klao@946: /* -*- C++ -*-
klao@946:  * src/lemon/graph_utils.h - Part of LEMON, a generic C++ optimization library
klao@946:  *
alpar@1164:  * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
alpar@1359:  * (Egervary Research Group on Combinatorial Optimization, EGRES).
klao@946:  *
klao@946:  * Permission to use, modify and distribute this software is granted
klao@946:  * provided that this copyright notice appears in all copies. For
klao@946:  * precise terms see the accompanying LICENSE file.
klao@946:  *
klao@946:  * This software is provided "AS IS" with no warranty of any kind,
klao@946:  * express or implied, and with no claim as to its suitability for any
klao@946:  * purpose.
klao@946:  *
klao@946:  */
klao@946: 
klao@946: #ifndef LEMON_GRAPH_UTILS_H
klao@946: #define LEMON_GRAPH_UTILS_H
klao@946: 
klao@946: #include <iterator>
alpar@1402: #include <map>
klao@946: 
klao@946: #include <lemon/invalid.h>
klao@977: #include <lemon/utility.h>
klao@946: 
alpar@947: ///\ingroup gutils
klao@946: ///\file
alpar@947: ///\brief Graph utilities.
klao@946: ///
alpar@964: ///\todo Please
alpar@964: ///revise the documentation.
alpar@964: ///
klao@946: 
klao@946: 
klao@946: namespace lemon {
klao@946: 
deba@1267:   /// \addtogroup gutils
deba@1267:   /// @{
alpar@947: 
klao@946:   /// \brief Function to count the items in the graph.
klao@946:   ///
klao@946:   /// This function counts the items in the graph.
klao@946:   /// The complexity of the function is O(n) because
klao@946:   /// it iterates on all of the items.
klao@946: 
klao@946:   template <typename Graph, typename ItemIt>
klao@977:   inline int countItems(const Graph& g) {
klao@946:     int num = 0;
klao@977:     for (ItemIt it(g); it != INVALID; ++it) {
klao@946:       ++num;
klao@946:     }
klao@946:     return num;
klao@946:   }
klao@946: 
klao@977:   // Node counting:
klao@977: 
klao@977:   template <typename Graph>
klao@977:   inline
klao@977:   typename enable_if<typename Graph::NodeNumTag, int>::type
klao@977:   _countNodes(const Graph &g) {
klao@977:     return g.nodeNum();
klao@977:   }
klao@977: 
klao@977:   template <typename Graph>
klao@977:   inline int _countNodes(Wrap<Graph> w) {
klao@977:     return countItems<Graph, typename Graph::NodeIt>(w.value);
klao@977:   }
klao@977: 
klao@946:   /// \brief Function to count the nodes in the graph.
klao@946:   ///
klao@946:   /// This function counts the nodes in the graph.
klao@946:   /// The complexity of the function is O(n) but for some
alpar@964:   /// graph structure it is specialized to run in O(1).
klao@977:   ///
klao@977:   /// \todo refer how to specialize it
klao@946: 
klao@946:   template <typename Graph>
klao@977:   inline int countNodes(const Graph& g) {
klao@977:     return _countNodes<Graph>(g);
klao@977:   }
klao@977: 
klao@977:   // Edge counting:
klao@977: 
klao@977:   template <typename Graph>
klao@977:   inline
klao@977:   typename enable_if<typename Graph::EdgeNumTag, int>::type
klao@977:   _countEdges(const Graph &g) {
klao@977:     return g.edgeNum();
klao@977:   }
klao@977: 
klao@977:   template <typename Graph>
klao@977:   inline int _countEdges(Wrap<Graph> w) {
klao@977:     return countItems<Graph, typename Graph::EdgeIt>(w.value);
klao@946:   }
klao@946: 
klao@946:   /// \brief Function to count the edges in the graph.
klao@946:   ///
klao@946:   /// This function counts the edges in the graph.
