lemon/list_graph.h
changeset 783 ef88c0a30f85
parent 740 819ca5b50de0
parent 739 32baeb8e5c8f
child 786 e20173729589
child 787 c2230649a493
     1.1 --- a/lemon/list_graph.h	Mon Jan 12 23:11:39 2009 +0100
     1.2 +++ b/lemon/list_graph.h	Thu Nov 05 15:48:01 2009 +0100
     1.3 @@ -21,7 +21,7 @@
     1.4  
     1.5  ///\ingroup graphs
     1.6  ///\file
     1.7 -///\brief ListDigraph, ListGraph classes.
     1.8 +///\brief ListDigraph and ListGraph classes.
     1.9  
    1.10  #include <lemon/core.h>
    1.11  #include <lemon/error.h>
    1.12 @@ -32,6 +32,8 @@
    1.13  
    1.14  namespace lemon {
    1.15  
    1.16 +  class ListDigraph;
    1.17 +
    1.18    class ListDigraphBase {
    1.19  
    1.20    protected:
    1.21 @@ -62,6 +64,7 @@
    1.22  
    1.23      class Node {
    1.24        friend class ListDigraphBase;
    1.25 +      friend class ListDigraph;
    1.26      protected:
    1.27  
    1.28        int id;
    1.29 @@ -77,6 +80,7 @@
    1.30  
    1.31      class Arc {
    1.32        friend class ListDigraphBase;
    1.33 +      friend class ListDigraph;
    1.34      protected:
    1.35  
    1.36        int id;
    1.37 @@ -116,20 +120,20 @@
    1.38      void first(Arc& arc) const {
    1.39        int n;
    1.40        for(n = first_node;
    1.41 -          n!=-1 && nodes[n].first_in == -1;
    1.42 +          n != -1 && nodes[n].first_out == -1;
    1.43            n = nodes[n].next) {}
    1.44 -      arc.id = (n == -1) ? -1 : nodes[n].first_in;
    1.45 +      arc.id = (n == -1) ? -1 : nodes[n].first_out;
    1.46      }
    1.47  
    1.48      void next(Arc& arc) const {
    1.49 -      if (arcs[arc.id].next_in != -1) {
    1.50 -        arc.id = arcs[arc.id].next_in;
    1.51 +      if (arcs[arc.id].next_out != -1) {
    1.52 +        arc.id = arcs[arc.id].next_out;
    1.53        } else {
    1.54          int n;
    1.55 -        for(n = nodes[arcs[arc.id].target].next;
    1.56 -            n!=-1 && nodes[n].first_in == -1;
    1.57 +        for(n = nodes[arcs[arc.id].source].next;
    1.58 +            n != -1 && nodes[n].first_out == -1;
    1.59              n = nodes[n].next) {}
    1.60 -        arc.id = (n == -1) ? -1 : nodes[n].first_in;
    1.61 +        arc.id = (n == -1) ? -1 : nodes[n].first_out;
    1.62        }
    1.63      }
    1.64  
    1.65 @@ -311,37 +315,28 @@
    1.66  
    1.67    ///A general directed graph structure.
    1.68  
    1.69 -  ///\ref ListDigraph is a simple and fast <em>directed graph</em>
    1.70 -  ///implementation based on static linked lists that are stored in
    1.71 +  ///\ref ListDigraph is a versatile and fast directed graph
    1.72 +  ///implementation based on linked lists that are stored in
    1.73    ///\c std::vector structures.
    1.74    ///
    1.75 -  ///It conforms to the \ref concepts::Digraph "Digraph concept" and it
    1.76 -  ///also provides several useful additional functionalities.
    1.77 -  ///Most of the member functions and nested classes are documented
    1.78 +  ///This type fully conforms to the \ref concepts::Digraph "Digraph concept"
    1.79 +  ///and it also provides several useful additional functionalities.
    1.80 +  ///Most of its member functions and nested classes are documented
    1.81    ///only in the concept class.
    1.82    ///
    1.83 -  ///An important extra feature of this digraph implementation is that
    1.84 -  ///its maps are real \ref concepts::ReferenceMap "reference map"s.
    1.85 -  ///
    1.86    ///\sa concepts::Digraph
    1.87 +  ///\sa ListGraph
    1.88 +  class ListDigraph : public ExtendedListDigraphBase {
    1.89 +    typedef ExtendedListDigraphBase Parent;
    1.90  
    1.91 -  class ListDigraph : public ExtendedListDigraphBase {
    1.92    private:
    1.93 -    ///ListDigraph is \e not copy constructible. Use copyDigraph() instead.
    1.94 -
    1.95 -    ///ListDigraph is \e not copy constructible. Use copyDigraph() instead.
    1.96 -    ///
    1.97 +    /// Digraphs are \e not copy constructible. Use DigraphCopy instead.
    1.98      ListDigraph(const ListDigraph &) :ExtendedListDigraphBase() {};
    1.99 -    ///\brief Assignment of ListDigraph to another one is \e not allowed.
   1.100 -    ///Use copyDigraph() instead.
