alpar@906: /* -*- C++ -*-
alpar@921:  * src/lemon/smart_graph.h - Part of LEMON, a generic C++ optimization library
alpar@906:  *
alpar@906:  * Copyright (C) 2004 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
alpar@906:  * (Egervary Combinatorial Optimization Research Group, 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
alpar@242: ///\brief SmartGraph and SymSmartGraph classes.
alpar@242: 
alpar@104: #include <vector>
deba@782: #include <climits>
alpar@104: 
alpar@921: #include <lemon/invalid.h>
alpar@157: 
deba@937: 
alpar@921: #include <lemon/array_map.h>
alpar@919: 
alpar@921: #include <lemon/map_registry.h>
deba@782: 
alpar@921: #include <lemon/map_defines.h>
deba@782: 
alpar@921: namespace lemon {
alpar@104: 
alpar@407: /// \addtogroup graphs
alpar@407: /// @{
deba@782: //  class SymSmartGraph;
alpar@185: 
alpar@186:   ///A smart graph class.
alpar@186: 
alpar@186:   ///This is a simple and fast graph implementation.
alpar@186:   ///It is also quite memory efficient, but at the price
alpar@186:   ///that <b> it does not support node and edge deletion</b>.
alpar@880:   ///It conforms to 
alpar@880:   ///the \ref skeleton::ExtendableGraph "ExtendableGraph" concept.
alpar@880:   ///\sa skeleton::ExtendableGraph.
alpar@402:   ///
alpar@402:   ///\todo Some member functions could be \c static.
alpar@753:   ///
alpar@753:   ///\todo A possibly useful functionality: a function saveState() would
alpar@753:   ///give back a data sturcture X and then the function restoreState(X)
alpar@753:   ///would remove the nodes and edges added after the call of saveState().
alpar@753:   ///Of course it should be used as a stack. (Maybe X is not necessary.)
alpar@753:   ///
alpar@456:   ///\author Alpar Juttner
alpar@104:   class SmartGraph {
alpar@104: 
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@104:       int head, tail, 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: 
deba@782:     typedef SmartGraph Graph;
alpar@104: 
alpar@164:     class Node;
alpar@164:     class Edge;
alpar@108: 
alpar@164:     class NodeIt;
alpar@164:     class EdgeIt;
alpar@104:     class OutEdgeIt;
alpar@104:     class InEdgeIt;
alpar@104:     
alpar@904:     // Create map registries.
deba@782:     CREATE_MAP_REGISTRIES;
alpar@904:     // Create node and edge maps.
deba@897:     CREATE_MAPS(ArrayMap);
alpar@104:     
alpar@104:   public:
alpar@104: 
alpar@104:     SmartGraph() : nodes(), edges() { }
alpar@136:     SmartGraph(const SmartGraph &_g) : nodes(_g.nodes), edges(_g.edges) { }
alpar@104:     
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)
alpar@813:     int maxNodeId() const { return nodes.size()-1; }
alpar@813:     /// Maximum edge ID.
alpar@813:     
alpar@813:     /// Maximum edge ID.
alpar@813:     ///\sa id(Edge)
alpar@813:     int maxEdgeId() const { return edges.size()-1; }
alpar@108: 
alpar@164:     Node tail(Edge e) const { return edges[e.n].tail; }
alpar@164:     Node head(Edge e) const { return edges[e.n].head; }
alpar@104: 
alpar@164:     NodeIt& first(NodeIt& v) const { 
alpar@164:       v=NodeIt(*this); return v; }
alpar@164:     EdgeIt& first(EdgeIt& e) const { 
alpar@164:       e=EdgeIt(*this); return e; }
alpar@164:     OutEdgeIt& first(OutEdgeIt& e, const Node v) const { 
alpar@104:       e=OutEdgeIt(*this,v); return e; }
alpar@164:     InEdgeIt& first(InEdgeIt& e, const Node v) const { 
alpar@104:       e=InEdgeIt(*this,v); return e; }
alpar@104: 
alpar@813:     /// Node ID.
