lemon-0.x: lemon/smart_graph.h@9285f3777553

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

    80     typedef True NodeNumTag;

    81     typedef True EdgeNumTag;

    83     ///Number of nodes.

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

    85     ///Number of edges.

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

    88     /// Maximum node ID.

    90     /// Maximum node ID.

    91     ///\sa id(Node)

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

    93     /// Maximum edge ID.

    95     /// Maximum edge ID.

    96     ///\sa id(Edge)

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

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

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

   102     /// Node ID.

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

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

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

   107     ///

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

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

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

   111     /// Edge ID.

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

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

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

   116     ///

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

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

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

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

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

   125     Node addNode() {

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

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

   128       return n;

   129     }

   131     Edge addEdge(Node u, Node v) {

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

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

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

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

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

   138       return e;

   139     }

   141     void clear() {

   142       edges.clear();

   143       nodes.clear();

   144     }

   147     class Node {

   148       friend class SmartGraphBase;

   149       friend class SmartGraph;

   151     protected:

   152       int n;

   153       ///\e

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

   156       ///

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

   158     public:

   159       Node() {}

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

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

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

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

   164     };

   167     class Edge {

   168       friend class SmartGraphBase;

   169       friend class SmartGraph;

   171     protected:

   172       int n;

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

   174       ///

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

   176     public:

   177       Edge() { }

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

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

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

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

   182     };

   184     void first(Node& node) const {

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

   186     }

   188     static void next(Node& node) {

   189       --node.n;

   190     }

   192     void first(Edge& edge) const {

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

   194     }

   196     static void next(Edge& edge) {

   197       --edge.n;

   198     }

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

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

   202     }

   204     void nextOut(Edge& edge) const {

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

   206     }

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

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

   210     }

   212     void nextIn(Edge& edge) const {

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

   214     }

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

   217     {

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

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

   220       prev.n=e;

   221       return prev;

   222     }

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

   225     {

   226       Node b = addNode();

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

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

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

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

   231       return b;

   232     }

   234   };

   236   typedef AlterableGraphExtender<SmartGraphBase> AlterableSmartGraphBase;

   237   typedef IterableGraphExtender<AlterableSmartGraphBase> IterableSmartGraphBase;

   238   typedef DefaultMappableGraphExtender<IterableSmartGraphBase> MappableSmartGraphBase;

   239   typedef ExtendableGraphExtender<MappableSmartGraphBase> ExtendableSmartGraphBase;

   240   typedef ClearableGraphExtender<ExtendableSmartGraphBase> ClearableSmartGraphBase;

   242   /// \addtogroup graphs

   243   /// @{

   245   ///A smart graph class.

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

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

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

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

   251   ///It conforms to

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

   253   ///\sa concept::ExtendableGraph.

   254   ///

   255   ///\author Alpar Juttner

   256   class SmartGraph : public ClearableSmartGraphBase {

   257   public:

   258     /// Finds an edge between two nodes.

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

   261     ///

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

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

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

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

   266     ///

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

   268     /// \code

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

   270     ///   ...

   271     /// }

   272     /// \endcode

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

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

   275     {

   276       return _findEdge(u,v,prev);

   277     }

   279     class SnapShot;

   280     friend class SnapShot;

   282   protected:

   283     void restoreSnapShot(const SnapShot &s)

   284     {

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

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

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

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

   289 	edges.pop_back();

   290       }

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

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

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

   294 	nodes.pop_back();

   295       }

   296     }

   298   public:

   300     ///Split a node.

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

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

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

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

   306     ///\return The newly created node.

   307     ///

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

   309     ///referencing a moved edge remain

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

   311     ///may be invalidated.

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

   313     ///feature.

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

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

   316     {

   317       return _split(n,connect);

   318     }

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

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

   324     ///

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

   326     ///restore() function.

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

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

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

   330     ///

   331     class SnapShot

   332     {

   333       SmartGraph *g;

   334     protected:

   335       friend class SmartGraph;

   336       unsigned int node_num;

   337       unsigned int edge_num;

   338     public:

   339       ///Default constructor.

   341       ///Default constructor.

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

   343       ///

   344       SnapShot() : g(0) {}

   345       ///Constructor that immediately makes a snapshot

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

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

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

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

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

   352       }

   354       ///Make a snapshot.

   356       ///Make a snapshot of the graph.

   357       ///

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

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

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

   361       void save(SmartGraph &_g)

   362       {

   363 	g=&_g;

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

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

   366       }

   368       ///Undo the changes until a snapshot.

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

   371       ///

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

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

   374       ///by restore().

   375       ///

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

   378       void restore()

   379       {

   380 	g->restoreSnapShot(*this);

   381       }

   382     };

   383   };

   386   /**************** Undirected List Graph ****************/

   388   typedef ClearableUndirGraphExtender<

   389     ExtendableUndirGraphExtender<

   390     MappableUndirGraphExtender<

   391     IterableUndirGraphExtender<

   392     AlterableUndirGraphExtender<

   393     UndirGraphExtender<SmartGraphBase> > > > > > UndirSmartGraphBase;

   395   ///A smart undirected graph class.

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

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

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

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

   401   ///Except from this it conforms to

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

   403   ///\sa concept::UndirGraph.

   404   ///

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

   406   ///

   407   class UndirSmartGraph : public UndirSmartGraphBase {

   408   };

   411   /// @}

   412 } //namespace lemon

   415 #endif //LEMON_SMART_GRAPH_H

author	alpar
	Thu, 18 Aug 2005 13:33:49 +0000
changeset 1643	9285f3777553
parent 1631	e15162d8eca1
child 1669	66ae78d29f1e
permissions	-rw-r--r--