source: lemon-0.x/lemon/concept/undir_graph.h @ 1620:09feafe81053

/* -*- C++ -*-
 *
 * lemon/concept/undir_graph_component.h - Part of LEMON, a generic
 * C++ optimization library
 *
 * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi
 * Kutatocsoport (Egervary Research Group on Combinatorial Optimization,
 * EGRES).
 *
 * Permission to use, modify and distribute this software is granted
 * provided that this copyright notice appears in all copies. For
 * precise terms see the accompanying LICENSE file.
 *
 * This software is provided "AS IS" with no warranty of any kind,
 * express or implied, and with no claim as to its suitability for any
 * purpose.
 *
 */

///\ingroup graph_concepts
///\file
///\brief Undirected graphs and components of.


#ifndef LEMON_CONCEPT_UNDIR_GRAPH_H
#define LEMON_CONCEPT_UNDIR_GRAPH_H

#include <lemon/concept/graph_component.h>
#include <lemon/concept/graph.h>
#include <lemon/utility.h>

namespace lemon {
  namespace concept {

    /// Skeleton class which describes an edge with direction in \ref
    /// UndirGraph "undirected graph".
    template <typename UndirGraph>
    class UndirGraphEdge : public UndirGraph::UndirEdge {
      typedef typename UndirGraph::UndirEdge UndirEdge;
      typedef typename UndirGraph::Node Node;
    public:

      /// \e
      UndirGraphEdge() {}

      /// \e
      UndirGraphEdge(const UndirGraphEdge& e) : UndirGraph::UndirEdge(e) {}

      /// \e
      UndirGraphEdge(Invalid) {}

      /// \brief Directed edge from undirected edge and a source node.
      ///
      /// Constructs a directed edge from undirected edge and a source node.
      ///
      /// \note You have to specify the graph for this constructor.
      UndirGraphEdge(const UndirGraph &g,
                     UndirEdge undir_edge, Node n) {
        ignore_unused_variable_warning(undir_edge);
        ignore_unused_variable_warning(g);
        ignore_unused_variable_warning(n);
      }

      /// \e
      UndirGraphEdge& operator=(UndirGraphEdge) { return *this; }

      /// \e
      bool operator==(UndirGraphEdge) const { return true; }
      /// \e
      bool operator!=(UndirGraphEdge) const { return false; }

      /// \e
      bool operator<(UndirGraphEdge) const { return false; }

      template <typename Edge>
      struct Constraints {
        void constraints() {
          const_constraints();
        }
        void const_constraints() const {
          /// \bug This should be is_base_and_derived ...
          UndirEdge ue = e;
          ue = e;

          Edge e_with_source(graph,ue,n);
          ignore_unused_variable_warning(e_with_source);
        }
        Edge e;
        UndirEdge ue;
        UndirGraph graph;
        Node n;
      };
    };
    

    struct BaseIterableUndirGraphConcept {

      template <typename Graph>
      struct Constraints {

        typedef typename Graph::UndirEdge UndirEdge;
        typedef typename Graph::Edge Edge;
        typedef typename Graph::Node Node;

        void constraints() {
          checkConcept<BaseIterableGraphComponent, Graph>();
          checkConcept<GraphItem<>, UndirEdge>();
          //checkConcept<UndirGraphEdge<Graph>, Edge>();

          graph.first(ue);
          graph.next(ue);

          const_constraints();
        }
        void const_constraints() {
          Node n;
          n = graph.target(ue);
          n = graph.source(ue);
          n = graph.oppositeNode(n0, ue);

          bool b;
          b = graph.forward(e);
          ignore_unused_variable_warning(b);
        }

        Graph graph;
        Edge e;
        Node n0;
        UndirEdge ue;
      };

    };


    struct IterableUndirGraphConcept {

      template <typename Graph>
      struct Constraints {
        void constraints() {
          /// \todo we don't need the iterable component to be base iterable
          /// Don't we really???
          //checkConcept< BaseIterableUndirGraphConcept, Graph > ();

          checkConcept<IterableGraphComponent, Graph> ();

          typedef typename Graph::UndirEdge UndirEdge;
          typedef typename Graph::UndirEdgeIt UndirEdgeIt;
          typedef typename Graph::IncEdgeIt IncEdgeIt;

          checkConcept<GraphIterator<Graph, UndirEdge>, UndirEdgeIt>();
          checkConcept<GraphIncIterator<Graph, UndirEdge>, IncEdgeIt>();
        }
      };

