deba@220: /* -*- mode: C++; indent-tabs-mode: nil; -*-
deba@220:  *
deba@220:  * This file is a part of LEMON, a generic C++ optimization library.
deba@220:  *
alpar@440:  * Copyright (C) 2003-2009
deba@220:  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
deba@220:  * (Egervary Research Group on Combinatorial Optimization, EGRES).
deba@220:  *
deba@220:  * Permission to use, modify and distribute this software is granted
deba@220:  * provided that this copyright notice appears in all copies. For
deba@220:  * precise terms see the accompanying LICENSE file.
deba@220:  *
deba@220:  * This software is provided "AS IS" with no warranty of any kind,
deba@220:  * express or implied, and with no claim as to its suitability for any
deba@220:  * purpose.
deba@220:  *
deba@220:  */
deba@220: 
deba@220: #ifndef LEMON_CORE_H
deba@220: #define LEMON_CORE_H
deba@220: 
deba@220: #include <vector>
deba@220: #include <algorithm>
deba@220: 
alpar@502: #include <lemon/core.h>
deba@220: #include <lemon/bits/enable_if.h>
deba@220: #include <lemon/bits/traits.h>
alpar@319: #include <lemon/assert.h>
deba@220: 
deba@220: ///\file
deba@220: ///\brief LEMON core utilities.
kpeter@229: ///
kpeter@229: ///This header file contains core utilities for LEMON.
deba@233: ///It is automatically included by all graph types, therefore it usually
kpeter@229: ///do not have to be included directly.
deba@220: 
deba@220: namespace lemon {
deba@220: 
deba@220:   /// \brief Dummy type to make it easier to create invalid iterators.
deba@220:   ///
deba@220:   /// Dummy type to make it easier to create invalid iterators.
deba@220:   /// See \ref INVALID for the usage.
deba@220:   struct Invalid {
deba@220:   public:
deba@220:     bool operator==(Invalid) { return true;  }
deba@220:     bool operator!=(Invalid) { return false; }
deba@220:     bool operator< (Invalid) { return false; }
deba@220:   };
deba@220: 
deba@220:   /// \brief Invalid iterators.
deba@220:   ///
deba@220:   /// \ref Invalid is a global type that converts to each iterator
deba@220:   /// in such a way that the value of the target iterator will be invalid.
deba@220: #ifdef LEMON_ONLY_TEMPLATES
deba@220:   const Invalid INVALID = Invalid();
deba@220: #else
deba@220:   extern const Invalid INVALID;
deba@220: #endif
deba@220: 
deba@220:   /// \addtogroup gutils
deba@220:   /// @{
deba@220: 
kpeter@300:   ///Create convenience typedefs for the digraph types and iterators
deba@220: 
kpeter@282:   ///This \c \#define creates convenient type definitions for the following
kpeter@282:   ///types of \c Digraph: \c Node,  \c NodeIt, \c Arc, \c ArcIt, \c InArcIt,
deba@220:   ///\c OutArcIt, \c BoolNodeMap, \c IntNodeMap, \c DoubleNodeMap,
deba@220:   ///\c BoolArcMap, \c IntArcMap, \c DoubleArcMap.
deba@220:   ///
deba@220:   ///\note If the graph type is a dependent type, ie. the graph type depend
deba@220:   ///on a template parameter, then use \c TEMPLATE_DIGRAPH_TYPEDEFS()
deba@220:   ///macro.
deba@220: #define DIGRAPH_TYPEDEFS(Digraph)                                       \
deba@220:   typedef Digraph::Node Node;                                           \
deba@220:   typedef Digraph::NodeIt NodeIt;                                       \
deba@220:   typedef Digraph::Arc Arc;                                             \
deba@220:   typedef Digraph::ArcIt ArcIt;                                         \
deba@220:   typedef Digraph::InArcIt InArcIt;                                     \
deba@220:   typedef Digraph::OutArcIt OutArcIt;                                   \
deba@220:   typedef Digraph::NodeMap<bool> BoolNodeMap;                           \
deba@220:   typedef Digraph::NodeMap<int> IntNodeMap;                             \
deba@220:   typedef Digraph::NodeMap<double> DoubleNodeMap;                       \
deba@220:   typedef Digraph::ArcMap<bool> BoolArcMap;                             \
deba@220:   typedef Digraph::ArcMap<int> IntArcMap;                               \
kpeter@300:   typedef Digraph::ArcMap<double> DoubleArcMap
deba@220: 
kpeter@300:   ///Create convenience typedefs for the digraph types and iterators
deba@220: 
deba@220:   ///\see DIGRAPH_TYPEDEFS
deba@220:   ///
deba@220:   ///\note Use this macro, if the graph type is a dependent type,
deba@220:   ///ie. the graph type depend on a template parameter.
deba@220: #define TEMPLATE_DIGRAPH_TYPEDEFS(Digraph)                              \
deba@220:   typedef typename Digraph::Node Node;                                  \
deba@220:   typedef typename Digraph::NodeIt NodeIt;                              \
deba@220:   typedef typename Digraph::Arc Arc;                                    \
deba@220:   typedef typename Digraph::ArcIt ArcIt;                                \
deba@220:   typedef typename Digraph::InArcIt InArcIt;                            \
deba@220:   typedef typename Digraph::OutArcIt OutArcIt;                          \
deba@220:   typedef typename Digraph::template NodeMap<bool> BoolNodeMap;         \
deba@220:   typedef typename Digraph::template NodeMap<int> IntNodeMap;           \
deba@220:   typedef typename Digraph::template NodeMap<double> DoubleNodeMap;     \
deba@220:   typedef typename Digraph::template ArcMap<bool> BoolArcMap;           \
deba@220:   typedef typename Digraph::template ArcMap<int> IntArcMap;             \
kpeter@300:   typedef typename Digraph::template ArcMap<double> DoubleArcMap
deba@220: 
kpeter@300:   ///Create convenience typedefs for the graph types and iterators
deba@220: 
kpeter@282:   ///This \c \#define creates the same convenient type definitions as defined
deba@220:   ///by \ref DIGRAPH_TYPEDEFS(Graph) and six more, namely it creates
deba@220:   ///\c Edge, \c EdgeIt, \c IncEdgeIt, \c BoolEdgeMap, \c IntEdgeMap,
deba@220:   ///\c DoubleEdgeMap.
deba@220:   ///
deba@220:   ///\note If the graph type is a dependent type, ie. the graph type depend
kpeter@282:   ///on a template parameter, then use \c TEMPLATE_GRAPH_TYPEDEFS()
deba@220:   ///macro.
deba@220: #define GRAPH_TYPEDEFS(Graph)                                           \
deba@220:   DIGRAPH_TYPEDEFS(Graph);                                              \
deba@220:   typedef Graph::Edge Edge;                                             \
deba@220:   typedef Graph::EdgeIt EdgeIt;                                         \
deba@220:   typedef Graph::IncEdgeIt IncEdgeIt;                                   \
deba@220:   typedef Graph::EdgeMap<bool> BoolEdgeMap;                             \
deba@220:   typedef Graph::EdgeMap<int> IntEdgeMap;                               \
kpeter@300:   typedef Graph::EdgeMap<double> DoubleEdgeMap
deba@220: 
kpeter@300:   ///Create convenience typedefs for the graph types and iterators
deba@220: 
deba@220:   ///\see GRAPH_TYPEDEFS
deba@220:   ///
deba@220:   ///\note Use this macro, if the graph type is a dependent type,
deba@220:   ///ie. the graph type depend on a template parameter.
deba@220: #define TEMPLATE_GRAPH_TYPEDEFS(Graph)                                  \
deba@220:   TEMPLATE_DIGRAPH_TYPEDEFS(Graph);                                     \
deba@220:   typedef typename Graph::Edge Edge;                                    \
deba@220:   typedef typename Graph::EdgeIt EdgeIt;                                \
deba@220:   typedef typename Graph::IncEdgeIt IncEdgeIt;                          \
deba@220:   typedef typename Graph::template EdgeMap<bool> BoolEdgeMap;           \
deba@220:   typedef typename Graph::template EdgeMap<int> IntEdgeMap;             \
kpeter@300:   typedef typename Graph::template EdgeMap<double> DoubleEdgeMap
deba@220: 
kpeter@282:   /// \brief Function to count the items in a graph.
deba@220:   ///
kpeter@282:   /// This function counts the items (nodes, arcs etc.) in a graph.
kpeter@282:   /// The complexity of the function is linear because
deba@220:   /// it iterates on all of the items.
deba@220:   template <typename Graph, typename Item>
deba@220:   inline int countItems(const Graph& g) {
deba@220:     typedef typename ItemSetTraits<Graph, Item>::ItemIt ItemIt;
deba@220:     int num = 0;
deba@220:     for (ItemIt it(g); it != INVALID; ++it) {
deba@220:       ++num;
deba@220:     }
deba@220:     return num;
deba@220:   }
deba@220: 
deba@220:   // Node counting:
deba@220: 
deba@220:   namespace _core_bits {
deba@220: 
deba@220:     template <typename Graph, typename Enable = void>
deba@220:     struct CountNodesSelector {
deba@220:       static int count(const Graph &g) {
deba@220:         return countItems<Graph, typename Graph::Node>(g);
deba@220:       }
deba@220:     };
deba@220: 
deba@220:     template <typename Graph>
deba@220:     struct CountNodesSelector<
deba@220:       Graph, typename
deba@220:       enable_if<typename Graph::NodeNumTag, void>::type>
deba@220:     {
deba@220:       static int count(const Graph &g) {
deba@220:         return g.nodeNum();
deba@220:       }
deba@220:     };
deba@220:   }
deba@220: 
deba@220:   /// \brief Function to count the nodes in the graph.
deba@220:   ///
deba@220:   /// This function counts the nodes in the graph.
kpeter@282:   /// The complexity of the function is <em>O</em>(<em>n</em>), but for some
kpeter@282:   /// graph structures it is specialized to run in <em>O</em>(1).
deba@220:   ///
kpeter@282:   /// \note If the graph contains a \c nodeNum() member function and a
kpeter@282:   /// \c NodeNumTag tag then this function calls directly the member
deba@220:   /// function to query the cardinality of the node set.
deba@220:   template <typename Graph>
deba@220:   inline int countNodes(const Graph& g) {
deba@220:     return _core_bits::CountNodesSelector<Graph>::count(g);
deba@220:   }
deba@220: 
deba@220:   // Arc counting:
deba@220: 
deba@220:   namespace _core_bits {
deba@220: 
deba@220:     template <typename Graph, typename Enable = void>
deba@220:     struct CountArcsSelector {
deba@220:       static int count(const Graph &g) {
deba@220:         return countItems<Graph, typename Graph::Arc>(g);
deba@220:       }
deba@220:     };
deba@220: 
deba@220:     template <typename Graph>
deba@220:     struct CountArcsSelector<
deba@220:       Graph,
deba@220:       typename enable_if<typename Graph::ArcNumTag, void>::type>
deba@220:     {
deba@220:       static int count(const Graph &g) {
deba@220:         return g.arcNum();
deba@220:       }
deba@220:     };
deba@220:   }
deba@220: 
deba@220:   /// \brief Function to count the arcs in the graph.
