 
    2.57 +    {
    2.58 +      int target, source, next_in, next_out;      
    2.59 +      ArcT() {}  
    2.60 +    };
    2.61 +
    2.62 +    std::vector<NodeT> nodes;
    2.63 +    std::vector<ArcT> arcs;
    2.64 +        
    2.65 +  public:
    2.66 +
    2.67 +    typedef SmartDigraphBase Graph;
    2.68 +
    2.69 +    class Node;
    2.70 +    class Arc;
    2.71 +
    2.72 +  public:
    2.73 +
    2.74 +    SmartDigraphBase() : nodes(), arcs() { }
    2.75 +    SmartDigraphBase(const SmartDigraphBase &_g) 
    2.76 +      : nodes(_g.nodes), arcs(_g.arcs) { }
    2.77 +    
    2.78 +    typedef True NodeNumTag;
    2.79 +    typedef True ArcNumTag;
    2.80 +
    2.81 +    int nodeNum() const { return nodes.size(); }
    2.82 +    int arcNum() const { return arcs.size(); }
    2.83 +
    2.84 +    int maxNodeId() const { return nodes.size()-1; }
    2.85 +    int maxArcId() const { return arcs.size()-1; }
    2.86 +
    2.87 +    Node addNode() {
    2.88 +      int n = nodes.size();     
    2.89 +      nodes.push_back(NodeT());
    2.90 +      nodes[n].first_in = -1;
    2.91 +      nodes[n].first_out = -1;
    2.92 +      return Node(n);
    2.93 +    }
    2.94 +    
    2.95 +    Arc addArc(Node u, Node v) {
    2.96 +      int n = arcs.size(); 
    2.97 +      arcs.push_back(ArcT());
    2.98 +      arcs[n].source = u._id; 
    2.99 +      arcs[n].target = v._id;
   2.100 +      arcs[n].next_out = nodes[u._id].first_out;
   2.101 +      arcs[n].next_in = nodes[v._id].first_in;
   2.102 +      nodes[u._id].first_out = nodes[v._id].first_in = n;
   2.103 +
   2.104 +      return Arc(n);
   2.105 +    }
   2.106 +
   2.107 +    void clear() {
   2.108 +      arcs.clear();
   2.109 +      nodes.clear();
   2.110 +    }
   2.111 +
   2.112 +    Node source(Arc a) const { return Node(arcs[a._id].source); }
   2.113 +    Node target(Arc a) const { return Node(arcs[a._id].target); }
   2.114 +
   2.115 +    static int id(Node v) { return v._id; }
   2.116 +    static int id(Arc a) { return a._id; }
   2.117 +
   2.118 +    static Node nodeFromId(int id) { return Node(id);}
   2.119 +    static Arc arcFromId(int id) { return Arc(id);}
   2.120 +
   2.121 +    class Node {
   2.122 +      friend class SmartDigraphBase;
   2.123 +      friend class SmartDigraph;
   2.124 +
   2.125 +    protected:
   2.126 +      int _id;
   2.127 +      explicit Node(int id) : _id(id) {}
   2.128 +    public:
   2.129 +      Node() {}
   2.130 +      Node (Invalid) : _id(-1) {}
   2.131 +      bool operator==(const Node i) const {return _id == i._id;}
   2.132 +      bool operator!=(const Node i) const {return _id != i._id;}
   2.133 +      bool operator<(const Node i) const {return _id < i._id;}
   2.134 +    };
   2.135 +    
   2.136 +
   2.137 +    class Arc {
   2.138 +      friend class SmartDigraphBase;
   2.139 +      friend class SmartDigraph;
   2.140 +
   2.141 +    protected:
   2.142 +      int _id;
   2.143 +      explicit Arc(int id) : _id(id) {}
   2.144 +    public:
   2.145 +      Arc() { }
   2.146 +      Arc (Invalid) : _id(-1) {}
   2.147 +      bool operator==(const Arc i) const {return _id == i._id;}
   2.148 +      bool operator!=(const Arc i) const {return _id != i._id;}
