alpar@906: /* -*- C++ -*-
alpar@921:  * src/lemon/skeletons/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@906: 
alpar@921: #ifndef LEMON_SKELETON_GRAPH_H
alpar@921: #define LEMON_SKELETON_GRAPH_H
alpar@52: 
alpar@794: ///\ingroup skeletons
alpar@242: ///\file
alpar@880: ///\brief Declaration of Graph.
alpar@242: 
alpar@921: #include <lemon/invalid.h>
alpar@921: #include <lemon/skeletons/maps.h>
alpar@145: 
alpar@921: namespace lemon {
alpar@732:   namespace skeleton {
alpar@732:     
alpar@794:     /// \addtogroup skeletons
alpar@794:     /// @{
alpar@163: 
alpar@732:     /// An empty static graph class.
alpar@732:   
alpar@732:     /// This class provides all the common features of a graph structure,
alpar@732:     /// however completely without implementations and real data structures
alpar@732:     /// behind the interface.
alpar@732:     /// All graph algorithms should compile with this class, but it will not
alpar@732:     /// run properly, of course.
alpar@732:     ///
alpar@732:     /// It can be used for checking the interface compatibility,
alpar@732:     /// or it can serve as a skeleton of a new graph structure.
alpar@732:     /// 
alpar@732:     /// Also, you will find here the full documentation of a certain graph
alpar@732:     /// feature, the documentation of a real graph imlementation
alpar@732:     /// like @ref ListGraph or
alpar@732:     /// @ref SmartGraph will just refer to this structure.
alpar@880:     class StaticGraph
alpar@732:     {
alpar@732:     public:
alpar@732:       /// Defalult constructor.
alpar@801: 
alpar@801:       /// Defalult constructor.
alpar@801:       ///
alpar@880:       StaticGraph() { }
alpar@732:       ///Copy consructor.
alpar@163: 
alpar@801: //       ///\todo It is not clear, what we expect from a copy constructor.
alpar@801: //       ///E.g. How to assign the nodes/edges to each other? What about maps?
alpar@880: //       StaticGraph(const StaticGraph& g) { }
alpar@732: 
alpar@774:       /// The base type of node iterators, 
alpar@774:       /// or in other words, the trivial node iterator.
alpar@732: 
alpar@774:       /// This is the base type of each node iterator,
alpar@774:       /// thus each kind of node iterator converts to this.
alpar@801:       /// More precisely each kind of node iterator should be inherited 
alpar@774:       /// from the trivial node iterator.
alpar@732:       class Node {
alpar@732:       public:
alpar@801: 	/// Default constructor
alpar@801: 
alpar@732: 	/// @warning The default constructor sets the iterator
alpar@732: 	/// to an undefined value.
alpar@774: 	Node() { }
alpar@774: 	/// Copy constructor.
alpar@801: 
alpar@801: 	/// Copy constructor.
alpar@801: 	///
alpar@774: 	Node(const Node&) { }
alpar@801: 
alpar@732: 	/// Invalid constructor \& conversion.
alpar@732: 
alpar@732: 	/// This constructor initializes the iterator to be invalid.
alpar@732: 	/// \sa Invalid for more details.
alpar@774: 	Node(Invalid) { }
alpar@801: 	/// Equality operator
alpar@801: 
alpar@732: 	/// Two iterators are equal if and only if they point to the
alpar@732: 	/// same object or both are invalid.
alpar@732: 	bool operator==(Node) const { return true; }
alpar@732: 
alpar@801: 	/// Inequality operator
alpar@801: 	
alpar@911: 	/// \sa operator==(Node n)
alpar@732: 	///
alpar@732: 	bool operator!=(Node) const { return true; }
alpar@732: 
alpar@801:  	///Comparison operator.
alpar@801: 
alpar@801: 	///This is a strict ordering between the nodes.
alpar@801: 	///
alpar@801: 	///This ordering can be different from the order in which NodeIt
alpar@801: 	///goes through the nodes.
alpar@801: 	///\todo Possibly we don't need it.
alpar@732: 	bool operator<(Node) const { return true; }
alpar@732:       };
alpar@732:     
alpar@732:       /// This iterator goes through each node.
alpar@732: 
alpar@732:       /// This iterator goes through each node.
