alpar@906: /* -*- C++ -*-
alpar@906:  *
alpar@1956:  * This file is a part of LEMON, a generic C++ optimization library
alpar@1956:  *
alpar@1956:  * Copyright (C) 2003-2006
alpar@1956:  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
alpar@1359:  * (Egervary Research Group on Combinatorial Optimization, EGRES).
alpar@906:  *
alpar@906:  * Permission to use, modify and distribute this software is granted
alpar@906:  * provided that this copyright notice appears in all copies. For
alpar@906:  * precise terms see the accompanying LICENSE file.
alpar@906:  *
alpar@906:  * This software is provided "AS IS" with no warranty of any kind,
alpar@906:  * express or implied, and with no claim as to its suitability for any
alpar@906:  * purpose.
alpar@906:  *
alpar@906:  */
alpar@105: 
alpar@921: #ifndef LEMON_SMART_GRAPH_H
alpar@921: #define LEMON_SMART_GRAPH_H
alpar@104: 
klao@491: ///\ingroup graphs
alpar@242: ///\file
deba@2116: ///\brief SmartGraph and SmartUGraph classes.
alpar@242: 
alpar@104: #include <vector>
alpar@104: 
deba@1993: #include <lemon/bits/invalid.h>
alpar@157: 
deba@2116: #include <lemon/bits/base_extender.h>
deba@1791: #include <lemon/bits/graph_extender.h>
klao@1034: 
deba@1993: #include <lemon/bits/utility.h>
deba@2116: #include <lemon/error.h>
deba@782: 
deba@1979: #include <lemon/bits/graph_extender.h>
deba@1979: 
alpar@921: namespace lemon {
alpar@104: 
alpar@973:   class SmartGraph;
alpar@969:   ///Base of SmartGraph
alpar@969: 
alpar@969:   ///Base of SmartGraph
alpar@969:   ///
klao@946:   class SmartGraphBase {
alpar@104: 
alpar@973:     friend class SmatGraph;
alpar@973: 
alpar@973:   protected:
alpar@104:     struct NodeT 
alpar@104:     {
alpar@104:       int first_in,first_out;      
alpar@157:       NodeT() : first_in(-1), first_out(-1) {}
alpar@104:     };
alpar@104:     struct EdgeT 
alpar@104:     {
alpar@986:       int target, source, next_in, next_out;      
alpar@104:       //FIXME: is this necessary?
alpar@157:       EdgeT() : next_in(-1), next_out(-1) {}  
alpar@104:     };
alpar@104: 
alpar@104:     std::vector<NodeT> nodes;
alpar@129: 
alpar@104:     std::vector<EdgeT> edges;
alpar@104:     
alpar@185:     
alpar@104:   public:
deba@782: 
klao@946:     typedef SmartGraphBase Graph;
alpar@104: 
alpar@164:     class Node;
alpar@164:     class Edge;
alpar@108: 
alpar@104:     
alpar@104:   public:
alpar@104: 
klao@946:     SmartGraphBase() : nodes(), edges() { }
deba@1718:     SmartGraphBase(const SmartGraphBase &_g) 
deba@1718:       : nodes(_g.nodes), edges(_g.edges) { }
alpar@104:     
klao@977:     typedef True NodeNumTag;
klao@977:     typedef True EdgeNumTag;
klao@977: 
alpar@813:     ///Number of nodes.
alpar@813:     int nodeNum() const { return nodes.size(); }
alpar@813:     ///Number of edges.
alpar@813:     int edgeNum() const { return edges.size(); }
alpar@104: 
alpar@813:     /// Maximum node ID.
alpar@813:     
alpar@813:     /// Maximum node ID.
alpar@813:     ///\sa id(Node)
deba@1791:     int maxNodeId() const { return nodes.size()-1; }
alpar@813:     /// Maximum edge ID.
alpar@813:     
alpar@813:     /// Maximum edge ID.
alpar@813:     ///\sa id(Edge)
deba@1791:     int maxEdgeId() const { return edges.size()-1; }
alpar@108: 
alpar@2128:     Node addNode() {
alpar@2128:       Node n; n.n=nodes.size();
alpar@2128:       nodes.push_back(NodeT()); //FIXME: Hmmm...