   2.149 +      bool operator<(const Arc i) const {return _id < i._id;}
   2.150 +    };
   2.151 +
   2.152 +    void first(Node& node) const {
   2.153 +      node._id = nodes.size() - 1;
   2.154 +    }
   2.155 +
   2.156 +    static void next(Node& node) {
   2.157 +      --node._id;
   2.158 +    }
   2.159 +
   2.160 +    void first(Arc& arc) const {
   2.161 +      arc._id = arcs.size() - 1;
   2.162 +    }
   2.163 +
   2.164 +    static void next(Arc& arc) {
   2.165 +      --arc._id;
   2.166 +    }
   2.167 +
   2.168 +    void firstOut(Arc& arc, const Node& node) const {
   2.169 +      arc._id = nodes[node._id].first_out;
   2.170 +    }
   2.171 +
   2.172 +    void nextOut(Arc& arc) const {
   2.173 +      arc._id = arcs[arc._id].next_out;
   2.174 +    }
   2.175 +
   2.176 +    void firstIn(Arc& arc, const Node& node) const {
   2.177 +      arc._id = nodes[node._id].first_in;
   2.178 +    }
   2.179 +    
   2.180 +    void nextIn(Arc& arc) const {
   2.181 +      arc._id = arcs[arc._id].next_in;
   2.182 +    }
   2.183 +
   2.184 +  };
   2.185 +
   2.186 +  typedef DigraphExtender<SmartDigraphBase> ExtendedSmartDigraphBase;
   2.187 +
   2.188 +  ///\ingroup graphs
   2.189 +  ///
   2.190 +  ///\brief A smart directed graph class.
   2.191 +  ///
   2.192 +  ///This is a simple and fast digraph implementation.
   2.193 +  ///It is also quite memory efficient, but at the price
   2.194 +  ///that <b> it does support only limited (only stack-like)
   2.195 +  ///node and arc deletions</b>.
   2.196 +  ///It conforms to the \ref concepts::Digraph "Digraph concept" with
   2.197 +  ///an important extra feature that its maps are real \ref
   2.198 +  ///concepts::ReferenceMap "reference map"s.
   2.199 +  ///
   2.200 +  ///\sa concepts::Digraph.
   2.201 +  ///
   2.202 +  ///\author Alpar Juttner
   2.203 +  class SmartDigraph : public ExtendedSmartDigraphBase {
   2.204 +  public:
   2.205 +
   2.206 +    typedef ExtendedSmartDigraphBase Parent;
   2.207 +
   2.208 +  private:
   2.209 +
   2.210 +    ///SmartDigraph is \e not copy constructible. Use DigraphCopy() instead.
   2.211 +
   2.212 +    ///SmartDigraph is \e not copy constructible. Use DigraphCopy() instead.
   2.213 +    ///
   2.214 +    SmartDigraph(const SmartDigraph &) : ExtendedSmartDigraphBase() {};
   2.215 +    ///\brief Assignment of SmartDigraph to another one is \e not allowed.
   2.216 +    ///Use DigraphCopy() instead.
   2.217 +
   2.218 +    ///Assignment of SmartDigraph to another one is \e not allowed.
   2.219 +    ///Use DigraphCopy() instead.
   2.220 +    void operator=(const SmartDigraph &) {}
   2.221 +
   2.222 +  public:
   2.223 +    
   2.224 +    /// Constructor
   2.225 +    
   2.226 +    /// Constructor.
   2.227 +    ///
   2.228 +    SmartDigraph() {};
   2.229 +    
   2.230 +    ///Add a new node to the digraph.
   2.231 +    
   2.232 +    /// \return the new node.
   2.233 +    ///
   2.234 +    Node addNode() { return Parent::addNode(); }
   2.235 +    
   2.236 +    ///Add a new arc to the digraph.
   2.237 +    
   2.238 +    ///Add a new arc to the digraph with source node \c s
   2.239 +    ///and target node \c t.
   2.240 +    ///\return the new arc.