klao@946:   /// The complexity of the function is O(e) but for some
alpar@964:   /// graph structure it is specialized to run in O(1).
klao@977: 
klao@946:   template <typename Graph>
klao@977:   inline int countEdges(const Graph& g) {
klao@977:     return _countEdges<Graph>(g);
klao@946:   }
klao@946: 
klao@1053:   // Undirected edge counting:
klao@1053: 
klao@1053:   template <typename Graph>
klao@1053:   inline
klao@1053:   typename enable_if<typename Graph::EdgeNumTag, int>::type
klao@1053:   _countUndirEdges(const Graph &g) {
klao@1053:     return g.undirEdgeNum();
klao@1053:   }
klao@1053: 
klao@1053:   template <typename Graph>
klao@1053:   inline int _countUndirEdges(Wrap<Graph> w) {
klao@1053:     return countItems<Graph, typename Graph::UndirEdgeIt>(w.value);
klao@1053:   }
klao@1053: 
klao@1053:   /// \brief Function to count the edges in the graph.
klao@946:   ///
klao@1053:   /// This function counts the edges in the graph.
klao@946:   /// The complexity of the function is O(e) but for some
alpar@964:   /// graph structure it is specialized to run in O(1).
klao@1053: 
klao@946:   template <typename Graph>
klao@1053:   inline int countUndirEdges(const Graph& g) {
klao@1053:     return _countUndirEdges<Graph>(g);
klao@946:   }
klao@946: 
klao@977: 
klao@1053: 
klao@946:   template <typename Graph, typename DegIt>
klao@946:   inline int countNodeDegree(const Graph& _g, const typename Graph::Node& _n) {
klao@946:     int num = 0;
klao@946:     for (DegIt it(_g, _n); it != INVALID; ++it) {
klao@946:       ++num;
klao@946:     }
klao@946:     return num;
klao@946:   }
alpar@967: 
alpar@967:   /// Finds an edge between two nodes of a graph.
alpar@967: 
alpar@967:   /// Finds an edge from node \c u to node \c v in graph \c g.
alpar@967:   ///
alpar@967:   /// If \c prev is \ref INVALID (this is the default value), then
alpar@967:   /// it finds the first edge from \c u to \c v. Otherwise it looks for
alpar@967:   /// the next edge from \c u to \c v after \c prev.
alpar@967:   /// \return The found edge or \ref INVALID if there is no such an edge.
alpar@967:   ///
alpar@967:   /// Thus you can iterate through each edge from \c u to \c v as it follows.
alpar@967:   /// \code
alpar@967:   /// for(Edge e=findEdge(g,u,v);e!=INVALID;e=findEdge(g,u,v,e)) {
alpar@967:   ///   ...
alpar@967:   /// }
alpar@967:   /// \endcode
alpar@967:   /// \todo We may want to use the \ref concept::GraphBase "GraphBase"
alpar@967:   /// interface here...
alpar@967:   /// \bug Untested ...
alpar@967:   template <typename Graph>
alpar@967:   typename Graph::Edge findEdge(const Graph &g,
deba@1267: 				typename Graph::Node u, typename Graph::Node v,
deba@1267: 				typename Graph::Edge prev = INVALID) 
alpar@967:   {
alpar@967:     typename Graph::OutEdgeIt e(g,prev);
alpar@1079:     //    if(prev==INVALID) g.first(e,u);
alpar@1079:     if(prev==INVALID) e=typename Graph::OutEdgeIt(g,u);
alpar@967:     else ++e;
alpar@1079:     while(e!=INVALID && g.target(e)!=v) ++e;
alpar@967:     return e;
alpar@967:   }
alpar@964:   
alpar@964:   ///\e
klao@946: 
alpar@964:   ///\todo Please document.