alpar@2128:       return n;
alpar@2128:     }
alpar@2128:     
alpar@2128:     Edge addEdge(Node u, Node v) {
alpar@2128:       Edge e; e.n=edges.size(); edges.push_back(EdgeT()); //FIXME: Hmmm...
alpar@2128:       edges[e.n].source=u.n; edges[e.n].target=v.n;
alpar@2128:       edges[e.n].next_out=nodes[u.n].first_out;
alpar@2128:       edges[e.n].next_in=nodes[v.n].first_in;
alpar@2128:       nodes[u.n].first_out=nodes[v.n].first_in=e.n;
alpar@2128: 
alpar@2128:       return e;
alpar@2128:     }
alpar@2128: 
alpar@2128: 
alpar@986:     Node source(Edge e) const { return edges[e.n].source; }
alpar@986:     Node target(Edge e) const { return edges[e.n].target; }
alpar@104: 
alpar@813:     /// Node ID.
alpar@813:     
alpar@813:     /// The ID of a valid Node is a nonnegative integer not greater than
deba@1791:     /// \ref maxNodeId(). The range of the ID's is not surely continuous
deba@1791:     /// and the greatest node ID can be actually less then \ref maxNodeId().
alpar@813:     ///
alpar@813:     /// The ID of the \ref INVALID node is -1.
alpar@813:     ///\return The ID of the node \c v. 
alpar@713:     static int id(Node v) { return v.n; }
alpar@813:     /// Edge ID.
alpar@813:     
alpar@813:     /// The ID of a valid Edge is a nonnegative integer not greater than
deba@1791:     /// \ref maxEdgeId(). The range of the ID's is not surely continuous
deba@1791:     /// and the greatest edge ID can be actually less then \ref maxEdgeId().
alpar@813:     ///
alpar@813:     /// The ID of the \ref INVALID edge is -1.
alpar@813:     ///\return The ID of the edge \c e. 
alpar@713:     static int id(Edge e) { return e.n; }
alpar@104: 
deba@2076:     /// \brief Returns the node from its \c id.
deba@2076:     ///
deba@2076:     /// Returns the node from its \c id. If there is not node
deba@2076:     /// with the given id the effect of the function is undefinied.
deba@1791:     static Node nodeFromId(int id) { return Node(id);}
deba@1106: 
deba@2076:     /// \brief Returns the edge from its \c id.
deba@2076:     ///
deba@2076:     /// Returns the edge from its \c id. If there is not edge
deba@2076:     /// with the given id the effect of the function is undefinied.
deba@1791:     static Edge edgeFromId(int id) { return Edge(id);}
deba@1106: 
alpar@164:     class Node {
klao@946:       friend class SmartGraphBase;
alpar@973:       friend class SmartGraph;
alpar@104: 
alpar@104:     protected:
alpar@104:       int n;
alpar@164:       Node(int nn) {n=nn;}
alpar@104:     public:
alpar@164:       Node() {}
alpar@503:       Node (Invalid) { n=-1; }
alpar@164:       bool operator==(const Node i) const {return n==i.n;}
alpar@164:       bool operator!=(const Node i) const {return n!=i.n;}
alpar@164:       bool operator<(const Node i) const {return n<i.n;}
alpar@104:     };
alpar@104:     
alpar@104: 
alpar@164:     class Edge {
klao@946:       friend class SmartGraphBase;
alpar@973:       friend class SmartGraph;
alpar@185: 
alpar@104:     protected:
alpar@104:       int n;
alpar@905:       Edge(int nn) {n=nn;}
alpar@706:     public:
alpar@164:       Edge() { }
marci@174:       Edge (Invalid) { n=-1; }
alpar@164:       bool operator==(const Edge i) const {return n==i.n;}
alpar@164:       bool operator!=(const Edge i) const {return n!=i.n;}
alpar@164:       bool operator<(const Edge i) const {return n<i.n;}
klao@946:     };
alpar@905: 
klao@946:     void first(Node& node) const {
klao@946:       node.n = nodes.size() - 1;
klao@946:     }
klao@946: 
klao@946:     static void next(Node& node) {
klao@946:       --node.n;
klao@946:     }
klao@946: 
klao@946:     void first(Edge& edge) const {
klao@946:       edge.n = edges.size() - 1;
klao@946:     }
klao@946: 
klao@946:     static void next(Edge& edge) {
klao@946:       --edge.n;
klao@946:     }
klao@946: 
klao@946:     void firstOut(Edge& edge, const Node& node) const {
klao@946:       edge.n = nodes[node.n].first_out;
klao@946:     }
klao@946: 
klao@946:     void nextOut(Edge& edge) const {
klao@946:       edge.n = edges[edge.n].next_out;
klao@946:     }
klao@946: 
klao@946:     void firstIn(Edge& edge, const Node& node) const {
klao@946:       edge.n = nodes[node.n].first_in;
klao@946:     }
alpar@104:     
klao@946:     void nextIn(Edge& edge) const {
klao@946:       edge.n = edges[edge.n].next_in;
klao@946:     }
alpar@105: 
alpar@104:   };
alpar@185: 
deba@1979:   typedef GraphExtender<SmartGraphBase> ExtendedSmartGraphBase;
deba@937: 
deba@1791:   /// \ingroup graphs
alpar@1161: 
alpar@950:   ///A smart graph class.