   2.241 +    Arc addArc(const Node& s, const Node& t) { 
   2.242 +      return Parent::addArc(s, t); 
   2.243 +    }
   2.244 +
   2.245 +    /// \brief Using this it is possible to avoid the superfluous memory
   2.246 +    /// allocation.
   2.247 +
   2.248 +    /// Using this it is possible to avoid the superfluous memory
   2.249 +    /// allocation: if you know that the digraph you want to build will
   2.250 +    /// be very large (e.g. it will contain millions of nodes and/or arcs)
   2.251 +    /// then it is worth reserving space for this amount before starting
   2.252 +    /// to build the digraph.
   2.253 +    /// \sa reserveArc
   2.254 +    void reserveNode(int n) { nodes.reserve(n); };
   2.255 +
   2.256 +    /// \brief Using this it is possible to avoid the superfluous memory
   2.257 +    /// allocation.
   2.258 +
   2.259 +    /// Using this it is possible to avoid the superfluous memory
   2.260 +    /// allocation: if you know that the digraph you want to build will
   2.261 +    /// be very large (e.g. it will contain millions of nodes and/or arcs)
   2.262 +    /// then it is worth reserving space for this amount before starting
   2.263 +    /// to build the digraph.
   2.264 +    /// \sa reserveNode
   2.265 +    void reserveArc(int m) { arcs.reserve(m); };
   2.266 +
   2.267 +    ///Clear the digraph.
   2.268 +    
   2.269 +    ///Erase all the nodes and arcs from the digraph.
   2.270 +    ///
   2.271 +    void clear() {
   2.272 +      Parent::clear();
   2.273 +    }
   2.274 +
   2.275 +    ///Split a node.
   2.276 +    
   2.277 +    ///This function splits a node. First a new node is added to the digraph,
   2.278 +    ///then the source of each outgoing arc of \c n is moved to this new node.
   2.279 +    ///If \c connect is \c true (this is the default value), then a new arc
   2.280 +    ///from \c n to the newly created node is also added.
   2.281 +    ///\return The newly created node.
   2.282 +    ///
   2.283 +    ///\note The <tt>Arc</tt>s
   2.284 +    ///referencing a moved arc remain
   2.285 +    ///valid. However <tt>InArc</tt>'s and <tt>OutArc</tt>'s
   2.286 +    ///may be invalidated.
   2.287 +    ///\warning This functionality cannot be used together with the Snapshot
   2.288 +    ///feature.
   2.289 +    ///\todo It could be implemented in a bit faster way.
   2.290 +    Node split(Node n, bool connect = true)
   2.291 +    {
   2.292 +      Node b = addNode();
   2.293 +      nodes[b._id].first_out=nodes[n._id].first_out;
   2.294 +      nodes[n._id].first_out=-1;
   2.295 +      for(int i=nodes[b._id].first_out;i!=-1;i++) arcs[i].source=b._id;
   2.296 +      if(connect) addArc(n,b);
   2.297 +      return b;
   2.298 +    }
   2.299 +
   2.300 +  public:
   2.301 +    
   2.302 +    class Snapshot;
   2.303 +
   2.304 +  protected:
   2.305 +
   2.306 +    void restoreSnapshot(const Snapshot &s)
   2.307 +    {
   2.308 +      while(s.arc_num<arcs.size()) {
   2.309 +        Arc arc = arcFromId(arcs.size()-1);
   2.310 +	Parent::notifier(Arc()).erase(arc);
   2.311 +	nodes[arcs.back().source].first_out=arcs.back().next_out;
   2.312 +	nodes[arcs.back().target].first_in=arcs.back().next_in;
   2.313 +	arcs.pop_back();
   2.314 +      }
   2.315 +      while(s.node_num<nodes.size()) {
   2.316 +        Node node = nodeFromId(nodes.size()-1);
   2.317 +	Parent::notifier(Node()).erase(node);
   2.318 +	nodes.pop_back();
   2.319 +      }
   2.320 +    }    
   2.321 +
   2.322 +  public:
   2.323 +
   2.324 +    ///Class to make a snapshot of the digraph and to restrore to it later.
