diff -r 89d97db9c927 -r 625de6f1e766 src/work/deba/list_graph.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/work/deba/list_graph.h	Fri Jul 09 07:33:12 2004 +0000
@@ -0,0 +1,1305 @@
+// -*- mode:C++ -*-
+
+#ifndef HUGO_LIST_GRAPH_H
+#define HUGO_LIST_GRAPH_H
+
+///\ingroup graphs
+///\file
+///\brief ListGraph, SymListGraph, NodeSet and EdgeSet classes.
+
+#include <vector>
+#include <climits>
+
+#include "invalid.h"
+
+#include "vector_map_factory.h"
+#include "map_registry.h"
+
+#include "map_defines.h"
+
+namespace hugo {
+
+/// \addtogroup graphs
+/// @{
+
+  ///A list graph class.
+
+  ///This is a simple and fast erasable graph implementation.
+  ///
+  ///It conforms to the graph interface documented under
+  ///the description of \ref GraphSkeleton.
+  ///\sa \ref GraphSkeleton.
+  class ListGraph {
+
+    //Nodes are double linked.
+    //The free nodes are only single linked using the "next" field.
+    struct NodeT 
+    {
+      int first_in,first_out;
+      int prev, next;
+      //      NodeT() {}
+    };
+    //Edges are double linked.
+    //The free edges are only single linked using the "next_in" field.
+    struct EdgeT 
+    {
+      int head, tail;
+      int prev_in, prev_out;
+      int next_in, next_out;
+      //FIXME: is this necessary?
+      //      EdgeT() : next_in(-1), next_out(-1) prev_in(-1), prev_out(-1) {}  
+    };
+
+    std::vector<NodeT> nodes;
+    //The first node
+    int first_node;
+    //The first free node
+    int first_free_node;
+    std::vector<EdgeT> edges;
+    //The first free edge
+    int first_free_edge;
+    
+  protected:
+    
+  public:
+    
+    class Node;
+    class Edge;
+
+    typedef ListGraph Graph;
+
+  public:
+
+    class NodeIt;
+    class EdgeIt;
+    class OutEdgeIt;
+    class InEdgeIt;
+    
+    CREATE_MAP_REGISTRIES;
+    CREATE_MAPS(VectorMapFactory);
+
+  public:
+
+    ListGraph() : nodes(), first_node(-1),
+		  first_free_node(-1), edges(), first_free_edge(-1) {}
+    ListGraph(const ListGraph &_g) : nodes(_g.nodes), first_node(_g.first_node),
+				     first_free_node(_g.first_free_node),
+				     edges(_g.edges),
+				     first_free_edge(_g.first_free_edge) {}
+    
+
+    int nodeNum() const { return nodes.size(); }  //FIXME: What is this?
+    int edgeNum() const { return edges.size(); }  //FIXME: What is this?
+
+    ///Set the expected number of edges
+
+    ///With this function, it is possible to set the expected number of edges.
+    ///The use of this fasten the building of the graph and makes
+    ///it possible to avoid the superfluous memory allocation.
+    void reserveEdge(int n) { edges.reserve(n); };
+    
+    ///\bug This function does something different than
+    ///its name would suggests...
+    int maxNodeId() const { return nodes.size(); }  //FIXME: What is this?
+    ///\bug This function does something different than
+    ///its name would suggests...
+    int maxEdgeId() const { return edges.size(); }  //FIXME: What is this?
+
+    Node tail(Edge e) const { return edges[e.n].tail; }
+    Node head(Edge e) const { return edges[e.n].head; }
+
+    Node aNode(OutEdgeIt e) const { return edges[e.n].tail; }
+    Node aNode(InEdgeIt e) const { return edges[e.n].head; }
+
+    Node bNode(OutEdgeIt e) const { return edges[e.n].head; }
+    Node bNode(InEdgeIt e) const { return edges[e.n].tail; }
+
+    NodeIt& first(NodeIt& v) const { 
+      v=NodeIt(*this); return v; }
+    EdgeIt& first(EdgeIt& e) const { 
+      e=EdgeIt(*this); return e; }
+    OutEdgeIt& first(OutEdgeIt& e, const Node v) const { 
+      e=OutEdgeIt(*this,v); return e; }
+    InEdgeIt& first(InEdgeIt& e, const Node v) const { 
+      e=InEdgeIt(*this,v); return e; }
+
+//     template< typename It >
+//     It first() const { It e; first(e); return e; }
+
+//     template< typename It >
+//     It first(Node v) const { It e; first(e,v); return e; }
+
+    bool valid(Edge e) const { return e.n!=-1; }
+    bool valid(Node n) const { return n.n!=-1; }
+    
+    void setInvalid(Edge &e) { e.n=-1; }
+    void setInvalid(Node &n) { n.n=-1; }
+    
+    template <typename It> It getNext(It it) const
+    { It tmp(it); return next(tmp); }
+
+    NodeIt& next(NodeIt& it) const { 
+      it.n=nodes[it.n].next; 
+      return it; 
+    }
+    OutEdgeIt& next(OutEdgeIt& it) const
+    { it.n=edges[it.n].next_out; return it; }
+    InEdgeIt& next(InEdgeIt& it) const
+    { it.n=edges[it.n].next_in; return it; }
+    EdgeIt& next(EdgeIt& it) const {
+      if(edges[it.n].next_in!=-1) { 
+	it.n=edges[it.n].next_in;
+      }
+      else {
+	int n;
+	for(n=nodes[edges[it.n].head].next;
+	    n!=-1 && nodes[n].first_in == -1;
+	    n = nodes[n].next) ;
+	it.n = (n==-1)?-1:nodes[n].first_in;
+      }
+      return it;
+    }
+
+    int id(Node v) const { return v.n; }
+    int id(Edge e) const { return e.n; }
+
+    /// Adds a new node to the graph.