deba@937: 
alpar@950:   ///This is a simple and fast graph implementation.
alpar@950:   ///It is also quite memory efficient, but at the price
alpar@974:   ///that <b> it does support only limited (only stack-like)
alpar@974:   ///node and edge deletions</b>.
alpar@950:   ///It conforms to 
alpar@2123:   ///the \ref concept::Graph "Graph concept".
deba@2111:   ///\sa concept::Graph.
alpar@950:   ///
alpar@950:   ///\author Alpar Juttner
deba@1669:   class SmartGraph : public ExtendedSmartGraphBase {
alpar@969:   public:
deba@1979: 
deba@1979:     typedef ExtendedSmartGraphBase Parent;
deba@1979: 
alpar@1770:     class Snapshot;
alpar@1770:     friend class Snapshot;
alpar@973: 
alpar@2128:   private:
alpar@2128:     ///SmartGraph is \e not copy constructible. Use GraphCopy() instead.
alpar@2128: 
alpar@2128:     ///SmartGraph is \e not copy constructible. Use GraphCopy() instead.
alpar@2128:     ///
alpar@2128:     SmartGraph(const SmartGraph &) :ExtendedSmartGraphBase() {};
alpar@2132:     ///\brief Assignment of SmartGraph to another one is \e not allowed.
alpar@2128:     ///Use GraphCopy() instead.
alpar@2128: 
alpar@2132:     ///Assignment of SmartGraph to another one is \e not allowed.
alpar@2128:     ///Use GraphCopy() instead.
alpar@2128:     void operator=(const SmartGraph &) {}
alpar@1011:   protected:
alpar@1770:     void restoreSnapshot(const Snapshot &s)
alpar@973:     {
alpar@1457:       while(s.edge_num<edges.size()) {
deba@1040: 	Parent::getNotifier(Edge()).erase(Edge(edges.size()-1));
alpar@986: 	nodes[edges.back().target].first_in=edges.back().next_in;
alpar@986: 	nodes[edges.back().source].first_out=edges.back().next_out;
alpar@973: 	edges.pop_back();
alpar@973:       }
alpar@973:       //nodes.resize(s.nodes_num);
alpar@1457:       while(s.node_num<nodes.size()) {
deba@1040: 	Parent::getNotifier(Node()).erase(Node(nodes.size()-1));
alpar@973: 	nodes.pop_back();
alpar@973:       }
alpar@1011:     }    
alpar@1011: 
alpar@1011:   public:
alpar@2128:     
alpar@2128:     /// Constructor
alpar@2128:     
alpar@2128:     /// Constructor.
alpar@2128:     ///
alpar@2128:     SmartGraph() {};
alpar@2128:     
alpar@2128:     ///Add a new node to the graph.
alpar@2128:     
alpar@2128:     /// \return the new node.
alpar@2128:     ///
alpar@2128:     Node addNode() { return Parent::addNode(); }
alpar@2128:     
alpar@2128:     ///Add a new edge to the graph.
alpar@2128:     
alpar@2128:     ///Add a new edge to the graph with source node \c s
alpar@2128:     ///and target node \c t.
alpar@2128:     ///\return the new edge.