   1.101 -
   1.102 -    ///Assignment of ListDigraph to another one is \e not allowed.
   1.103 -    ///Use copyDigraph() instead.
   1.104 +    /// \brief Assignment of a digraph to another one is \e not allowed.
   1.105 +    /// Use DigraphCopy instead.
   1.106      void operator=(const ListDigraph &) {}
   1.107    public:
   1.108  
   1.109 -    typedef ExtendedListDigraphBase Parent;
   1.110 -
   1.111      /// Constructor
   1.112  
   1.113      /// Constructor.
   1.114 @@ -350,71 +345,65 @@
   1.115  
   1.116      ///Add a new node to the digraph.
   1.117  
   1.118 -    ///Add a new node to the digraph.
   1.119 -    ///\return the new node.
   1.120 +    ///This function adds a new node to the digraph.
   1.121 +    ///\return The new node.
   1.122      Node addNode() { return Parent::addNode(); }
   1.123  
   1.124      ///Add a new arc to the digraph.
   1.125  
   1.126 -    ///Add a new arc to the digraph with source node \c s
   1.127 +    ///This function adds a new arc to the digraph with source node \c s
   1.128      ///and target node \c t.
   1.129 -    ///\return the new arc.
   1.130 -    Arc addArc(const Node& s, const Node& t) {
   1.131 +    ///\return The new arc.
   1.132 +    Arc addArc(Node s, Node t) {
   1.133        return Parent::addArc(s, t);
   1.134      }
   1.135  
   1.136      ///\brief Erase a node from the digraph.
   1.137      ///
   1.138 -    ///Erase a node from the digraph.
   1.139 -    ///
   1.140 -    void erase(const Node& n) { Parent::erase(n); }
   1.141 +    ///This function erases the given node from the digraph.
   1.142 +    void erase(Node n) { Parent::erase(n); }
   1.143  
   1.144      ///\brief Erase an arc from the digraph.
   1.145      ///
   1.146 -    ///Erase an arc from the digraph.
   1.147 -    ///
   1.148 -    void erase(const Arc& a) { Parent::erase(a); }
   1.149 +    ///This function erases the given arc from the digraph.
   1.150 +    void erase(Arc a) { Parent::erase(a); }
   1.151  
   1.152      /// Node validity check
   1.153  
   1.154 -    /// This function gives back true if the given node is valid,
   1.155 -    /// ie. it is a real node of the graph.
   1.156 +    /// This function gives back \c true if the given node is valid,
   1.157 +    /// i.e. it is a real node of the digraph.
   1.158      ///
   1.159 -    /// \warning A Node pointing to a removed item
   1.160 -    /// could become valid again later if new nodes are
   1.161 -    /// added to the graph.
   1.162 +    /// \warning A removed node could become valid again if new nodes are
   1.163 +    /// added to the digraph.
   1.164      bool valid(Node n) const { return Parent::valid(n); }
   1.165  
   1.166      /// Arc validity check
   1.167  
   1.168 -    /// This function gives back true if the given arc is valid,
   1.169 -    /// ie. it is a real arc of the graph.
   1.170 +    /// This function gives back \c true if the given arc is valid,
   1.171 +    /// i.e. it is a real arc of the digraph.
   1.172      ///
   1.173 -    /// \warning An Arc pointing to a removed item
   1.174 -    /// could become valid again later if new nodes are
   1.175 -    /// added to the graph.
   1.176 +    /// \warning A removed arc could become valid again if new arcs are
   1.177 +    /// added to the digraph.
   1.178      bool valid(Arc a) const { return Parent::valid(a); }
   1.179  
   1.180 -    /// Change the target of \c a to \c n
   1.181 +    /// Change the target node of an arc
   1.182  
   1.183 -    /// Change the target of \c a to \c n
   1.184 +    /// This function changes the target node of the given arc \c a to \c n.
   1.185      ///
   1.186 -    ///\note The <tt>ArcIt</tt>s and <tt>OutArcIt</tt>s referencing
   1.187 -    ///the changed arc remain valid. However <tt>InArcIt</tt>s are
   1.188 -    ///invalidated.
   1.189 +    ///\note \c ArcIt and \c OutArcIt iterators referencing the changed
   1.190 +    ///arc remain valid, however \c InArcIt iterators are invalidated.
   1.191      ///
   1.192      ///\warning This functionality cannot be used together with the Snapshot
   1.193      ///feature.
   1.194      void changeTarget(Arc a, Node n) {
   1.195        Parent::changeTarget(a,n);
   1.196      }
   1.197 -    /// Change the source of \c a to \c n
   1.198 +    /// Change the source node of an arc
   1.199  
   1.200 -    /// Change the source of \c a to \c n
   1.201 +    /// This function changes the source node of the given arc \c a to \c n.
   1.202      ///
   1.203 -    ///\note The <tt>InArcIt</tt>s referencing the changed arc remain
   1.204 -    ///valid. However the <tt>ArcIt</tt>s and <tt>OutArcIt</tt>s are
   1.205 -    ///invalidated.
   1.206 +    ///\note \c InArcIt iterators referencing the changed arc remain
   1.207 +    ///valid, however \c ArcIt and \c OutArcIt iterators are invalidated.