alpar@732:       /// Its usage is quite simple, for example you can count the number
alpar@774:       /// of nodes in graph \c g of type \c Graph like this:
alpar@732:       /// \code
alpar@774:       /// int count=0;
alpar@801:       /// for (Graph::NodeIt n(g); n!=INVALID; ++n) ++count;
alpar@732:       /// \endcode
alpar@732:       class NodeIt : public Node {
alpar@732:       public:
alpar@801: 	/// Default constructor
alpar@801: 
alpar@732: 	/// @warning The default constructor sets the iterator
alpar@732: 	/// to an undefined value.
alpar@774: 	NodeIt() { }
alpar@774: 	/// Copy constructor.
alpar@801: 	
alpar@801: 	/// Copy constructor.
alpar@801: 	///
alpar@774: 	NodeIt(const NodeIt&) { }
alpar@732: 	/// Invalid constructor \& conversion.
alpar@732: 
alpar@774: 	/// Initialize the iterator to be invalid.
alpar@732: 	/// \sa Invalid for more details.
alpar@774: 	NodeIt(Invalid) { }
alpar@801: 	/// Sets the iterator to the first node.
alpar@801: 
alpar@774: 	/// Sets the iterator to the first node of \c g.
alpar@801: 	///
alpar@880: 	NodeIt(const StaticGraph& g) { }
alpar@801: 	/// Node -> NodeIt conversion.
alpar@801: 
alpar@774: 	/// Sets the iterator to the node of \c g pointed by the trivial 
alpar@801: 	/// iterator n.
alpar@801: 	/// This feature necessitates that each time we 
alpar@801: 	/// iterate the edge-set, the iteration order is the same.
alpar@880: 	NodeIt(const StaticGraph& g, const Node& n) { }
alpar@801: 	/// Next node.
alpar@801: 
alpar@774: 	/// Assign the iterator to the next node.
alpar@801: 	///
alpar@774: 	NodeIt& operator++() { return *this; }
alpar@732:       };
alpar@732:     
alpar@732:     
alpar@732:       /// The base type of the edge iterators.
alpar@801: 
alpar@801:       /// The base type of the edge iterators.
alpar@801:       ///
alpar@732:       class Edge {
alpar@732:       public:
alpar@801: 	/// Default constructor
alpar@801: 
alpar@732: 	/// @warning The default constructor sets the iterator
alpar@732: 	/// to an undefined value.
alpar@774: 	Edge() { }
alpar@774: 	/// Copy constructor.
alpar@801: 
alpar@801: 	/// Copy constructor.
alpar@801: 	///
alpar@774: 	Edge(const Edge&) { }
alpar@774: 	/// Initialize the iterator to be invalid.
alpar@801: 
alpar@801: 	/// Initialize the iterator to be invalid.
alpar@801: 	///
alpar@774: 	Edge(Invalid) { }
alpar@801: 	/// Equality operator
alpar@801: 
alpar@732: 	/// Two iterators are equal if and only if they point to the
alpar@732: 	/// same object or both are invalid.
alpar@732: 	bool operator==(Edge) const { return true; }
alpar@801: 	/// Inequality operator
alpar@801: 
alpar@911: 	/// \sa operator==(Node n)
alpar@801: 	///
alpar@732: 	bool operator!=(Edge) const { return true; }
alpar@801:  	///Comparison operator.
alpar@801: 
alpar@801: 	///This is a strict ordering between the nodes.
alpar@801: 	///
alpar@801: 	///This ordering can be different from the order in which NodeIt
alpar@801: 	///goes through the nodes.
alpar@801: 	///\todo Possibly we don't need it.
alpar@801:  	bool operator<(Edge) const { return true; }
alpar@732:       };
alpar@732:     
alpar@732:       /// This iterator goes trough the outgoing edges of a node.
alpar@732: 
alpar@732:       /// This iterator goes trough the \e outgoing edges of a certain node
alpar@732:       /// of a graph.
alpar@732:       /// Its usage is quite simple, for example you can count the number
alpar@732:       /// of outgoing edges of a node \c n
alpar@774:       /// in graph \c g of type \c Graph as follows.
alpar@732:       /// \code
alpar@774:       /// int count=0;
alpar@801:       /// for (Graph::OutEdgeIt e(g, n); e!=INVALID; ++e) ++count;
alpar@732:       /// \endcode
alpar@732:     
alpar@732:       class OutEdgeIt : public Edge {
alpar@732:       public:
alpar@801: 	/// Default constructor
alpar@801: 
alpar@732: 	/// @warning The default constructor sets the iterator
alpar@732: 	/// to an undefined value.
alpar@774: 	OutEdgeIt() { }
alpar@774: 	/// Copy constructor.