alpar@2128:     Edge addEdge(const Node& s, const Node& t) { 
alpar@2128:       return Parent::addEdge(s, t); 
alpar@2128:     }
alpar@2128: 
alpar@2128:     ///\e
alpar@2128:     
alpar@2128:     ///\bug Undocumented
alpar@2128:     ///\bug Doesn't destruct the maps.
alpar@2128:     void clear() {
alpar@2128:       edges.clear();
alpar@2128:       nodes.clear();
alpar@2128:     }
alpar@1284: 
alpar@1284:     ///Split a node.
alpar@1284:     
alpar@1284:     ///This function splits a node. First a new node is added to the graph,
alpar@1284:     ///then the source of each outgoing edge of \c n is moved to this new node.
alpar@1284:     ///If \c connect is \c true (this is the default value), then a new edge
alpar@1284:     ///from \c n to the newly created node is also added.
alpar@1284:     ///\return The newly created node.
alpar@1284:     ///
alpar@1284:     ///\note The <tt>Edge</tt>s
alpar@1284:     ///referencing a moved edge remain
alpar@1284:     ///valid. However <tt>InEdge</tt>'s and <tt>OutEdge</tt>'s
alpar@1284:     ///may be invalidated.
alpar@1770:     ///\warning This functionality cannot be used together with the Snapshot
alpar@1284:     ///feature.
alpar@1284:     ///\todo It could be implemented in a bit faster way.
alpar@2128:     Node split(Node n, bool connect = true)
alpar@1284:     {
alpar@2128:       Node b = addNode();
alpar@2128:       nodes[b.n].first_out=nodes[n.n].first_out;
alpar@2128:       nodes[n.n].first_out=-1;
alpar@2128:       for(int i=nodes[b.n].first_out;i!=-1;i++) edges[i].source=b.n;
alpar@2128:       if(connect) addEdge(n,b);
deba@1718:       return b;
alpar@1284:     }
alpar@1284: 
alpar@1011:     ///Class to make a snapshot of the graph and to restrore to it later.
alpar@1011: 
alpar@1011:     ///Class to make a snapshot of the graph and to restrore to it later.
alpar@1011:     ///
alpar@1011:     ///The newly added nodes and edges can be removed using the
alpar@1011:     ///restore() function.
alpar@1011:     ///\note After you restore a state, you cannot restore
alpar@1011:     ///a later state, in other word you cannot add again the edges deleted
alpar@2132:     ///by restore() using another one Snapshot instance.
alpar@1011:     ///
alpar@1770:     class Snapshot 
alpar@1011:     {
alpar@1011:       SmartGraph *g;
alpar@1011:     protected:
alpar@1011:       friend class SmartGraph;
alpar@1011:       unsigned int node_num;
alpar@1011:       unsigned int edge_num;
alpar@1011:     public:
zsuzska@1274:       ///Default constructor.
alpar@1011:       
zsuzska@1274:       ///Default constructor.
alpar@1011:       ///To actually make a snapshot you must call save().
alpar@1011:       ///
alpar@1770:       Snapshot() : g(0) {}
alpar@1011:       ///Constructor that immediately makes a snapshot
alpar@1011:       
alpar@1011:       ///This constructor immediately makes a snapshot of the graph.
alpar@1011:       ///\param _g The graph we make a snapshot of.
alpar@1770:       Snapshot(SmartGraph &_g) :g(&_g) {
alpar@1011: 	node_num=g->nodes.size();
alpar@1011: 	edge_num=g->edges.size();
alpar@1011:       }
alpar@1011: 
alpar@1011:       ///Make a snapshot.
alpar@1011: 
alpar@1011:       ///Make a snapshot of the graph.
alpar@1011:       ///
alpar@1011:       ///This function can be called more than once. In case of a repeated
alpar@1011:       ///call, the previous snapshot gets lost.
alpar@1011:       ///\param _g The graph we make the snapshot of.
alpar@1011:       void save(SmartGraph &_g) 
alpar@1011:       {
alpar@1011: 	g=&_g;
alpar@1011: 	node_num=g->nodes.size();
alpar@1011: 	edge_num=g->edges.size();
alpar@1011:       }
alpar@1011: 
alpar@1011:       ///Undo the changes until a snapshot.
alpar@1011:       
alpar@1011:       ///Undo the changes until a snapshot created by save().
alpar@1011:       ///
alpar@1011:       ///\note After you restored a state, you cannot restore
alpar@1011:       ///a later state, in other word you cannot add again the edges deleted
alpar@1011:       ///by restore().