alpar@964:   ///
klao@946:   template <typename Graph>
klao@946:   inline int countOutEdges(const Graph& _g,  const typename Graph::Node& _n) {
klao@946:     return countNodeDegree<Graph, typename Graph::OutEdgeIt>(_g, _n);
klao@946:   }
klao@946: 
alpar@964:   ///\e
alpar@964: 
alpar@964:   ///\todo Please document.
alpar@964:   ///
klao@946:   template <typename Graph>
klao@946:   inline int countInEdges(const Graph& _g,  const typename Graph::Node& _n) {
klao@946:     return countNodeDegree<Graph, typename Graph::InEdgeIt>(_g, _n);
klao@946:   }
klao@946: 
klao@946:   // graph copy
klao@946: 
klao@946:   template <
klao@946:     typename DestinationGraph, 
klao@946:     typename SourceGraph, 
klao@946:     typename NodeBijection>
klao@946:   void copyNodes(DestinationGraph& _d, const SourceGraph& _s, 
klao@946: 		 NodeBijection& _nb) {    
klao@946:     for (typename SourceGraph::NodeIt it(_s); it != INVALID; ++it) {
klao@946:       _nb[it] = _d.addNode();
klao@946:     }
klao@946:   }
klao@946: 
klao@946:   template <
klao@946:     typename DestinationGraph, 
klao@946:     typename SourceGraph, 
klao@946:     typename NodeBijection,
klao@946:     typename EdgeBijection>
klao@946:   void copyEdges(DestinationGraph& _d, const SourceGraph& _s,
klao@946: 		 const NodeBijection& _nb, EdgeBijection& _eb) {    
klao@946:     for (typename SourceGraph::EdgeIt it(_s); it != INVALID; ++it) {
alpar@986:       _eb[it] = _d.addEdge(_nb[_s.source(it)], _nb[_s.target(it)]);
klao@946:     }
klao@946:   }
klao@946: 
klao@946:   template <
klao@946:     typename DestinationGraph, 
klao@946:     typename SourceGraph, 
klao@946:     typename NodeBijection,
klao@946:     typename EdgeBijection>
klao@946:   void copyGraph(DestinationGraph& _d, const SourceGraph& _s, 
klao@946: 		 NodeBijection& _nb, EdgeBijection& _eb) {
klao@946:     nodeCopy(_d, _s, _nb);
klao@946:     edgeCopy(_d, _s, _nb, _eb);
klao@946:   }
klao@946:  
deba@1267:   template <
klao@946:     typename _DestinationGraph, 
klao@946:     typename _SourceGraph, 
klao@946:     typename _NodeBijection 
klao@946:     =typename _SourceGraph::template NodeMap<typename _DestinationGraph::Node>,
klao@946:     typename _EdgeBijection 
deba@1267:     = typename _SourceGraph::template EdgeMap<typename _DestinationGraph::Edge>
deba@1267:   >
deba@1267:   class GraphCopy {
deba@1267:   public:
deba@1267:     
deba@1267:     typedef _DestinationGraph DestinationGraph;
deba@1267:     typedef _SourceGraph SourceGraph;
klao@946: 
deba@1267:     typedef _NodeBijection NodeBijection;
deba@1267:     typedef _EdgeBijection EdgeBijection;
deba@1267:     
deba@1267:   protected:          
deba@1267:     
deba@1267:     NodeBijection node_bijection;
deba@1267:     EdgeBijection edge_bijection;     
klao@946: 
deba@1267:   public:
deba@1267:      
deba@1267:     GraphCopy(DestinationGraph& _d, const SourceGraph& _s) {
deba@1267:       copyGraph(_d, _s, node_bijection, edge_bijection);
deba@1267:     }
deba@1267:     
deba@1267:     const NodeBijection& getNodeBijection() const {
deba@1267:       return node_bijection;
deba@1267:     }
klao@946: 
deba@1267:     const EdgeBijection& getEdgeBijection() const {
deba@1267:       return edge_bijection;
deba@1267:     }
deba@1267:      
deba@1267:   };