+
+    /// \todo It adds the nodes in a reversed order.
+    /// (i.e. the lastly added node becomes the first.)
+    Node addNode() {
+      int n;
+      
+      if(first_free_node==-1)
+	{
+	  n = nodes.size();
+	  nodes.push_back(NodeT());
+	}
+      else {
+	n = first_free_node;
+	first_free_node = nodes[n].next;
+      }
+      
+      nodes[n].next = first_node;
+      if(first_node != -1) nodes[first_node].prev = n;
+      first_node = n;
+      nodes[n].prev = -1;
+      
+      nodes[n].first_in = nodes[n].first_out = -1;
+      
+      Node nn; nn.n=n;
+
+      //Update dynamic maps
+      node_maps.add(nn);
+
+      return nn;
+    }
+    
+    Edge addEdge(Node u, Node v) {
+      int n;
+      
+      if(first_free_edge==-1)
+	{
+	  n = edges.size();
+	  edges.push_back(EdgeT());
+	}
+      else {
+	n = first_free_edge;
+	first_free_edge = edges[n].next_in;
+      }
+      
+      edges[n].tail = u.n; edges[n].head = v.n;
+
+      edges[n].next_out = nodes[u.n].first_out;
+      if(nodes[u.n].first_out != -1) edges[nodes[u.n].first_out].prev_out = n;
+      edges[n].next_in = nodes[v.n].first_in;
+      if(nodes[v.n].first_in != -1) edges[nodes[v.n].first_in].prev_in = n;
+      edges[n].prev_in = edges[n].prev_out = -1;
+	
+      nodes[u.n].first_out = nodes[v.n].first_in = n;
+
+      Edge e; e.n=n;
+
+      //Update dynamic maps
+      edge_maps.add(e);
+
+      return e;
+    }
+
+  private:
+    void eraseEdge(int n) {
+      
+      if(edges[n].next_in!=-1)
+	edges[edges[n].next_in].prev_in = edges[n].prev_in;
+      if(edges[n].prev_in!=-1)
+	edges[edges[n].prev_in].next_in = edges[n].next_in;
+      else nodes[edges[n].head].first_in = edges[n].next_in;
+      
+      if(edges[n].next_out!=-1)
+	edges[edges[n].next_out].prev_out = edges[n].prev_out;
+      if(edges[n].prev_out!=-1)
+	edges[edges[n].prev_out].next_out = edges[n].next_out;
+      else nodes[edges[n].tail].first_out = edges[n].next_out;
+      
+      edges[n].next_in = first_free_edge;
+      first_free_edge = n;      
+
+      //Update dynamic maps
+      Edge e; e.n=n;
+    }
+      
+  public:
+
+    void erase(Node nn) {
+      int n=nn.n;
+      
+      int m;
+      while((m=nodes[n].first_in)!=-1) eraseEdge(m);
+      while((m=nodes[n].first_out)!=-1) eraseEdge(m);
+
+      if(nodes[n].next != -1) nodes[nodes[n].next].prev = nodes[n].prev;
+      if(nodes[n].prev != -1) nodes[nodes[n].prev].next = nodes[n].next;
+      else first_node = nodes[n].next;
+      
+      nodes[n].next = first_free_node;
+      first_free_node = n;
+
+      //Update dynamic maps
+      node_maps.erase(nn);
+     }
+    
+    void erase(Edge e) { 
+      edge_maps.erase(e);
+      eraseEdge(e.n); 
+    }
+
+    ///\bug Dynamic maps must be updated!
+    ///
+    void clear() {
+      nodes.clear();edges.clear();
+      first_node=first_free_node=first_free_edge=-1;
+    }
+
+    class Node {
+      friend class ListGraph;
+      template <typename T> friend class NodeMap;
+       
+      friend class Edge;
+      friend class OutEdgeIt;
+      friend class InEdgeIt;
+      friend class SymEdge;
+
+    protected:
+      int n;
+      friend int ListGraph::id(Node v) const; 
+      Node(int nn) {n=nn;}
+    public:
+      Node() {}
+      Node (Invalid) { n=-1; }
+      bool operator==(const Node i) const {return n==i.n;}
+      bool operator!=(const Node i) const {return n!=i.n;}
+      bool operator<(const Node i) const {return n<i.n;}
+    };
+    
+    class NodeIt : public Node {
+      friend class ListGraph;
+    public:
+      NodeIt() : Node() { }
+      NodeIt(Invalid i) : Node(i) { }
+      NodeIt(const ListGraph& G) : Node(G.first_node) { }
+      ///\todo Undocumented conversion Node -\> NodeIt.