deba@220:   ///
deba@220:   /// This function counts the arcs in the graph.
kpeter@282:   /// The complexity of the function is <em>O</em>(<em>m</em>), but for some
kpeter@282:   /// graph structures it is specialized to run in <em>O</em>(1).
deba@220:   ///
kpeter@282:   /// \note If the graph contains a \c arcNum() member function and a
kpeter@282:   /// \c ArcNumTag tag then this function calls directly the member
deba@220:   /// function to query the cardinality of the arc set.
deba@220:   template <typename Graph>
deba@220:   inline int countArcs(const Graph& g) {
deba@220:     return _core_bits::CountArcsSelector<Graph>::count(g);
deba@220:   }
deba@220: 
deba@220:   // Edge counting:
kpeter@282: 
deba@220:   namespace _core_bits {
deba@220: 
deba@220:     template <typename Graph, typename Enable = void>
deba@220:     struct CountEdgesSelector {
deba@220:       static int count(const Graph &g) {
deba@220:         return countItems<Graph, typename Graph::Edge>(g);
deba@220:       }
deba@220:     };
deba@220: 
deba@220:     template <typename Graph>
deba@220:     struct CountEdgesSelector<
deba@220:       Graph,
deba@220:       typename enable_if<typename Graph::EdgeNumTag, void>::type>
deba@220:     {
deba@220:       static int count(const Graph &g) {
deba@220:         return g.edgeNum();
deba@220:       }
deba@220:     };
deba@220:   }
deba@220: 
deba@220:   /// \brief Function to count the edges in the graph.
deba@220:   ///
deba@220:   /// This function counts the edges in the graph.
kpeter@282:   /// The complexity of the function is <em>O</em>(<em>m</em>), but for some
kpeter@282:   /// graph structures it is specialized to run in <em>O</em>(1).
deba@220:   ///
kpeter@282:   /// \note If the graph contains a \c edgeNum() member function and a
kpeter@282:   /// \c EdgeNumTag tag then this function calls directly the member
deba@220:   /// function to query the cardinality of the edge set.
deba@220:   template <typename Graph>
deba@220:   inline int countEdges(const Graph& g) {
deba@220:     return _core_bits::CountEdgesSelector<Graph>::count(g);
deba@220: 
deba@220:   }
deba@220: 
deba@220: 
deba@220:   template <typename Graph, typename DegIt>
deba@220:   inline int countNodeDegree(const Graph& _g, const typename Graph::Node& _n) {
deba@220:     int num = 0;
deba@220:     for (DegIt it(_g, _n); it != INVALID; ++it) {
deba@220:       ++num;
deba@220:     }
deba@220:     return num;
deba@220:   }
deba@220: 
deba@220:   /// \brief Function to count the number of the out-arcs from node \c n.
deba@220:   ///
deba@220:   /// This function counts the number of the out-arcs from node \c n
kpeter@282:   /// in the graph \c g.
deba@220:   template <typename Graph>
kpeter@282:   inline int countOutArcs(const Graph& g,  const typename Graph::Node& n) {
kpeter@282:     return countNodeDegree<Graph, typename Graph::OutArcIt>(g, n);
deba@220:   }
deba@220: 
deba@220:   /// \brief Function to count the number of the in-arcs to node \c n.
deba@220:   ///
deba@220:   /// This function counts the number of the in-arcs to node \c n
kpeter@282:   /// in the graph \c g.
deba@220:   template <typename Graph>
kpeter@282:   inline int countInArcs(const Graph& g,  const typename Graph::Node& n) {
kpeter@282:     return countNodeDegree<Graph, typename Graph::InArcIt>(g, n);
deba@220:   }
deba@220: 
deba@220:   /// \brief Function to count the number of the inc-edges to node \c n.
deba@220:   ///
deba@220:   /// This function counts the number of the inc-edges to node \c n
kpeter@282:   /// in the undirected graph \c g.
deba@220:   template <typename Graph>
kpeter@282:   inline int countIncEdges(const Graph& g,  const typename Graph::Node& n) {
kpeter@282:     return countNodeDegree<Graph, typename Graph::IncEdgeIt>(g, n);
deba@220:   }
deba@220: 
deba@220:   namespace _core_bits {
deba@220: 
deba@220:     template <typename Digraph, typename Item, typename RefMap>
deba@220:     class MapCopyBase {
deba@220:     public:
deba@220:       virtual void copy(const Digraph& from, const RefMap& refMap) = 0;
deba@220: 
deba@220:       virtual ~MapCopyBase() {}
deba@220:     };
deba@220: 
deba@220:     template <typename Digraph, typename Item, typename RefMap,
kpeter@282:               typename FromMap, typename ToMap>
deba@220:     class MapCopy : public MapCopyBase<Digraph, Item, RefMap> {
deba@220:     public:
deba@220: 
kpeter@282:       MapCopy(const FromMap& map, ToMap& tmap)
kpeter@282:         : _map(map), _tmap(tmap) {}
deba@220: 
deba@220:       virtual void copy(const Digraph& digraph, const RefMap& refMap) {
deba@220:         typedef typename ItemSetTraits<Digraph, Item>::ItemIt ItemIt;
deba@220:         for (ItemIt it(digraph); it != INVALID; ++it) {
deba@220:           _tmap.set(refMap[it], _map[it]);
deba@220:         }
deba@220:       }
deba@220: 
deba@220:     private:
kpeter@282:       const FromMap& _map;
deba@220:       ToMap& _tmap;
deba@220:     };
deba@220: 
deba@220:     template <typename Digraph, typename Item, typename RefMap, typename It>
deba@220:     class ItemCopy : public MapCopyBase<Digraph, Item, RefMap> {
deba@220:     public:
deba@220: 
kpeter@282:       ItemCopy(const Item& item, It& it) : _item(item), _it(it) {}
deba@220: 
deba@220:       virtual void copy(const Digraph&, const RefMap& refMap) {
deba@220:         _it = refMap[_item];
deba@220:       }
deba@220: 
deba@220:     private:
kpeter@282:       Item _item;
deba@220:       It& _it;
deba@220:     };
deba@220: 
deba@220:     template <typename Digraph, typename Item, typename RefMap, typename Ref>
deba@220:     class RefCopy : public MapCopyBase<Digraph, Item, RefMap> {
deba@220:     public:
deba@220: 
deba@220:       RefCopy(Ref& map) : _map(map) {}
deba@220: 
deba@220:       virtual void copy(const Digraph& digraph, const RefMap& refMap) {
deba@220:         typedef typename ItemSetTraits<Digraph, Item>::ItemIt ItemIt;
deba@220:         for (ItemIt it(digraph); it != INVALID; ++it) {
deba@220:           _map.set(it, refMap[it]);
deba@220:         }
deba@220:       }
deba@220: 
deba@220:     private:
deba@220:       Ref& _map;
deba@220:     };
deba@220: 
deba@220:     template <typename Digraph, typename Item, typename RefMap,
deba@220:               typename CrossRef>
deba@220:     class CrossRefCopy : public MapCopyBase<Digraph, Item, RefMap> {
deba@220:     public:
deba@220: 
deba@220:       CrossRefCopy(CrossRef& cmap) : _cmap(cmap) {}
deba@220: 
deba@220:       virtual void copy(const Digraph& digraph, const RefMap& refMap) {
deba@220:         typedef typename ItemSetTraits<Digraph, Item>::ItemIt ItemIt;
deba@220:         for (ItemIt it(digraph); it != INVALID; ++it) {
deba@220:           _cmap.set(refMap[it], it);
deba@220:         }
deba@220:       }
deba@220: 
deba@220:     private:
deba@220:       CrossRef& _cmap;
deba@220:     };
deba@220: 
deba@220:     template <typename Digraph, typename Enable = void>
deba@220:     struct DigraphCopySelector {
deba@220:       template <typename From, typename NodeRefMap, typename ArcRefMap>
kpeter@282:       static void copy(const From& from, Digraph &to,
deba@220:                        NodeRefMap& nodeRefMap, ArcRefMap& arcRefMap) {
deba@220:         for (typename From::NodeIt it(from); it != INVALID; ++it) {
deba@220:           nodeRefMap[it] = to.addNode();
deba@220:         }
deba@220:         for (typename From::ArcIt it(from); it != INVALID; ++it) {
deba@220:           arcRefMap[it] = to.addArc(nodeRefMap[from.source(it)],
deba@220:                                     nodeRefMap[from.target(it)]);
deba@220:         }
deba@220:       }
deba@220:     };
deba@220: 
deba@220:     template <typename Digraph>
deba@220:     struct DigraphCopySelector<
deba@220:       Digraph,
deba@220:       typename enable_if<typename Digraph::BuildTag, void>::type>
deba@220:     {
deba@220:       template <typename From, typename NodeRefMap, typename ArcRefMap>
kpeter@282:       static void copy(const From& from, Digraph &to,
deba@220:                        NodeRefMap& nodeRefMap, ArcRefMap& arcRefMap) {
deba@220:         to.build(from, nodeRefMap, arcRefMap);
deba@220:       }
deba@220:     };
deba@220: 
deba@220:     template <typename Graph, typename Enable = void>
deba@220:     struct GraphCopySelector {
deba@220:       template <typename From, typename NodeRefMap, typename EdgeRefMap>
kpeter@282:       static void copy(const From& from, Graph &to,
deba@220:                        NodeRefMap& nodeRefMap, EdgeRefMap& edgeRefMap) {
deba@220:         for (typename From::NodeIt it(from); it != INVALID; ++it) {
deba@220:           nodeRefMap[it] = to.addNode();
deba@220:         }
deba@220:         for (typename From::EdgeIt it(from); it != INVALID; ++it) {
deba@220:           edgeRefMap[it] = to.addEdge(nodeRefMap[from.u(it)],
deba@220:                                       nodeRefMap[from.v(it)]);
deba@220:         }
deba@220:       }
deba@220:     };
deba@220: 
deba@220:     template <typename Graph>
deba@220:     struct GraphCopySelector<
deba@220:       Graph,
deba@220:       typename enable_if<typename Graph::BuildTag, void>::type>
deba@220:     {
deba@220:       template <typename From, typename NodeRefMap, typename EdgeRefMap>
kpeter@282:       static void copy(const From& from, Graph &to,
deba@220:                        NodeRefMap& nodeRefMap, EdgeRefMap& edgeRefMap) {
deba@220:         to.build(from, nodeRefMap, edgeRefMap);
deba@220:       }
deba@220:     };
deba@220: 
deba@220:   }
deba@220: 
deba@220:   /// \brief Class to copy a digraph.
deba@220:   ///
deba@220:   /// Class to copy a digraph to another digraph (duplicate a digraph). The
kpeter@282:   /// simplest way of using it is through the \c digraphCopy() function.
