lemon-0.x: lemon/smart_graph.h@616bc933c2bc

     1 /* -*- C++ -*-

     2  * lemon/smart_graph.h - Part of LEMON, a generic C++ optimization library

     3  *

     4  * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport

     5  * (Egervary Research Group on Combinatorial Optimization, EGRES).

     6  *

     7  * Permission to use, modify and distribute this software is granted

     8  * provided that this copyright notice appears in all copies. For

     9  * precise terms see the accompanying LICENSE file.

    10  *

    11  * This software is provided "AS IS" with no warranty of any kind,

    12  * express or implied, and with no claim as to its suitability for any

    13  * purpose.

    14  *

    15  */

    17 #ifndef LEMON_SMART_GRAPH_H

    18 #define LEMON_SMART_GRAPH_H

    20 ///\ingroup graphs

    21 ///\file

    22 ///\brief SmartGraph and UndirSmartGraph classes.

    24 #include <vector>

    26 #include <lemon/invalid.h>

    28 #include <lemon/bits/clearable_graph_extender.h>

    29 #include <lemon/bits/extendable_graph_extender.h>

    30 #include <lemon/bits/iterable_graph_extender.h>

    31 #include <lemon/bits/alteration_notifier.h>

    32 #include <lemon/bits/default_map.h>

    34 #include <lemon/bits/undir_graph_extender.h>

    36 #include <lemon/utility.h>

    38 namespace lemon {

    40   class SmartGraph;

    41   ///Base of SmartGraph

    43   ///Base of SmartGraph

    44   ///

    45   class SmartGraphBase {

    47     friend class SmatGraph;

    49   protected:

    50     struct NodeT

    51     {

    52       int first_in,first_out;

    53       NodeT() : first_in(-1), first_out(-1) {}

    54     };

    55     struct EdgeT

    56     {

    57       int target, source, next_in, next_out;

    58       //FIXME: is this necessary?

    59       EdgeT() : next_in(-1), next_out(-1) {}

    60     };

    62     std::vector<NodeT> nodes;

    64     std::vector<EdgeT> edges;

    67   public:

    69     typedef SmartGraphBase Graph;

    71     class Node;

    72     class Edge;

    75   public:

    77     SmartGraphBase() : nodes(), edges() { }

    78     SmartGraphBase(const SmartGraphBase &_g)

    79       : nodes(_g.nodes), edges(_g.edges) { }

    81     typedef True NodeNumTag;

    82     typedef True EdgeNumTag;

    84     ///Number of nodes.

    85     int nodeNum() const { return nodes.size(); }

    86     ///Number of edges.

    87     int edgeNum() const { return edges.size(); }

    89     /// Maximum node ID.

    91     /// Maximum node ID.

    92     ///\sa id(Node)

    93     int maxId(Node) const { return nodes.size()-1; }

    94     /// Maximum edge ID.

    96     /// Maximum edge ID.

    97     ///\sa id(Edge)

    98     int maxId(Edge) const { return edges.size()-1; }

   100     Node source(Edge e) const { return edges[e.n].source; }

   101     Node target(Edge e) const { return edges[e.n].target; }

   103     /// Node ID.

   105     /// The ID of a valid Node is a nonnegative integer not greater than

   106     /// \ref maxId(Node). The range of the ID's is not surely continuous

   107     /// and the greatest node ID can be actually less then \ref maxId(Node).

   108     ///

   109     /// The ID of the \ref INVALID node is -1.

   110     ///\return The ID of the node \c v.

   111     static int id(Node v) { return v.n; }

   112     /// Edge ID.

   114     /// The ID of a valid Edge is a nonnegative integer not greater than

   115     /// \ref maxId(Edge). The range of the ID's is not surely continuous

   116     /// and the greatest edge ID can be actually less then \ref maxId(Edge).

   117     ///

   118     /// The ID of the \ref INVALID edge is -1.

   119     ///\return The ID of the edge \c e.

   120     static int id(Edge e) { return e.n; }

   122     static Node fromId(int id, Node) { return Node(id);}

   124     static Edge fromId(int id, Edge) { return Edge(id);}

   126     Node addNode() {

   127       Node n; n.n=nodes.size();

   128       nodes.push_back(NodeT()); //FIXME: Hmmm...

   129       return n;

   130     }

   132     Edge addEdge(Node u, Node v) {

   133       Edge e; e.n=edges.size(); edges.push_back(EdgeT()); //FIXME: Hmmm...

   134       edges[e.n].source=u.n; edges[e.n].target=v.n;

   135       edges[e.n].next_out=nodes[u.n].first_out;

   136       edges[e.n].next_in=nodes[v.n].first_in;

   137       nodes[u.n].first_out=nodes[v.n].first_in=e.n;

   139       return e;

   140     }

   142     void clear() {

   143       edges.clear();

   144       nodes.clear();

   145     }

   148     class Node {

   149       friend class SmartGraphBase;

   150       friend class SmartGraph;

   152     protected:

   153       int n;

   154       ///\e

   156       ///\todo It should be removed (or at least define a setToId() instead).