alpar@1011:       ///
alpar@1011:       ///\todo This function might be called undo().
alpar@1011:       
alpar@1011:       void restore()
alpar@1011:       {
alpar@1770: 	g->restoreSnapshot(*this);
alpar@1011:       }
alpar@1011:     };
alpar@973:   };
klao@1034: 
klao@1034: 
deba@2116:   /**************** Undirected List Graph ****************/
deba@2116: 
deba@2116:   typedef UGraphExtender<UndirGraphExtender<SmartGraphBase> >
deba@2116:   ExtendedSmartUGraphBase;
deba@2116: 
deba@2116:   /// \ingroup graphs
deba@2116:   ///
deba@2116:   /// \brief A smart undirected graph class.
deba@2116:   ///
deba@2116:   /// This is a simple and fast undirected graph implementation.
deba@2116:   /// It is also quite memory efficient, but at the price
deba@2116:   /// that <b> it does support only limited (only stack-like)
deba@2116:   /// node and edge deletions</b>.
deba@2116:   /// Except from this it conforms to 
alpar@2123:   /// the \ref concept::UGraph "UGraph concept".
deba@2116:   /// \sa concept::UGraph.
deba@2116:   ///
deba@2116:   /// \todo Snapshot hasn't been implemented yet.
deba@2116:   ///
deba@2116:   class SmartUGraph : public ExtendedSmartUGraphBase {
alpar@2128:   private:
alpar@2128:     ///SmartUGraph is \e not copy constructible. Use UGraphCopy() instead.
alpar@2128: 
alpar@2128:     ///SmartUGraph is \e not copy constructible. Use UGraphCopy() instead.
alpar@2128:     ///
alpar@2128:     SmartUGraph(const SmartUGraph &) : ExtendedSmartUGraphBase() {};
alpar@2132:     ///\brief Assignment of SmartUGraph to another one is \e not allowed.
alpar@2128:     ///Use UGraphCopy() instead.
alpar@2128: 
alpar@2132:     ///Assignment of SmartUGraph to another one is \e not allowed.
alpar@2128:     ///Use UGraphCopy() instead.
alpar@2128:     void operator=(const SmartUGraph &) {}
alpar@2128:   public:
alpar@2128:     /// Constructor
alpar@2128:     
alpar@2128:     /// Constructor.
alpar@2128:     ///
alpar@2128:     SmartUGraph() {}
deba@2116:   };
deba@2116: 
deba@2116: 
deba@2116:   class SmartBpUGraphBase {
deba@2116:   public:
deba@2116: 
deba@2116:     class NodeSetError : public LogicError {
deba@2162:     public:
alpar@2151:       virtual const char* what() const throw() { 
deba@2116: 	return "lemon::SmartBpUGraph::NodeSetError";
deba@2116:       }
deba@2116:     };
deba@2116: 
deba@2116:   protected:
deba@2116: 
deba@2116:     struct NodeT {
deba@2116:       int first;
deba@2116:       NodeT() {}
deba@2116:       NodeT(int _first) : first(_first) {}
deba@2116:     };
deba@2116: 
deba@2116:     struct UEdgeT {
deba@2116:       int aNode, next_out;
deba@2116:       int bNode, next_in;
deba@2116:     };
deba@2116: 
deba@2116:     std::vector<NodeT> aNodes;
deba@2116:     std::vector<NodeT> bNodes;
deba@2116: 
deba@2116:     std::vector<UEdgeT> edges;
deba@2116: 
deba@2116:   public:
deba@2116:   
deba@2116:     class Node {
deba@2116:       friend class SmartBpUGraphBase;
deba@2116:     protected:
deba@2116:       int id;
deba@2116: 
deba@2116:       Node(int _id) : id(_id) {}
deba@2116:     public:
deba@2116:       Node() {}
deba@2116:       Node(Invalid) { id = -1; }
deba@2116:       bool operator==(const Node i) const {return id==i.id;}
deba@2116:       bool operator!=(const Node i) const {return id!=i.id;}
deba@2116:       bool operator<(const Node i) const {return id<i.id;}
deba@2116:     };
deba@2116: 
deba@2116:     class UEdge {
deba@2116:       friend class SmartBpUGraphBase;
deba@2116:     protected:
deba@2116:       int id;
deba@2116: 
deba@2116:       UEdge(int _id) { id = _id;}
deba@2116:     public:
deba@2116:       UEdge() {}
deba@2116:       UEdge (Invalid) { id = -1; }
deba@2116:       bool operator==(const UEdge i) const {return id==i.id;}
deba@2116:       bool operator!=(const UEdge i) const {return id!=i.id;}
deba@2116:       bool operator<(const UEdge i) const {return id<i.id;}
deba@2116:     };
deba@2116: 
deba@2116:     void firstANode(Node& node) const {
deba@2116:       node.id = 2 * aNodes.size() - 2;
deba@2116:       if (node.id < 0) node.id = -1; 
deba@2116:     }
deba@2116:     void nextANode(Node& node) const {
deba@2116:       node.id -= 2;
deba@2116:       if (node.id < 0) node.id = -1; 
deba@2116:     }
deba@2116: 
deba@2116:     void firstBNode(Node& node) const {
deba@2116:       node.id = 2 * bNodes.size() - 1;
deba@2116:     }
deba@2116:     void nextBNode(Node& node) const {
deba@2116:       node.id -= 2;
deba@2116:     }
deba@2116: 
deba@2116:     void first(Node& node) const {
deba@2116:       if (aNodes.size() > 0) {
deba@2116: 	node.id = 2 * aNodes.size() - 2;
deba@2116:       } else {
deba@2116: 	node.id = 2 * bNodes.size() - 1;
deba@2116:       }
deba@2116:     }
deba@2116:     void next(Node& node) const {
deba@2116:       node.id -= 2;
deba@2116:       if (node.id == -2) {
deba@2116: 	node.id = 2 * bNodes.size() - 1;
deba@2116:       }
deba@2116:     }
deba@2116:   
deba@2116:     void first(UEdge& edge) const {
deba@2116:       edge.id = edges.size() - 1;
deba@2116:     }
deba@2116:     void next(UEdge& edge) const {
deba@2116:       --edge.id;
deba@2116:     }
deba@2116: 
deba@2116:     void firstFromANode(UEdge& edge, const Node& node) const {
deba@2116:       LEMON_ASSERT((node.id & 1) == 0, NodeSetError());
deba@2116:       edge.id = aNodes[node.id >> 1].first;
deba@2116:     }
deba@2116:     void nextFromANode(UEdge& edge) const {
deba@2116:       edge.id = edges[edge.id].next_out;
deba@2116:     }
deba@2116: 
deba@2116:     void firstFromBNode(UEdge& edge, const Node& node) const {
deba@2116:       LEMON_ASSERT((node.id & 1) == 1, NodeSetError());
deba@2116:       edge.id = bNodes[node.id >> 1].first;
deba@2116:     }
deba@2116:     void nextFromBNode(UEdge& edge) const {
deba@2116:       edge.id = edges[edge.id].next_in;
deba@2116:     }
deba@2116: 
deba@2116:     static int id(const Node& node) {
deba@2116:       return node.id;
deba@2116:     }
deba@2116:     static Node nodeFromId(int id) {
deba@2116:       return Node(id);
deba@2116:     }
deba@2116:     int maxNodeId() const {
deba@2116:       return aNodes.size() > bNodes.size() ?