deba@220:   ///
kpeter@282:   /// This class not only make a copy of a digraph, but it can create
deba@220:   /// references and cross references between the nodes and arcs of
kpeter@282:   /// the two digraphs, and it can copy maps to use with the newly created
kpeter@282:   /// digraph.
deba@220:   ///
kpeter@282:   /// To make a copy from a digraph, first an instance of DigraphCopy
kpeter@282:   /// should be created, then the data belongs to the digraph should
deba@220:   /// assigned to copy. In the end, the \c run() member should be
deba@220:   /// called.
deba@220:   ///
kpeter@282:   /// The next code copies a digraph with several data:
deba@220:   ///\code
kpeter@282:   ///  DigraphCopy<OrigGraph, NewGraph> cg(orig_graph, new_graph);
kpeter@282:   ///  // Create references for the nodes
deba@220:   ///  OrigGraph::NodeMap<NewGraph::Node> nr(orig_graph);
kpeter@282:   ///  cg.nodeRef(nr);
kpeter@282:   ///  // Create cross references (inverse) for the arcs
deba@220:   ///  NewGraph::ArcMap<OrigGraph::Arc> acr(new_graph);
kpeter@282:   ///  cg.arcCrossRef(acr);
kpeter@282:   ///  // Copy an arc map
deba@220:   ///  OrigGraph::ArcMap<double> oamap(orig_graph);
deba@220:   ///  NewGraph::ArcMap<double> namap(new_graph);
kpeter@282:   ///  cg.arcMap(oamap, namap);
kpeter@282:   ///  // Copy a node
deba@220:   ///  OrigGraph::Node on;
deba@220:   ///  NewGraph::Node nn;
kpeter@282:   ///  cg.node(on, nn);
kpeter@282:   ///  // Execute copying
kpeter@282:   ///  cg.run();
deba@220:   ///\endcode
kpeter@282:   template <typename From, typename To>
deba@220:   class DigraphCopy {
deba@220:   private:
deba@220: 
deba@220:     typedef typename From::Node Node;
deba@220:     typedef typename From::NodeIt NodeIt;
deba@220:     typedef typename From::Arc Arc;
deba@220:     typedef typename From::ArcIt ArcIt;
deba@220: 
deba@220:     typedef typename To::Node TNode;
deba@220:     typedef typename To::Arc TArc;
deba@220: 
deba@220:     typedef typename From::template NodeMap<TNode> NodeRefMap;
deba@220:     typedef typename From::template ArcMap<TArc> ArcRefMap;
deba@220: 
deba@220:   public:
deba@220: 
kpeter@282:     /// \brief Constructor of DigraphCopy.
deba@220:     ///
kpeter@282:     /// Constructor of DigraphCopy for copying the content of the
kpeter@282:     /// \c from digraph into the \c to digraph.
kpeter@282:     DigraphCopy(const From& from, To& to)
deba@220:       : _from(from), _to(to) {}
deba@220: 
kpeter@282:     /// \brief Destructor of DigraphCopy
deba@220:     ///
kpeter@282:     /// Destructor of DigraphCopy.
deba@220:     ~DigraphCopy() {
deba@220:       for (int i = 0; i < int(_node_maps.size()); ++i) {
deba@220:         delete _node_maps[i];
deba@220:       }
deba@220:       for (int i = 0; i < int(_arc_maps.size()); ++i) {
deba@220:         delete _arc_maps[i];
deba@220:       }
deba@220: 
deba@220:     }
deba@220: 
kpeter@282:     /// \brief Copy the node references into the given map.
deba@220:     ///
kpeter@282:     /// This function copies the node references into the given map.
kpeter@282:     /// The parameter should be a map, whose key type is the Node type of
kpeter@282:     /// the source digraph, while the value type is the Node type of the
kpeter@282:     /// destination digraph.
deba@220:     template <typename NodeRef>
deba@220:     DigraphCopy& nodeRef(NodeRef& map) {
deba@220:       _node_maps.push_back(new _core_bits::RefCopy<From, Node,
deba@220:                            NodeRefMap, NodeRef>(map));
deba@220:       return *this;
deba@220:     }
deba@220: 
kpeter@282:     /// \brief Copy the node cross references into the given map.
deba@220:     ///
kpeter@282:     /// This function copies the node cross references (reverse references)
kpeter@282:     /// into the given map. The parameter should be a map, whose key type
kpeter@282:     /// is the Node type of the destination digraph, while the value type is
kpeter@282:     /// the Node type of the source digraph.
deba@220:     template <typename NodeCrossRef>
deba@220:     DigraphCopy& nodeCrossRef(NodeCrossRef& map) {
deba@220:       _node_maps.push_back(new _core_bits::CrossRefCopy<From, Node,
deba@220:                            NodeRefMap, NodeCrossRef>(map));
deba@220:       return *this;
deba@220:     }
deba@220: 
kpeter@282:     /// \brief Make a copy of the given node map.
deba@220:     ///
kpeter@282:     /// This function makes a copy of the given node map for the newly
kpeter@282:     /// created digraph.
kpeter@282:     /// The key type of the new map \c tmap should be the Node type of the
kpeter@282:     /// destination digraph, and the key type of the original map \c map
kpeter@282:     /// should be the Node type of the source digraph.
kpeter@282:     template <typename FromMap, typename ToMap>
kpeter@282:     DigraphCopy& nodeMap(const FromMap& map, ToMap& tmap) {
deba@220:       _node_maps.push_back(new _core_bits::MapCopy<From, Node,
kpeter@282:                            NodeRefMap, FromMap, ToMap>(map, tmap));
deba@220:       return *this;
deba@220:     }
deba@220: 
deba@220:     /// \brief Make a copy of the given node.
deba@220:     ///
kpeter@282:     /// This function makes a copy of the given node.
kpeter@282:     DigraphCopy& node(const Node& node, TNode& tnode) {
deba@220:       _node_maps.push_back(new _core_bits::ItemCopy<From, Node,
kpeter@282:                            NodeRefMap, TNode>(node, tnode));
deba@220:       return *this;
deba@220:     }
deba@220: 
kpeter@282:     /// \brief Copy the arc references into the given map.
deba@220:     ///
kpeter@282:     /// This function copies the arc references into the given map.
kpeter@282:     /// The parameter should be a map, whose key type is the Arc type of
kpeter@282:     /// the source digraph, while the value type is the Arc type of the
kpeter@282:     /// destination digraph.
deba@220:     template <typename ArcRef>
deba@220:     DigraphCopy& arcRef(ArcRef& map) {
deba@220:       _arc_maps.push_back(new _core_bits::RefCopy<From, Arc,
deba@220:                           ArcRefMap, ArcRef>(map));
deba@220:       return *this;
deba@220:     }
deba@220: 
kpeter@282:     /// \brief Copy the arc cross references into the given map.
deba@220:     ///
kpeter@282:     /// This function copies the arc cross references (reverse references)
kpeter@282:     /// into the given map. The parameter should be a map, whose key type
kpeter@282:     /// is the Arc type of the destination digraph, while the value type is
kpeter@282:     /// the Arc type of the source digraph.
deba@220:     template <typename ArcCrossRef>
deba@220:     DigraphCopy& arcCrossRef(ArcCrossRef& map) {
deba@220:       _arc_maps.push_back(new _core_bits::CrossRefCopy<From, Arc,
deba@220:                           ArcRefMap, ArcCrossRef>(map));
deba@220:       return *this;
deba@220:     }
deba@220: 
kpeter@282:     /// \brief Make a copy of the given arc map.
deba@220:     ///
kpeter@282:     /// This function makes a copy of the given arc map for the newly
kpeter@282:     /// created digraph.
kpeter@282:     /// The key type of the new map \c tmap should be the Arc type of the
kpeter@282:     /// destination digraph, and the key type of the original map \c map
kpeter@282:     /// should be the Arc type of the source digraph.
kpeter@282:     template <typename FromMap, typename ToMap>
kpeter@282:     DigraphCopy& arcMap(const FromMap& map, ToMap& tmap) {
deba@220:       _arc_maps.push_back(new _core_bits::MapCopy<From, Arc,
kpeter@282:                           ArcRefMap, FromMap, ToMap>(map, tmap));
deba@220:       return *this;
deba@220:     }
deba@220: 
deba@220:     /// \brief Make a copy of the given arc.
deba@220:     ///
kpeter@282:     /// This function makes a copy of the given arc.
kpeter@282:     DigraphCopy& arc(const Arc& arc, TArc& tarc) {
deba@220:       _arc_maps.push_back(new _core_bits::ItemCopy<From, Arc,
kpeter@282:                           ArcRefMap, TArc>(arc, tarc));
deba@220:       return *this;
deba@220:     }
deba@220: 
kpeter@282:     /// \brief Execute copying.
deba@220:     ///
kpeter@282:     /// This function executes the copying of the digraph along with the
kpeter@282:     /// copying of the assigned data.
deba@220:     void run() {
deba@220:       NodeRefMap nodeRefMap(_from);
deba@220:       ArcRefMap arcRefMap(_from);
deba@220:       _core_bits::DigraphCopySelector<To>::
kpeter@282:         copy(_from, _to, nodeRefMap, arcRefMap);
deba@220:       for (int i = 0; i < int(_node_maps.size()); ++i) {
deba@220:         _node_maps[i]->copy(_from, nodeRefMap);
deba@220:       }
deba@220:       for (int i = 0; i < int(_arc_maps.size()); ++i) {
deba@220:         _arc_maps[i]->copy(_from, arcRefMap);
deba@220:       }
deba@220:     }
deba@220: 
deba@220:   protected:
deba@220: 
deba@220:     const From& _from;
deba@220:     To& _to;
deba@220: 
deba@220:     std::vector<_core_bits::MapCopyBase<From, Node, NodeRefMap>* >
kpeter@282:       _node_maps;
deba@220: 
deba@220:     std::vector<_core_bits::MapCopyBase<From, Arc, ArcRefMap>* >
kpeter@282:       _arc_maps;
deba@220: 
deba@220:   };
deba@220: 
deba@220:   /// \brief Copy a digraph to another digraph.
deba@220:   ///
kpeter@282:   /// This function copies a digraph to another digraph.
kpeter@282:   /// The complete usage of it is detailed in the DigraphCopy class, but
kpeter@282:   /// a short example shows a basic work:
deba@220:   ///\code
kpeter@282:   /// digraphCopy(src, trg).nodeRef(nr).arcCrossRef(acr).run();
deba@220:   ///\endcode
deba@220:   ///
deba@220:   /// After the copy the \c nr map will contain the mapping from the
deba@220:   /// nodes of the \c from digraph to the nodes of the \c to digraph and
kpeter@282:   /// \c acr will contain the mapping from the arcs of the \c to digraph
deba@220:   /// to the arcs of the \c from digraph.