   2.325 +
   2.326 +    ///Class to make a snapshot of the digraph and to restrore to it later.
   2.327 +    ///
   2.328 +    ///The newly added nodes and arcs can be removed using the
   2.329 +    ///restore() function.
   2.330 +    ///\note After you restore a state, you cannot restore
   2.331 +    ///a later state, in other word you cannot add again the arcs deleted
   2.332 +    ///by restore() using another one Snapshot instance.
   2.333 +    ///
   2.334 +    ///\warning If you do not use correctly the snapshot that can cause
   2.335 +    ///either broken program, invalid state of the digraph, valid but
   2.336 +    ///not the restored digraph or no change. Because the runtime performance
   2.337 +    ///the validity of the snapshot is not stored.
   2.338 +    class Snapshot 
   2.339 +    {
   2.340 +      SmartDigraph *_graph;
   2.341 +    protected:
   2.342 +      friend class SmartDigraph;
   2.343 +      unsigned int node_num;
   2.344 +      unsigned int arc_num;
   2.345 +    public:
   2.346 +      ///Default constructor.
   2.347 +      
   2.348 +      ///Default constructor.
   2.349 +      ///To actually make a snapshot you must call save().
   2.350 +      ///
   2.351 +      Snapshot() : _graph(0) {}
   2.352 +      ///Constructor that immediately makes a snapshot
   2.353 +      
   2.354 +      ///This constructor immediately makes a snapshot of the digraph.
   2.355 +      ///\param _g The digraph we make a snapshot of.
   2.356 +      Snapshot(SmartDigraph &graph) : _graph(&graph) {
   2.357 +	node_num=_graph->nodes.size();
   2.358 +	arc_num=_graph->arcs.size();
   2.359 +      }
   2.360 +
   2.361 +      ///Make a snapshot.
   2.362 +
   2.363 +      ///Make a snapshot of the digraph.
   2.364 +      ///
   2.365 +      ///This function can be called more than once. In case of a repeated
   2.366 +      ///call, the previous snapshot gets lost.
   2.367 +      ///\param _g The digraph we make the snapshot of.
   2.368 +      void save(SmartDigraph &graph) 
   2.369 +      {
   2.370 +	_graph=&graph;
   2.371 +	node_num=_graph->nodes.size();
   2.372 +	arc_num=_graph->arcs.size();
   2.373 +      }
   2.374 +
   2.375 +      ///Undo the changes until a snapshot.
   2.376 +      
   2.377 +      ///Undo the changes until a snapshot created by save().
   2.378 +      ///
   2.379 +      ///\note After you restored a state, you cannot restore
   2.380 +      ///a later state, in other word you cannot add again the arcs deleted
   2.381 +      ///by restore().
   2.382 +      void restore()
   2.383 +      {
   2.384 +	_graph->restoreSnapshot(*this);
   2.385 +      }
   2.386 +    };
   2.387 +  };
   2.388 +
   2.389 +
   2.390 +  class SmartGraphBase {
   2.391 +
   2.392 +  protected:
   2.393 +
   2.394 +    struct NodeT {
   2.395 +      int first_out;
   2.396 +    };
   2.397 + 
   2.398 +    struct ArcT {
   2.399 +      int target;
   2.400 +      int next_out;
   2.401 +    };
   2.402 +
   2.403 +    std::vector<NodeT> nodes;
   2.404 +    std::vector<ArcT> arcs;
   2.405 +
   2.406 +    int first_free_arc;
   2.407 +    
   2.408 +  public:
   2.409 +    
   2.410 +    typedef SmartGraphBase Digraph;
   2.411 +
   2.412 +    class Node;
   2.413 +    class Arc;
   2.414 +    class Edge;
   2.415 +    
   2.416 +    class Node {