   1.208      ///
   1.209      ///\warning This functionality cannot be used together with the Snapshot
   1.210      ///feature.
   1.211 @@ -422,94 +411,76 @@
   1.212        Parent::changeSource(a,n);
   1.213      }
   1.214  
   1.215 -    /// Invert the direction of an arc.
   1.216 +    /// Reverse the direction of an arc.
   1.217  
   1.218 -    ///\note The <tt>ArcIt</tt>s referencing the changed arc remain
   1.219 -    ///valid. However <tt>OutArcIt</tt>s and <tt>InArcIt</tt>s are
   1.220 -    ///invalidated.
   1.221 +    /// This function reverses the direction of the given arc.
   1.222 +    ///\note \c ArcIt, \c OutArcIt and \c InArcIt iterators referencing
   1.223 +    ///the changed arc are invalidated.
   1.224      ///
   1.225      ///\warning This functionality cannot be used together with the Snapshot
   1.226      ///feature.
   1.227 -    void reverseArc(Arc e) {
   1.228 -      Node t=target(e);
   1.229 -      changeTarget(e,source(e));
   1.230 -      changeSource(e,t);
   1.231 +    void reverseArc(Arc a) {
   1.232 +      Node t=target(a);
   1.233 +      changeTarget(a,source(a));
   1.234 +      changeSource(a,t);
   1.235      }
   1.236  
   1.237 -    /// Reserve memory for nodes.
   1.238 -
   1.239 -    /// Using this function it is possible to avoid the superfluous memory
   1.240 -    /// allocation: if you know that the digraph you want to build will
   1.241 -    /// be very large (e.g. it will contain millions of nodes and/or arcs)
   1.242 -    /// then it is worth reserving space for this amount before starting
   1.243 -    /// to build the digraph.
   1.244 -    /// \sa reserveArc
   1.245 -    void reserveNode(int n) { nodes.reserve(n); };
   1.246 -
   1.247 -    /// Reserve memory for arcs.
   1.248 -
   1.249 -    /// Using this function it is possible to avoid the superfluous memory
   1.250 -    /// allocation: if you know that the digraph you want to build will
   1.251 -    /// be very large (e.g. it will contain millions of nodes and/or arcs)
   1.252 -    /// then it is worth reserving space for this amount before starting
   1.253 -    /// to build the digraph.
   1.254 -    /// \sa reserveNode
   1.255 -    void reserveArc(int m) { arcs.reserve(m); };
   1.256 -
   1.257      ///Contract two nodes.
   1.258  
   1.259 -    ///This function contracts two nodes.
   1.260 -    ///Node \p b will be removed but instead of deleting
   1.261 -    ///incident arcs, they will be joined to \p a.
   1.262 -    ///The last parameter \p r controls whether to remove loops. \c true
   1.263 -    ///means that loops will be removed.
   1.264 +    ///This function contracts the given two nodes.
   1.265 +    ///Node \c v is removed, but instead of deleting its
   1.266 +    ///incident arcs, they are joined to node \c u.
   1.267 +    ///If the last parameter \c r is \c true (this is the default value),
   1.268 +    ///then the newly created loops are removed.
   1.269      ///
   1.270 -    ///\note The <tt>ArcIt</tt>s referencing a moved arc remain
   1.271 -    ///valid. However <tt>InArcIt</tt>s and <tt>OutArcIt</tt>s
   1.272 -    ///may be invalidated.
   1.273 +    ///\note The moved arcs are joined to node \c u using changeSource()
   1.274 +    ///or changeTarget(), thus \c ArcIt and \c OutArcIt iterators are
   1.275 +    ///invalidated for the outgoing arcs of node \c v and \c InArcIt
   1.276 +    ///iterators are invalidated for the incomming arcs of \c v.
   1.277 +    ///Moreover all iterators referencing node \c v or the removed 
   1.278 +    ///loops are also invalidated. Other iterators remain valid.
   1.279      ///
   1.280      ///\warning This functionality cannot be used together with the Snapshot
   1.281      ///feature.
   1.282 -    void contract(Node a, Node b, bool r = true)
   1.283 +    void contract(Node u, Node v, bool r = true)
   1.284      {
   1.285 -      for(OutArcIt e(*this,b);e!=INVALID;) {
   1.286 +      for(OutArcIt e(*this,v);e!=INVALID;) {
   1.287          OutArcIt f=e;
   1.288          ++f;
   1.289 -        if(r && target(e)==a) erase(e);
   1.290 -        else changeSource(e,a);
   1.291 +        if(r && target(e)==u) erase(e);
   1.292 +        else changeSource(e,u);
   1.293          e=f;
   1.294        }
   1.295 -      for(InArcIt e(*this,b);e!=INVALID;) {
   1.296 +      for(InArcIt e(*this,v);e!=INVALID;) {
   1.297          InArcIt f=e;
   1.298          ++f;
   1.299 -        if(r && source(e)==a) erase(e);
   1.300 -        else changeTarget(e,a);
   1.301 +        if(r && source(e)==u) erase(e);
   1.302 +        else changeTarget(e,u);
   1.303          e=f;
   1.304        }
   1.305 -      erase(b);
   1.306 +      erase(v);
   1.307      }
   1.308  
   1.309      ///Split a node.