    };

    struct MappableUndirGraphConcept {

      template <typename Graph>
      struct Constraints {

        struct Dummy {
          int value;
          Dummy() : value(0) {}
          Dummy(int _v) : value(_v) {}
        };

        void constraints() {
          checkConcept<MappableGraphComponent, Graph>();

          typedef typename Graph::template UndirEdgeMap<int> IntMap;
          checkConcept<GraphMap<Graph, typename Graph::UndirEdge, int>,
            IntMap >();

          typedef typename Graph::template UndirEdgeMap<bool> BoolMap;
          checkConcept<GraphMap<Graph, typename Graph::UndirEdge, bool>,
            BoolMap >();

          typedef typename Graph::template UndirEdgeMap<Dummy> DummyMap;
          checkConcept<GraphMap<Graph, typename Graph::UndirEdge, Dummy>,
            DummyMap >();
        }
      };

    };

    struct ExtendableUndirGraphConcept {

      template <typename Graph>
      struct Constraints {
        void constraints() {
          node_a = graph.addNode();
          uedge = graph.addEdge(node_a, node_b);
        }
        typename Graph::Node node_a, node_b;
        typename Graph::UndirEdge uedge;
        Graph graph;
      };

    };

    struct ErasableUndirGraphConcept {

      template <typename Graph>
      struct Constraints {
        void constraints() {
          graph.erase(n);
          graph.erase(e);
        }
        Graph graph;
        typename Graph::Node n;
        typename Graph::UndirEdge e;
      };

    };

    /// \addtogroup graph_concepts
    /// @{


    /// Class describing the concept of Undirected Graphs.

    /// This class describes the common interface of all Undirected
    /// Graphs.
    ///
    /// As all concept describing classes it provides only interface
    /// without any sensible implementation. So any algorithm for
    /// undirected graph should compile with this class, but it will not
    /// run properly, of couse.
    ///
    /// In LEMON undirected graphs also fulfill the concept of directed
    /// graphs (\ref lemon::concept::Graph "Graph Concept"). For
    /// explanation of this and more see also the page \ref undir_graphs,
    /// a tutorial about undirected graphs.

    class UndirGraph : public StaticGraph {
    public:
      ///\e

      ///\todo undocumented
      ///
      typedef True UndirTag;

      /// The base type of the undirected edge iterators.
      
      /// The base type of the undirected edge iterators.
      ///
      class UndirEdge {
      public:
        /// Default constructor

        /// @warning The default constructor sets the iterator
        /// to an undefined value.
        UndirEdge() { }
        /// Copy constructor.

        /// Copy constructor.
        ///
        UndirEdge(const UndirEdge&) { }
        /// Edge -> UndirEdge conversion

        /// Edge -> UndirEdge conversion
        ///
        UndirEdge(const Edge&) { }
        /// Initialize the iterator to be invalid.

        /// Initialize the iterator to be invalid.
        ///
        UndirEdge(Invalid) { }
        /// Equality operator

        /// Two iterators are equal if and only if they point to the
        /// same object or both are invalid.
        bool operator==(UndirEdge) const { return true; }
        /// Inequality operator

        /// \sa operator==(UndirEdge n)
        ///
        bool operator!=(UndirEdge) const { return true; }

        ///\e

        ///\todo Do we need this?
        ///
        bool operator<(const UndirEdge &that) const { return true; }
      };
    
      /// This iterator goes through each undirected edge.

      /// This iterator goes through each undirected edge of a graph.
      /// Its usage is quite simple, for example you can count the number
      /// of edges in a graph \c g of type \c Graph as follows:
      /// \code
      /// int count=0;
      /// for(Graph::UndirEdgeIt e(g); e!=INVALID; ++e) ++count;
      /// \endcode
      class UndirEdgeIt : public UndirEdge {
      public:
        /// Default constructor
        
        /// @warning The default constructor sets the iterator
        /// to an undefined value.
        UndirEdgeIt() { }
        /// Copy constructor.
        
        /// Copy constructor.
        ///
        UndirEdgeIt(const UndirEdgeIt& e) : UndirEdge(e) { }
        /// Initialize the iterator to be invalid.