   2.417 +      friend class SmartGraphBase;
   2.418 +    protected:
   2.419 +
   2.420 +      int _id;
   2.421 +      explicit Node(int id) { _id = id;}
   2.422 +
   2.423 +    public:
   2.424 +      Node() {}
   2.425 +      Node (Invalid) { _id = -1; }
   2.426 +      bool operator==(const Node& node) const {return _id == node._id;}
   2.427 +      bool operator!=(const Node& node) const {return _id != node._id;}
   2.428 +      bool operator<(const Node& node) const {return _id < node._id;}
   2.429 +    };
   2.430 +
   2.431 +    class Edge {
   2.432 +      friend class SmartGraphBase;
   2.433 +    protected:
   2.434 +
   2.435 +      int _id;
   2.436 +      explicit Edge(int id) { _id = id;}
   2.437 +
   2.438 +    public:
   2.439 +      Edge() {}
   2.440 +      Edge (Invalid) { _id = -1; }
   2.441 +      bool operator==(const Edge& arc) const {return _id == arc._id;}
   2.442 +      bool operator!=(const Edge& arc) const {return _id != arc._id;}
   2.443 +      bool operator<(const Edge& arc) const {return _id < arc._id;}
   2.444 +    };
   2.445 +
   2.446 +    class Arc {
   2.447 +      friend class SmartGraphBase;
   2.448 +    protected:
   2.449 +
   2.450 +      int _id;
   2.451 +      explicit Arc(int id) { _id = id;}
   2.452 +
   2.453 +    public:
   2.454 +      operator Edge() const { return edgeFromId(_id / 2); }
   2.455 +
   2.456 +      Arc() {}
   2.457 +      Arc (Invalid) { _id = -1; }
   2.458 +      bool operator==(const Arc& arc) const {return _id == arc._id;}
   2.459 +      bool operator!=(const Arc& arc) const {return _id != arc._id;}
   2.460 +      bool operator<(const Arc& arc) const {return _id < arc._id;}
   2.461 +    };
   2.462 +
   2.463 +
   2.464 +
   2.465 +    SmartGraphBase()
   2.466 +      : nodes(), arcs() {}
   2.467 +
   2.468 +    
   2.469 +    int maxNodeId() const { return nodes.size()-1; } 
   2.470 +    int maxEdgeId() const { return arcs.size() / 2 - 1; }
   2.471 +    int maxArcId() const { return arcs.size()-1; }
   2.472 +
   2.473 +    Node source(Arc e) const { return Node(arcs[e._id ^ 1].target); }
   2.474 +    Node target(Arc e) const { return Node(arcs[e._id].target); }
   2.475 +
   2.476 +    Node source(Edge e) const { return Node(arcs[2 * e._id].target); }
   2.477 +    Node target(Edge e) const { return Node(arcs[2 * e._id + 1].target); }
   2.478 +
   2.479 +    static bool direction(Arc e) {
   2.480 +      return (e._id & 1) == 1;
   2.481 +    }
   2.482 +
   2.483 +    static Arc direct(Edge e, bool d) {
   2.484 +      return Arc(e._id * 2 + (d ? 1 : 0));
   2.485 +    }
   2.486 +
   2.487 +    void first(Node& node) const { 
   2.488 +      node._id = nodes.size() - 1;
   2.489 +    }
   2.490 +
   2.491 +    void next(Node& node) const {
   2.492 +      --node._id;
   2.493 +    }
   2.494 +
   2.495 +    void first(Arc& arc) const { 
   2.496 +      arc._id = arcs.size() - 1;
   2.497 +    }
   2.498 +
   2.499 +    void next(Arc& arc) const {
   2.500 +      --arc._id;
   2.501 +    }
   2.502 +
   2.503 +    void first(Edge& arc) const { 
   2.504 +      arc._id = arcs.size() / 2 - 1;
   2.505 +    }
   2.506 +
   2.507 +    void next(Edge& arc) const {
   2.508 +      --arc._id;
   2.509 +    }
   2.510 +
   2.511 +    void firstOut(Arc &arc, const Node& v) const {
   2.512 +      arc._id = nodes[v._id].first_out;