   1.310  
   1.311 -    ///This function splits a node. First a new node is added to the digraph,
   1.312 -    ///then the source of each outgoing arc of \c n is moved to this new node.
   1.313 -    ///If \c connect is \c true (this is the default value), then a new arc
   1.314 -    ///from \c n to the newly created node is also added.
   1.315 +    ///This function splits the given node. First, a new node is added
   1.316 +    ///to the digraph, then the source of each outgoing arc of node \c n
   1.317 +    ///is moved to this new node.
   1.318 +    ///If the second parameter \c connect is \c true (this is the default
   1.319 +    ///value), then a new arc from node \c n to the newly created node
   1.320 +    ///is also added.
   1.321      ///\return The newly created node.
   1.322      ///
   1.323 -    ///\note The <tt>ArcIt</tt>s referencing a moved arc remain
   1.324 -    ///valid. However <tt>InArcIt</tt>s and <tt>OutArcIt</tt>s may
   1.325 -    ///be invalidated.
   1.326 +    ///\note All iterators remain valid.
   1.327      ///
   1.328 -    ///\warning This functionality cannot be used in conjunction with the
   1.329 +    ///\warning This functionality cannot be used together with the
   1.330      ///Snapshot feature.
   1.331      Node split(Node n, bool connect = true) {
   1.332        Node b = addNode();
   1.333 -      for(OutArcIt e(*this,n);e!=INVALID;) {
   1.334 -        OutArcIt f=e;
   1.335 -        ++f;
   1.336 -        changeSource(e,b);
   1.337 -        e=f;
   1.338 +      nodes[b.id].first_out=nodes[n.id].first_out;
   1.339 +      nodes[n.id].first_out=-1;
   1.340 +      for(int i=nodes[b.id].first_out; i!=-1; i=arcs[i].next_out) {
   1.341 +        arcs[i].source=b.id;
   1.342        }
   1.343        if (connect) addArc(n,b);
   1.344        return b;
   1.345 @@ -517,21 +488,52 @@
   1.346  
   1.347      ///Split an arc.
   1.348  
   1.349 -    ///This function splits an arc. First a new node \c b is added to
   1.350 -    ///the digraph, then the original arc is re-targeted to \c
   1.351 -    ///b. Finally an arc from \c b to the original target is added.
   1.352 +    ///This function splits the given arc. First, a new node \c v is
   1.353 +    ///added to the digraph, then the target node of the original arc
   1.354 +    ///is set to \c v. Finally, an arc from \c v to the original target
   1.355 +    ///is added.
   1.356 +    ///\return The newly created node.
   1.357      ///
   1.358 -    ///\return The newly created node.
   1.359 +    ///\note \c InArcIt iterators referencing the original arc are
   1.360 +    ///invalidated. Other iterators remain valid.
   1.361      ///
   1.362      ///\warning This functionality cannot be used together with the
   1.363      ///Snapshot feature.
   1.364 -    Node split(Arc e) {
   1.365 -      Node b = addNode();
   1.366 -      addArc(b,target(e));
   1.367 -      changeTarget(e,b);
   1.368 -      return b;
   1.369 +    Node split(Arc a) {
   1.370 +      Node v = addNode();
   1.371 +      addArc(v,target(a));
   1.372 +      changeTarget(a,v);
   1.373 +      return v;
   1.374      }
   1.375  
   1.376 +    ///Clear the digraph.
   1.377 +
   1.378 +    ///This function erases all nodes and arcs from the digraph.
   1.379 +    ///
   1.380 +    void clear() {
   1.381 +      Parent::clear();
   1.382 +    }
   1.383 +
   1.384 +    /// Reserve memory for nodes.
   1.385 +
   1.386 +    /// Using this function, it is possible to avoid superfluous memory
   1.387 +    /// allocation: if you know that the digraph you want to build will
   1.388 +    /// be large (e.g. it will contain millions of nodes and/or arcs),
   1.389 +    /// then it is worth reserving space for this amount before starting
   1.390 +    /// to build the digraph.
   1.391 +    /// \sa reserveArc()
   1.392 +    void reserveNode(int n) { nodes.reserve(n); };
   1.393 +
   1.394 +    /// Reserve memory for arcs.
   1.395 +
   1.396 +    /// Using this function, it is possible to avoid superfluous memory
   1.397 +    /// allocation: if you know that the digraph you want to build will
   1.398 +    /// be large (e.g. it will contain millions of nodes and/or arcs),
   1.399 +    /// then it is worth reserving space for this amount before starting
   1.400 +    /// to build the digraph.
   1.401 +    /// \sa reserveNode()
   1.402 +    void reserveArc(int m) { arcs.reserve(m); };
   1.403 +
   1.404      /// \brief Class to make a snapshot of the digraph and restore
   1.405      /// it later.