deba@220:   ///
deba@220:   /// \see DigraphCopy
kpeter@282:   template <typename From, typename To>
kpeter@282:   DigraphCopy<From, To> digraphCopy(const From& from, To& to) {
kpeter@282:     return DigraphCopy<From, To>(from, to);
deba@220:   }
deba@220: 
deba@220:   /// \brief Class to copy a graph.
deba@220:   ///
deba@220:   /// Class to copy a graph to another graph (duplicate a graph). The
kpeter@282:   /// simplest way of using it is through the \c graphCopy() function.
deba@220:   ///
kpeter@282:   /// This class not only make a copy of a graph, but it can create
deba@220:   /// references and cross references between the nodes, edges and arcs of
kpeter@282:   /// the two graphs, and it can copy maps for using with the newly created
kpeter@282:   /// graph.
deba@220:   ///
deba@220:   /// To make a copy from a graph, first an instance of GraphCopy
deba@220:   /// should be created, then the data belongs to the graph should
deba@220:   /// assigned to copy. In the end, the \c run() member should be
deba@220:   /// called.
deba@220:   ///
deba@220:   /// The next code copies a graph with several data:
deba@220:   ///\code
kpeter@282:   ///  GraphCopy<OrigGraph, NewGraph> cg(orig_graph, new_graph);
kpeter@282:   ///  // Create references for the nodes
deba@220:   ///  OrigGraph::NodeMap<NewGraph::Node> nr(orig_graph);
kpeter@282:   ///  cg.nodeRef(nr);
kpeter@282:   ///  // Create cross references (inverse) for the edges
kpeter@282:   ///  NewGraph::EdgeMap<OrigGraph::Edge> ecr(new_graph);
kpeter@282:   ///  cg.edgeCrossRef(ecr);
kpeter@282:   ///  // Copy an edge map
kpeter@282:   ///  OrigGraph::EdgeMap<double> oemap(orig_graph);
kpeter@282:   ///  NewGraph::EdgeMap<double> nemap(new_graph);
kpeter@282:   ///  cg.edgeMap(oemap, nemap);
kpeter@282:   ///  // Copy a node
deba@220:   ///  OrigGraph::Node on;
deba@220:   ///  NewGraph::Node nn;
kpeter@282:   ///  cg.node(on, nn);
kpeter@282:   ///  // Execute copying
kpeter@282:   ///  cg.run();
deba@220:   ///\endcode
kpeter@282:   template <typename From, typename To>
deba@220:   class GraphCopy {
deba@220:   private:
deba@220: 
deba@220:     typedef typename From::Node Node;
deba@220:     typedef typename From::NodeIt NodeIt;
deba@220:     typedef typename From::Arc Arc;
deba@220:     typedef typename From::ArcIt ArcIt;
deba@220:     typedef typename From::Edge Edge;
deba@220:     typedef typename From::EdgeIt EdgeIt;
deba@220: 
deba@220:     typedef typename To::Node TNode;
deba@220:     typedef typename To::Arc TArc;
deba@220:     typedef typename To::Edge TEdge;
deba@220: 
deba@220:     typedef typename From::template NodeMap<TNode> NodeRefMap;
deba@220:     typedef typename From::template EdgeMap<TEdge> EdgeRefMap;
deba@220: 
deba@220:     struct ArcRefMap {
kpeter@282:       ArcRefMap(const From& from, const To& to,
deba@220:                 const EdgeRefMap& edge_ref, const NodeRefMap& node_ref)
kpeter@282:         : _from(from), _to(to),
deba@220:           _edge_ref(edge_ref), _node_ref(node_ref) {}
deba@220: 
deba@220:       typedef typename From::Arc Key;
deba@220:       typedef typename To::Arc Value;
deba@220: 
deba@220:       Value operator[](const Key& key) const {
deba@220:         bool forward = _from.u(key) != _from.v(key) ?
deba@220:           _node_ref[_from.source(key)] ==
deba@220:           _to.source(_to.direct(_edge_ref[key], true)) :
deba@220:           _from.direction(key);
deba@220:         return _to.direct(_edge_ref[key], forward);
deba@220:       }
deba@220: 
kpeter@282:       const From& _from;
deba@220:       const To& _to;
deba@220:       const EdgeRefMap& _edge_ref;
deba@220:       const NodeRefMap& _node_ref;
deba@220:     };
deba@220: 
deba@220:   public:
deba@220: 
kpeter@282:     /// \brief Constructor of GraphCopy.
deba@220:     ///
kpeter@282:     /// Constructor of GraphCopy for copying the content of the
kpeter@282:     /// \c from graph into the \c to graph.
kpeter@282:     GraphCopy(const From& from, To& to)
deba@220:       : _from(from), _to(to) {}
deba@220: 
kpeter@282:     /// \brief Destructor of GraphCopy
deba@220:     ///
kpeter@282:     /// Destructor of GraphCopy.
deba@220:     ~GraphCopy() {
deba@220:       for (int i = 0; i < int(_node_maps.size()); ++i) {
deba@220:         delete _node_maps[i];
deba@220:       }
deba@220:       for (int i = 0; i < int(_arc_maps.size()); ++i) {
deba@220:         delete _arc_maps[i];
deba@220:       }
deba@220:       for (int i = 0; i < int(_edge_maps.size()); ++i) {
deba@220:         delete _edge_maps[i];
deba@220:       }
deba@220:     }
deba@220: 
kpeter@282:     /// \brief Copy the node references into the given map.
deba@220:     ///
kpeter@282:     /// This function copies the node references into the given map.
kpeter@282:     /// The parameter should be a map, whose key type is the Node type of
kpeter@282:     /// the source graph, while the value type is the Node type of the
kpeter@282:     /// destination graph.
deba@220:     template <typename NodeRef>
deba@220:     GraphCopy& nodeRef(NodeRef& map) {
deba@220:       _node_maps.push_back(new _core_bits::RefCopy<From, Node,
deba@220:                            NodeRefMap, NodeRef>(map));
deba@220:       return *this;
deba@220:     }
deba@220: 
kpeter@282:     /// \brief Copy the node cross references into the given map.
deba@220:     ///
kpeter@282:     /// This function copies the node cross references (reverse references)
kpeter@282:     /// into the given map. The parameter should be a map, whose key type
kpeter@282:     /// is the Node type of the destination graph, while the value type is
kpeter@282:     /// the Node type of the source graph.
deba@220:     template <typename NodeCrossRef>
deba@220:     GraphCopy& nodeCrossRef(NodeCrossRef& map) {
deba@220:       _node_maps.push_back(new _core_bits::CrossRefCopy<From, Node,
deba@220:                            NodeRefMap, NodeCrossRef>(map));
deba@220:       return *this;
deba@220:     }
deba@220: 
kpeter@282:     /// \brief Make a copy of the given node map.
deba@220:     ///
kpeter@282:     /// This function makes a copy of the given node map for the newly
kpeter@282:     /// created graph.
kpeter@282:     /// The key type of the new map \c tmap should be the Node type of the
kpeter@282:     /// destination graph, and the key type of the original map \c map
kpeter@282:     /// should be the Node type of the source graph.
kpeter@282:     template <typename FromMap, typename ToMap>
kpeter@282:     GraphCopy& nodeMap(const FromMap& map, ToMap& tmap) {
deba@220:       _node_maps.push_back(new _core_bits::MapCopy<From, Node,
kpeter@282:                            NodeRefMap, FromMap, ToMap>(map, tmap));
deba@220:       return *this;
deba@220:     }
deba@220: 
deba@220:     /// \brief Make a copy of the given node.
deba@220:     ///
kpeter@282:     /// This function makes a copy of the given node.
kpeter@282:     GraphCopy& node(const Node& node, TNode& tnode) {
deba@220:       _node_maps.push_back(new _core_bits::ItemCopy<From, Node,
kpeter@282:                            NodeRefMap, TNode>(node, tnode));
deba@220:       return *this;
deba@220:     }
deba@220: 
kpeter@282:     /// \brief Copy the arc references into the given map.
deba@220:     ///
kpeter@282:     /// This function copies the arc references into the given map.
kpeter@282:     /// The parameter should be a map, whose key type is the Arc type of
kpeter@282:     /// the source graph, while the value type is the Arc type of the
kpeter@282:     /// destination graph.
deba@220:     template <typename ArcRef>
deba@220:     GraphCopy& arcRef(ArcRef& map) {
deba@220:       _arc_maps.push_back(new _core_bits::RefCopy<From, Arc,
deba@220:                           ArcRefMap, ArcRef>(map));
deba@220:       return *this;
deba@220:     }
deba@220: 
kpeter@282:     /// \brief Copy the arc cross references into the given map.
deba@220:     ///
kpeter@282:     /// This function copies the arc cross references (reverse references)
kpeter@282:     /// into the given map. The parameter should be a map, whose key type
kpeter@282:     /// is the Arc type of the destination graph, while the value type is
kpeter@282:     /// the Arc type of the source graph.
deba@220:     template <typename ArcCrossRef>
deba@220:     GraphCopy& arcCrossRef(ArcCrossRef& map) {
deba@220:       _arc_maps.push_back(new _core_bits::CrossRefCopy<From, Arc,
deba@220:                           ArcRefMap, ArcCrossRef>(map));
deba@220:       return *this;
deba@220:     }
deba@220: 
kpeter@282:     /// \brief Make a copy of the given arc map.
deba@220:     ///
kpeter@282:     /// This function makes a copy of the given arc map for the newly
kpeter@282:     /// created graph.
kpeter@282:     /// The key type of the new map \c tmap should be the Arc type of the
kpeter@282:     /// destination graph, and the key type of the original map \c map
kpeter@282:     /// should be the Arc type of the source graph.
kpeter@282:     template <typename FromMap, typename ToMap>
kpeter@282:     GraphCopy& arcMap(const FromMap& map, ToMap& tmap) {
deba@220:       _arc_maps.push_back(new _core_bits::MapCopy<From, Arc,
kpeter@282:                           ArcRefMap, FromMap, ToMap>(map, tmap));
deba@220:       return *this;
deba@220:     }
deba@220: 
deba@220:     /// \brief Make a copy of the given arc.
deba@220:     ///
kpeter@282:     /// This function makes a copy of the given arc.
kpeter@282:     GraphCopy& arc(const Arc& arc, TArc& tarc) {
deba@220:       _arc_maps.push_back(new _core_bits::ItemCopy<From, Arc,
kpeter@282:                           ArcRefMap, TArc>(arc, tarc));
deba@220:       return *this;
deba@220:     }
deba@220: 
kpeter@282:     /// \brief Copy the edge references into the given map.
deba@220:     ///
kpeter@282:     /// This function copies the edge references into the given map.
kpeter@282:     /// The parameter should be a map, whose key type is the Edge type of
kpeter@282:     /// the source graph, while the value type is the Edge type of the
kpeter@282:     /// destination graph.