+      NodeIt(const ListGraph& G, const Node &n) : Node(n) { }
+    };
+
+    class Edge {
+      friend class ListGraph;
+      template <typename T> friend class EdgeMap;
+
+      //template <typename T> friend class SymListGraph::SymEdgeMap;      
+      //friend Edge SymListGraph::opposite(Edge) const;
+      
+      friend class Node;
+      friend class NodeIt;
+    protected:
+      int n;
+      friend int ListGraph::id(Edge e) const;
+
+      Edge(int nn) {n=nn;}
+    public:
+      Edge() { }
+      Edge (Invalid) { n=-1; }
+      bool operator==(const Edge i) const {return n==i.n;}
+      bool operator!=(const Edge i) const {return n!=i.n;}
+      bool operator<(const Edge i) const {return n<i.n;}
+      ///\bug This is a workaround until somebody tells me how to
+      ///make class \c SymListGraph::SymEdgeMap friend of Edge
+      int &idref() {return n;}
+      const int &idref() const {return n;}
+    };
+    
+    class EdgeIt : public Edge {
+      friend class ListGraph;
+    public:
+      EdgeIt(const ListGraph& G) : Edge() {
+      	int m;
+	for(m=G.first_node;
+	    m!=-1 && G.nodes[m].first_in == -1; m = G.nodes[m].next);
+	n = (m==-1)?-1:G.nodes[m].first_in;
+      }
+      EdgeIt (Invalid i) : Edge(i) { }
+      EdgeIt() : Edge() { }
+      ///\bug This is a workaround until somebody tells me how to
+      ///make class \c SymListGraph::SymEdgeMap friend of Edge
+      int &idref() {return n;}
+    };
+    
+    class OutEdgeIt : public Edge {
+      friend class ListGraph;
+    public: 
+      OutEdgeIt() : Edge() { }
+      OutEdgeIt (Invalid i) : Edge(i) { }
+
+      OutEdgeIt(const ListGraph& G,const Node v)
+	: Edge(G.nodes[v.n].first_out) {}
+    };
+    
+    class InEdgeIt : public Edge {
+      friend class ListGraph;
+    public: 
+      InEdgeIt() : Edge() { }
+      InEdgeIt (Invalid i) : Edge(i) { }
+      InEdgeIt(const ListGraph& G,Node v) :Edge(G.nodes[v.n].first_in) {}
+    };
+
+  };
+
+  ///Graph for bidirectional edges.
+
+  ///The purpose of this graph structure is to handle graphs
+  ///having bidirectional edges. Here the function \c addEdge(u,v) adds a pair
+  ///of oppositely directed edges.
+  ///There is a new edge map type called
+  ///\ref SymListGraph::SymEdgeMap "SymEdgeMap"
+  ///that complements this
+  ///feature by
+  ///storing shared values for the edge pairs. The usual
+  ///\ref GraphSkeleton::EdgeMap "EdgeMap"
+  ///can be used
+  ///as well.
+  ///
+  ///The oppositely directed edge can also be obtained easily
+  ///using \ref opposite.
+  ///
+  ///Here erase(Edge) deletes a pair of edges.
+  ///
+  ///\todo this date structure need some reconsiderations. Maybe it
+  ///should be implemented independently from ListGraph.
+
+  };
+  
+
+  ///A graph class containing only nodes.
+
+  ///This class implements a graph structure without edges.
+  ///The most useful application of this class is to be the node set of an
+  ///\ref EdgeSet class.
+  ///
+  ///It conforms to the graph interface documented under
+  ///the description of \ref GraphSkeleton with the exception that you cannot
+  ///add (or delete) edges. The usual edge iterators are exists, but they are
+  ///always \ref INVALID.
+  ///\sa \ref GraphSkeleton
+  ///\sa \ref EdgeSet
+  class NodeSet {
+
+    //Nodes are double linked.
+    //The free nodes are only single linked using the "next" field.
+    struct NodeT 
+    {
+      int first_in,first_out;
+      int prev, next;
+      //      NodeT() {}
+    };
+
+    std::vector<NodeT> nodes;
+    //The first node
+    int first_node;
+    //The first free node
+    int first_free_node;
+    
+  protected:
+    
+    template <typename Key> class DynMapBase
+    {
+    protected:
+      const NodeSet* G; 
+    public:
+      virtual void add(const Key k) = 0;
+      virtual void erase(const Key k) = 0;
+      DynMapBase(const NodeSet &_G) : G(&_G) {}
+      virtual ~DynMapBase() {}
+      friend class NodeSet;
+    };
+    
+  public:
+    template <typename T> class EdgeMap;
+    template <typename T> class NodeMap;
+    
+    class Node;
+    class Edge;
+
+    //  protected:
+    // HELPME:
+  protected:
+    ///\bug It must be public because of SymEdgeMap.
+    ///
+    mutable std::vector<DynMapBase<Node> * > dyn_node_maps;
+    //mutable std::vector<DynMapBase<Edge> * > dyn_edge_maps;
+    
+  public:
+
+    class NodeIt;
+    class EdgeIt;
+    class OutEdgeIt;
+    class InEdgeIt;
+    
+    template <typename T> class NodeMap;
+    template <typename T> class EdgeMap;
+    
+  public:
+
+    ///Default constructor
+    NodeSet() : nodes(), first_node(-1),
+		  first_free_node(-1) {}
+    ///Copy constructor
+    NodeSet(const NodeSet &_g) : nodes(_g.nodes), first_node(_g.first_node),
+				     first_free_node(_g.first_free_node) {}
+    
+    ~NodeSet()
+    {
+      for(std::vector<DynMapBase<Node> * >::iterator i=dyn_node_maps.begin();
+	  i!=dyn_node_maps.end(); ++i) (**i).G=NULL;
+      //for(std::vector<DynMapBase<Edge> * >::iterator i=dyn_edge_maps.begin();
+      //	  i!=dyn_edge_maps.end(); ++i) (**i).G=NULL;
+    }
+
+    int nodeNum() const { return nodes.size(); }  //FIXME: What is this?
+    int edgeNum() const { return 0; }  //FIXME: What is this?
+
+    ///\bug This function does something different than
+    ///its name would suggests...
+    int maxNodeId() const { return nodes.size(); }  //FIXME: What is this?
+    ///\bug This function does something different than
+    ///its name would suggests...
+    int maxEdgeId() const { return 0; }  //FIXME: What is this?