alpar@813:     
alpar@813:     /// The ID of a valid Node is a nonnegative integer not greater than
alpar@813:     /// \ref maxNodeId(). The range of the ID's is not surely continuous
alpar@813:     /// 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
alpar@813:     /// \ref maxEdgeId(). The range of the ID's is not surely continuous
alpar@813:     /// 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: 
alpar@164:     Node addNode() {
alpar@164:       Node n; n.n=nodes.size();
alpar@104:       nodes.push_back(NodeT()); //FIXME: Hmmm...
alpar@108: 
deba@782:       
deba@782:       node_maps.add(n);
alpar@104:       return n;
alpar@104:     }
alpar@108:     
alpar@164:     Edge addEdge(Node u, Node v) {
alpar@164:       Edge e; e.n=edges.size(); edges.push_back(EdgeT()); //FIXME: Hmmm...
alpar@104:       edges[e.n].tail=u.n; edges[e.n].head=v.n;
alpar@104:       edges[e.n].next_out=nodes[u.n].first_out;
alpar@104:       edges[e.n].next_in=nodes[v.n].first_in;
alpar@104:       nodes[u.n].first_out=nodes[v.n].first_in=e.n;
alpar@108: 
deba@782:       edge_maps.add(e);
alpar@108: 
alpar@104:       return e;
alpar@104:     }
alpar@104: 
alpar@774:     /// Finds an edge between two nodes.
alpar@774: 
alpar@774:     /// Finds an edge from node \c u to node \c v.
alpar@774:     ///
alpar@774:     /// If \c prev is \ref INVALID (this is the default value), then
alpar@774:     /// It finds the first edge from \c u to \c v. Otherwise it looks for
alpar@774:     /// the next edge from \c u to \c v after \c prev.
alpar@774:     /// \return The found edge or INVALID if there is no such an edge.
alpar@774:     Edge findEdge(Node u,Node v, Edge prev = INVALID) 
alpar@774:     {
alpar@774:       int e = (prev.n==-1)? nodes[u.n].first_out : edges[prev.n].next_out;
alpar@774:       while(e!=-1 && edges[e].tail!=v.n) e = edges[e].next_out;
alpar@774:       prev.n=e;
alpar@774:       return prev;
alpar@774:     }
alpar@774:     
deba@782:     void clear() {
deba@782:       edge_maps.clear();
deba@782:       edges.clear();
deba@782:       node_maps.clear();
deba@782:       nodes.clear();
deba@782:     }
alpar@104: 
alpar@164:     class Node {
alpar@104:       friend class SmartGraph;
alpar@104:       template <typename T> friend class NodeMap;
alpar@104:       
alpar@164:       friend class Edge;
alpar@104:       friend class OutEdgeIt;
alpar@104:       friend class InEdgeIt;
alpar@164:       friend class SymEdge;
alpar@104: 
alpar@104:     protected:
alpar@104:       int n;
alpar@722:       friend int SmartGraph::id(Node v); 
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@774:       //      ///Validity check
alpar@774:       //      operator bool() { return n!=-1; }
alpar@104:     };
alpar@104:     
alpar@164:     class NodeIt : public Node {
alpar@774:       const SmartGraph *G;
alpar@104:       friend class SmartGraph;
alpar@104:     public:
alpar@402:       NodeIt() : Node() { }
alpar@774:       NodeIt(const SmartGraph& _G,Node n) : Node(n), G(&_G) { }
alpar@402:       NodeIt(Invalid i) : Node(i) { }
alpar@774:       NodeIt(const SmartGraph& _G) : Node(_G.nodes.size()?0:-1), G(&_G) { }
alpar@774:       NodeIt &operator++() {
alpar@774: 	n=(n+2)%(G->nodes.size()+1)-1; 
alpar@774: 	return *this; 
alpar@774:       }
alpar@774: //       ///Validity check
alpar@774: //       operator bool() { return Node::operator bool(); }      
alpar@104:     };
alpar@104: 
alpar@164:     class Edge {
alpar@104:       friend class SmartGraph;
alpar@104:       template <typename T> friend class EdgeMap;
alpar@185: 
alpar@905:       friend class SymSmartGraph;
alpar@104:       
alpar@164:       friend class Node;
alpar@104:       friend class NodeIt;
alpar@104:     protected:
alpar@104:       int n;
alpar@722:       friend int SmartGraph::id(Edge e);
alpar@905:       Edge(int nn) {n=nn;}
alpar@706:     public:
alpar@706:       /// An Edge with id \c n.