deba@220:     template <typename EdgeRef>
deba@220:     GraphCopy& edgeRef(EdgeRef& map) {
deba@220:       _edge_maps.push_back(new _core_bits::RefCopy<From, Edge,
deba@220:                            EdgeRefMap, EdgeRef>(map));
deba@220:       return *this;
deba@220:     }
deba@220: 
kpeter@282:     /// \brief Copy the edge cross references into the given map.
deba@220:     ///
kpeter@282:     /// This function copies the edge cross references (reverse references)
kpeter@282:     /// into the given map. The parameter should be a map, whose key type
kpeter@282:     /// is the Edge type of the destination graph, while the value type is
kpeter@282:     /// the Edge type of the source graph.
deba@220:     template <typename EdgeCrossRef>
deba@220:     GraphCopy& edgeCrossRef(EdgeCrossRef& map) {
deba@220:       _edge_maps.push_back(new _core_bits::CrossRefCopy<From,
deba@220:                            Edge, EdgeRefMap, EdgeCrossRef>(map));
deba@220:       return *this;
deba@220:     }
deba@220: 
kpeter@282:     /// \brief Make a copy of the given edge map.
deba@220:     ///
kpeter@282:     /// This function makes a copy of the given edge map for the newly
kpeter@282:     /// created graph.
kpeter@282:     /// The key type of the new map \c tmap should be the Edge type of the
kpeter@282:     /// destination graph, and the key type of the original map \c map
kpeter@282:     /// should be the Edge type of the source graph.
kpeter@282:     template <typename FromMap, typename ToMap>
kpeter@282:     GraphCopy& edgeMap(const FromMap& map, ToMap& tmap) {
deba@220:       _edge_maps.push_back(new _core_bits::MapCopy<From, Edge,
kpeter@282:                            EdgeRefMap, FromMap, ToMap>(map, tmap));
deba@220:       return *this;
deba@220:     }
deba@220: 
deba@220:     /// \brief Make a copy of the given edge.
deba@220:     ///
kpeter@282:     /// This function makes a copy of the given edge.
kpeter@282:     GraphCopy& edge(const Edge& edge, TEdge& tedge) {
deba@220:       _edge_maps.push_back(new _core_bits::ItemCopy<From, Edge,
kpeter@282:                            EdgeRefMap, TEdge>(edge, tedge));
deba@220:       return *this;
deba@220:     }
deba@220: 
kpeter@282:     /// \brief Execute copying.
deba@220:     ///
kpeter@282:     /// This function executes the copying of the graph along with the
kpeter@282:     /// copying of the assigned data.
deba@220:     void run() {
deba@220:       NodeRefMap nodeRefMap(_from);
deba@220:       EdgeRefMap edgeRefMap(_from);
kpeter@282:       ArcRefMap arcRefMap(_from, _to, edgeRefMap, nodeRefMap);
deba@220:       _core_bits::GraphCopySelector<To>::
kpeter@282:         copy(_from, _to, nodeRefMap, edgeRefMap);
deba@220:       for (int i = 0; i < int(_node_maps.size()); ++i) {
deba@220:         _node_maps[i]->copy(_from, nodeRefMap);
deba@220:       }
deba@220:       for (int i = 0; i < int(_edge_maps.size()); ++i) {
deba@220:         _edge_maps[i]->copy(_from, edgeRefMap);
deba@220:       }
deba@220:       for (int i = 0; i < int(_arc_maps.size()); ++i) {
deba@220:         _arc_maps[i]->copy(_from, arcRefMap);
deba@220:       }
deba@220:     }
deba@220: 
deba@220:   private:
deba@220: 
deba@220:     const From& _from;
deba@220:     To& _to;
deba@220: 
deba@220:     std::vector<_core_bits::MapCopyBase<From, Node, NodeRefMap>* >
kpeter@282:       _node_maps;
deba@220: 
deba@220:     std::vector<_core_bits::MapCopyBase<From, Arc, ArcRefMap>* >
kpeter@282:       _arc_maps;
deba@220: 
deba@220:     std::vector<_core_bits::MapCopyBase<From, Edge, EdgeRefMap>* >
kpeter@282:       _edge_maps;
deba@220: 
deba@220:   };
deba@220: 
deba@220:   /// \brief Copy a graph to another graph.
deba@220:   ///
kpeter@282:   /// This function copies a graph to another graph.
kpeter@282:   /// The complete usage of it is detailed in the GraphCopy class,
kpeter@282:   /// but a short example shows a basic work:
deba@220:   ///\code
kpeter@282:   /// graphCopy(src, trg).nodeRef(nr).edgeCrossRef(ecr).run();
deba@220:   ///\endcode
deba@220:   ///
deba@220:   /// After the copy the \c nr map will contain the mapping from the
deba@220:   /// nodes of the \c from graph to the nodes of the \c to graph and
kpeter@282:   /// \c ecr will contain the mapping from the edges of the \c to graph
kpeter@282:   /// to the edges of the \c from graph.
deba@220:   ///
deba@220:   /// \see GraphCopy
kpeter@282:   template <typename From, typename To>
kpeter@282:   GraphCopy<From, To>
kpeter@282:   graphCopy(const From& from, To& to) {
kpeter@282:     return GraphCopy<From, To>(from, to);
deba@220:   }
deba@220: 
deba@220:   namespace _core_bits {
deba@220: 
deba@220:     template <typename Graph, typename Enable = void>
deba@220:     struct FindArcSelector {
deba@220:       typedef typename Graph::Node Node;
deba@220:       typedef typename Graph::Arc Arc;
deba@220:       static Arc find(const Graph &g, Node u, Node v, Arc e) {
deba@220:         if (e == INVALID) {
deba@220:           g.firstOut(e, u);
deba@220:         } else {
deba@220:           g.nextOut(e);
deba@220:         }
deba@220:         while (e != INVALID && g.target(e) != v) {
deba@220:           g.nextOut(e);
deba@220:         }
deba@220:         return e;
deba@220:       }
deba@220:     };
deba@220: 
deba@220:     template <typename Graph>
deba@220:     struct FindArcSelector<
deba@220:       Graph,
kpeter@282:       typename enable_if<typename Graph::FindArcTag, void>::type>
deba@220:     {
deba@220:       typedef typename Graph::Node Node;
deba@220:       typedef typename Graph::Arc Arc;
deba@220:       static Arc find(const Graph &g, Node u, Node v, Arc prev) {
deba@220:         return g.findArc(u, v, prev);
deba@220:       }
deba@220:     };
deba@220:   }
deba@220: 
kpeter@282:   /// \brief Find an arc between two nodes of a digraph.
deba@220:   ///
kpeter@282:   /// This function finds an arc from node \c u to node \c v in the
kpeter@282:   /// digraph \c g.
deba@220:   ///
deba@220:   /// If \c prev is \ref INVALID (this is the default value), then
deba@220:   /// it finds the first arc from \c u to \c v. Otherwise it looks for
deba@220:   /// the next arc from \c u to \c v after \c prev.
deba@220:   /// \return The found arc or \ref INVALID if there is no such an arc.
deba@220:   ///
deba@220:   /// Thus you can iterate through each arc from \c u to \c v as it follows.
deba@220:   ///\code
kpeter@282:   /// for(Arc e = findArc(g,u,v); e != INVALID; e = findArc(g,u,v,e)) {
deba@220:   ///   ...
deba@220:   /// }
deba@220:   ///\endcode
deba@220:   ///
kpeter@282:   /// \note \ref ConArcIt provides iterator interface for the same
kpeter@282:   /// functionality.
kpeter@282:   ///
deba@220:   ///\sa ConArcIt
kpeter@282:   ///\sa ArcLookUp, AllArcLookUp, DynArcLookUp
deba@220:   template <typename Graph>
deba@220:   inline typename Graph::Arc
deba@220:   findArc(const Graph &g, typename Graph::Node u, typename Graph::Node v,
deba@220:           typename Graph::Arc prev = INVALID) {
deba@220:     return _core_bits::FindArcSelector<Graph>::find(g, u, v, prev);
deba@220:   }
deba@220: 
kpeter@282:   /// \brief Iterator for iterating on parallel arcs connecting the same nodes.
deba@220:   ///
kpeter@282:   /// Iterator for iterating on parallel arcs connecting the same nodes. It is
kpeter@282:   /// a higher level interface for the \ref findArc() function. You can
deba@220:   /// use it the following way:
deba@220:   ///\code
deba@220:   /// for (ConArcIt<Graph> it(g, src, trg); it != INVALID; ++it) {
deba@220:   ///   ...
deba@220:   /// }
deba@220:   ///\endcode
deba@220:   ///
deba@220:   ///\sa findArc()
kpeter@282:   ///\sa ArcLookUp, AllArcLookUp, DynArcLookUp
kpeter@559:   template <typename GR>
kpeter@559:   class ConArcIt : public GR::Arc {
deba@220:   public:
deba@220: 
kpeter@559:     typedef GR Graph;
deba@220:     typedef typename Graph::Arc Parent;
deba@220: 
deba@220:     typedef typename Graph::Arc Arc;
deba@220:     typedef typename Graph::Node Node;
deba@220: 
deba@220:     /// \brief Constructor.
deba@220:     ///
kpeter@282:     /// Construct a new ConArcIt iterating on the arcs that
kpeter@282:     /// connects nodes \c u and \c v.
deba@220:     ConArcIt(const Graph& g, Node u, Node v) : _graph(g) {
deba@220:       Parent::operator=(findArc(_graph, u, v));
deba@220:     }
deba@220: 
deba@220:     /// \brief Constructor.
deba@220:     ///
kpeter@282:     /// Construct a new ConArcIt that continues the iterating from arc \c a.
deba@220:     ConArcIt(const Graph& g, Arc a) : Parent(a), _graph(g) {}
deba@220: 
deba@220:     /// \brief Increment operator.
deba@220:     ///
deba@220:     /// It increments the iterator and gives back the next arc.
deba@220:     ConArcIt& operator++() {
deba@220:       Parent::operator=(findArc(_graph, _graph.source(*this),
deba@220:                                 _graph.target(*this), *this));
deba@220:       return *this;
deba@220:     }
deba@220:   private:
deba@220:     const Graph& _graph;
deba@220:   };
deba@220: 
deba@220:   namespace _core_bits {
deba@220: 
deba@220:     template <typename Graph, typename Enable = void>
deba@220:     struct FindEdgeSelector {
deba@220:       typedef typename Graph::Node Node;
deba@220:       typedef typename Graph::Edge Edge;
deba@220:       static Edge find(const Graph &g, Node u, Node v, Edge e) {
deba@220:         bool b;
deba@220:         if (u != v) {
deba@220:           if (e == INVALID) {
deba@220:             g.firstInc(e, b, u);
deba@220:           } else {
deba@220:             b = g.u(e) == u;
deba@220:             g.nextInc(e, b);
deba@220:           }
deba@220:           while (e != INVALID && (b ? g.v(e) : g.u(e)) != v) {
deba@220:             g.nextInc(e, b);
deba@220:           }
deba@220:         } else {
deba@220:           if (e == INVALID) {
deba@220:             g.firstInc(e, b, u);
deba@220:           } else {
deba@220:             b = true;
deba@220:             g.nextInc(e, b);
deba@220:           }
deba@220:           while (e != INVALID && (!b || g.v(e) != v)) {
deba@220:             g.nextInc(e, b);
deba@220:           }
deba@220:         }
deba@220:         return e;
deba@220:       }
deba@220:     };
deba@220: 
deba@220:     template <typename Graph>
deba@220:     struct FindEdgeSelector<
deba@220:       Graph,
deba@220:       typename enable_if<typename Graph::FindEdgeTag, void>::type>
deba@220:     {
deba@220:       typedef typename Graph::Node Node;
deba@220:       typedef typename Graph::Edge Edge;
deba@220:       static Edge find(const Graph &g, Node u, Node v, Edge prev) {
deba@220:         return g.findEdge(u, v, prev);
deba@220:       }
deba@220:     };
deba@220:   }
deba@220: 
kpeter@282:   /// \brief Find an edge between two nodes of a graph.