+
+    Node tail(Edge e) const { return INVALID; }
+    Node head(Edge e) const { return INVALID; }
+
+    Node aNode(OutEdgeIt e) const { return INVALID; }
+    Node aNode(InEdgeIt e) const { return INVALID; }
+
+    Node bNode(OutEdgeIt e) const { return INVALID; }
+    Node bNode(InEdgeIt e) const { return INVALID; }
+
+    NodeIt& first(NodeIt& v) const { 
+      v=NodeIt(*this); return v; }
+    EdgeIt& first(EdgeIt& e) const { 
+      e=EdgeIt(*this); return e; }
+    OutEdgeIt& first(OutEdgeIt& e, const Node v) const { 
+      e=OutEdgeIt(*this,v); return e; }
+    InEdgeIt& first(InEdgeIt& e, const Node v) const { 
+      e=InEdgeIt(*this,v); return e; }
+
+//     template< typename It >
+//     It first() const { It e; first(e); return e; }
+
+//     template< typename It >
+//     It first(Node v) const { It e; first(e,v); return e; }
+
+    bool valid(Edge e) const { return false; }
+    bool valid(Node n) const { return n.n!=-1; }
+    
+    void setInvalid(Edge &e) { }
+    void setInvalid(Node &n) { n.n=-1; }
+    
+    template <typename It> It getNext(It it) const
+    { It tmp(it); return next(tmp); }
+
+    NodeIt& next(NodeIt& it) const { 
+      it.n=nodes[it.n].next; 
+      return it; 
+    }
+    OutEdgeIt& next(OutEdgeIt& it) const { return it; }
+    InEdgeIt& next(InEdgeIt& it) const { return it; }
+    EdgeIt& next(EdgeIt& it) const { return it; }
+
+    int id(Node v) const { return v.n; }
+    int id(Edge e) const { return -1; }
+
+    /// Adds a new node to the graph.
+
+    /// \todo It adds the nodes in a reversed order.
+    /// (i.e. the lastly added node becomes the first.)
+    Node addNode() {
+      int n;
+      
+      if(first_free_node==-1)
+	{
+	  n = nodes.size();
+	  nodes.push_back(NodeT());
+	}
+      else {
+	n = first_free_node;
+	first_free_node = nodes[n].next;
+      }
+      
+      nodes[n].next = first_node;
+      if(first_node != -1) nodes[first_node].prev = n;
+      first_node = n;
+      nodes[n].prev = -1;
+      
+      nodes[n].first_in = nodes[n].first_out = -1;
+      
+      Node nn; nn.n=n;
+
+      //Update dynamic maps
+      for(std::vector<DynMapBase<Node> * >::iterator i=dyn_node_maps.begin();
+	  i!=dyn_node_maps.end(); ++i) (**i).add(nn);
+
+      return nn;
+    }
+    
+    void erase(Node nn) {
+      int n=nn.n;
+      
+      if(nodes[n].next != -1) nodes[nodes[n].next].prev = nodes[n].prev;
+      if(nodes[n].prev != -1) nodes[nodes[n].prev].next = nodes[n].next;
+      else first_node = nodes[n].next;
+      
+      nodes[n].next = first_free_node;
+      first_free_node = n;
+
+      //Update dynamic maps
+      for(std::vector<DynMapBase<Node> * >::iterator i=dyn_node_maps.begin();
+	  i!=dyn_node_maps.end(); ++i) (**i).erase(nn);
+    }
+    
+    ///\bug Dynamic maps must be updated!
+    ///
+    void clear() {
+      nodes.clear();
+      first_node = first_free_node = -1;
+    }
+
+    class Node {
+      friend class NodeSet;
+      template <typename T> friend class NodeMap;
+      
+      friend class Edge;
+      friend class OutEdgeIt;
+      friend class InEdgeIt;
+
+    protected:
+      int n;
+      friend int NodeSet::id(Node v) const; 
+      Node(int nn) {n=nn;}
+    public:
+      Node() {}
+      Node (Invalid i) { n=-1; }
+      bool operator==(const Node i) const {return n==i.n;}
+      bool operator!=(const Node i) const {return n!=i.n;}
+      bool operator<(const Node i) const {return n<i.n;}
+    };
+    
+    class NodeIt : public Node {
+      friend class NodeSet;
+    public:
+      NodeIt() : Node() { }
+      NodeIt(Invalid i) : Node(i) { }
+      NodeIt(const NodeSet& G) : Node(G.first_node) { }
+      ///\todo Undocumented conversion Node -\> NodeIt.
+      NodeIt(const NodeSet& G, const Node &n) : Node(n) { }
+
+    };
+
+    class Edge {
+      //friend class NodeSet;
+      //template <typename T> friend class EdgeMap;
+
+      //template <typename T> friend class SymNodeSet::SymEdgeMap;      
+      //friend Edge SymNodeSet::opposite(Edge) const;
+      
+      //      friend class Node;
+      //      friend class NodeIt;
+    protected:
+      //friend int NodeSet::id(Edge e) const;
+      //      Edge(int nn) {}
+    public:
+      Edge() { }
+      Edge (Invalid) { }
+      bool operator==(const Edge i) const {return true;}
+      bool operator!=(const Edge i) const {return false;}
+      bool operator<(const Edge i) const {return false;}
+      ///\bug This is a workaround until somebody tells me how to
+      ///make class \c SymNodeSet::SymEdgeMap friend of Edge
+      //      int idref() {return -1;}
+      //      int idref() const {return -1;}
+    };
+    
+    class EdgeIt : public Edge {
+      //friend class NodeSet;
+    public:
+      EdgeIt(const NodeSet& G) : Edge() { }
+      EdgeIt (Invalid i) : Edge(i) { }
+      EdgeIt() : Edge() { }
+      ///\bug This is a workaround until somebody tells me how to
+      ///make class \c SymNodeSet::SymEdgeMap friend of Edge
+      //      int idref() {return -1;}
+    };
+    
+    class OutEdgeIt : public Edge {
+      friend class NodeSet;
+    public: 
+      OutEdgeIt() : Edge() { }
+      OutEdgeIt (Invalid i) : Edge(i) { }
+      OutEdgeIt(const NodeSet& G,const Node v)	: Edge() {}
+    };
+    
+    class InEdgeIt : public Edge {
+      friend class NodeSet;
+    public: 
+      InEdgeIt() : Edge() { }
+      InEdgeIt (Invalid i) : Edge(i) { }
+      InEdgeIt(const NodeSet& G,Node v) :Edge() {}
+    };
+
+    template <typename T> class NodeMap : public DynMapBase<Node>
+    {
+      std::vector<T> container;
+
+    public:
+      typedef T ValueType;
+      typedef Node KeyType;
+
+      NodeMap(const NodeSet &_G) :
+	DynMapBase<Node>(_G), container(_G.maxNodeId())
+      {
+	G->dyn_node_maps.push_back(this);
+      }
+      NodeMap(const NodeSet &_G,const T &t) :
+	DynMapBase<Node>(_G), container(_G.maxNodeId(),t)
+      {
+	G->dyn_node_maps.push_back(this);
+      }
+      
+      NodeMap(const NodeMap<T> &m) :
+ 	DynMapBase<Node>(*m.G), container(m.container)
+      {
+ 	G->dyn_node_maps.push_back(this);
+      }
+
+      template<typename TT> friend class NodeMap;
+ 
+      ///\todo It can copy between different types.