alpar@706: 
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;}
alpar@774: //       ///Validity check
alpar@774: //       operator bool() { return n!=-1; }
alpar@905: 
alpar@905:       ///Set the edge to that have ID \c ID.
alpar@905:       void setToId(int id) { n=id; }
alpar@774:    };
alpar@104:     
alpar@164:     class EdgeIt : public Edge {
alpar@774:       const SmartGraph *G;
alpar@104:       friend class SmartGraph;
alpar@104:     public:
alpar@774:       EdgeIt(const SmartGraph& _G) : Edge(_G.edges.size()-1), G(&_G) { }
alpar@774:       EdgeIt(const SmartGraph& _G, Edge e) : Edge(e), G(&_G) { }
alpar@164:       EdgeIt (Invalid i) : Edge(i) { }
alpar@164:       EdgeIt() : Edge() { }
alpar@774:       EdgeIt &operator++() { --n; return *this; }
alpar@774: //       ///Validity check
alpar@774: //       operator bool() { return Edge::operator bool(); }      
alpar@104:     };
alpar@104:     
alpar@164:     class OutEdgeIt : public Edge {
alpar@774:       const SmartGraph *G;
alpar@104:       friend class SmartGraph;
alpar@104:     public: 
alpar@164:       OutEdgeIt() : Edge() { }
alpar@774:       OutEdgeIt(const SmartGraph& _G, Edge e) : Edge(e), G(&_G) { }
alpar@164:       OutEdgeIt (Invalid i) : Edge(i) { }
alpar@157: 
alpar@774:       OutEdgeIt(const SmartGraph& _G,const Node v)
alpar@774: 	: Edge(_G.nodes[v.n].first_out), G(&_G) {}
alpar@774:       OutEdgeIt &operator++() { n=G->edges[n].next_out; return *this; }
alpar@774: //       ///Validity check
alpar@774: //       operator bool() { return Edge::operator bool(); }      
alpar@104:     };
alpar@104:     
alpar@164:     class InEdgeIt : public Edge {
alpar@774:       const SmartGraph *G;
alpar@104:       friend class SmartGraph;
alpar@104:     public: 
alpar@164:       InEdgeIt() : Edge() { }
alpar@774:       InEdgeIt(const SmartGraph& _G, Edge e) : Edge(e), G(&_G) { }
alpar@164:       InEdgeIt (Invalid i) : Edge(i) { }
alpar@774:       InEdgeIt(const SmartGraph& _G,Node v)
alpar@774: 	: Edge(_G.nodes[v.n].first_in), G(&_G) { }
alpar@774:       InEdgeIt &operator++() { n=G->edges[n].next_in; return *this; }
alpar@774: //       ///Validity check
alpar@774: //       operator bool() { return Edge::operator bool(); }      
alpar@104:     };
alpar@105: 
alpar@104:   };
alpar@185: 
deba@937: 
deba@937: 
deba@937:   class SymSmartGraph : public SmartGraph {
deba@937:     typedef SmartGraph Parent;
deba@937:   public:
deba@937: 
deba@937:     typedef SymSmartGraph Graph;
deba@937: 
deba@937:     typedef SmartGraph::Node Node;
deba@937:     typedef SmartGraph::NodeIt NodeIt;
deba@937: 
deba@937:     class SymEdge;
deba@937:     class SymEdgeIt;
deba@937: 
deba@937:     class Edge;
deba@937:     class EdgeIt;
deba@937:     class OutEdgeIt;
deba@937:     class InEdgeIt;
deba@937: 
deba@937:     template <typename Value>
deba@937:     class NodeMap : public Parent::NodeMap<Value> {      
deba@937:     public:
deba@937:       NodeMap(const SymSmartGraph& g) 
deba@937: 	: SymSmartGraph::Parent::NodeMap<Value>(g) {}
deba@937:       NodeMap(const SymSmartGraph& g, Value v) 