deba@220:   ///
kpeter@282:   /// This function finds an edge from node \c u to node \c v in graph \c g.
kpeter@282:   /// If node \c u and node \c v is equal then each loop edge
deba@220:   /// will be enumerated once.
deba@220:   ///
deba@220:   /// If \c prev is \ref INVALID (this is the default value), then
kpeter@282:   /// it finds the first edge from \c u to \c v. Otherwise it looks for
kpeter@282:   /// the next edge from \c u to \c v after \c prev.
kpeter@282:   /// \return The found edge or \ref INVALID if there is no such an edge.
deba@220:   ///
kpeter@282:   /// Thus you can iterate through each edge between \c u and \c v
kpeter@282:   /// as it follows.
deba@220:   ///\code
kpeter@282:   /// for(Edge e = findEdge(g,u,v); e != INVALID; e = findEdge(g,u,v,e)) {
deba@220:   ///   ...
deba@220:   /// }
deba@220:   ///\endcode
deba@220:   ///
kpeter@282:   /// \note \ref ConEdgeIt provides iterator interface for the same
kpeter@282:   /// functionality.
kpeter@282:   ///
deba@220:   ///\sa ConEdgeIt
deba@220:   template <typename Graph>
deba@220:   inline typename Graph::Edge
deba@220:   findEdge(const Graph &g, typename Graph::Node u, typename Graph::Node v,
deba@220:             typename Graph::Edge p = INVALID) {
deba@220:     return _core_bits::FindEdgeSelector<Graph>::find(g, u, v, p);
deba@220:   }
deba@220: 
kpeter@282:   /// \brief Iterator for iterating on parallel edges connecting the same nodes.
deba@220:   ///
kpeter@282:   /// Iterator for iterating on parallel edges connecting the same nodes.
kpeter@282:   /// It is a higher level interface for the findEdge() function. You can
deba@220:   /// use it the following way:
deba@220:   ///\code
kpeter@282:   /// for (ConEdgeIt<Graph> it(g, u, v); it != INVALID; ++it) {
deba@220:   ///   ...
deba@220:   /// }
deba@220:   ///\endcode
deba@220:   ///
deba@220:   ///\sa findEdge()
kpeter@559:   template <typename GR>
kpeter@559:   class ConEdgeIt : public GR::Edge {
deba@220:   public:
deba@220: 
kpeter@559:     typedef GR Graph;
deba@220:     typedef typename Graph::Edge Parent;
deba@220: 
deba@220:     typedef typename Graph::Edge Edge;
deba@220:     typedef typename Graph::Node Node;
deba@220: 
deba@220:     /// \brief Constructor.
deba@220:     ///
kpeter@282:     /// Construct a new ConEdgeIt iterating on the edges that
kpeter@282:     /// connects nodes \c u and \c v.
kpeter@429:     ConEdgeIt(const Graph& g, Node u, Node v) : _graph(g), _u(u), _v(v) {
kpeter@429:       Parent::operator=(findEdge(_graph, _u, _v));
deba@220:     }
deba@220: 
deba@220:     /// \brief Constructor.
deba@220:     ///
kpeter@282:     /// Construct a new ConEdgeIt that continues iterating from edge \c e.
deba@220:     ConEdgeIt(const Graph& g, Edge e) : Parent(e), _graph(g) {}
deba@220: 
deba@220:     /// \brief Increment operator.
deba@220:     ///
deba@220:     /// It increments the iterator and gives back the next edge.
deba@220:     ConEdgeIt& operator++() {
kpeter@429:       Parent::operator=(findEdge(_graph, _u, _v, *this));
deba@220:       return *this;
deba@220:     }
deba@220:   private:
deba@220:     const Graph& _graph;
kpeter@429:     Node _u, _v;
deba@220:   };
deba@220: 
deba@220: 
kpeter@282:   ///Dynamic arc look-up between given endpoints.
deba@220: 
deba@220:   ///Using this class, you can find an arc in a digraph from a given
kpeter@282:   ///source to a given target in amortized time <em>O</em>(log<em>d</em>),
deba@220:   ///where <em>d</em> is the out-degree of the source node.
deba@220:   ///
deba@220:   ///It is possible to find \e all parallel arcs between two nodes with
deba@233:   ///the \c operator() member.
deba@220:   ///
kpeter@282:   ///This is a dynamic data structure. Consider to use \ref ArcLookUp or
kpeter@282:   ///\ref AllArcLookUp if your digraph is not changed so frequently.
deba@220:   ///
kpeter@282:   ///This class uses a self-adjusting binary search tree, the Splay tree
kpeter@282:   ///of Sleator and Tarjan to guarantee the logarithmic amortized
kpeter@282:   ///time bound for arc look-ups. This class also guarantees the
deba@220:   ///optimal time bound in a constant factor for any distribution of
deba@220:   ///queries.
deba@220:   ///
kpeter@559:   ///\tparam GR The type of the underlying digraph.
deba@220:   ///
deba@220:   ///\sa ArcLookUp
deba@220:   ///\sa AllArcLookUp
kpeter@559:   template <typename GR>
deba@220:   class DynArcLookUp
kpeter@559:     : protected ItemSetTraits<GR, typename GR::Arc>::ItemNotifier::ObserverBase
deba@220:   {
deba@220:   public:
kpeter@559:     typedef typename ItemSetTraits<GR, typename GR::Arc>
deba@220:     ::ItemNotifier::ObserverBase Parent;
deba@220: 
kpeter@559:     TEMPLATE_DIGRAPH_TYPEDEFS(GR);
kpeter@559:     typedef GR Digraph;
deba@220: 
deba@220:   protected:
deba@220: 
kpeter@559:     class AutoNodeMap : public ItemSetTraits<GR, Node>::template Map<Arc>::Type {
deba@220:     public:
deba@220: 
kpeter@559:       typedef typename ItemSetTraits<GR, Node>::template Map<Arc>::Type Parent;
deba@220: 
kpeter@559:       AutoNodeMap(const GR& digraph) : Parent(digraph, INVALID) {}
deba@220: 
deba@220:       virtual void add(const Node& node) {
deba@220:         Parent::add(node);
deba@220:         Parent::set(node, INVALID);
deba@220:       }
deba@220: 
deba@220:       virtual void add(const std::vector<Node>& nodes) {
deba@220:         Parent::add(nodes);
deba@220:         for (int i = 0; i < int(nodes.size()); ++i) {
deba@220:           Parent::set(nodes[i], INVALID);
deba@220:         }
deba@220:       }
deba@220: 
deba@220:       virtual void build() {
deba@220:         Parent::build();
deba@220:         Node it;
deba@220:         typename Parent::Notifier* nf = Parent::notifier();
deba@220:         for (nf->first(it); it != INVALID; nf->next(it)) {
deba@220:           Parent::set(it, INVALID);
deba@220:         }
deba@220:       }
deba@220:     };
deba@220: 
deba@220:     const Digraph &_g;
deba@220:     AutoNodeMap _head;
deba@220:     typename Digraph::template ArcMap<Arc> _parent;
deba@220:     typename Digraph::template ArcMap<Arc> _left;
deba@220:     typename Digraph::template ArcMap<Arc> _right;
deba@220: 
deba@220:     class ArcLess {
deba@220:       const Digraph &g;
deba@220:     public:
deba@220:       ArcLess(const Digraph &_g) : g(_g) {}
deba@220:       bool operator()(Arc a,Arc b) const
deba@220:       {
deba@220:         return g.target(a)<g.target(b);
deba@220:       }
deba@220:     };
deba@220: 
deba@220:   public:
deba@220: 
deba@220:     ///Constructor
deba@220: 
deba@220:     ///Constructor.
deba@220:     ///
deba@220:     ///It builds up the search database.