   1.406      ///
   1.407 @@ -540,9 +542,15 @@
   1.408      /// The newly added nodes and arcs can be removed using the
   1.409      /// restore() function.
   1.410      ///
   1.411 -    /// \warning Arc and node deletions and other modifications (e.g.
   1.412 -    /// contracting, splitting, reversing arcs or nodes) cannot be
   1.413 +    /// \note After a state is restored, you cannot restore a later state, 
   1.414 +    /// i.e. you cannot add the removed nodes and arcs again using
   1.415 +    /// another Snapshot instance.
   1.416 +    ///
   1.417 +    /// \warning Node and arc deletions and other modifications (e.g.
   1.418 +    /// reversing, contracting, splitting arcs or nodes) cannot be
   1.419      /// restored. These events invalidate the snapshot.
   1.420 +    /// However the arcs and nodes that were added to the digraph after
   1.421 +    /// making the current snapshot can be removed without invalidating it.
   1.422      class Snapshot {
   1.423      protected:
   1.424  
   1.425 @@ -712,39 +720,40 @@
   1.426        /// \brief Default constructor.
   1.427        ///
   1.428        /// Default constructor.
   1.429 -      /// To actually make a snapshot you must call save().
   1.430 +      /// You have to call save() to actually make a snapshot.
   1.431        Snapshot()
   1.432          : digraph(0), node_observer_proxy(*this),
   1.433            arc_observer_proxy(*this) {}
   1.434  
   1.435        /// \brief Constructor that immediately makes a snapshot.
   1.436        ///
   1.437 -      /// This constructor immediately makes a snapshot of the digraph.
   1.438 -      /// \param _digraph The digraph we make a snapshot of.
   1.439 -      Snapshot(ListDigraph &_digraph)
   1.440 +      /// This constructor immediately makes a snapshot of the given digraph.
   1.441 +      Snapshot(ListDigraph &gr)
   1.442          : node_observer_proxy(*this),
   1.443            arc_observer_proxy(*this) {
   1.444 -        attach(_digraph);
   1.445 +        attach(gr);
   1.446        }
   1.447  
   1.448        /// \brief Make a snapshot.
   1.449        ///
   1.450 -      /// Make a snapshot of the digraph.
   1.451 -      ///
   1.452 -      /// This function can be called more than once. In case of a repeated
   1.453 +      /// This function makes a snapshot of the given digraph.
   1.454 +      /// It can be called more than once. In case of a repeated
   1.455        /// call, the previous snapshot gets lost.
   1.456 -      /// \param _digraph The digraph we make the snapshot of.
   1.457 -      void save(ListDigraph &_digraph) {
   1.458 +      void save(ListDigraph &gr) {
   1.459          if (attached()) {
   1.460            detach();
   1.461            clear();
   1.462          }
   1.463 -        attach(_digraph);
   1.464 +        attach(gr);
   1.465        }
   1.466  
   1.467        /// \brief Undo the changes until the last snapshot.
   1.468 -      //
   1.469 -      /// Undo the changes until the last snapshot created by save().
   1.470 +      ///
   1.471 +      /// This function undos the changes until the last snapshot
   1.472 +      /// created by save() or Snapshot(ListDigraph&).
   1.473 +      ///
   1.474 +      /// \warning This method invalidates the snapshot, i.e. repeated
   1.475 +      /// restoring is not supported unless you call save() again.
   1.476        void restore() {
   1.477          detach();
   1.478          for(std::list<Arc>::iterator it = added_arcs.begin();
   1.479 @@ -758,9 +767,9 @@
   1.480          clear();
   1.481        }
   1.482  
   1.483 -      /// \brief Gives back true when the snapshot is valid.
   1.484 +      /// \brief Returns \c true if the snapshot is valid.
   1.485        ///
   1.486 -      /// Gives back true when the snapshot is valid.
   1.487 +      /// This function returns \c true if the snapshot is valid.
   1.488        bool valid() const {
   1.489          return attached();
   1.490        }
   1.491 @@ -796,11 +805,7 @@
   1.492  
   1.493    public:
   1.494  
   1.495 -    typedef ListGraphBase Digraph;
   1.496 -
   1.497 -    class Node;
   1.498 -    class Arc;
   1.499 -    class Edge;
   1.500 +    typedef ListGraphBase Graph;
   1.501  
   1.502      class Node {
   1.503        friend class ListGraphBase;
   1.504 @@ -851,8 +856,6 @@
   1.505        bool operator<(const Arc& arc) const {return id < arc.id;}
   1.506      };
   1.507  
   1.508 -
   1.509 -
   1.510      ListGraphBase()
   1.511        : nodes(), first_node(-1),
   1.512          first_free_node(-1), arcs(), first_free_arc(-1) {}
   1.513 @@ -1167,32 +1170,25 @@
   1.514  
   1.515    ///A general undirected graph structure.
   1.516  
   1.517 -  ///\ref ListGraph is a simple and fast <em>undirected graph</em>
   1.518 -  ///implementation based on static linked lists that are stored in
   1.519 +  ///\ref ListGraph is a versatile and fast undirected graph
   1.520 +  ///implementation based on linked lists that are stored in
   1.521    ///\c std::vector structures.