klao@946: 
klao@946: 
deba@1267:   template <typename _Graph, typename _Item>
deba@1267:   class ItemSetTraits {
deba@1267:   };
deba@1192:   
deba@1192:   template <typename _Graph>
deba@1267:   class ItemSetTraits<_Graph, typename _Graph::Node> {
deba@1192:   public:
deba@1192:     
deba@1192:     typedef _Graph Graph;
alpar@947: 
deba@1192:     typedef typename Graph::Node Item;
deba@1192:     typedef typename Graph::NodeIt ItemIt;
deba@1192: 
deba@1192:     template <typename _Value>
deba@1192:     class Map : public Graph::template NodeMap<_Value> {
deba@1192:     public:
deba@1192:       typedef typename Graph::template NodeMap<_Value> Parent; 
deba@1192:       typedef typename Parent::Value Value;
deba@1192: 
deba@1192:       Map(const Graph& _graph) : Parent(_graph) {}
deba@1192:       Map(const Graph& _graph, const Value& _value) 
deba@1192: 	: Parent(_graph, _value) {}
deba@1192:     };
deba@1192: 
deba@1192:   };
deba@1192: 
deba@1192:   template <typename _Graph>
deba@1267:   class ItemSetTraits<_Graph, typename _Graph::Edge> {
deba@1192:   public:
deba@1192:     
deba@1192:     typedef _Graph Graph;
deba@1192: 
deba@1192:     typedef typename Graph::Edge Item;
deba@1192:     typedef typename Graph::EdgeIt ItemIt;
deba@1192: 
deba@1192:     template <typename _Value>
deba@1192:     class Map : public Graph::template EdgeMap<_Value> {
deba@1192:     public:
deba@1192:       typedef typename Graph::template EdgeMap<_Value> Parent; 
deba@1192:       typedef typename Parent::Value Value;
deba@1192: 
deba@1192:       Map(const Graph& _graph) : Parent(_graph) {}
deba@1192:       Map(const Graph& _graph, const Value& _value) 
deba@1192: 	: Parent(_graph, _value) {}
deba@1192:     };
deba@1192: 
deba@1192:   };
deba@1192: 
deba@1267:   template <typename _Graph>
deba@1267:   class ItemSetTraits<_Graph, typename _Graph::UndirEdge> {
deba@1267:   public:
deba@1267:     
deba@1267:     typedef _Graph Graph;
deba@1267: 
deba@1267:     typedef typename Graph::UndirEdge Item;
deba@1267:     typedef typename Graph::UndirEdgeIt ItemIt;
deba@1267: 
deba@1267:     template <typename _Value>
deba@1267:     class Map : public Graph::template UndirEdgeMap<_Value> {
deba@1267:     public:
deba@1267:       typedef typename Graph::template UndirEdgeMap<_Value> Parent; 
deba@1267:       typedef typename Parent::Value Value;
deba@1267: 
deba@1267:       Map(const Graph& _graph) : Parent(_graph) {}
deba@1267:       Map(const Graph& _graph, const Value& _value) 
deba@1267: 	: Parent(_graph, _value) {}
deba@1267:     };
deba@1267: 
deba@1267:   };
deba@1192: 
deba@1192:   /// @}
alpar@1402: 
alpar@1402:   /// \addtogroup graph_maps
alpar@1402:   /// @{
alpar@1402: 
alpar@1402:   /// Provides an immutable and unique id for each item in the graph.
alpar@1402: 
alpar@1402:   /// The IdMap class provides an unique and immutable mapping for each item
alpar@1402:   /// in the graph.
alpar@1402:   ///
alpar@1402:   template <typename _Graph, typename _Item>
alpar@1402:   class IdMap {
alpar@1402:   public:
alpar@1402:     typedef _Graph Graph;
alpar@1402:     typedef int Value;
alpar@1402:     typedef _Item Item;
alpar@1402:     typedef _Item Key;
alpar@1402: 
alpar@1402:     /// \brief The class represents the inverse of the map.