        /// Initialize the iterator to be invalid.
        ///
        UndirEdgeIt(Invalid) { }
        /// This constructor sets the iterator to the first edge.
    
        /// This constructor sets the iterator to the first edge of \c g.
        ///@param g the graph
        UndirEdgeIt(const UndirGraph&) { }
        /// UndirEdge -> UndirEdgeIt conversion

        /// Sets the iterator to the value of the trivial iterator \c e.
        /// This feature necessitates that each time we 
        /// iterate the edge-set, the iteration order is the same.
        UndirEdgeIt(const UndirGraph&, const UndirEdge&) { } 
        ///Next edge
        
        /// Assign the iterator to the next edge.
        UndirEdgeIt& operator++() { return *this; }
      };

      /// This iterator goes trough the incident undirected edges of a node.

      /// This iterator goes trough the incident undirected edges
      /// of a certain node
      /// of a graph.
      /// Its usage is quite simple, for example you can compute the
      /// degree (i.e. count the number
      /// of incident edges of a node \c n
      /// in graph \c g of type \c Graph as follows.
      /// \code
      /// int count=0;
      /// for(Graph::IncEdgeIt e(g, n); e!=INVALID; ++e) ++count;
      /// \endcode
      class IncEdgeIt : public UndirEdge {
      public:
        /// Default constructor

        /// @warning The default constructor sets the iterator
        /// to an undefined value.
        IncEdgeIt() { }
        /// Copy constructor.

        /// Copy constructor.
        ///
        IncEdgeIt(const IncEdgeIt& e) : UndirEdge(e) { }
        /// Initialize the iterator to be invalid.

        /// Initialize the iterator to be invalid.
        ///
        IncEdgeIt(Invalid) { }
        /// This constructor sets the iterator to first incident edge.
    
        /// This constructor set the iterator to the first incident edge of
        /// the node.
        ///@param n the node
        ///@param g the graph
        IncEdgeIt(const UndirGraph&, const Node&) { }
        /// UndirEdge -> IncEdgeIt conversion

        /// Sets the iterator to the value of the trivial iterator \c e.
        /// This feature necessitates that each time we 
        /// iterate the edge-set, the iteration order is the same.
        IncEdgeIt(const UndirGraph&, const UndirEdge&) { }
        /// Next incident edge

        /// Assign the iterator to the next incident edge
        /// of the corresponding node.
        IncEdgeIt& operator++() { return *this; }
      };

      /// Read write map of the undirected edges to type \c T.

      /// Reference map of the edges to type \c T.
      /// \sa Reference
      /// \warning Making maps that can handle bool type (UndirEdgeMap<bool>)
      /// needs some extra attention!
      template<class T> 
      class UndirEdgeMap : public ReadWriteMap<UndirEdge,T>
      {
      public:

        ///\e
        UndirEdgeMap(const UndirGraph&) { }
        ///\e
        UndirEdgeMap(const UndirGraph&, T) { }
        ///Copy constructor
        UndirEdgeMap(const UndirEdgeMap& em) : ReadWriteMap<UndirEdge,T>(em) { }
        ///Assignment operator
        UndirEdgeMap &operator=(const UndirEdgeMap&) { return *this; }
        // \todo fix this concept    
      };

      /// Is the Edge oriented "forward"?

      /// Returns whether the given directed edge is same orientation as
      /// the corresponding undirected edge.
      ///
      /// \todo "What does the direction of an undirected edge mean?"
      bool forward(Edge) const { return true; }

      /// Opposite node on an edge

      /// \return the opposite of the given Node on the given Edge
      ///
      /// \todo What should we do if given Node and Edge are not incident?
      Node oppositeNode(Node, UndirEdge) const { return INVALID; }

      /// First node of the undirected edge.

      /// \return the first node of the given UndirEdge.
      ///
      /// Naturally undirectected edges don't have direction and thus
      /// don't have source and target node. But we use these two methods
      /// to query the two endnodes of the edge. The direction of the edge
      /// which arises this way is called the inherent direction of the
      /// undirected edge, and is used to define the "forward" direction
      /// of the directed versions of the edges.
      /// \sa forward
      Node source(UndirEdge) const { return INVALID; }

      /// Second node of the undirected edge.
      Node target(UndirEdge) const { return INVALID; }

      /// Source node of the directed edge.
      Node source(Edge) const { return INVALID; }

      /// Target node of the directed edge.
      Node target(Edge) const { return INVALID; }