deba@937: 	: SymSmartGraph::Parent::NodeMap<Value>(g, v) {}
deba@937:       template<typename TT> 
deba@937:       NodeMap(const NodeMap<TT>& copy) 
deba@937: 	: SymSmartGraph::Parent::NodeMap<Value>(copy) { }            
deba@937:     };
deba@937: 
deba@937:     template <typename Value>
deba@937:     class SymEdgeMap : public Parent::EdgeMap<Value> {
deba@937:     public:
deba@937:       typedef SymEdge KeyType;
deba@937: 
deba@937:       SymEdgeMap(const SymSmartGraph& g) 
deba@937: 	: SymSmartGraph::Parent::EdgeMap<Value>(g) {}
deba@937:       SymEdgeMap(const SymSmartGraph& g, Value v) 
deba@937: 	: SymSmartGraph::Parent::EdgeMap<Value>(g, v) {}
deba@937:       template<typename TT> 
deba@937:       SymEdgeMap(const SymEdgeMap<TT>& copy) 
deba@937: 	: SymSmartGraph::Parent::EdgeMap<Value>(copy) { }
deba@937:       
deba@937:     };
deba@937: 
deba@937:     // Create edge map registry.
deba@937:     CREATE_EDGE_MAP_REGISTRY;
deba@937:     // Create edge maps.
deba@937:     CREATE_EDGE_MAP(ArrayMap);
deba@937: 
deba@937:     class Edge {
deba@937:       friend class SymSmartGraph;
deba@937:       friend class SymSmartGraph::EdgeIt;
deba@937:       friend class SymSmartGraph::OutEdgeIt;
deba@937:       friend class SymSmartGraph::InEdgeIt;
deba@937:       
deba@937:     protected:
deba@937:       int id;
deba@937: 
deba@937:       Edge(int pid) { id = pid; }
deba@937: 
deba@937:     public:
deba@937:       /// An Edge with id \c n.
deba@937: 
deba@937:       Edge() { }
deba@937:       Edge (Invalid) { id = -1; }
deba@937: 
deba@937:       operator SymEdge(){ return SymEdge(id >> 1);}
deba@937:       
deba@937:       bool operator==(const Edge i) const {return id == i.id;}
deba@937:       bool operator!=(const Edge i) const {return id != i.id;}
deba@937:       bool operator<(const Edge i) const {return id < i.id;}
deba@937:       //      ///Validity check
deba@937:       //      operator bool() { return n!=-1; }
deba@937:     };
deba@937: 
deba@937:     class SymEdge : public SmartGraph::Edge {
deba@937:       friend class SymSmartGraph;
deba@937:       friend class SymSmartGraph::Edge;
deba@937:       typedef SmartGraph::Edge Parent;
deba@937: 
deba@937:     protected:      
deba@937:       SymEdge(int pid) : Parent(pid) {}
deba@937:     public:
deba@937: 
deba@937:       SymEdge() { }
deba@937:       SymEdge(const SmartGraph::Edge& i) : Parent(i) {} 
deba@937:       SymEdge (Invalid) : Parent(INVALID) {}
deba@937: 
deba@937:     };
deba@937: 
deba@937:     class OutEdgeIt {
deba@937:       Parent::OutEdgeIt out;
deba@937:       Parent::InEdgeIt in;      
deba@937:     public: 
deba@937:       OutEdgeIt() {}
deba@937:       OutEdgeIt(const SymSmartGraph& g, Edge e) { 
deba@937: 	if ((e.id & 1) == 0) {	
deba@937: 	  out = Parent::OutEdgeIt(g, SymEdge(e));
deba@937: 	  in = Parent::InEdgeIt(g, g.tail(e));
deba@937: 	} else {
deba@937: 	  out = Parent::OutEdgeIt(INVALID);
deba@937: 	  in = Parent::InEdgeIt(g, SymEdge(e));
deba@937: 	}
deba@937:       }
deba@937:       OutEdgeIt (Invalid i) : out(INVALID), in(INVALID) { }
deba@937: 