alpar@801: 
alpar@801: 	/// Copy constructor.
alpar@801: 	///
alpar@774: 	OutEdgeIt(const OutEdgeIt&) { }
alpar@774: 	/// Initialize the iterator to be invalid.
alpar@801: 
alpar@801: 	/// Initialize the iterator to be invalid.
alpar@801: 	///
alpar@774: 	OutEdgeIt(Invalid) { }
alpar@732: 	/// This constructor sets the iterator to first outgoing edge.
alpar@732:     
alpar@732: 	/// This constructor set the iterator to the first outgoing edge of
alpar@732: 	/// node
alpar@732: 	///@param n the node
alpar@774: 	///@param g the graph
alpar@880: 	OutEdgeIt(const StaticGraph& g, const Node& n) { }
alpar@801: 	/// Edge -> OutEdgeIt conversion
alpar@801: 
alpar@774: 	/// Sets the iterator to the value of the trivial iterator \c e.
alpar@774: 	/// This feature necessitates that each time we 
alpar@774: 	/// iterate the edge-set, the iteration order is the same.
alpar@880: 	OutEdgeIt(const StaticGraph& g, const Edge& e) { }
alpar@801: 	///Next outgoing edge
alpar@801: 	
alpar@801: 	/// Assign the iterator to the next 
alpar@801: 	/// outgoing edge of the corresponding node.
alpar@774: 	OutEdgeIt& operator++() { return *this; }
alpar@732:       };
alpar@732: 
alpar@732:       /// This iterator goes trough the incoming edges of a node.
alpar@732: 
alpar@732:       /// This iterator goes trough the \e incoming edges of a certain node
alpar@732:       /// of a graph.
alpar@732:       /// Its usage is quite simple, for example you can count the number
alpar@732:       /// of outgoing edges of a node \c n
alpar@774:       /// in graph \c g of type \c Graph as follows.
alpar@732:       /// \code
alpar@774:       /// int count=0;
alpar@801:       /// for(Graph::InEdgeIt e(g, n); e!=INVALID; ++e) ++count;
alpar@732:       /// \endcode
alpar@732: 
alpar@732:       class InEdgeIt : public Edge {
alpar@732:       public:
alpar@801: 	/// Default constructor
alpar@801: 
alpar@732: 	/// @warning The default constructor sets the iterator
alpar@732: 	/// to an undefined value.
alpar@774: 	InEdgeIt() { }
alpar@774: 	/// Copy constructor.
alpar@801: 
alpar@801: 	/// Copy constructor.
alpar@801: 	///
alpar@774: 	InEdgeIt(const InEdgeIt&) { }
alpar@774: 	/// Initialize the iterator to be invalid.
alpar@801: 
alpar@801: 	/// Initialize the iterator to be invalid.
alpar@801: 	///
alpar@774: 	InEdgeIt(Invalid) { }
alpar@801: 	/// This constructor sets the iterator to first incoming edge.
alpar@801:     
alpar@801: 	/// This constructor set the iterator to the first incoming edge of
alpar@801: 	/// node
alpar@801: 	///@param n the node
alpar@801: 	///@param g the graph
alpar@880: 	InEdgeIt(const StaticGraph& g, const Node& n) { }
alpar@801: 	/// Edge -> InEdgeIt conversion
alpar@801: 
alpar@801: 	/// Sets the iterator to the value of the trivial iterator \c e.
alpar@801: 	/// This feature necessitates that each time we 
alpar@801: 	/// iterate the edge-set, the iteration order is the same.
alpar@880: 	InEdgeIt(const StaticGraph& g, const Edge& n) { }
alpar@801: 	/// Next incoming edge
alpar@801: 
alpar@774: 	/// Assign the iterator to the next inedge of the corresponding node.
alpar@801: 	///
alpar@774: 	InEdgeIt& operator++() { return *this; }
alpar@732:       };
alpar@732:       /// This iterator goes through each edge.
alpar@732: 
alpar@732:       /// This iterator goes through each edge of a graph.
alpar@732:       /// Its usage is quite simple, for example you can count the number
alpar@774:       /// of edges in a graph \c g of type \c Graph as follows:
alpar@732:       /// \code
alpar@774:       /// int count=0;
alpar@801:       /// for(Graph::EdgeIt e(g); e!=INVALID; ++e) ++count;
alpar@732:       /// \endcode
alpar@732:       class EdgeIt : public Edge {
alpar@732:       public:
alpar@801: 	/// Default constructor
alpar@801: 
alpar@732: 	/// @warning The default constructor sets the iterator
alpar@732: 	/// to an undefined value.