   1.522    ///
   1.523 -  ///It conforms to the \ref concepts::Graph "Graph concept" and it
   1.524 -  ///also provides several useful additional functionalities.
   1.525 -  ///Most of the member functions and nested classes are documented
   1.526 +  ///This type fully conforms to the \ref concepts::Graph "Graph concept"
   1.527 +  ///and it also provides several useful additional functionalities.
   1.528 +  ///Most of its member functions and nested classes are documented
   1.529    ///only in the concept class.
   1.530    ///
   1.531 -  ///An important extra feature of this graph implementation is that
   1.532 -  ///its maps are real \ref concepts::ReferenceMap "reference map"s.
   1.533 -  ///
   1.534    ///\sa concepts::Graph
   1.535 +  ///\sa ListDigraph
   1.536 +  class ListGraph : public ExtendedListGraphBase {
   1.537 +    typedef ExtendedListGraphBase Parent;
   1.538  
   1.539 -  class ListGraph : public ExtendedListGraphBase {
   1.540    private:
   1.541 -    ///ListGraph is \e not copy constructible. Use copyGraph() instead.
   1.542 -
   1.543 -    ///ListGraph is \e not copy constructible. Use copyGraph() instead.
   1.544 -    ///
   1.545 +    /// Graphs are \e not copy constructible. Use GraphCopy instead.
   1.546      ListGraph(const ListGraph &) :ExtendedListGraphBase()  {};
   1.547 -    ///\brief Assignment of ListGraph to another one is \e not allowed.
   1.548 -    ///Use copyGraph() instead.
   1.549 -
   1.550 -    ///Assignment of ListGraph to another one is \e not allowed.
   1.551 -    ///Use copyGraph() instead.
   1.552 +    /// \brief Assignment of a graph to another one is \e not allowed.
   1.553 +    /// Use GraphCopy instead.
   1.554      void operator=(const ListGraph &) {}
   1.555    public:
   1.556      /// Constructor
   1.557 @@ -1201,100 +1197,99 @@
   1.558      ///
   1.559      ListGraph() {}
   1.560  
   1.561 -    typedef ExtendedListGraphBase Parent;
   1.562 -
   1.563      typedef Parent::OutArcIt IncEdgeIt;
   1.564  
   1.565      /// \brief Add a new node to the graph.
   1.566      ///
   1.567 -    /// Add a new node to the graph.
   1.568 -    /// \return the new node.
   1.569 +    /// This function adds a new node to the graph.
   1.570 +    /// \return The new node.
   1.571      Node addNode() { return Parent::addNode(); }
   1.572  
   1.573      /// \brief Add a new edge to the graph.
   1.574      ///
   1.575 -    /// Add a new edge to the graph with source node \c s
   1.576 -    /// and target node \c t.
   1.577 -    /// \return the new edge.
   1.578 -    Edge addEdge(const Node& s, const Node& t) {
   1.579 -      return Parent::addEdge(s, t);
   1.580 +    /// This function adds a new edge to the graph between nodes
   1.581 +    /// \c u and \c v with inherent orientation from node \c u to
   1.582 +    /// node \c v.
   1.583 +    /// \return The new edge.
   1.584 +    Edge addEdge(Node u, Node v) {
   1.585 +      return Parent::addEdge(u, v);
   1.586      }
   1.587  
   1.588 -    /// \brief Erase a node from the graph.
   1.589 +    ///\brief Erase a node from the graph.
   1.590      ///
   1.591 -    /// Erase a node from the graph.
   1.592 +    /// This function erases the given node from the graph.
   1.593 +    void erase(Node n) { Parent::erase(n); }
   1.594 +
   1.595 +    ///\brief Erase an edge from the graph.
   1.596      ///
   1.597 -    void erase(const Node& n) { Parent::erase(n); }
   1.598 -
   1.599 -    /// \brief Erase an edge from the graph.
   1.600 -    ///
   1.601 -    /// Erase an edge from the graph.
   1.602 -    ///
   1.603 -    void erase(const Edge& e) { Parent::erase(e); }
   1.604 +    /// This function erases the given edge from the graph.
   1.605 +    void erase(Edge e) { Parent::erase(e); }
   1.606      /// Node validity check
   1.607  
   1.608 -    /// This function gives back true if the given node is valid,
   1.609 -    /// ie. it is a real node of the graph.
   1.610 +    /// This function gives back \c true if the given node is valid,
   1.611 +    /// i.e. it is a real node of the graph.
   1.612      ///
   1.613 -    /// \warning A Node pointing to a removed item
   1.614 -    /// could become valid again later if new nodes are
   1.615 +    /// \warning A removed node could become valid again if new nodes are
   1.616      /// added to the graph.
   1.617      bool valid(Node n) const { return Parent::valid(n); }
   1.618 +    /// Edge validity check
   1.619 +
   1.620 +    /// This function gives back \c true if the given edge is valid,
   1.621 +    /// i.e. it is a real edge of the graph.