+      ///
+      template<typename TT> NodeMap(const NodeMap<TT> &m) :
+	DynMapBase<Node>(*m.G), container(m.container.size())
+      {
+	G->dyn_node_maps.push_back(this);
+	typename std::vector<TT>::const_iterator i;
+	for(typename std::vector<TT>::const_iterator i=m.container.begin();
+	    i!=m.container.end();
+	    i++)
+	  container.push_back(*i);
+      }
+      ~NodeMap()
+      {
+	if(G) {
+	  std::vector<DynMapBase<Node>* >::iterator i;
+	  for(i=G->dyn_node_maps.begin();
+	      i!=G->dyn_node_maps.end() && *i!=this; ++i) ;
+	  //if(*i==this) G->dyn_node_maps.erase(i); //FIXME: Way too slow...
+	  //A better way to do that: (Is this really important?)
+	  if(*i==this) {
+	    *i=G->dyn_node_maps.back();
+	    G->dyn_node_maps.pop_back();
+	  }
+	}
+      }
+
+      void add(const Node k) 
+      {
+	if(k.n>=int(container.size())) container.resize(k.n+1);
+      }
+
+      void erase(const Node) { }
+      
+      void set(Node n, T a) { container[n.n]=a; }
+      //'T& operator[](Node n)' would be wrong here
+      typename std::vector<T>::reference
+      operator[](Node n) { return container[n.n]; }
+      //'const T& operator[](Node n)' would be wrong here
+      typename std::vector<T>::const_reference 
+      operator[](Node n) const { return container[n.n]; }
+
+      ///\warning There is no safety check at all!
+      ///Using operator = between maps attached to different graph may
+      ///cause serious problem.
+      ///\todo Is this really so?
+      ///\todo It can copy between different types.
+      const NodeMap<T>& operator=(const NodeMap<T> &m)
+      {
+	container = m.container;
+	return *this;
+      }
+      template<typename TT>
+      const NodeMap<T>& operator=(const NodeMap<TT> &m)
+      {
+	std::copy(m.container.begin(), m.container.end(), container.begin());
+	return *this;
+      }
+      
+      void update() {}    //Useless for Dynamic Maps
+      void update(T a) {}  //Useless for Dynamic Maps
+    };
+    
+    template <typename T> class EdgeMap
+    {
+    public:
+      typedef T ValueType;
+      typedef Edge KeyType;
+
+      EdgeMap(const NodeSet &) { }
+      EdgeMap(const NodeSet &,const T &) { }
+      EdgeMap(const EdgeMap<T> &) { }
+      //      template<typename TT> friend class EdgeMap;
+
+      ///\todo It can copy between different types.
+      ///
+      template<typename TT> EdgeMap(const EdgeMap<TT> &) { }
+      ~EdgeMap() { }
+
+      void add(const Edge  ) { }
+      void erase(const Edge) { }
+      
+      void set(Edge, T) { }
+      //T get(Edge n) const { return container[n.n]; }
+      ValueType &operator[](Edge) { return *((T*)(NULL)); }
+      const ValueType &operator[](Edge) const { return *((T*)(NULL)); }
+
+      const EdgeMap<T>& operator=(const EdgeMap<T> &) { return *this; }
+    
+      template<typename TT>
+      const EdgeMap<T>& operator=(const EdgeMap<TT> &m) { return *this; }
+      
+      void update() {}
+      void update(T a) {}
+    };
+  };
+
+
+
+  ///Graph structure using a node set of another graph.
+
+  ///This structure can be used to establish another graph over a node set
+  /// of an existing one. The node iterator will go through the nodes of the
+  /// original graph, and the NodeMap's of both graphs will convert to
+  /// each other.
+  ///
+  ///\warning Adding or deleting nodes from the graph is not safe if an
+  ///\ref EdgeSet is currently attached to it!
+  ///
+  ///\todo Make it possible to add/delete edges from the base graph
+  ///(and from \ref EdgeSet, as well)
+  ///
+  ///\param GG The type of the graph which shares its node set with this class.
+  ///Its interface must conform with \ref GraphSkeleton.
+  ///
+  ///It conforms to the graph interface documented under
+  ///the description of \ref GraphSkeleton.
+  ///\sa \ref GraphSkeleton.
+  ///\sa \ref NodeSet.