deba@220:     DynArcLookUp(const Digraph &g)
deba@220:       : _g(g),_head(g),_parent(g),_left(g),_right(g)
deba@220:     {
deba@220:       Parent::attach(_g.notifier(typename Digraph::Arc()));
deba@220:       refresh();
deba@220:     }
deba@220: 
deba@220:   protected:
deba@220: 
deba@220:     virtual void add(const Arc& arc) {
deba@220:       insert(arc);
deba@220:     }
deba@220: 
deba@220:     virtual void add(const std::vector<Arc>& arcs) {
deba@220:       for (int i = 0; i < int(arcs.size()); ++i) {
deba@220:         insert(arcs[i]);
deba@220:       }
deba@220:     }
deba@220: 
deba@220:     virtual void erase(const Arc& arc) {
deba@220:       remove(arc);
deba@220:     }
deba@220: 
deba@220:     virtual void erase(const std::vector<Arc>& arcs) {
deba@220:       for (int i = 0; i < int(arcs.size()); ++i) {
deba@220:         remove(arcs[i]);
deba@220:       }
deba@220:     }
deba@220: 
deba@220:     virtual void build() {
deba@220:       refresh();
deba@220:     }
deba@220: 
deba@220:     virtual void clear() {
deba@220:       for(NodeIt n(_g);n!=INVALID;++n) {
deba@220:         _head.set(n, INVALID);
deba@220:       }
deba@220:     }
deba@220: 
deba@220:     void insert(Arc arc) {
deba@220:       Node s = _g.source(arc);
deba@220:       Node t = _g.target(arc);
deba@220:       _left.set(arc, INVALID);
deba@220:       _right.set(arc, INVALID);
deba@220: 
deba@220:       Arc e = _head[s];
deba@220:       if (e == INVALID) {
deba@220:         _head.set(s, arc);
deba@220:         _parent.set(arc, INVALID);
deba@220:         return;
deba@220:       }
deba@220:       while (true) {
deba@220:         if (t < _g.target(e)) {
deba@220:           if (_left[e] == INVALID) {
deba@220:             _left.set(e, arc);
deba@220:             _parent.set(arc, e);
deba@220:             splay(arc);
deba@220:             return;
deba@220:           } else {
deba@220:             e = _left[e];
deba@220:           }
deba@220:         } else {
deba@220:           if (_right[e] == INVALID) {
deba@220:             _right.set(e, arc);
deba@220:             _parent.set(arc, e);
deba@220:             splay(arc);
deba@220:             return;
deba@220:           } else {
deba@220:             e = _right[e];
deba@220:           }
deba@220:         }
deba@220:       }
deba@220:     }
deba@220: 
deba@220:     void remove(Arc arc) {
deba@220:       if (_left[arc] == INVALID) {
deba@220:         if (_right[arc] != INVALID) {
deba@220:           _parent.set(_right[arc], _parent[arc]);
deba@220:         }
deba@220:         if (_parent[arc] != INVALID) {
deba@220:           if (_left[_parent[arc]] == arc) {
deba@220:             _left.set(_parent[arc], _right[arc]);
deba@220:           } else {
deba@220:             _right.set(_parent[arc], _right[arc]);
deba@220:           }
deba@220:         } else {
deba@220:           _head.set(_g.source(arc), _right[arc]);
deba@220:         }
deba@220:       } else if (_right[arc] == INVALID) {
deba@220:         _parent.set(_left[arc], _parent[arc]);
deba@220:         if (_parent[arc] != INVALID) {
deba@220:           if (_left[_parent[arc]] == arc) {
deba@220:             _left.set(_parent[arc], _left[arc]);
deba@220:           } else {
deba@220:             _right.set(_parent[arc], _left[arc]);
deba@220:           }
deba@220:         } else {
deba@220:           _head.set(_g.source(arc), _left[arc]);
deba@220:         }
deba@220:       } else {
deba@220:         Arc e = _left[arc];
deba@220:         if (_right[e] != INVALID) {
deba@220:           e = _right[e];
deba@220:           while (_right[e] != INVALID) {
deba@220:             e = _right[e];
deba@220:           }
deba@220:           Arc s = _parent[e];
deba@220:           _right.set(_parent[e], _left[e]);
deba@220:           if (_left[e] != INVALID) {
deba@220:             _parent.set(_left[e], _parent[e]);
deba@220:           }
deba@220: 
deba@220:           _left.set(e, _left[arc]);
deba@220:           _parent.set(_left[arc], e);
deba@220:           _right.set(e, _right[arc]);
deba@220:           _parent.set(_right[arc], e);
deba@220: 
deba@220:           _parent.set(e, _parent[arc]);
deba@220:           if (_parent[arc] != INVALID) {
deba@220:             if (_left[_parent[arc]] == arc) {
deba@220:               _left.set(_parent[arc], e);
deba@220:             } else {
deba@220:               _right.set(_parent[arc], e);
deba@220:             }
deba@220:           }
deba@220:           splay(s);
deba@220:         } else {
deba@220:           _right.set(e, _right[arc]);
deba@220:           _parent.set(_right[arc], e);
deba@232:           _parent.set(e, _parent[arc]);
deba@220: 
deba@220:           if (_parent[arc] != INVALID) {
deba@220:             if (_left[_parent[arc]] == arc) {
deba@220:               _left.set(_parent[arc], e);
deba@220:             } else {
deba@220:               _right.set(_parent[arc], e);
deba@220:             }
deba@220:           } else {
deba@220:             _head.set(_g.source(arc), e);
deba@220:           }
deba@220:         }
deba@220:       }
deba@220:     }
deba@220: 
deba@220:     Arc refreshRec(std::vector<Arc> &v,int a,int b)
deba@220:     {
deba@220:       int m=(a+b)/2;
deba@220:       Arc me=v[m];
deba@220:       if (a < m) {
deba@220:         Arc left = refreshRec(v,a,m-1);
deba@220:         _left.set(me, left);
deba@220:         _parent.set(left, me);
deba@220:       } else {
deba@220:         _left.set(me, INVALID);
deba@220:       }
deba@220:       if (m < b) {
deba@220:         Arc right = refreshRec(v,m+1,b);
deba@220:         _right.set(me, right);
deba@220:         _parent.set(right, me);
deba@220:       } else {
deba@220:         _right.set(me, INVALID);
deba@220:       }
deba@220:       return me;
deba@220:     }
deba@220: 
deba@220:     void refresh() {
deba@220:       for(NodeIt n(_g);n!=INVALID;++n) {
deba@220:         std::vector<Arc> v;
deba@233:         for(OutArcIt a(_g,n);a!=INVALID;++a) v.push_back(a);
deba@233:         if (!v.empty()) {
deba@220:           std::sort(v.begin(),v.end(),ArcLess(_g));
deba@220:           Arc head = refreshRec(v,0,v.size()-1);
deba@220:           _head.set(n, head);
deba@220:           _parent.set(head, INVALID);
deba@220:         }
deba@220:         else _head.set(n, INVALID);
deba@220:       }
deba@220:     }
deba@220: 
deba@220:     void zig(Arc v) {
deba@220:       Arc w = _parent[v];
deba@220:       _parent.set(v, _parent[w]);
deba@220:       _parent.set(w, v);
deba@220:       _left.set(w, _right[v]);
deba@220:       _right.set(v, w);
deba@220:       if (_parent[v] != INVALID) {
deba@220:         if (_right[_parent[v]] == w) {
deba@220:           _right.set(_parent[v], v);
deba@220:         } else {
deba@220:           _left.set(_parent[v], v);
deba@220:         }
deba@220:       }
deba@220:       if (_left[w] != INVALID){
deba@220:         _parent.set(_left[w], w);
deba@220:       }
deba@220:     }
deba@220: 
deba@220:     void zag(Arc v) {
deba@220:       Arc w = _parent[v];
deba@220:       _parent.set(v, _parent[w]);
deba@220:       _parent.set(w, v);
deba@220:       _right.set(w, _left[v]);
deba@220:       _left.set(v, w);
deba@220:       if (_parent[v] != INVALID){
deba@220:         if (_left[_parent[v]] == w) {
deba@220:           _left.set(_parent[v], v);
deba@220:         } else {
deba@220:           _right.set(_parent[v], v);
deba@220:         }
deba@220:       }
deba@220:       if (_right[w] != INVALID){
deba@220:         _parent.set(_right[w], w);
deba@220:       }
deba@220:     }
deba@220: 
deba@220:     void splay(Arc v) {
deba@220:       while (_parent[v] != INVALID) {
deba@220:         if (v == _left[_parent[v]]) {
deba@220:           if (_parent[_parent[v]] == INVALID) {
deba@220:             zig(v);
deba@220:           } else {
deba@220:             if (_parent[v] == _left[_parent[_parent[v]]]) {
deba@220:               zig(_parent[v]);
deba@220:               zig(v);
deba@220:             } else {
deba@220:               zig(v);
deba@220:               zag(v);
deba@220:             }
deba@220:           }
deba@220:         } else {
deba@220:           if (_parent[_parent[v]] == INVALID) {
deba@220:             zag(v);
deba@220:           } else {
deba@220:             if (_parent[v] == _left[_parent[_parent[v]]]) {
deba@220:               zag(v);
deba@220:               zig(v);
deba@220:             } else {
deba@220:               zag(_parent[v]);
deba@220:               zag(v);
deba@220:             }
deba@220:           }
deba@220:         }
deba@220:       }
deba@220:       _head[_g.source(v)] = v;
deba@220:     }
deba@220: 
deba@220: 
deba@220:   public:
deba@220: 
deba@220:     ///Find an arc between two nodes.
deba@220: 
deba@233:     ///Find an arc between two nodes.
kpeter@282:     ///\param s The source node.
kpeter@282:     ///\param t The target node.
deba@233:     ///\param p The previous arc between \c s and \c t. It it is INVALID or
deba@233:     ///not given, the operator finds the first appropriate arc.
deba@233:     ///\return An arc from \c s to \c t after \c p or
deba@233:     ///\ref INVALID if there is no more.
deba@233:     ///
deba@233:     ///For example, you can count the number of arcs from \c u to \c v in the
deba@233:     ///following way.
deba@233:     ///\code
deba@233:     ///DynArcLookUp<ListDigraph> ae(g);
deba@233:     ///...
kpeter@282:     ///int n = 0;
kpeter@282:     ///for(Arc a = ae(u,v); a != INVALID; a = ae(u,v,a)) n++;
deba@233:     ///\endcode
deba@233:     ///
kpeter@282:     ///Finding the arcs take at most <em>O</em>(log<em>d</em>)
deba@233:     ///amortized time, specifically, the time complexity of the lookups
deba@233:     ///is equal to the optimal search tree implementation for the
deba@233:     ///current query distribution in a constant factor.
deba@233:     ///
deba@233:     ///\note This is a dynamic data structure, therefore the data
kpeter@282:     ///structure is updated after each graph alteration. Thus although
kpeter@282:     ///this data structure is theoretically faster than \ref ArcLookUp
kpeter@313:     ///and \ref AllArcLookUp, it often provides worse performance than
deba@233:     ///them.
deba@233:     Arc operator()(Node s, Node t, Arc p = INVALID) const  {
deba@233:       if (p == INVALID) {
deba@233:         Arc a = _head[s];
deba@233:         if (a == INVALID) return INVALID;
deba@233:         Arc r = INVALID;
deba@233:         while (true) {
deba@233:           if (_g.target(a) < t) {
deba@233:             if (_right[a] == INVALID) {
deba@233:               const_cast<DynArcLookUp&>(*this).splay(a);
deba@233:               return r;
deba@233:             } else {
deba@233:               a = _right[a];
deba@233:             }
deba@233:           } else {
deba@233:             if (_g.target(a) == t) {
deba@233:               r = a;
deba@233:             }
deba@233:             if (_left[a] == INVALID) {
deba@233:               const_cast<DynArcLookUp&>(*this).splay(a);
deba@233:               return r;
deba@233:             } else {
deba@233:               a = _left[a];
deba@233:             }
deba@233:           }
deba@233:         }
deba@233:       } else {
deba@233:         Arc a = p;
deba@233:         if (_right[a] != INVALID) {
deba@233:           a = _right[a];
deba@233:           while (_left[a] != INVALID) {
deba@233:             a = _left[a];
deba@233:           }
deba@220:           const_cast<DynArcLookUp&>(*this).splay(a);
deba@233:         } else {
deba@233:           while (_parent[a] != INVALID && _right[_parent[a]] ==  a) {
deba@233:             a = _parent[a];
deba@233:           }
deba@233:           if (_parent[a] == INVALID) {
deba@220:             return INVALID;
deba@220:           } else {
deba@233:             a = _parent[a];
deba@220:             const_cast<DynArcLookUp&>(*this).splay(a);
deba@220:           }
deba@220:         }
deba@233:         if (_g.target(a) == t) return a;
deba@233:         else return INVALID;
deba@220:       }
deba@220:     }
deba@220: 
deba@220:   };
deba@220: 
kpeter@282:   ///Fast arc look-up between given endpoints.
deba@220: 
deba@220:   ///Using this class, you can find an arc in a digraph from a given
kpeter@282:   ///source to a given target in time <em>O</em>(log<em>d</em>),
deba@220:   ///where <em>d</em> is the out-degree of the source node.