alpar@774: 	EdgeIt() { }
alpar@774: 	/// Copy constructor.
alpar@801: 
alpar@801: 	/// Copy constructor.
alpar@801: 	///
alpar@774: 	EdgeIt(const EdgeIt&) { }
alpar@774: 	/// Initialize the iterator to be invalid.
alpar@801: 
alpar@801: 	/// Initialize the iterator to be invalid.
alpar@801: 	///
alpar@774: 	EdgeIt(Invalid) { }
alpar@801: 	/// This constructor sets the iterator to first edge.
alpar@801:     
alpar@801: 	/// This constructor set the iterator to the first edge of
alpar@801: 	/// node
alpar@801: 	///@param g the graph
alpar@880: 	EdgeIt(const StaticGraph& g) { }
alpar@801: 	/// Edge -> EdgeIt conversion
alpar@801: 
alpar@801: 	/// Sets the iterator to the value of the trivial iterator \c e.
alpar@801: 	/// This feature necessitates that each time we 
alpar@801: 	/// iterate the edge-set, the iteration order is the same.
alpar@880: 	EdgeIt(const StaticGraph&, const Edge&) { } 
alpar@801:     	///Next edge
alpar@801: 	
alpar@801: 	/// Assign the iterator to the next 
alpar@801: 	/// edge of the corresponding node.
alpar@774: 	EdgeIt& operator++() { return *this; }
alpar@732:       };
alpar@732: 
alpar@732:       /// First node of the graph.
alpar@732: 
alpar@732:       /// \retval i the first node.
alpar@732:       /// \return the first node.
alpar@732:       ///
alpar@774:       NodeIt& first(NodeIt& i) const { return i; }
alpar@732: 
alpar@732:       /// The first incoming edge.
alpar@801: 
alpar@801:       /// The first incoming edge.
alpar@801:       ///
alpar@774:       InEdgeIt& first(InEdgeIt &i, Node) const { return i; }
alpar@732:       /// The first outgoing edge.
alpar@801: 
alpar@801:       /// The first outgoing edge.
alpar@801:       ///
alpar@774:       OutEdgeIt& first(OutEdgeIt& i, Node) const { return i; }
alpar@732:       /// The first edge of the Graph.
alpar@801: 
alpar@801:       /// The first edge of the Graph.
alpar@801:       ///
alpar@774:       EdgeIt& first(EdgeIt& i) const { return i; }
alpar@732: 
alpar@801:       ///Gives back the head node of an edge.
alpar@732: 
alpar@732:       ///Gives back the head node of an edge.
alpar@801:       ///
alpar@732:       Node head(Edge) const { return INVALID; }
alpar@732:       ///Gives back the tail node of an edge.
alpar@801: 
alpar@801:       ///Gives back the tail node of an edge.
alpar@801:       ///
alpar@732:       Node tail(Edge) const { return INVALID; }
alpar@163:   
alpar@732:       ///Gives back the \e id of a node.
alpar@182: 
alpar@732:       ///\warning Not all graph structures provide this feature.
alpar@732:       ///
alpar@801:       ///\todo Should each graph provide \c id?
alpar@774:       int id(const Node&) const { return 0; }
alpar@732:       ///Gives back the \e id of an edge.
alpar@182: 
alpar@732:       ///\warning Not all graph structures provide this feature.
alpar@182:       ///
alpar@801:       ///\todo Should each graph provide \c id?
alpar@774:       int id(const Edge&) const { return 0; }
alpar@182: 
alpar@911:       ///\e
alpar@801:       
alpar@880:       ///\todo Should it be in the concept?
alpar@801:       ///
alpar@774:       int nodeNum() const { return 0; }
alpar@911:       ///\e
alpar@880: 
alpar@880:       ///\todo Should it be in the concept?
alpar@801:       ///
alpar@774:       int edgeNum() const { return 0; }
alpar@732: 
alpar@732: 
alpar@732:       ///Reference map of the nodes to type \c T.
alpar@732: 
alpar@880:       /// \ingroup skeletons
alpar@732:       ///Reference map of the nodes to type \c T.
alpar@880:       /// \sa Reference
alpar@732:       /// \warning Making maps that can handle bool type (NodeMap<bool>)
alpar@801:       /// needs some extra attention!