   2.513 +    }
   2.514 +    void nextOut(Arc &arc) const {
   2.515 +      arc._id = arcs[arc._id].next_out;
   2.516 +    }
   2.517 +
   2.518 +    void firstIn(Arc &arc, const Node& v) const {
   2.519 +      arc._id = ((nodes[v._id].first_out) ^ 1);
   2.520 +      if (arc._id == -2) arc._id = -1;
   2.521 +    }
   2.522 +    void nextIn(Arc &arc) const {
   2.523 +      arc._id = ((arcs[arc._id ^ 1].next_out) ^ 1);
   2.524 +      if (arc._id == -2) arc._id = -1;
   2.525 +    }
   2.526 +
   2.527 +    void firstInc(Edge &arc, bool& d, const Node& v) const {
   2.528 +      int de = nodes[v._id].first_out;
   2.529 +      if (de != -1) {
   2.530 +        arc._id = de / 2;
   2.531 +        d = ((de & 1) == 1);
   2.532 +      } else {
   2.533 +        arc._id = -1;
   2.534 +        d = true;
   2.535 +      }
   2.536 +    }
   2.537 +    void nextInc(Edge &arc, bool& d) const {
   2.538 +      int de = (arcs[(arc._id * 2) | (d ? 1 : 0)].next_out);
   2.539 +      if (de != -1) {
   2.540 +        arc._id = de / 2;
   2.541 +        d = ((de & 1) == 1);
   2.542 +      } else {
   2.543 +        arc._id = -1;
   2.544 +        d = true;      
   2.545 +      }
   2.546 +    }
   2.547 +    
   2.548 +    static int id(Node v) { return v._id; }
   2.549 +    static int id(Arc e) { return e._id; }
   2.550 +    static int id(Edge e) { return e._id; }
   2.551 +
   2.552 +    static Node nodeFromId(int id) { return Node(id);}
   2.553 +    static Arc arcFromId(int id) { return Arc(id);}
   2.554 +    static Edge edgeFromId(int id) { return Edge(id);}
   2.555 +
   2.556 +    Node addNode() {     
   2.557 +      int n = nodes.size();
   2.558 +      nodes.push_back(NodeT());
   2.559 +      nodes[n].first_out = -1;
   2.560 +      
   2.561 +      return Node(n);
   2.562 +    }
   2.563 +    
   2.564 +    Edge addArc(Node u, Node v) {
   2.565 +      int n = arcs.size();
   2.566 +      arcs.push_back(ArcT());
   2.567 +      arcs.push_back(ArcT());
   2.568 +      
   2.569 +      arcs[n].target = u._id;
   2.570 +      arcs[n | 1].target = v._id;
   2.571 +
   2.572 +      arcs[n].next_out = nodes[v._id].first_out;
   2.573 +      nodes[v._id].first_out = n;
   2.574 +
   2.575 +      arcs[n | 1].next_out = nodes[u._id].first_out;	
   2.576 +      nodes[u._id].first_out = (n | 1);
   2.577 +
   2.578 +      return Edge(n / 2);
   2.579 +    }
   2.580 +    
   2.581 +    void clear() {
   2.582 +      arcs.clear();
   2.583 +      nodes.clear();
   2.584 +    }
   2.585 +
   2.586 +  };
   2.587 +
   2.588 +  typedef GraphExtender<SmartGraphBase> ExtendedSmartGraphBase;
   2.589 +
   2.590 +  /// \ingroup graphs
   2.591 +  ///
   2.592 +  /// \brief A smart undirected graph class.
   2.593 +  ///
   2.594 +  /// This is a simple and fast graph implementation.
   2.595 +  /// It is also quite memory efficient, but at the price
   2.596 +  /// that <b> it does support only limited (only stack-like)
   2.597 +  /// node and arc deletions</b>.
   2.598 +  /// Except from this it conforms to 
   2.599 +  /// the \ref concepts::Graph "Graph concept".
   2.600 +  ///
   2.601 +  /// It also has an
   2.602 +  /// important extra feature that
   2.603 +  /// its maps are real \ref concepts::ReferenceMap "reference map"s.
   2.604 +  ///
   2.605 +  /// \sa concepts::Graph.