deba@220:   ///
deba@220:   ///It is not possible to find \e all parallel arcs between two nodes.
deba@220:   ///Use \ref AllArcLookUp for this purpose.
deba@220:   ///
kpeter@282:   ///\warning This class is static, so you should call refresh() (or at
kpeter@282:   ///least refresh(Node)) to refresh this data structure whenever the
kpeter@282:   ///digraph changes. This is a time consuming (superlinearly proportional
kpeter@282:   ///(<em>O</em>(<em>m</em> log<em>m</em>)) to the number of arcs).
deba@220:   ///
kpeter@559:   ///\tparam GR The type of the underlying digraph.
deba@220:   ///
deba@220:   ///\sa DynArcLookUp
deba@220:   ///\sa AllArcLookUp
kpeter@559:   template<class GR>
deba@220:   class ArcLookUp
deba@220:   {
deba@220:   public:
kpeter@559:     TEMPLATE_DIGRAPH_TYPEDEFS(GR);
kpeter@559:     typedef GR Digraph;
deba@220: 
deba@220:   protected:
deba@220:     const Digraph &_g;
deba@220:     typename Digraph::template NodeMap<Arc> _head;
deba@220:     typename Digraph::template ArcMap<Arc> _left;
deba@220:     typename Digraph::template ArcMap<Arc> _right;
deba@220: 
deba@220:     class ArcLess {
deba@220:       const Digraph &g;
deba@220:     public:
deba@220:       ArcLess(const Digraph &_g) : g(_g) {}
deba@220:       bool operator()(Arc a,Arc b) const
deba@220:       {
deba@220:         return g.target(a)<g.target(b);
deba@220:       }
deba@220:     };
deba@220: 
deba@220:   public:
deba@220: 
deba@220:     ///Constructor
deba@220: 
deba@220:     ///Constructor.
deba@220:     ///
deba@220:     ///It builds up the search database, which remains valid until the digraph
deba@220:     ///changes.
deba@220:     ArcLookUp(const Digraph &g) :_g(g),_head(g),_left(g),_right(g) {refresh();}
deba@220: 
deba@220:   private:
deba@220:     Arc refreshRec(std::vector<Arc> &v,int a,int b)
deba@220:     {
deba@220:       int m=(a+b)/2;
deba@220:       Arc me=v[m];
deba@220:       _left[me] = a<m?refreshRec(v,a,m-1):INVALID;
deba@220:       _right[me] = m<b?refreshRec(v,m+1,b):INVALID;
deba@220:       return me;
deba@220:     }
deba@220:   public:
kpeter@282:     ///Refresh the search data structure at a node.
deba@220: 
deba@220:     ///Build up the search database of node \c n.
deba@220:     ///
kpeter@282:     ///It runs in time <em>O</em>(<em>d</em> log<em>d</em>), where <em>d</em>
kpeter@282:     ///is the number of the outgoing arcs of \c n.
deba@220:     void refresh(Node n)
deba@220:     {
deba@220:       std::vector<Arc> v;
deba@220:       for(OutArcIt e(_g,n);e!=INVALID;++e) v.push_back(e);
deba@220:       if(v.size()) {
deba@220:         std::sort(v.begin(),v.end(),ArcLess(_g));
deba@220:         _head[n]=refreshRec(v,0,v.size()-1);
deba@220:       }
deba@220:       else _head[n]=INVALID;
deba@220:     }
deba@220:     ///Refresh the full data structure.
deba@220: 
deba@220:     ///Build up the full search database. In fact, it simply calls
deba@220:     ///\ref refresh(Node) "refresh(n)" for each node \c n.
deba@220:     ///
kpeter@282:     ///It runs in time <em>O</em>(<em>m</em> log<em>D</em>), where <em>m</em> is
kpeter@282:     ///the number of the arcs in the digraph and <em>D</em> is the maximum
deba@220:     ///out-degree of the digraph.
deba@220:     void refresh()
deba@220:     {
deba@220:       for(NodeIt n(_g);n!=INVALID;++n) refresh(n);
deba@220:     }
deba@220: 
deba@220:     ///Find an arc between two nodes.
deba@220: 
kpeter@313:     ///Find an arc between two nodes in time <em>O</em>(log<em>d</em>),
kpeter@313:     ///where <em>d</em> is the number of outgoing arcs of \c s.
kpeter@282:     ///\param s The source node.
kpeter@282:     ///\param t The target node.
deba@220:     ///\return An arc from \c s to \c t if there exists,
deba@220:     ///\ref INVALID otherwise.
deba@220:     ///
deba@220:     ///\warning If you change the digraph, refresh() must be called before using
deba@220:     ///this operator. If you change the outgoing arcs of
kpeter@282:     ///a single node \c n, then \ref refresh(Node) "refresh(n)" is enough.
deba@220:     Arc operator()(Node s, Node t) const
deba@220:     {
deba@220:       Arc e;
deba@220:       for(e=_head[s];
deba@220:           e!=INVALID&&_g.target(e)!=t;
deba@220:           e = t < _g.target(e)?_left[e]:_right[e]) ;
deba@220:       return e;
deba@220:     }
deba@220: 
deba@220:   };
deba@220: 
kpeter@282:   ///Fast look-up of all arcs between given endpoints.
deba@220: 
deba@220:   ///This class is the same as \ref ArcLookUp, with the addition
kpeter@282:   ///that it makes it possible to find all parallel arcs between given
kpeter@282:   ///endpoints.
deba@220:   ///
kpeter@282:   ///\warning This class is static, so you should call refresh() (or at
kpeter@282:   ///least refresh(Node)) to refresh this data structure whenever the
kpeter@282:   ///digraph changes. This is a time consuming (superlinearly proportional
kpeter@282:   ///(<em>O</em>(<em>m</em> log<em>m</em>)) to the number of arcs).
deba@220:   ///
kpeter@559:   ///\tparam GR The type of the underlying digraph.
deba@220:   ///
deba@220:   ///\sa DynArcLookUp
deba@220:   ///\sa ArcLookUp
kpeter@559:   template<class GR>
kpeter@559:   class AllArcLookUp : public ArcLookUp<GR>
deba@220:   {
kpeter@559:     using ArcLookUp<GR>::_g;
kpeter@559:     using ArcLookUp<GR>::_right;
kpeter@559:     using ArcLookUp<GR>::_left;
kpeter@559:     using ArcLookUp<GR>::_head;
deba@220: 
kpeter@559:     TEMPLATE_DIGRAPH_TYPEDEFS(GR);
kpeter@559:     typedef GR Digraph;
deba@220: 
deba@220:     typename Digraph::template ArcMap<Arc> _next;
deba@220: 
deba@220:     Arc refreshNext(Arc head,Arc next=INVALID)
deba@220:     {
deba@220:       if(head==INVALID) return next;
deba@220:       else {
deba@220:         next=refreshNext(_right[head],next);
deba@220:         _next[head]=( next!=INVALID && _g.target(next)==_g.target(head))
deba@220:           ? next : INVALID;
deba@220:         return refreshNext(_left[head],head);
deba@220:       }
deba@220:     }
deba@220: 
deba@220:     void refreshNext()
deba@220:     {
deba@220:       for(NodeIt n(_g);n!=INVALID;++n) refreshNext(_head[n]);
deba@220:     }
deba@220: 
deba@220:   public:
deba@220:     ///Constructor
deba@220: 
deba@220:     ///Constructor.
deba@220:     ///
deba@220:     ///It builds up the search database, which remains valid until the digraph
deba@220:     ///changes.
kpeter@559:     AllArcLookUp(const Digraph &g) : ArcLookUp<GR>(g), _next(g) {refreshNext();}
deba@220: 
deba@220:     ///Refresh the data structure at a node.
deba@220: 
deba@220:     ///Build up the search database of node \c n.
deba@220:     ///
kpeter@282:     ///It runs in time <em>O</em>(<em>d</em> log<em>d</em>), where <em>d</em> is
deba@220:     ///the number of the outgoing arcs of \c n.
deba@220:     void refresh(Node n)
deba@220:     {
kpeter@559:       ArcLookUp<GR>::refresh(n);
deba@220:       refreshNext(_head[n]);
deba@220:     }
deba@220: 
deba@220:     ///Refresh the full data structure.
deba@220: 
deba@220:     ///Build up the full search database. In fact, it simply calls
deba@220:     ///\ref refresh(Node) "refresh(n)" for each node \c n.
deba@220:     ///
kpeter@282:     ///It runs in time <em>O</em>(<em>m</em> log<em>D</em>), where <em>m</em> is
kpeter@282:     ///the number of the arcs in the digraph and <em>D</em> is the maximum
deba@220:     ///out-degree of the digraph.
deba@220:     void refresh()
deba@220:     {
deba@220:       for(NodeIt n(_g);n!=INVALID;++n) refresh(_head[n]);
deba@220:     }
deba@220: 
deba@220:     ///Find an arc between two nodes.
deba@220: 
deba@220:     ///Find an arc between two nodes.
kpeter@282:     ///\param s The source node.
kpeter@282:     ///\param t The target node.
deba@220:     ///\param prev The previous arc between \c s and \c t. It it is INVALID or
deba@220:     ///not given, the operator finds the first appropriate arc.
deba@220:     ///\return An arc from \c s to \c t after \c prev or
deba@220:     ///\ref INVALID if there is no more.
deba@220:     ///
deba@220:     ///For example, you can count the number of arcs from \c u to \c v in the
deba@220:     ///following way.
deba@220:     ///\code
deba@220:     ///AllArcLookUp<ListDigraph> ae(g);
deba@220:     ///...
kpeter@282:     ///int n = 0;
kpeter@282:     ///for(Arc a = ae(u,v); a != INVALID; a=ae(u,v,a)) n++;
deba@220:     ///\endcode
deba@220:     ///
kpeter@313:     ///Finding the first arc take <em>O</em>(log<em>d</em>) time,
kpeter@313:     ///where <em>d</em> is the number of outgoing arcs of \c s. Then the
deba@220:     ///consecutive arcs are found in constant time.
deba@220:     ///
deba@220:     ///\warning If you change the digraph, refresh() must be called before using
deba@220:     ///this operator. If you change the outgoing arcs of
kpeter@282:     ///a single node \c n, then \ref refresh(Node) "refresh(n)" is enough.
deba@220:     ///
deba@220: #ifdef DOXYGEN
deba@220:     Arc operator()(Node s, Node t, Arc prev=INVALID) const {}
deba@220: #else
kpeter@559:     using ArcLookUp<GR>::operator() ;
deba@220:     Arc operator()(Node s, Node t, Arc prev) const
deba@220:     {
deba@220:       return prev==INVALID?(*this)(s,t):_next[prev];
deba@220:     }
deba@220: #endif
deba@220: 
deba@220:   };
deba@220: 
deba@220:   /// @}
deba@220: 
deba@220: } //namespace lemon
deba@220: 
deba@220: #endif