alpar@880:       template<class T> class NodeMap : public ReferenceMap< Node, T >
alpar@732:       {
alpar@732:       public:
alpar@732: 
alpar@911: 	///\e
alpar@880: 	NodeMap(const StaticGraph&) { }
alpar@911: 	///\e
alpar@880: 	NodeMap(const StaticGraph&, T) { }
alpar@732: 
alpar@732: 	///Copy constructor
alpar@774: 	template<typename TT> NodeMap(const NodeMap<TT>&) { }
alpar@732: 	///Assignment operator
alpar@774: 	template<typename TT> NodeMap& operator=(const NodeMap<TT>&)
alpar@774: 	{ return *this; }
alpar@732:       };
alpar@732: 
alpar@732:       ///Reference map of the edges to type \c T.
alpar@732: 
alpar@880:       /// \ingroup skeletons
alpar@732:       ///Reference map of the edges to type \c T.
alpar@880:       /// \sa Reference
alpar@732:       /// \warning Making maps that can handle bool type (EdgeMap<bool>)
alpar@801:       /// needs some extra attention!
alpar@732:       template<class T> class EdgeMap
alpar@732: 	: public ReferenceMap<Edge,T>
alpar@732:       {
alpar@732:       public:
alpar@732: 
alpar@911: 	///\e
alpar@880: 	EdgeMap(const StaticGraph&) { }
alpar@911: 	///\e
alpar@880: 	EdgeMap(const StaticGraph&, T) { }
alpar@147:     
alpar@732: 	///Copy constructor
alpar@774: 	template<typename TT> EdgeMap(const EdgeMap<TT>&) { }
alpar@732: 	///Assignment operator
alpar@774: 	template<typename TT> EdgeMap &operator=(const EdgeMap<TT>&)
alpar@774: 	{ return *this; }
alpar@732:       };
alpar@163:     };
alpar@163: 
alpar@186: 
alpar@732:   
alpar@801:     /// An empty non-static graph class.
alpar@186: 
alpar@880:     /// This class provides everything that \ref StaticGraph
alpar@732:     /// with additional functionality which enables to build a
alpar@732:     /// graph from scratch.
alpar@880:     class ExtendableGraph : public StaticGraph
alpar@732:     {
alpar@163:     public:
alpar@732:       /// Defalult constructor.
alpar@801: 
alpar@801:       /// Defalult constructor.
alpar@801:       ///
alpar@880:       ExtendableGraph() { }
alpar@732:       ///Add a new node to the graph.
alpar@732: 
alpar@732:       /// \return the new node.
alpar@732:       ///
alpar@774:       Node addNode() { return INVALID; }
alpar@732:       ///Add a new edge to the graph.
alpar@732: 
alpar@880:       ///Add a new edge to the graph with tail node \c t
alpar@880:       ///and head node \c h.
alpar@732:       ///\return the new edge.
alpar@880:       Edge addEdge(Node h, Node t) { return INVALID; }
alpar@732:     
alpar@732:       /// Resets the graph.
alpar@732: 
alpar@732:       /// This function deletes all edges and nodes of the graph.
alpar@732:       /// It also frees the memory allocated to store them.
alpar@880:       /// \todo It might belong to \ref ErasableGraph.
alpar@774:       void clear() { }
alpar@163:     };
alpar@163: 
alpar@826:     /// An empty erasable graph class.
alpar@52:   
alpar@880:     /// This class is an extension of \ref ExtendableGraph. It also makes it
alpar@732:     /// possible to erase edges or nodes.
alpar@880:     class ErasableGraph : public ExtendableGraph
alpar@163:     {
alpar@163:     public:
alpar@801:       /// Defalult constructor.
alpar@801: 
alpar@801:       /// Defalult constructor.
alpar@801:       ///
alpar@880:       ErasableGraph() { }
alpar@732:       /// Deletes a node.
alpar@801: 
alpar@801:       /// Deletes node \c n node.
alpar@801:       ///
alpar@774:       void erase(Node n) { }
alpar@732:       /// Deletes an edge.
alpar@801: 
alpar@801:       /// Deletes edge \c e edge.
alpar@801:       ///
alpar@774:       void erase(Edge e) { }
alpar@163:     };
alpar@163: 
alpar@732:     // @}
alpar@801:   } //namespace skeleton  
alpar@921: } //namespace lemon
alpar@52: 
alpar@145: 
alpar@145: 
alpar@921: #endif // LEMON_SKELETON_GRAPH_H