   2.606 +  ///
   2.607 +  class SmartGraph : public ExtendedSmartGraphBase {
   2.608 +  private:
   2.609 +
   2.610 +    ///SmartGraph is \e not copy constructible. Use GraphCopy() instead.
   2.611 +
   2.612 +    ///SmartGraph is \e not copy constructible. Use GraphCopy() instead.
   2.613 +    ///
   2.614 +    SmartGraph(const SmartGraph &) : ExtendedSmartGraphBase() {};
   2.615 +
   2.616 +    ///\brief Assignment of SmartGraph to another one is \e not allowed.
   2.617 +    ///Use GraphCopy() instead.
   2.618 +
   2.619 +    ///Assignment of SmartGraph to another one is \e not allowed.
   2.620 +    ///Use GraphCopy() instead.
   2.621 +    void operator=(const SmartGraph &) {}
   2.622 +
   2.623 +  public:
   2.624 +
   2.625 +    typedef ExtendedSmartGraphBase Parent;
   2.626 +
   2.627 +    /// Constructor
   2.628 +    
   2.629 +    /// Constructor.
   2.630 +    ///
   2.631 +    SmartGraph() {}
   2.632 +
   2.633 +    ///Add a new node to the graph.
   2.634 +    
   2.635 +    /// \return the new node.
   2.636 +    ///
   2.637 +    Node addNode() { return Parent::addNode(); }
   2.638 +    
   2.639 +    ///Add a new edge to the graph.
   2.640 +    
   2.641 +    ///Add a new edge to the graph with node \c s
   2.642 +    ///and \c t.
   2.643 +    ///\return the new edge.
   2.644 +    Edge addEdge(const Node& s, const Node& t) { 
   2.645 +      return Parent::addArc(s, t); 
   2.646 +    }
   2.647 +
   2.648 +    ///Clear the graph.
   2.649 +    
   2.650 +    ///Erase all the nodes and edges from the graph.
   2.651 +    ///
   2.652 +    void clear() {
   2.653 +      Parent::clear();
   2.654 +    }
   2.655 +
   2.656 +  public:
   2.657 +    
   2.658 +    class Snapshot;
   2.659 +
   2.660 +  protected:
   2.661 +
   2.662 +    void saveSnapshot(Snapshot &s)
   2.663 +    {
   2.664 +      s._graph = this;
   2.665 +      s.node_num = nodes.size();
   2.666 +      s.arc_num = arcs.size();
   2.667 +    }
   2.668 +
   2.669 +    void restoreSnapshot(const Snapshot &s)
   2.670 +    {
   2.671 +      while(s.arc_num<arcs.size()) {
   2.672 +        int n=arcs.size()-1;
   2.673 +        Edge arc=edgeFromId(n/2);
   2.674 +	Parent::notifier(Edge()).erase(arc);
   2.675 +        std::vector<Arc> dir;
   2.676 +        dir.push_back(arcFromId(n));
   2.677 +        dir.push_back(arcFromId(n-1));
   2.678 +	Parent::notifier(Arc()).erase(dir);
   2.679 +	nodes[arcs[n].target].first_out=arcs[n].next_out;
   2.680 +	nodes[arcs[n-1].target].first_out=arcs[n-1].next_out;
   2.681 +	arcs.pop_back();
   2.682 +	arcs.pop_back();
   2.683 +      }
   2.684 +      while(s.node_num<nodes.size()) {
   2.685 +        int n=nodes.size()-1;
   2.686 +        Node node = nodeFromId(n);
   2.687 +	Parent::notifier(Node()).erase(node);
   2.688 +	nodes.pop_back();
   2.689 +      }
   2.690 +    }    
   2.691 +
   2.692 +  public:
   2.693 +
   2.694 +    ///Class to make a snapshot of the digraph and to restrore to it later.
   2.695 +
   2.696 +    ///Class to make a snapshot of the digraph and to restrore to it later.
   2.697 +    ///
   2.698 +    ///The newly added nodes and arcs can be removed using the
   2.699 +    ///restore() function.