deba@937:       OutEdgeIt(const SymSmartGraph& g, const Node v)
deba@937: 	: out(g, v), in(g, v) {}
deba@937:       OutEdgeIt &operator++() { 
deba@937: 	if (out != INVALID) {
deba@937: 	  ++out;
deba@937: 	} else {
deba@937: 	  ++in;
deba@937: 	}
deba@937: 	return *this; 
deba@937:       }
deba@937: 
deba@937:       operator Edge() const {
deba@937: 	if (out == INVALID && in == INVALID) return INVALID;
deba@937: 	return out != INVALID ? forward(out) : backward(in);
deba@937:       }
deba@937: 
deba@937:       bool operator==(const Edge i) const {return Edge(*this) == i;}
deba@937:       bool operator!=(const Edge i) const {return Edge(*this) != i;}
deba@937:       bool operator<(const Edge i) const {return Edge(*this) < i;}
deba@937:     };
deba@937: 
deba@937:     class InEdgeIt {
deba@937:       Parent::OutEdgeIt out;
deba@937:       Parent::InEdgeIt in;      
deba@937:     public: 
deba@937:       InEdgeIt() {}
deba@937:       InEdgeIt(const SymSmartGraph& g, Edge e) { 
deba@937: 	if ((e.id & 1) == 0) {	
deba@937: 	  out = Parent::OutEdgeIt(g, SymEdge(e));
deba@937: 	  in = Parent::InEdgeIt(g, g.tail(e));
deba@937: 	} else {
deba@937: 	  out = Parent::OutEdgeIt(INVALID);
deba@937: 	  in = Parent::InEdgeIt(g, SymEdge(e));
deba@937: 	}
deba@937:       }
deba@937:       InEdgeIt (Invalid i) : out(INVALID), in(INVALID) { }
deba@937: 
deba@937:       InEdgeIt(const SymSmartGraph& g, const Node v)
deba@937: 	: out(g, v), in(g, v) {}
deba@937: 
deba@937:       InEdgeIt &operator++() { 
deba@937: 	if (out != INVALID) {
deba@937: 	  ++out;
deba@937: 	} else {
deba@937: 	  ++in;
deba@937: 	}
deba@937: 	return *this; 
deba@937:       }
deba@937: 
deba@937:       operator Edge() const {
deba@937: 	if (out == INVALID && in == INVALID) return INVALID;
deba@937: 	return out != INVALID ? backward(out) : forward(in);
deba@937:       }
deba@937: 
deba@937:       bool operator==(const Edge i) const {return Edge(*this) == i;}
deba@937:       bool operator!=(const Edge i) const {return Edge(*this) != i;}
deba@937:       bool operator<(const Edge i) const {return Edge(*this) < i;}
deba@937:     };
deba@937: 
deba@937:     class SymEdgeIt : public Parent::EdgeIt {
deba@937: 
deba@937:     public:
deba@937:       SymEdgeIt() {}
deba@937: 
deba@937:       SymEdgeIt(const SymSmartGraph& g) 
deba@937: 	: SymSmartGraph::Parent::EdgeIt(g) {}
deba@937: 
deba@937:       SymEdgeIt(const SymSmartGraph& g, SymEdge e) 
deba@937: 	: SymSmartGraph::Parent::EdgeIt(g, e) {}
deba@937: 
deba@937:       SymEdgeIt(Invalid i) 
deba@937: 	: SymSmartGraph::Parent::EdgeIt(INVALID) {}
deba@937: 
deba@937:       SymEdgeIt& operator++() {
deba@937: 	SymSmartGraph::Parent::EdgeIt::operator++();
deba@937: 	return *this;
deba@937:       }
deba@937: 
deba@937:       operator SymEdge() const {
deba@937: 	return SymEdge
deba@937: 	  (static_cast<const SymSmartGraph::Parent::EdgeIt&>(*this));
deba@937:       }
deba@937:       bool operator==(const SymEdge i) const {return SymEdge(*this) == i;}
deba@937:       bool operator!=(const SymEdge i) const {return SymEdge(*this) != i;}