   157       ///

   158       Node(int nn) {n=nn;}

   159     public:

   160       Node() {}

   161       Node (Invalid) { n=-1; }

   162       bool operator==(const Node i) const {return n==i.n;}

   163       bool operator!=(const Node i) const {return n!=i.n;}

   164       bool operator<(const Node i) const {return n<i.n;}

   165     };

   168     class Edge {

   169       friend class SmartGraphBase;

   170       friend class SmartGraph;

   172     protected:

   173       int n;

   174       ///\todo It should be removed (or at least define a setToId() instead).

   175       ///

   176       Edge(int nn) {n=nn;}

   177     public:

   178       Edge() { }

   179       Edge (Invalid) { n=-1; }

   180       bool operator==(const Edge i) const {return n==i.n;}

   181       bool operator!=(const Edge i) const {return n!=i.n;}

   182       bool operator<(const Edge i) const {return n<i.n;}

   183     };

   185     void first(Node& node) const {

   186       node.n = nodes.size() - 1;

   187     }

   189     static void next(Node& node) {

   190       --node.n;

   191     }

   193     void first(Edge& edge) const {

   194       edge.n = edges.size() - 1;

   195     }

   197     static void next(Edge& edge) {

   198       --edge.n;

   199     }

   201     void firstOut(Edge& edge, const Node& node) const {

   202       edge.n = nodes[node.n].first_out;

   203     }

   205     void nextOut(Edge& edge) const {

   206       edge.n = edges[edge.n].next_out;

   207     }

   209     void firstIn(Edge& edge, const Node& node) const {

   210       edge.n = nodes[node.n].first_in;

   211     }

   213     void nextIn(Edge& edge) const {

   214       edge.n = edges[edge.n].next_in;

   215     }

   217     Edge _findEdge(Node u,Node v, Edge prev = INVALID)

   218     {

   219       int e = (prev.n==-1)? nodes[u.n].first_out : edges[prev.n].next_out;

   220       while(e!=-1 && edges[e].target!=v.n) e = edges[e].next_out;

   221       prev.n=e;

   222       return prev;

   223     }

   225     Node _split(Node n, bool connect = true)

   226     {

   227       Node b = addNode();

   228       nodes[b.n].first_out=nodes[n.n].first_out;

   229       nodes[n.n].first_out=-1;

   230       for(int i=nodes[b.n].first_out;i!=-1;i++) edges[i].source=b.n;

   231       if(connect) addEdge(n,b);

   232       return b;

   233     }

   235   };

   237   typedef ClearableGraphExtender<

   238     ExtendableGraphExtender<

   239     MappableGraphExtender<

   240     IterableGraphExtender<

   241     AlterableGraphExtender<SmartGraphBase> > > > > ExtendedSmartGraphBase;

   243   /// \addtogroup graphs

   244   /// @{

   246   ///A smart graph class.

   248   ///This is a simple and fast graph implementation.

   249   ///It is also quite memory efficient, but at the price

   250   ///that <b> it does support only limited (only stack-like)

   251   ///node and edge deletions</b>.

   252   ///It conforms to

   253   ///the \ref concept::ExtendableGraph "ExtendableGraph" concept.

   254   ///\sa concept::ExtendableGraph.

   255   ///

   256   ///\author Alpar Juttner

   257   class SmartGraph : public ExtendedSmartGraphBase {

   258   public:

   259     /// Finds an edge between two nodes.

   261     /// Finds an edge from node \c u to node \c v.

   262     ///

   263     /// If \c prev is \ref INVALID (this is the default value), then

   264     /// it finds the first edge from \c u to \c v. Otherwise it looks for

   265     /// the next edge from \c u to \c v after \c prev.

   266     /// \return The found edge or \ref INVALID if there is no such an edge.

   267     ///

   268     /// Thus you can iterate through each edge from \c u to \c v as it follows.

   269     /// \code

   270     /// for(Edge e=G.findEdge(u,v);e!=INVALID;e=G.findEdge(u,v,e)) {

   271     ///   ...

   272     /// }

   273     /// \endcode

   274     /// \todo Possibly it should be a global function.