   2.700 +    ///
   2.701 +    ///\note After you restore a state, you cannot restore
   2.702 +    ///a later state, in other word you cannot add again the arcs deleted
   2.703 +    ///by restore() using another one Snapshot instance.
   2.704 +    ///
   2.705 +    ///\warning If you do not use correctly the snapshot that can cause
   2.706 +    ///either broken program, invalid state of the digraph, valid but
   2.707 +    ///not the restored digraph or no change. Because the runtime performance
   2.708 +    ///the validity of the snapshot is not stored.
   2.709 +    class Snapshot 
   2.710 +    {
   2.711 +      SmartGraph *_graph;
   2.712 +    protected:
   2.713 +      friend class SmartGraph;
   2.714 +      unsigned int node_num;
   2.715 +      unsigned int arc_num;
   2.716 +    public:
   2.717 +      ///Default constructor.
   2.718 +      
   2.719 +      ///Default constructor.
   2.720 +      ///To actually make a snapshot you must call save().
   2.721 +      ///
   2.722 +      Snapshot() : _graph(0) {}
   2.723 +      ///Constructor that immediately makes a snapshot
   2.724 +      
   2.725 +      ///This constructor immediately makes a snapshot of the digraph.
   2.726 +      ///\param g The digraph we make a snapshot of.
   2.727 +      Snapshot(SmartGraph &graph) {
   2.728 +        graph.saveSnapshot(*this);
   2.729 +      }
   2.730 +
   2.731 +      ///Make a snapshot.
   2.732 +
   2.733 +      ///Make a snapshot of the graph.
   2.734 +      ///
   2.735 +      ///This function can be called more than once. In case of a repeated
   2.736 +      ///call, the previous snapshot gets lost.
   2.737 +      ///\param g The digraph we make the snapshot of.
   2.738 +      void save(SmartGraph &graph) 
   2.739 +      {
   2.740 +        graph.saveSnapshot(*this);
   2.741 +      }
   2.742 +
   2.743 +      ///Undo the changes until a snapshot.
   2.744 +      
   2.745 +      ///Undo the changes until a snapshot created by save().
   2.746 +      ///
   2.747 +      ///\note After you restored a state, you cannot restore
   2.748 +      ///a later state, in other word you cannot add again the arcs deleted
   2.749 +      ///by restore().
   2.750 +      void restore()
   2.751 +      {
   2.752 +        _graph->restoreSnapshot(*this);
   2.753 +      }
   2.754 +    };
   2.755 +  };
   2.756 +  
   2.757 +} //namespace lemon
   2.758 +
   2.759 +
   2.760 +#endif //LEMON_SMART_GRAPH_H
     3.1 --- a/test/graph_test.cc	Tue Mar 25 16:36:44 2008 +0100
     3.2 +++ b/test/graph_test.cc	Wed Mar 26 17:28:28 2008 +0100
     3.3 @@ -18,7 +18,7 @@
     3.4  
     3.5  #include <lemon/concepts/graph.h>
     3.6  #include <lemon/list_graph.h>
     3.7 -// #include <lemon/smart_graph.h>
     3.8 +#include <lemon/smart_graph.h>
     3.9  // #include <lemon/full_graph.h>
    3.10  // #include <lemon/grid_graph.h>
    3.11  
    3.12 @@ -47,7 +47,7 @@
    3.13    }
    3.14    {
    3.15      checkConcept<Graph, ListGraph>();    
    3.16 -//     checkConcept<Graph, SmartGraph>();    
    3.17 +    checkConcept<Graph, SmartGraph>();    
    3.18  //     checkConcept<Graph, FullGraph>();    
    3.19  //     checkConcept<Graph, Graph>();    
    3.20  //     checkConcept<Graph, GridGraph>();
    3.21 @@ -188,7 +188,7 @@
    3.22    check_concepts();
    3.23  
    3.24    check_graph<ListGraph>();
    3.25 -//  check_graph<SmartGraph>();
    3.26 +  check_graph<SmartGraph>();
    3.27  
    3.28  //   {
    3.29  //     FullGraph g(5);