deba@937:       bool operator<(const SymEdge i) const {return SymEdge(*this) < i;}
deba@937:     };
deba@937: 
deba@937:     class EdgeIt {
deba@937:       SymEdgeIt it;
deba@937:       bool fw;
deba@937:     public:
deba@937:       EdgeIt(const SymSmartGraph& g) : it(g), fw(true) {}
deba@937:       EdgeIt (Invalid i) : it(i) { }
deba@937:       EdgeIt(const SymSmartGraph& g, Edge e) 
deba@937: 	: it(g, SymEdge(e)), fw(id(e) & 1 == 0) { }
deba@937:       EdgeIt() { }
deba@937:       EdgeIt& operator++() {
deba@937: 	fw = !fw;
deba@937: 	if (fw) ++it;
deba@937: 	return *this;
deba@937:       }
deba@937:       operator Edge() const {
deba@937: 	if (it == INVALID) return INVALID;
deba@937: 	return fw ? forward(it) : backward(it);
deba@937:       }
deba@937:       bool operator==(const Edge i) const {return Edge(*this) == i;}
deba@937:       bool operator!=(const Edge i) const {return Edge(*this) != i;}
deba@937:       bool operator<(const Edge i) const {return Edge(*this) < i;}
deba@937: 
deba@937:     };
deba@937: 
deba@937:     ///Number of nodes.
deba@937:     int nodeNum() const { return Parent::nodeNum(); }
deba@937:     ///Number of edges.
deba@937:     int edgeNum() const { return 2*Parent::edgeNum(); }
deba@937:     ///Number of symmetric edges.
deba@937:     int symEdgeNum() const { return Parent::edgeNum(); }
deba@937: 
deba@937:     /// Maximum node ID.
deba@937:     
deba@937:     /// Maximum node ID.
deba@937:     ///\sa id(Node)
deba@937:     int maxNodeId() const { return Parent::maxNodeId(); } 
deba@937:     /// Maximum edge ID.
deba@937:     
deba@937:     /// Maximum edge ID.
deba@937:     ///\sa id(Edge)
deba@937:     int maxEdgeId() const { return 2*Parent::maxEdgeId(); }
deba@937:     /// Maximum symmetric edge ID.
deba@937:     
deba@937:     /// Maximum symmetric edge ID.
deba@937:     ///\sa id(SymEdge)
deba@937:     int maxSymEdgeId() const { return Parent::maxEdgeId(); }
deba@937: 
deba@937: 
deba@937:     Node tail(Edge e) const { 
deba@937:       return (e.id & 1) == 0 ? 
deba@937: 	Parent::tail(SymEdge(e)) : Parent::head(SymEdge(e)); 
deba@937:     }
deba@937: 
deba@937:     Node head(Edge e) const { 
deba@937:       return (e.id & 1) == 0 ? 
deba@937: 	Parent::head(SymEdge(e)) : Parent::tail(SymEdge(e)); 
deba@937:     }
deba@937: 
deba@937:     Node tail(SymEdge e) const { 
deba@937:       return Parent::tail(e); 
deba@937:     }
deba@937: 
deba@937:     Node head(SymEdge e) const { 
deba@937:       return Parent::head(e); 
deba@937:     }
deba@937: 
deba@937:     NodeIt& first(NodeIt& v) const { 
deba@937:       v=NodeIt(*this); return v; }
deba@937:     EdgeIt& first(EdgeIt& e) const { 
deba@937:       e=EdgeIt(*this); return e; }
deba@937:     SymEdgeIt& first(SymEdgeIt& e) const {
deba@937:       e=SymEdgeIt(*this); return e; }
deba@937:     OutEdgeIt& first(OutEdgeIt& e, const Node v) const { 
deba@937:       e=OutEdgeIt(*this,v); return e; }
deba@937:     InEdgeIt& first(InEdgeIt& e, const Node v) const { 
deba@937:       e=InEdgeIt(*this,v); return e; }
deba@937: 
deba@937:     /// Node ID.