   1.622 +    ///
   1.623 +    /// \warning A removed edge could become valid again if new edges are
   1.624 +    /// added to the graph.
   1.625 +    bool valid(Edge e) const { return Parent::valid(e); }
   1.626      /// Arc validity check
   1.627  
   1.628 -    /// This function gives back true if the given arc is valid,
   1.629 -    /// ie. it is a real arc of the graph.
   1.630 +    /// This function gives back \c true if the given arc is valid,
   1.631 +    /// i.e. it is a real arc of the graph.
   1.632      ///
   1.633 -    /// \warning An Arc pointing to a removed item
   1.634 -    /// could become valid again later if new edges are
   1.635 +    /// \warning A removed arc could become valid again if new edges are
   1.636      /// added to the graph.
   1.637      bool valid(Arc a) const { return Parent::valid(a); }
   1.638 -    /// Edge validity check
   1.639  
   1.640 -    /// This function gives back true if the given edge is valid,
   1.641 -    /// ie. it is a real arc of the graph.
   1.642 +    /// \brief Change the first node of an edge.
   1.643      ///
   1.644 -    /// \warning A Edge pointing to a removed item
   1.645 -    /// could become valid again later if new edges are
   1.646 -    /// added to the graph.
   1.647 -    bool valid(Edge e) const { return Parent::valid(e); }
   1.648 -    /// \brief Change the end \c u of \c e to \c n
   1.649 +    /// This function changes the first node of the given edge \c e to \c n.
   1.650      ///
   1.651 -    /// This function changes the end \c u of \c e to node \c n.
   1.652 -    ///
   1.653 -    ///\note The <tt>EdgeIt</tt>s and <tt>ArcIt</tt>s referencing the
   1.654 -    ///changed edge are invalidated and if the changed node is the
   1.655 -    ///base node of an iterator then this iterator is also
   1.656 -    ///invalidated.
   1.657 +    ///\note \c EdgeIt and \c ArcIt iterators referencing the
   1.658 +    ///changed edge are invalidated and all other iterators whose
   1.659 +    ///base node is the changed node are also invalidated.
   1.660      ///
   1.661      ///\warning This functionality cannot be used together with the
   1.662      ///Snapshot feature.
   1.663      void changeU(Edge e, Node n) {
   1.664        Parent::changeU(e,n);
   1.665      }
   1.666 -    /// \brief Change the end \c v of \c e to \c n
   1.667 +    /// \brief Change the second node of an edge.
   1.668      ///
   1.669 -    /// This function changes the end \c v of \c e to \c n.
   1.670 +    /// This function changes the second node of the given edge \c e to \c n.
   1.671      ///
   1.672 -    ///\note The <tt>EdgeIt</tt>s referencing the changed edge remain
   1.673 -    ///valid, however <tt>ArcIt</tt>s and if the changed node is the
   1.674 -    ///base node of an iterator then this iterator is invalidated.
   1.675 +    ///\note \c EdgeIt iterators referencing the changed edge remain
   1.676 +    ///valid, however \c ArcIt iterators referencing the changed edge and
   1.677 +    ///all other iterators whose base node is the changed node are also
   1.678 +    ///invalidated.
   1.679      ///
   1.680      ///\warning This functionality cannot be used together with the
   1.681      ///Snapshot feature.
   1.682      void changeV(Edge e, Node n) {
   1.683        Parent::changeV(e,n);
   1.684      }
   1.685 +
   1.686      /// \brief Contract two nodes.
   1.687      ///
   1.688 -    /// This function contracts two nodes.
   1.689 -    /// Node \p b will be removed but instead of deleting
   1.690 -    /// its neighboring arcs, they will be joined to \p a.
   1.691 -    /// The last parameter \p r controls whether to remove loops. \c true
   1.692 -    /// means that loops will be removed.
   1.693 +    /// This function contracts the given two nodes.
   1.694 +    /// Node \c b is removed, but instead of deleting
   1.695 +    /// its incident edges, they are joined to node \c a.
   1.696 +    /// If the last parameter \c r is \c true (this is the default value),
   1.697 +    /// then the newly created loops are removed.
   1.698      ///
   1.699 -    /// \note The <tt>ArcIt</tt>s referencing a moved arc remain
   1.700 -    /// valid.
   1.701 +    /// \note The moved edges are joined to node \c a using changeU()
   1.702 +    /// or changeV(), thus all edge and arc iterators whose base node is
   1.703 +    /// \c b are invalidated.
   1.704 +    /// Moreover all iterators referencing node \c b or the removed 
   1.705 +    /// loops are also invalidated. Other iterators remain valid.
   1.706      ///
   1.707      ///\warning This functionality cannot be used together with the
   1.708      ///Snapshot feature.
   1.709 @@ -1313,6 +1308,33 @@
   1.710        erase(b);
   1.711      }
   1.712  
   1.713 +    ///Clear the graph.
   1.714 +
   1.715 +    ///This function erases all nodes and arcs from the graph.
   1.716 +    ///
   1.717 +    void clear() {
   1.718 +      Parent::clear();
   1.719 +    }
   1.720 +
   1.721 +    /// Reserve memory for nodes.