+  template<typename GG>
+  class EdgeSet {
+
+    typedef GG NodeGraphType;
+
+    NodeGraphType &G;
+
+  public:
+    class Node;
+    int id(Node v) const; 
+
+    class Node : public NodeGraphType::Node {
+      friend class EdgeSet;
+      //      template <typename T> friend class NodeMap;
+      
+      friend class Edge;
+      friend class OutEdgeIt;
+      friend class InEdgeIt;
+      friend class SymEdge;
+
+    public:
+      friend int EdgeSet::id(Node v) const; 
+      //      Node(int nn) {n=nn;}
+    public:
+      Node() : NodeGraphType::Node() {}
+      Node (Invalid i) : NodeGraphType::Node(i) {}
+      Node(const typename NodeGraphType::Node &n) : NodeGraphType::Node(n) {}
+    };
+    
+    class NodeIt : public NodeGraphType::NodeIt {
+      friend class EdgeSet;
+    public:
+      NodeIt() : NodeGraphType::NodeIt() { }
+      NodeIt (Invalid i) : NodeGraphType::NodeIt(i) {}
+      NodeIt(const EdgeSet& _G) : NodeGraphType::NodeIt(_G.G) { }
+      NodeIt(const typename NodeGraphType::NodeIt &n)
+	: NodeGraphType::NodeIt(n) {}
+      ///\todo Undocumented conversion Node -\> NodeIt.
+      NodeIt(const EdgeSet& _G, const Node &n)
+	: NodeGraphType::NodeIt(_G.G,n) { }
+
+      operator Node() { return Node(*this);}
+    };
+
+  private:
+    //Edges are double linked.
+    //The free edges are only single linked using the "next_in" field.
+    struct NodeT 
+    {
+      int first_in,first_out;
+      NodeT() : first_in(-1), first_out(-1) { }
+    };
+
+    struct EdgeT 
+    {
+      Node head, tail;
+      int prev_in, prev_out;
+      int next_in, next_out;
+    };
+
+    
+    typename NodeGraphType::template NodeMap<NodeT> nodes;
+    
+    std::vector<EdgeT> edges;
+    //The first free edge
+    int first_free_edge;
+    
+  protected:
+    
+    template <typename Key> class DynMapBase
+    {
+    protected:
+      const EdgeSet* G; 
+    public:
+      virtual void add(const Key k) = 0;
+      virtual void erase(const Key k) = 0;
+      DynMapBase(const EdgeSet &_G) : G(&_G) {}
+      virtual ~DynMapBase() {}
+      friend class EdgeSet;
+    };
+    
+  public:
+    //template <typename T> class NodeMap;
+    template <typename T> class EdgeMap;
+    
+    class Node;
+    class Edge;
+
+    //  protected:
+    // HELPME:
+  protected:
+    // mutable std::vector<DynMapBase<Node> * > dyn_node_maps;
+    ///\bug It must be public because of SymEdgeMap.
+    ///
+    mutable std::vector<DynMapBase<Edge> * > dyn_edge_maps;
+    
+  public:
+
+    class NodeIt;
+    class EdgeIt;
+    class OutEdgeIt;
+    class InEdgeIt;
+    
+    template <typename T> class NodeMap;
+    template <typename T> class EdgeMap;
+    
+  public:
+
+    ///Constructor
+    
+    ///Construates a new graph based on the nodeset of an existing one.
+    ///\param _G the base graph.
+    ///\todo It looks like a copy constructor, but it isn't.
+    EdgeSet(NodeGraphType &_G) : G(_G),
+				 nodes(_G), edges(),
+				 first_free_edge(-1) { }
+    ///Copy constructor
+
+    ///Makes a copy of an EdgeSet.
+    ///It will be based on the same graph.
+    EdgeSet(const EdgeSet &_g) : G(_g.G), nodes(_g.G), edges(_g.edges),
+				 first_free_edge(_g.first_free_edge) { }
+    
+    ~EdgeSet()
+    {
+      // for(std::vector<DynMapBase<Node> * >::iterator i=dyn_node_maps.begin();
+      //  i!=dyn_node_maps.end(); ++i) (**i).G=NULL;
+      for(typename std::vector<DynMapBase<Edge> * >::iterator
+	    i=dyn_edge_maps.begin();
+	  i!=dyn_edge_maps.end(); ++i) (**i).G=NULL;
+    }
+
+    int nodeNum() const { return G.nodeNum(); }  //FIXME: What is this?
+    int edgeNum() const { return edges.size(); }  //FIXME: What is this?
+
+    ///\bug This function does something different than
+    ///its name would suggests...
+    int maxNodeId() const { return G.maxNodeId(); }  //FIXME: What is this?
+    ///\bug This function does something different than
+    ///its name would suggests...
+    int maxEdgeId() const { return edges.size(); }  //FIXME: What is this?