   275     Edge findEdge(Node u,Node v, Edge prev = INVALID)

   276     {

   277       return _findEdge(u,v,prev);

   278     }

   280     class SnapShot;

   281     friend class SnapShot;

   283   protected:

   284     void restoreSnapShot(const SnapShot &s)

   285     {

   286       while(s.edge_num<edges.size()) {

   287 	Parent::getNotifier(Edge()).erase(Edge(edges.size()-1));

   288 	nodes[edges.back().target].first_in=edges.back().next_in;

   289 	nodes[edges.back().source].first_out=edges.back().next_out;

   290 	edges.pop_back();

   291       }

   292       //nodes.resize(s.nodes_num);

   293       while(s.node_num<nodes.size()) {

   294 	Parent::getNotifier(Node()).erase(Node(nodes.size()-1));

   295 	nodes.pop_back();

   296       }

   297     }

   299   public:

   301     ///Split a node.

   303     ///This function splits a node. First a new node is added to the graph,

   304     ///then the source of each outgoing edge of \c n is moved to this new node.

   305     ///If \c connect is \c true (this is the default value), then a new edge

   306     ///from \c n to the newly created node is also added.

   307     ///\return The newly created node.

   308     ///

   309     ///\note The <tt>Edge</tt>s

   310     ///referencing a moved edge remain

   311     ///valid. However <tt>InEdge</tt>'s and <tt>OutEdge</tt>'s

   312     ///may be invalidated.

   313     ///\warning This functionality cannot be used together with the SnapShot

   314     ///feature.

   315     ///\todo It could be implemented in a bit faster way.

   316     Node split(Node n, bool connect = true)

   317     {

   318       Node b = _split(n,connect);

   319       return b;

   320     }

   323     ///Class to make a snapshot of the graph and to restrore to it later.

   325     ///Class to make a snapshot of the graph and to restrore to it later.

   326     ///

   327     ///The newly added nodes and edges can be removed using the

   328     ///restore() function.

   329     ///\note After you restore a state, you cannot restore

   330     ///a later state, in other word you cannot add again the edges deleted

   331     ///by restore() using another SnapShot instance.

   332     ///

   333     class SnapShot

   334     {

   335       SmartGraph *g;

   336     protected:

   337       friend class SmartGraph;

   338       unsigned int node_num;

   339       unsigned int edge_num;

   340     public:

   341       ///Default constructor.

   343       ///Default constructor.

   344       ///To actually make a snapshot you must call save().

   345       ///

   346       SnapShot() : g(0) {}

   347       ///Constructor that immediately makes a snapshot

   349       ///This constructor immediately makes a snapshot of the graph.

   350       ///\param _g The graph we make a snapshot of.

   351       SnapShot(SmartGraph &_g) :g(&_g) {

   352 	node_num=g->nodes.size();

   353 	edge_num=g->edges.size();

   354       }

   356       ///Make a snapshot.

   358       ///Make a snapshot of the graph.

   359       ///

   360       ///This function can be called more than once. In case of a repeated

   361       ///call, the previous snapshot gets lost.

   362       ///\param _g The graph we make the snapshot of.

   363       void save(SmartGraph &_g)

   364       {

   365 	g=&_g;

   366 	node_num=g->nodes.size();

   367 	edge_num=g->edges.size();

   368       }

   370       ///Undo the changes until a snapshot.

   372       ///Undo the changes until a snapshot created by save().

   373       ///

   374       ///\note After you restored a state, you cannot restore

   375       ///a later state, in other word you cannot add again the edges deleted

   376       ///by restore().

   377       ///

   378       ///\todo This function might be called undo().

   380       void restore()

   381       {

   382 	g->restoreSnapShot(*this);

   383       }

   384     };

   385   };

   388   /**************** Undirected List Graph ****************/

   390   typedef ClearableUndirGraphExtender<

   391     ExtendableUndirGraphExtender<

   392     MappableUndirGraphExtender<

   393     IterableUndirGraphExtender<

   394     AlterableUndirGraphExtender<

   395     UndirGraphExtender<SmartGraphBase> > > > > > ExtendedUndirSmartGraphBase;

   397   ///A smart undirected graph class.

   399   ///This is a simple and fast undirected graph implementation.

   400   ///It is also quite memory efficient, but at the price

   401   ///that <b> it does support only limited (only stack-like)

   402   ///node and edge deletions</b>.

   403   ///Except from this it conforms to

   404   ///the \ref concept::UndirGraph "UndirGraph" concept.

   405   ///\sa concept::UndirGraph.

   406   ///

   407   ///\todo SnapShot hasn't been implemented yet.

   408   ///

   409   class UndirSmartGraph : public ExtendedUndirSmartGraphBase {

   410   };

   413   /// @}

   414 } //namespace lemon

   417 #endif //LEMON_SMART_GRAPH_H

author	hegyi
	Thu, 20 Oct 2005 15:50:23 +0000
changeset 1731	616bc933c2bc
parent 1718	6a958ab38386
child 1768	1e2e0238e7c8
permissions	-rw-r--r--