   1.722 +
   1.723 +    /// Using this function, it is possible to avoid superfluous memory
   1.724 +    /// allocation: if you know that the graph you want to build will
   1.725 +    /// be large (e.g. it will contain millions of nodes and/or edges),
   1.726 +    /// then it is worth reserving space for this amount before starting
   1.727 +    /// to build the graph.
   1.728 +    /// \sa reserveEdge()
   1.729 +    void reserveNode(int n) { nodes.reserve(n); };
   1.730 +
   1.731 +    /// Reserve memory for edges.
   1.732 +
   1.733 +    /// Using this function, it is possible to avoid superfluous memory
   1.734 +    /// allocation: if you know that the graph you want to build will
   1.735 +    /// be large (e.g. it will contain millions of nodes and/or edges),
   1.736 +    /// then it is worth reserving space for this amount before starting
   1.737 +    /// to build the graph.
   1.738 +    /// \sa reserveNode()
   1.739 +    void reserveEdge(int m) { arcs.reserve(2 * m); };
   1.740  
   1.741      /// \brief Class to make a snapshot of the graph and restore
   1.742      /// it later.
   1.743 @@ -1322,9 +1344,15 @@
   1.744      /// The newly added nodes and edges can be removed
   1.745      /// using the restore() function.
   1.746      ///
   1.747 -    /// \warning Edge and node deletions and other modifications
   1.748 -    /// (e.g. changing nodes of edges, contracting nodes) cannot be
   1.749 -    /// restored. These events invalidate the snapshot.
   1.750 +    /// \note After a state is restored, you cannot restore a later state, 
   1.751 +    /// i.e. you cannot add the removed nodes and edges again using
   1.752 +    /// another Snapshot instance.
   1.753 +    ///
   1.754 +    /// \warning Node and edge deletions and other modifications
   1.755 +    /// (e.g. changing the end-nodes of edges or contracting nodes)
   1.756 +    /// cannot be restored. These events invalidate the snapshot.
   1.757 +    /// However the edges and nodes that were added to the graph after
   1.758 +    /// making the current snapshot can be removed without invalidating it.
   1.759      class Snapshot {
   1.760      protected:
   1.761  
   1.762 @@ -1494,39 +1522,40 @@
   1.763        /// \brief Default constructor.
   1.764        ///
   1.765        /// Default constructor.
   1.766 -      /// To actually make a snapshot you must call save().
   1.767 +      /// You have to call save() to actually make a snapshot.
   1.768        Snapshot()
   1.769          : graph(0), node_observer_proxy(*this),
   1.770            edge_observer_proxy(*this) {}
   1.771  
   1.772        /// \brief Constructor that immediately makes a snapshot.
   1.773        ///
   1.774 -      /// This constructor immediately makes a snapshot of the graph.
   1.775 -      /// \param _graph The graph we make a snapshot of.
   1.776 -      Snapshot(ListGraph &_graph)
   1.777 +      /// This constructor immediately makes a snapshot of the given graph.
   1.778 +      Snapshot(ListGraph &gr)
   1.779          : node_observer_proxy(*this),
   1.780            edge_observer_proxy(*this) {
   1.781 -        attach(_graph);
   1.782 +        attach(gr);
   1.783        }
   1.784  
   1.785        /// \brief Make a snapshot.
   1.786        ///
   1.787 -      /// Make a snapshot of the graph.
   1.788 -      ///
   1.789 -      /// This function can be called more than once. In case of a repeated
   1.790 +      /// This function makes a snapshot of the given graph.
   1.791 +      /// It can be called more than once. In case of a repeated
   1.792        /// call, the previous snapshot gets lost.
   1.793 -      /// \param _graph The graph we make the snapshot of.
   1.794 -      void save(ListGraph &_graph) {
   1.795 +      void save(ListGraph &gr) {
   1.796          if (attached()) {
   1.797            detach();
   1.798            clear();
   1.799          }
   1.800 -        attach(_graph);
   1.801 +        attach(gr);
   1.802        }
   1.803  
   1.804        /// \brief Undo the changes until the last snapshot.
   1.805 -      //
   1.806 -      /// Undo the changes until the last snapshot created by save().
   1.807 +      ///
   1.808 +      /// This function undos the changes until the last snapshot
   1.809 +      /// created by save() or Snapshot(ListGraph&).
   1.810 +      ///
   1.811 +      /// \warning This method invalidates the snapshot, i.e. repeated
   1.812 +      /// restoring is not supported unless you call save() again.
   1.813        void restore() {
   1.814          detach();
   1.815          for(std::list<Edge>::iterator it = added_edges.begin();
   1.816 @@ -1540,9 +1569,9 @@
   1.817          clear();
   1.818        }
   1.819  
   1.820 -      /// \brief Gives back true when the snapshot is valid.
   1.821 +      /// \brief Returns \c true if the snapshot is valid.
   1.822        ///
   1.823 -      /// Gives back true when the snapshot is valid.
   1.824 +      /// This function returns \c true if the snapshot is valid.
   1.825        bool valid() const {
   1.826          return attached();
   1.827        }