+
+    Node tail(Edge e) const { return edges[e.n].tail; }
+    Node head(Edge e) const { return edges[e.n].head; }
+
+    Node aNode(OutEdgeIt e) const { return edges[e.n].tail; }
+    Node aNode(InEdgeIt e) const { return edges[e.n].head; }
+
+    Node bNode(OutEdgeIt e) const { return edges[e.n].head; }
+    Node bNode(InEdgeIt e) const { return edges[e.n].tail; }
+
+    NodeIt& first(NodeIt& v) const { 
+      v=NodeIt(*this); return v; }
+    EdgeIt& first(EdgeIt& e) const { 
+      e=EdgeIt(*this); return e; }
+    OutEdgeIt& first(OutEdgeIt& e, const Node v) const { 
+      e=OutEdgeIt(*this,v); return e; }
+    InEdgeIt& first(InEdgeIt& e, const Node v) const { 
+      e=InEdgeIt(*this,v); return e; }
+
+//     template< typename It >
+//     It first() const { It e; first(e); return e; }
+
+//     template< typename It >
+//     It first(Node v) const { It e; first(e,v); return e; }
+
+    bool valid(Edge e) const { return e.n!=-1; }
+    bool valid(Node n) const { return G.valid(n); }
+    
+    void setInvalid(Edge &e) { e.n=-1; }
+    void setInvalid(Node &n) { G.setInvalid(n); }
+    
+    template <typename It> It getNext(It it) const
+    { It tmp(it); return next(tmp); }
+
+    NodeIt& next(NodeIt& it) const { G.next(it); return it; }
+    OutEdgeIt& next(OutEdgeIt& it) const
+    { it.n=edges[it.n].next_out; return it; }
+    InEdgeIt& next(InEdgeIt& it) const
+    { it.n=edges[it.n].next_in; return it; }
+    EdgeIt& next(EdgeIt& it) const {
+      if(edges[it.n].next_in!=-1) { 
+	it.n=edges[it.n].next_in;
+      }
+      else {
+	NodeIt n(*this,edges[it.n].head);
+	for(n=next(n);
+	    valid(n) && nodes[n].first_in == -1;
+	    next(n)) ;
+	it.n = (valid(n))?-1:nodes[n].first_in;
+      }
+      return it;
+    }
+
+    int id(Edge e) const { return e.n; }
+
+    /// Adds a new node to the graph.
+    Node addNode() { return G.addNode(); }
+    
+    Edge addEdge(Node u, Node v) {
+      int n;
+      
+      if(first_free_edge==-1)
+	{
+	  n = edges.size();
+	  edges.push_back(EdgeT());
+	}
+      else {
+	n = first_free_edge;
+	first_free_edge = edges[n].next_in;
+      }
+      
+      edges[n].tail = u; edges[n].head = v;
+
+      edges[n].next_out = nodes[u].first_out;
+      if(nodes[u].first_out != -1) edges[nodes[u].first_out].prev_out = n;
+      edges[n].next_in = nodes[v].first_in;
+      if(nodes[v].first_in != -1) edges[nodes[v].first_in].prev_in = n;
+      edges[n].prev_in = edges[n].prev_out = -1;
+	
+      nodes[u].first_out = nodes[v].first_in = n;
+
+      Edge e; e.n=n;
+
+      //Update dynamic maps
+      for(typename std::vector<DynMapBase<Edge> * >::iterator
+	    i=dyn_edge_maps.begin();
+	  i!=dyn_edge_maps.end(); ++i) (**i).add(e);
+
+      return e;
+    }
+
+  private:
+    void eraseEdge(int n) {
+      
+      if(edges[n].next_in!=-1)
+	edges[edges[n].next_in].prev_in = edges[n].prev_in;
+      if(edges[n].prev_in!=-1)
+	edges[edges[n].prev_in].next_in = edges[n].next_in;
+      else nodes[edges[n].head].first_in = edges[n].next_in;
+      
+      if(edges[n].next_out!=-1)
+	edges[edges[n].next_out].prev_out = edges[n].prev_out;
+      if(edges[n].prev_out!=-1)
+	edges[edges[n].prev_out].next_out = edges[n].next_out;
+      else nodes[edges[n].tail].first_out = edges[n].next_out;
+      
+      edges[n].next_in = first_free_edge;
+      first_free_edge = -1;      
+
+      //Update dynamic maps
+      Edge e; e.n=n;
+      for(typename std::vector<DynMapBase<Edge> * >::iterator
+	    i=dyn_edge_maps.begin();
+	  i!=dyn_edge_maps.end(); ++i) (**i).erase(e);
+    }
+      
+  public:
+
+//     void erase(Node nn) {
+//       int n=nn.n;
+//       int m;
+//       while((m=nodes[n].first_in)!=-1) eraseEdge(m);
+//       while((m=nodes[n].first_out)!=-1) eraseEdge(m);
+//     }
+    
+    void erase(Edge e) { eraseEdge(e.n); }
+
+    ///Clear all edges. (Doesn't clear the nodes!)
+    void clear() {
+      edges.clear();
+      first_free_edge=-1;
+    }
+
+
+//     //\bug Dynamic maps must be updated!
+//     //
+//     void clear() {
+//       nodes.clear();edges.clear();
+//       first_node=first_free_node=first_free_edge=-1;
+//     }
+
+  public:
+    template <typename T> class EdgeMap;
+    
+    ///
+    class Edge {
+    public:
+      friend class EdgeSet;
+      template <typename T> friend class EdgeMap;
+
+      friend class Node;
+      friend class NodeIt;
+    public:
+      ///\bug It shoud be at least protected
+      ///
+      int n;
+    protected:
+      friend int EdgeSet::id(Edge e) const;
+
+      Edge(int nn) {n=nn;}
+    public:
+      Edge() { }
+      Edge (Invalid) { n=-1; }
+      bool operator==(const Edge i) const {return n==i.n;}
+      bool operator!=(const Edge i) const {return n!=i.n;}
+      bool operator<(const Edge i) const {return n<i.n;}
+      ///\bug This is a workaround until somebody tells me how to
+      ///make class \c SymEdgeSet::SymEdgeMap friend of Edge
+      int &idref() {return n;}
+      const int &idref() const {return n;}
+    };
+    
+    class EdgeIt : public Edge {
+      friend class EdgeSet;
+      template <typename T> friend class EdgeMap;
+    
+      
+    public:
+      EdgeIt(const EdgeSet& G) : Edge() {
+	//      	typename NodeGraphType::Node m;
+        NodeIt m;
+	for(G.first(m);
+	    G.valid(m) && G.nodes[m].first_in == -1;  G.next(m));
+	//AJJAJ! This is a non sense!!!!!!!