alpar@1402:     ///
alpar@1402:     /// The class represents the inverse of the map.
alpar@1402:     /// \see inverse()
alpar@1402:     class InverseMap {
alpar@1402:     public:
alpar@1402:       /// \brief Constructor.
alpar@1402:       ///
alpar@1402:       /// Constructor for creating an id-to-item map.
alpar@1402:       InverseMap(const Graph& _graph) : graph(&_graph) {}
alpar@1402:       /// \brief Gives back the given item from its id.
alpar@1402:       ///
alpar@1402:       /// Gives back the given item from its id.
alpar@1402:       /// 
alpar@1402:       Item operator[](int id) const { return graph->fromId(id, Item());}
alpar@1402:     private:
alpar@1402:       const Graph* graph;
alpar@1402:     };
alpar@1402: 
alpar@1402:     /// \brief Constructor.
alpar@1402:     ///
alpar@1402:     /// Constructor for creating id map.
alpar@1402:     IdMap(const Graph& _graph) : graph(&_graph) {}
alpar@1402: 
alpar@1402:     /// \brief Gives back the \e id of the item.
alpar@1402:     ///
alpar@1402:     /// Gives back the immutable and unique \e id of the map.
alpar@1402:     int operator[](const Item& item) const { return graph->id(item);}
alpar@1402: 
alpar@1402:     /// \brief Gives back the inverse of the map.
alpar@1402:     ///
alpar@1402:     /// Gives back the inverse of the map.
alpar@1402:     InverseMap inverse() const { return InverseMap(*graph);} 
alpar@1402: 
alpar@1402:   private:
alpar@1402:     const Graph* graph;
alpar@1402: 
alpar@1402:   };
alpar@1402: 
alpar@947:   
alpar@1402:   template <typename Map, typename Enable = void>
alpar@1402:   struct ReferenceMapTraits {
alpar@1402:     typedef typename Map::Value Value;
alpar@1402:     typedef typename Map::Value& Reference;
alpar@1402:     typedef const typename Map::Value& ConstReference;
alpar@1402:     typedef typename Map::Value* Pointer;
alpar@1402:     typedef const typename Map::Value* ConstPointer;
alpar@1402:   };
alpar@1402: 
alpar@1402:   template <typename Map>
alpar@1402:   struct ReferenceMapTraits<
alpar@1402:     Map, 
alpar@1402:     typename enable_if<typename Map::FullTypeTag, void>::type
alpar@1402:   > {
alpar@1402:     typedef typename Map::Value Value;
alpar@1402:     typedef typename Map::Reference Reference;
alpar@1402:     typedef typename Map::ConstReference ConstReference;
alpar@1402:     typedef typename Map::Pointer Pointer;
alpar@1402:     typedef typename Map::ConstPointer ConstPointer;
alpar@1402:   };
alpar@1402: 
alpar@1402:   /// \brief General inversable graph-map type.
alpar@1402: 
alpar@1402:   /// This type provides simple inversable map functions. 
alpar@1402:   /// The InversableMap wraps an arbitrary ReadWriteMap 
alpar@1402:   /// and if a key is setted to a new value then store it
alpar@1402:   /// in the inverse map.
alpar@1402:   /// \param _Graph The graph type.
alpar@1402:   /// \param _Map The map to extend with inversable functionality. 
alpar@1402:   template <
alpar@1402:     typename _Graph,
alpar@1402:     typename _Item, 
alpar@1402:     typename _Value,
alpar@1402:     typename _Map 
alpar@1402:     = typename ItemSetTraits<_Graph, _Item>::template Map<_Value> 
alpar@1402:   >
alpar@1402:   class InversableMap : protected _Map {
alpar@1402: 
alpar@1402:   public:
alpar@1402:  
alpar@1402:     typedef _Map Map;
alpar@1402:     typedef _Graph Graph;
alpar@1402:    /// The key type of InversableMap (Node, Edge, UndirEdge).