      /// First node of the graph

      /// \note This method is part of so called \ref
      /// developpers_interface "Developpers' interface", so it shouldn't
      /// be used in an end-user program.
      void first(Node&) const {}
      /// Next node of the graph

      /// \note This method is part of so called \ref
      /// developpers_interface "Developpers' interface", so it shouldn't
      /// be used in an end-user program.
      void next(Node&) const {}

      /// First undirected edge of the graph

      /// \note This method is part of so called \ref
      /// developpers_interface "Developpers' interface", so it shouldn't
      /// be used in an end-user program.
      void first(UndirEdge&) const {}
      /// Next undirected edge of the graph

      /// \note This method is part of so called \ref
      /// developpers_interface "Developpers' interface", so it shouldn't
      /// be used in an end-user program.
      void next(UndirEdge&) const {}

      /// First directed edge of the graph

      /// \note This method is part of so called \ref
      /// developpers_interface "Developpers' interface", so it shouldn't
      /// be used in an end-user program.
      void first(Edge&) const {}
      /// Next directed edge of the graph

      /// \note This method is part of so called \ref
      /// developpers_interface "Developpers' interface", so it shouldn't
      /// be used in an end-user program.
      void next(Edge&) const {}

      /// First outgoing edge from a given node

      /// \note This method is part of so called \ref
      /// developpers_interface "Developpers' interface", so it shouldn't
      /// be used in an end-user program.
      void firstOut(Edge&, Node) const {}
      /// Next outgoing edge to a node

      /// \note This method is part of so called \ref
      /// developpers_interface "Developpers' interface", so it shouldn't
      /// be used in an end-user program.
      void nextOut(Edge&) const {}

      /// First incoming edge to a given node

      /// \note This method is part of so called \ref
      /// developpers_interface "Developpers' interface", so it shouldn't
      /// be used in an end-user program.
      void firstIn(Edge&, Node) const {}
      /// Next incoming edge to a node

      /// \note This method is part of so called \ref
      /// developpers_interface "Developpers' interface", so it shouldn't
      /// be used in an end-user program.
      void nextIn(Edge&) const {}


      /// Base node of the iterator
      ///
      /// Returns the base node (the source in this case) of the iterator
      Node baseNode(OutEdgeIt e) const {
        return source(e);
      }
      /// Running node of the iterator
      ///
      /// Returns the running node (the target in this case) of the
      /// iterator
      Node runningNode(OutEdgeIt e) const {
        return target(e);
      }

      /// Base node of the iterator
      ///
      /// Returns the base node (the target in this case) of the iterator
      Node baseNode(InEdgeIt e) const {
        return target(e);
      }
      /// Running node of the iterator
      ///
      /// Returns the running node (the source in this case) of the
      /// iterator
      Node runningNode(InEdgeIt e) const {
        return source(e);
      }

      /// Base node of the iterator
      ///
      /// Returns the base node of the iterator
      Node baseNode(IncEdgeIt) const {
        return INVALID;
      }
      /// Running node of the iterator
      ///
      /// Returns the running node of the iterator
      Node runningNode(IncEdgeIt) const {
        return INVALID;
      }


      template <typename Graph>
      struct Constraints {
        void constraints() {
          checkConcept<BaseIterableUndirGraphConcept, Graph>();
          checkConcept<IterableUndirGraphConcept, Graph>();
          checkConcept<MappableUndirGraphConcept, Graph>();
        }
      };

    };

    class ExtendableUndirGraph : public UndirGraph {
    public:

      template <typename Graph>
      struct Constraints {
        void constraints() {
          checkConcept<BaseIterableUndirGraphConcept, Graph>();
          checkConcept<IterableUndirGraphConcept, Graph>();
          checkConcept<MappableUndirGraphConcept, Graph>();

          checkConcept<UndirGraph, Graph>();
          checkConcept<ExtendableUndirGraphConcept, Graph>();
          checkConcept<ClearableGraphComponent, Graph>();
        }
      };

    };

    class ErasableUndirGraph : public ExtendableUndirGraph {
    public:

      template <typename Graph>
      struct Constraints {
        void constraints() {
          checkConcept<ExtendableUndirGraph, Graph>();
          checkConcept<ErasableUndirGraphConcept, Graph>();
        }
      };

    };

    /// @}

  }

}

#endif