deba@937:     
deba@937:     /// The ID of a valid Node is a nonnegative integer not greater than
deba@937:     /// \ref maxNodeId(). The range of the ID's is not surely continuous
deba@937:     /// and the greatest node ID can be actually less then \ref maxNodeId().
deba@937:     ///
deba@937:     /// The ID of the \ref INVALID node is -1.
deba@937:     ///\return The ID of the node \c v. 
deba@937:     static int id(Node v) { return Parent::id(v); }
deba@937:     /// Edge ID.
deba@937:     
deba@937:     /// The ID of a valid Edge is a nonnegative integer not greater than
deba@937:     /// \ref maxEdgeId(). The range of the ID's is not surely continuous
deba@937:     /// and the greatest edge ID can be actually less then \ref maxEdgeId().
deba@937:     ///
deba@937:     /// The ID of the \ref INVALID edge is -1.
deba@937:     ///\return The ID of the edge \c e. 
deba@937:     static int id(Edge e) { return e.id; }
deba@937: 
deba@937:     /// The ID of a valid SymEdge is a nonnegative integer not greater than
deba@937:     /// \ref maxSymEdgeId(). The range of the ID's is not surely continuous
deba@937:     /// and the greatest edge ID can be actually less then \ref maxSymEdgeId().
deba@937:     ///
deba@937:     /// The ID of the \ref INVALID symmetric edge is -1.
deba@937:     ///\return The ID of the edge \c e. 
deba@937:     static int id(SymEdge e) { return Parent::id(e); }
deba@937: 
deba@937:     /// Adds a new node to the graph.
deba@937: 
deba@937:     /// \warning It adds the new node to the front of the list.
deba@937:     /// (i.e. the lastly added node becomes the first.)
deba@937:     Node addNode() {
deba@937:       return Parent::addNode();
deba@937:     }
deba@937:     
deba@937:     SymEdge addEdge(Node u, Node v) {
deba@937:       SymEdge se = Parent::addEdge(u, v);
deba@937:       edge_maps.add(forward(se));
deba@937:       edge_maps.add(backward(se));
deba@937:       return se;
deba@937:     }
deba@937:     
deba@937:     /// Finds an edge between two nodes.
deba@937: 
deba@937:     /// Finds an edge from node \c u to node \c v.
deba@937:     ///
deba@937:     /// If \c prev is \ref INVALID (this is the default value), then
deba@937:     /// It finds the first edge from \c u to \c v. Otherwise it looks for
deba@937:     /// the next edge from \c u to \c v after \c prev.
deba@937:     /// \return The found edge or INVALID if there is no such an edge.
deba@937:     Edge findEdge(Node u, Node v, Edge prev = INVALID) 
deba@937:     {     
deba@937:       if (prev == INVALID || id(prev) & 1 == 0) {
deba@937: 	SymEdge se = Parent::findEdge(u, v, SymEdge(prev));
deba@937: 	if (se != INVALID) return forward(se);
deba@937:       } else {
deba@937: 	SymEdge se = Parent::findEdge(v, u, SymEdge(prev));
deba@937: 	if (se != INVALID) return backward(se);	
deba@937:       }
deba@937:       return INVALID;
deba@937:     }
deba@937: 
deba@937: //     /// Finds an symmetric edge between two nodes.
deba@937: 
deba@937: //     /// Finds an symmetric edge from node \c u to node \c v.
deba@937: //     ///
deba@937: //     /// If \c prev is \ref INVALID (this is the default value), then
deba@937: //     /// It finds the first edge from \c u to \c v. Otherwise it looks for
deba@937: //     /// the next edge from \c u to \c v after \c prev.
deba@937: //     /// \return The found edge or INVALID if there is no such an edge.