+	this->n = G.valid(m)?-1:G.nodes[m].first_in;
+      }
+      EdgeIt (Invalid i) : Edge(i) { }
+      EdgeIt() : Edge() { }
+      ///\bug This is a workaround until somebody tells me how to
+      ///make class \c SymEdgeSet::SymEdgeMap friend of Edge
+      int &idref() {return this->n;}
+    };
+    
+    class OutEdgeIt : public Edge {
+      friend class EdgeSet;
+    public: 
+      OutEdgeIt() : Edge() { }
+      OutEdgeIt (Invalid i) : Edge(i) { }
+
+      OutEdgeIt(const EdgeSet& G,const Node v) : Edge(G.nodes[v].first_out) { }
+    };
+    
+    class InEdgeIt : public Edge {
+      friend class EdgeSet;
+    public: 
+      InEdgeIt() : Edge() { }
+      InEdgeIt (Invalid i) : Edge(i) { }
+      InEdgeIt(const EdgeSet& G,Node v) :Edge(G.nodes[v].first_in) { }
+    };
+
+    template <typename T> class NodeMap : 
+      public NodeGraphType::template NodeMap<T>
+    {
+      //This is a must, the constructors need it.
+      typedef typename NodeGraphType::template NodeMap<T> ParentNodeMap;
+    public:
+      NodeMap(const EdgeSet &_G) : ParentNodeMap(_G.G) { }
+      NodeMap(const EdgeSet &_G,const T &t) : ParentNodeMap(_G.G,t) { }
+      //It is unnecessary
+      NodeMap(const typename NodeGraphType::template NodeMap<T> &m) :
+	ParentNodeMap(m) { }
+
+      ///\todo It can copy between different types.
+      ///
+      template<typename TT>
+      NodeMap(const typename NodeGraphType::template NodeMap<TT> &m)
+	: ParentNodeMap(m) { }
+    };
+    
+    ///
+    template <typename T> class EdgeMap : public DynMapBase<Edge>
+    {
+    protected:
+    public:
+      ///\bug It should be at least protected
+      ///
+      std::vector<T> container;
+
+    public:
+      typedef T ValueType;
+      typedef Edge KeyType;
+
+      EdgeMap(const EdgeSet &_G) :
+	DynMapBase<Edge>(_G), container(_G.maxEdgeId())
+      {
+	//FIXME: What if there are empty Id's?
+	//FIXME: Can I use 'this' in a constructor?
+	G->dyn_edge_maps.push_back(this);
+      }
+      EdgeMap(const EdgeSet &_G,const T &t) :
+	DynMapBase<Edge>(_G), container(_G.maxEdgeId(),t)
+      {
+	G->dyn_edge_maps.push_back(this);
+      } 
+      EdgeMap(const EdgeMap<T> &m) :
+ 	DynMapBase<Edge>(*m.G), container(m.container)
+      {
+ 	G->dyn_edge_maps.push_back(this);
+      }
+
+      template<typename TT> friend class EdgeMap;
+
+      ///\todo It can copy between different types.
+      ///
+      template<typename TT> EdgeMap(const EdgeMap<TT> &m) :
+	DynMapBase<Edge>(*m.G), container(m.container.size())
+      {
+	G->dyn_edge_maps.push_back(this);
+	typename std::vector<TT>::const_iterator i;
+	for(typename std::vector<TT>::const_iterator i=m.container.begin();
+	    i!=m.container.end();
+	    i++)
+	  container.push_back(*i);
+      }
+      ~EdgeMap()
+      {
+	if(G) {
+	  typename std::vector<DynMapBase<Edge>* >::iterator i;
+	  for(i=G->dyn_edge_maps.begin();
+	      i!=G->dyn_edge_maps.end() && *i!=this; ++i) ;
+	  //if(*i==this) G->dyn_edge_maps.erase(i); //Way too slow...
+	  //A better way to do that: (Is this really important?)
+	  if(*i==this) {
+	    *i=G->dyn_edge_maps.back();
+	    G->dyn_edge_maps.pop_back();
+	  }
+	}
+      }
+      
+      void add(const Edge k) 
+      {
+	if(k.n>=int(container.size())) container.resize(k.n+1);
+      }
+      void erase(const Edge) { }
+      
+      ///\bug This doesn't work. Why?
+      ///      void set(Edge n, T a) { container[n.n]=a; }
+      void set(Edge n, T a) { container[G->id(n)]=a; }
+      //T get(Edge n) const { return container[n.n]; }
+      typename std::vector<T>::reference
+      ///\bug This doesn't work. Why?
+      ///      operator[](Edge n) { return container[n.n]; }
+      operator[](Edge n) { return container[G->id(n)]; }
+      typename std::vector<T>::const_reference
+      ///\bug This doesn't work. Why?
+      ///      operator[](Edge n) const { return container[n.n]; }
+      operator[](Edge n) const { return container[G->id(n)]; }
+
+      ///\warning There is no safety check at all!
+      ///Using operator = between maps attached to different graph may
+      ///cause serious problem.
+      ///\todo Is this really so?
+      ///\todo It can copy between different types.
+      const EdgeMap<T>& operator=(const EdgeMap<T> &m)
+      {
+	container = m.container;
+	return *this;
+      }
+      
+      template<typename TT> friend class EdgeMap;
+
+      template<typename TT>
+      const EdgeMap<T>& operator=(const EdgeMap<TT> &m)
+      {
+	std::copy(m.container.begin(), m.container.end(), container.begin());
+	return *this;
+      }
+      
+      void update() {}    //Useless for DynMaps
+      void update(T a) {}  //Useless for DynMaps
+    };
+
+  };
+
+  template<typename GG>
+  inline int EdgeSet<GG>::id(Node v) const { return G.id(v); }
+
+/// @}  
+
+} //namespace hugo
+
+#endif //HUGO_LIST_GRAPH_H