alpar@1402:     typedef typename _Map::Key Key;
alpar@1402:     /// The value type of the InversableMap.
alpar@1402:     typedef typename _Map::Value Value;
alpar@1402: 
alpar@1402:     typedef std::map<Value, Key> InverseMap;
alpar@1402:     
alpar@1402:     typedef typename _Map::ConstReference ConstReference;
alpar@1402: 
alpar@1402:     /// \brief Constructor.
alpar@1402:     ///
alpar@1402:     /// Construct a new InversableMap for the graph.
alpar@1402:     ///
alpar@1402:     InversableMap(const Graph& graph) : Map(graph) {} 
alpar@1402:     
alpar@1402:     /// \brief The setter function of the map.
alpar@1402:     ///
alpar@1402: 
alpar@1402:     void set(const Key& key, const Value& val) {
alpar@1402:       Value oldval = Map::operator[](key);
alpar@1402:       typename InverseMap::iterator it = invMap.find(oldval);
alpar@1402:       if (it != invMap.end() && it->second == key) {
alpar@1402: 	invMap.erase(it);
alpar@1402:       }      
alpar@1402:       invMap.insert(make_pair(val, key));
alpar@1402:       Map::set(key, val);
alpar@1402:     }
alpar@1402: 
alpar@1402:     /// \brief The getter function of the map.
alpar@1402:     ///
alpar@1402:     /// It gives back the value associated with the key.
alpar@1402:     ConstReference operator[](const Key& key) const {
alpar@1402:       return Map::operator[](key);
alpar@1402:     }
alpar@1402: 
alpar@1402:     /// \brief Add a new key to the map.
alpar@1402:     ///
alpar@1402:     /// Add a new key to the map. It is called by the
alpar@1402:     /// \c AlterationNotifier.
alpar@1402:     virtual void add(const Key& key) {
alpar@1402:       Map::add(key);
alpar@1402:     }
alpar@1402: 
alpar@1402:     /// \brief Erase the key from the map.
alpar@1402:     ///
alpar@1402:     /// Erase the key to the map. It is called by the
alpar@1402:     /// \c AlterationNotifier.
alpar@1402:     virtual void erase(const Key& key) {
alpar@1402:       Value val = Map::operator[](key);
alpar@1402:       typename InverseMap::iterator it = invMap.find(val);
alpar@1402:       if (it != invMap.end() && it->second == key) {
alpar@1402: 	invMap.erase(it);
alpar@1402:       }
alpar@1402:       Map::erase(key);
alpar@1402:     }
alpar@1402: 
alpar@1402:     /// \brief Clear the keys from the map and inverse map.
alpar@1402:     ///
alpar@1402:     /// Clear the keys from the map and inverse map. It is called by the
alpar@1402:     /// \c AlterationNotifier.
alpar@1402:     virtual void clear() {
alpar@1402:       invMap.clear();
alpar@1402:       Map::clear();
alpar@1402:     }
alpar@1402: 
alpar@1402:     /// \brief It gives back the just readeable inverse map.
alpar@1402:     ///
alpar@1402:     /// It gives back the just readeable inverse map.
alpar@1402:     const InverseMap& inverse() const {
alpar@1402:       return invMap;
alpar@1402:     } 
alpar@1402: 
alpar@1402: 
alpar@1402:   private:
alpar@1402:     InverseMap invMap;    
alpar@1402:   };
alpar@1402: 
alpar@1402:   /// \brief Provides a mutable, continuous and unique descriptor for each 
alpar@1402:   /// item in the graph.
alpar@1402:   ///
alpar@1402:   /// The DescriptorMap class provides a mutable, continuous and immutable
alpar@1402:   /// mapping for each item in the graph.
alpar@1402:   ///
alpar@1402:   /// \param _Graph The graph class the \c DescriptorMap belongs to.