deba@937: 
deba@937: //     SymEdge findEdge(Node u, Node v, SymEdge prev = INVALID) 
deba@937: //     {     
deba@937: //       if (prev == INVALID || id(prev) & 1 == 0) {
deba@937: // 	SymEdge se = Parent::findEdge(u, v, SymEdge(prev));
deba@937: // 	if (se != INVALID) return se;
deba@937: //       } else {
deba@937: // 	SymEdge se = Parent::findEdge(v, u, SymEdge(prev));
deba@937: // 	if (se != INVALID) return se;	
deba@937: //       }
deba@937: //       return INVALID;
deba@937: //     }
deba@937:     
deba@937:   public:
deba@937: 
deba@937:     void clear() {
deba@937:       edge_maps.clear();
deba@937:       Parent::clear();
deba@937:     }
deba@937: 
deba@937:     static Edge opposite(Edge e) {
deba@937:       return Edge(id(e) ^ 1);
deba@937:     }
deba@937: 
deba@937:     static Edge forward(SymEdge e) {
deba@937:       return Edge(id(e) << 1);
deba@937:     }
deba@937: 
deba@937:     static Edge backward(SymEdge e) {
deba@937:       return Edge((id(e) << 1) | 1);
deba@937:     }
deba@937: 
deba@937:   };
alpar@185:   ///Graph for bidirectional edges.
alpar@185: 
alpar@185:   ///The purpose of this graph structure is to handle graphs
alpar@185:   ///having bidirectional edges. Here the function \c addEdge(u,v) adds a pair
alpar@186:   ///of oppositely directed edges.
alpar@186:   ///There is a new edge map type called
alpar@186:   ///\ref SymSmartGraph::SymEdgeMap "SymEdgeMap"
alpar@186:   ///that complements this
alpar@186:   ///feature by
alpar@186:   ///storing shared values for the edge pairs. The usual
alpar@880:   ///\ref Graph::EdgeMap "EdgeMap"
alpar@186:   ///can be used
alpar@185:   ///as well.
alpar@185:   ///
alpar@186:   ///The oppositely directed edge can also be obtained easily
alpar@186:   ///using \ref opposite.
alpar@186:   ///\warning It shares the similarity with \ref SmartGraph that
alpar@186:   ///it is not possible to delete edges or nodes from the graph.
alpar@880:   //\sa SmartGraph.
alpar@185: 
deba@937:   /*  class SymSmartGraph : public SmartGraph
alpar@185:   {
alpar@185:   public:
deba@782:     typedef SymSmartGraph Graph;
deba@782: 
alpar@904:     // Create symmetric map registry.
deba@782:     CREATE_SYM_EDGE_MAP_REGISTRY;
alpar@904:     // Create symmetric edge map.
deba@897:     CREATE_SYM_EDGE_MAP(ArrayMap);
deba@822: 
alpar@186: 
alpar@185:     SymSmartGraph() : SmartGraph() { }
alpar@185:     SymSmartGraph(const SmartGraph &_g) : SmartGraph(_g) { }
alpar@398:     ///Adds a pair of oppositely directed edges to the graph.
alpar@185:     Edge addEdge(Node u, Node v)
alpar@185:     {
alpar@185:       Edge e = SmartGraph::addEdge(u,v);
deba@798:       Edge f = SmartGraph::addEdge(v,u);
deba@798:       sym_edge_maps.add(e);
deba@798:       sym_edge_maps.add(f);
alpar@185:       return e;
alpar@185:     }
alpar@185: 
alpar@186:     ///The oppositely directed edge.
alpar@186: 
alpar@186:     ///Returns the oppositely directed
alpar@186:     ///pair of the edge \c e.
alpar@713:     static Edge opposite(Edge e)
alpar@185:     {
alpar@185:       Edge f;
alpar@905:       f.n = e.n - 2*(e.n%2) + 1;
alpar@185:       return f;
alpar@185:     }
alpar@185:     
alpar@185: 
deba@937:     };*/
alpar@185:   
alpar@407:   /// @}  
alpar@921: } //namespace lemon
alpar@104: 
alpar@157: 
alpar@157: 
alpar@157: 
alpar@921: #endif //LEMON_SMART_GRAPH_H