deba@2116: 	aNodes.size() * 2 - 2 : bNodes.size() * 2 - 1;
deba@2116:     }
deba@2116:   
deba@2116:     static int id(const UEdge& edge) {
deba@2116:       return edge.id;
deba@2116:     }
deba@2116:     static UEdge uEdgeFromId(int id) {
deba@2116:       return UEdge(id);
deba@2116:     }
deba@2116:     int maxUEdgeId() const {
deba@2116:       return edges.size();
deba@2116:     }
deba@2116:   
deba@2116:     static int aNodeId(const Node& node) {
deba@2116:       return node.id >> 1;
deba@2116:     }
deba@2116:     static Node fromANodeId(int id) {
deba@2116:       return Node(id << 1);
deba@2116:     }
deba@2116:     int maxANodeId() const {
deba@2116:       return aNodes.size();
deba@2116:     }
deba@2116: 
deba@2116:     static int bNodeId(const Node& node) {
deba@2116:       return node.id >> 1;
deba@2116:     }
deba@2116:     static Node fromBNodeId(int id) {
deba@2116:       return Node((id << 1) + 1);
deba@2116:     }
deba@2116:     int maxBNodeId() const {
deba@2116:       return bNodes.size();
deba@2116:     }
deba@2116: 
deba@2116:     Node aNode(const UEdge& edge) const {
deba@2116:       return Node(edges[edge.id].aNode);
deba@2116:     }
deba@2116:     Node bNode(const UEdge& edge) const {
deba@2116:       return Node(edges[edge.id].bNode);
deba@2116:     }
deba@2116: 
deba@2116:     static bool aNode(const Node& node) {
deba@2116:       return (node.id & 1) == 0;
deba@2116:     }
deba@2116: 
deba@2116:     static bool bNode(const Node& node) {
deba@2116:       return (node.id & 1) == 1;
deba@2116:     }
deba@2116: 
deba@2116:     Node addANode() {
deba@2116:       NodeT nodeT;
deba@2116:       nodeT.first = -1;
deba@2116:       aNodes.push_back(nodeT);
deba@2116:       return Node(aNodes.size() * 2 - 2);
deba@2116:     }
deba@2116: 
deba@2116:     Node addBNode() {
deba@2116:       NodeT nodeT;
deba@2116:       nodeT.first = -1;
deba@2116:       bNodes.push_back(nodeT);
deba@2116:       return Node(bNodes.size() * 2 - 1);
deba@2116:     }
deba@2116: 
deba@2116:     UEdge addEdge(const Node& source, const Node& target) {
deba@2116:       LEMON_ASSERT(((source.id ^ target.id) & 1) == 1, NodeSetError());
deba@2116:       UEdgeT edgeT;
deba@2116:       if ((source.id & 1) == 0) {
deba@2116: 	edgeT.aNode = source.id;
deba@2116: 	edgeT.bNode = target.id;
deba@2116:       } else {
deba@2116: 	edgeT.aNode = target.id;
deba@2116: 	edgeT.bNode = source.id;
deba@2116:       }
deba@2116:       edgeT.next_out = aNodes[edgeT.aNode >> 1].first;
deba@2116:       aNodes[edgeT.aNode >> 1].first = edges.size();
deba@2116:       edgeT.next_in = bNodes[edgeT.bNode >> 1].first;
deba@2116:       bNodes[edgeT.bNode >> 1].first = edges.size();
deba@2116:       edges.push_back(edgeT);
deba@2116:       return UEdge(edges.size() - 1);
deba@2116:     }
deba@2116: 
deba@2116:     void clear() {
deba@2116:       aNodes.clear();
deba@2116:       bNodes.clear();
deba@2116:       edges.clear();
deba@2116:     }
deba@2116: 
deba@2116:     typedef True NodeNumTag;
deba@2116:     int nodeNum() const { return aNodes.size() + bNodes.size(); }
deba@2116:     int aNodeNum() const { return aNodes.size(); }
deba@2116:     int bNodeNum() const { return bNodes.size(); }
deba@2116: 
deba@2116:     typedef True EdgeNumTag;
deba@2116:     int uEdgeNum() const { return edges.size(); }
deba@2116: 
deba@2116:   };
deba@2116: 
deba@2116: 
deba@2116:   typedef BpUGraphExtender<SmartBpUGraphBase> ExtendedSmartBpUGraphBase;
deba@2116: 
deba@2116:   /// \ingroup graphs
deba@2116:   ///
deba@2116:   /// \brief A smart bipartite undirected graph class.
deba@2116:   ///
deba@2116:   /// This is a simple and fast bipartite undirected graph implementation.
deba@2116:   /// It is also quite memory efficient, but at the price
deba@2116:   /// that <b> it does not support node and edge deletions</b>.
deba@2116:   /// Except from this it conforms to 
alpar@2123:   /// the \ref concept::BpUGraph "BpUGraph concept".
deba@2116:   /// \sa concept::BpUGraph.
deba@2116:   ///
deba@2116:   class SmartBpUGraph : public ExtendedSmartBpUGraphBase {};
deba@2116: 
deba@2116:   
deba@2116:   /// @}  
alpar@921: } //namespace lemon
alpar@104: 
alpar@157: 
alpar@921: #endif //LEMON_SMART_GRAPH_H