alpar@1402:   /// \param _Item The Item is the Key of the Map. It may be Node, Edge or 
alpar@1402:   /// UndirEdge.
alpar@1402:   /// \param _Map A ReadWriteMap mapping from the item type to integer.
alpar@1402: 
alpar@1402:   template <
alpar@1402:     typename _Graph,   
alpar@1402:     typename _Item,
alpar@1402:     typename _Map = typename ItemSetTraits<_Graph, _Item>::template Map<int>
alpar@1402:   >
alpar@1402:   class DescriptorMap : protected _Map {
alpar@1402: 
alpar@1402:     typedef _Item Item;
alpar@1402:     typedef _Map Map;
alpar@1402: 
alpar@1402:   public:
alpar@1402:     /// The graph class of DescriptorMap.
alpar@1402:     typedef _Graph Graph;
alpar@1402: 
alpar@1402:     /// The key type of DescriptorMap (Node, Edge, UndirEdge).
alpar@1402:     typedef typename _Map::Key Key;
alpar@1402:     /// The value type of DescriptorMap.
alpar@1402:     typedef typename _Map::Value Value;
alpar@1402: 
alpar@1402:     typedef std::vector<Item> InverseMap;
alpar@1402: 
alpar@1402:     /// \brief Constructor.
alpar@1402:     ///
alpar@1402:     /// Constructor for creating descriptor map.
alpar@1402:     DescriptorMap(const Graph& _graph) : Map(_graph) {
alpar@1402:       build();
alpar@1402:     }
alpar@1402: 
alpar@1402:     /// \brief Add a new key to the map.
alpar@1402:     ///
alpar@1402:     /// Add a new key to the map. It is called by the
alpar@1402:     /// \c AlterationNotifier.
alpar@1402:     virtual void add(const Item& item) {
alpar@1402:       Map::add(item);
alpar@1402:       Map::set(item, invMap.size());
alpar@1402:       invMap.push_back(item);
alpar@1402:     }
alpar@1402: 
alpar@1402:     /// \brief Erase the key from the map.
alpar@1402:     ///
alpar@1402:     /// Erase the key to the map. It is called by the
alpar@1402:     /// \c AlterationNotifier.
alpar@1402:     virtual void erase(const Item& item) {
alpar@1402:       Map::set(invMap.back(), Map::operator[](item));
alpar@1402:       invMap[Map::operator[](item)] = invMap.back();
alpar@1402:       Map::erase(item);
alpar@1402:     }
alpar@1402: 
alpar@1402:     /// \brief Build the unique map.
alpar@1402:     ///
alpar@1402:     /// Build the unique map. It is called by the
alpar@1402:     /// \c AlterationNotifier.
alpar@1402:     virtual void build() {
alpar@1402:       Map::build();
alpar@1402:       Item it;
alpar@1402:       const typename Map::Graph* graph = Map::getGraph(); 
alpar@1402:       for (graph->first(it); it != INVALID; graph->next(it)) {
alpar@1402: 	Map::set(it, invMap.size());
alpar@1402: 	invMap.push_back(it);	
alpar@1402:       }      
alpar@1402:     }
alpar@1402:     
alpar@1402:     /// \brief Clear the keys from the map.
alpar@1402:     ///
alpar@1402:     /// Clear the keys from the map. It is called by the
alpar@1402:     /// \c AlterationNotifier.
alpar@1402:     virtual void clear() {
alpar@1402:       invMap.clear();
alpar@1402:       Map::clear();
alpar@1402:     }
alpar@1402: 
alpar@1402:     /// \brief Gives back the \e descriptor of the item.
alpar@1402:     ///
alpar@1402:     /// Gives back the mutable and unique \e descriptor of the map.
alpar@1402:     int operator[](const Item& item) const {
alpar@1402:       return Map::operator[](item);
alpar@1402:     }
alpar@1402:     
alpar@1402:     /// \brief Gives back the inverse of the map.
alpar@1402:     ///
alpar@1402:     /// Gives back the inverse of the map.
alpar@1402:     const InverseMap inverse() const {
alpar@1402:       return invMap;
alpar@1402:     }
alpar@1402: 
alpar@1402:   private:
alpar@1402:     std::vector<Item> invMap;
alpar@1402:   };
alpar@1402: 
alpar@1402:   /// \brief Returns the source of the given edge.
alpar@1402:   ///
alpar@1402:   /// The SourceMap gives back the source Node of the given edge. 
alpar@1402:   /// \author Balazs Dezso
alpar@1402:   template <typename Graph>
alpar@1402:   class SourceMap {
alpar@1402:   public:
alpar@1402:     typedef typename Graph::Node Value;
alpar@1402:     typedef typename Graph::Edge Key;
alpar@1402: 
alpar@1402:     /// \brief Constructor
alpar@1402:     ///
alpar@1402:     /// Constructor
alpar@1402:     /// \param _graph The graph that the map belongs to.
alpar@1402:     SourceMap(const Graph& _graph) : graph(_graph) {}
alpar@1402: 
alpar@1402:     /// \brief The subscript operator.
alpar@1402:     ///
alpar@1402:     /// The subscript operator.
alpar@1402:     /// \param edge The edge 
alpar@1402:     /// \return The source of the edge 
alpar@1402:     Value operator[](const Key& edge) {
alpar@1402:       return graph.source(edge);
alpar@1402:     }
alpar@1402: 
alpar@1402:   private:
alpar@1402:     const Graph& graph;
alpar@1402:   };
alpar@1402: 
alpar@1402:   /// \brief Returns a \ref SourceMap class
alpar@1402:   ///
alpar@1402:   /// This function just returns an \ref SourceMap class.
alpar@1402:   /// \relates SourceMap
alpar@1402:   template <typename Graph>
alpar@1402:   inline SourceMap<Graph> sourceMap(const Graph& graph) {
alpar@1402:     return SourceMap<Graph>(graph);
alpar@1402:   } 
alpar@1402: 
alpar@1402:   /// \brief Returns the target of the given edge.
alpar@1402:   ///
alpar@1402:   /// The TargetMap gives back the target Node of the given edge. 
alpar@1402:   /// \author Balazs Dezso
alpar@1402:   template <typename Graph>
alpar@1402:   class TargetMap {
alpar@1402:   public:
alpar@1402:     typedef typename Graph::Node Value;
alpar@1402:     typedef typename Graph::Edge Key;
alpar@1402: 
alpar@1402:     /// \brief Constructor
alpar@1402:     ///
alpar@1402:     /// Constructor
alpar@1402:     /// \param _graph The graph that the map belongs to.
alpar@1402:     TargetMap(const Graph& _graph) : graph(_graph) {}
alpar@1402: 
alpar@1402:     /// \brief The subscript operator.
alpar@1402:     ///
alpar@1402:     /// The subscript operator.
alpar@1402:     /// \param edge The edge 
alpar@1402:     /// \return The target of the edge 
alpar@1402:     Value operator[](const Key& key) {
alpar@1402:       return graph.target(key);
alpar@1402:     }
alpar@1402: 
alpar@1402:   private:
alpar@1402:     const Graph& graph;
alpar@1402:   };
alpar@1402: 
alpar@1402:   /// \brief Returns a \ref TargetMap class
alpar@1402: 
alpar@1402:   /// This function just returns an \ref TargetMap class.
alpar@1402:   /// \relates TargetMap
alpar@1402:   template <typename Graph>
alpar@1402:   inline TargetMap<Graph> targetMap(const Graph& graph) {
alpar@1402:     return TargetMap<Graph>(graph);
alpar@1402:   }
alpar@1402: 
alpar@1402: 
alpar@1402:   /// @}
alpar@1402: 
alpar@947: } //END OF NAMESPACE LEMON
klao@946: 
klao@946: #endif