source: lemon-main/lemon/vf2pp.h @ 1186:3feba0ea1bda

/* -*- mode: C++; indent-tabs-mode: nil; -*-
 *
 * This file is a part of LEMON, a generic C++ optimization library.
 *
 * Copyright (C) 2015-2017
 * EMAXA Kutato-fejleszto Kft. (EMAXA Research Ltd.)
 *
 * Permission to use, modify and distribute this software is granted
 * provided that this copyright notice appears in all copies. For
 * precise terms see the accompanying LICENSE file.
 *
 * This software is provided "AS IS" with no warranty of any kind,
 * express or implied, and with no claim as to its suitability for any
 * purpose.
 *
 */

#ifndef LEMON_VF2PP_H
#define LEMON_VF2PP_H

///\ingroup graph_properties
///\file
///\brief VF2 Plus Plus algorithm.

#include <lemon/core.h>
#include <lemon/concepts/graph.h>
#include <lemon/dfs.h>
#include <lemon/bfs.h>
#include <lemon/bits/vf2_internals.h>


#include <vector>
#include <algorithm>
#include <utility>


namespace lemon {
  namespace bits {
    namespace vf2pp {

      template <class G>
      class DfsLeaveOrder : public DfsVisitor<G> {
        int i;
        const G &_g;
        std::vector<typename G::Node> &_order;
      public:
        DfsLeaveOrder(const G &g, std::vector<typename G::Node> &order)
          : i(countNodes(g)), _g(g), _order(order) {
        }
        void leave(const typename G::Node &node) {
          _order[--i]=node;
        }
      };

      template <class G>
      class BfsLeaveOrder : public BfsVisitor<G> {
        int i;
        const G &_g;
        std::vector<typename G::Node> &_order;
      public:
        BfsLeaveOrder(const G &g, std::vector<typename G::Node> &order) { }
        void process(const typename G::Node &node) {
          _order[i++]=node;
        }
      };
    }
  }


  ///%VF2 Plus Plus algorithm class.

  ///\ingroup graph_isomorphism This class provides an efficient
  ///implementation of the %VF2 Plus Plus algorithm
  ///for variants of the (Sub)graph Isomorphism problem.
  ///
  ///There is also a \ref vf2pp() "function-type interface" called
  ///\ref vf2pp() for the %VF2 Plus Plus algorithm, which is probably
  ///more convenient in most use-cases.
  ///
  ///\tparam G1 The type of the graph to be embedded.
  ///The default type is \ref ListDigraph.
  ///\tparam G2 The type of the graph g1 will be embedded into.
  ///The default type is \ref ListDigraph.
  ///\tparam M The type of the NodeMap storing the mapping.
  ///By default, it is G1::NodeMap<G2::Node>
  ///\tparam M1 The type of the NodeMap storing the integer node labels of G1.
  ///The labels must be the numbers {0,1,2,..,K-1}, where K is the number of
  ///different labels. By default, it is G1::NodeMap<int>.
  ///\tparam M2 The type of the NodeMap storing the integer node labels of G2.
  ///The labels must be the numbers {0,1,2,..,K-1}, where K is the number of
  ///different labels. By default, it is G2::NodeMap<int>.
  ///
  ///\sa vf2pp()
#ifdef DOXYGEN
  template<class G1, class G2, class M, class M1, class M2 >
#else
  template<class G1=ListDigraph,
           class G2=ListDigraph,
           class M = typename G1::template NodeMap<G2::Node>,//the mapping
           //labels of G1,the labels are the numbers {0,1,2,..,K-1},
           //where K is the number of different labels
           class M1 = typename G1::template NodeMap<int>,
           //labels of G2, ...
           class M2 = typename G2::template NodeMap<int> >
#endif
  class Vf2pp {
    //Current depth in the search tree.
    int _depth;

    //_conn[v2] = number of covered neighbours of v2
    typename G2::template NodeMap<int> _conn;

    //The current mapping. _mapping[v1]=v2 iff v1 has been mapped to v2,
    //where v1 is a node of G1 and v2 is a node of G2
    M &_mapping;

    //order[i] is a node of g1, for which a pair is searched if depth=i
    std::vector<typename G1::Node> order;

    //currEdgeIts[i] is the last used edge iterator in the ith
    //depth to find a pair for node order[i]
    std::vector<typename G2::IncEdgeIt> currEdgeIts;

    //The small graph.
    const G1 &_g1;

    //The large graph.
    const G2 &_g2;

    //rNewLabels1[v] is a pair of form
    //(label; num. of uncov. nodes with such label and no covered neighbours)
    typename G1::template NodeMap<std::vector<std::pair<int,int> > >
    rNewLabels1;

    //rInOutLabels1[v] is the number of covered neighbours of v for each label
    //in form (label,number of such labels)
    typename G1::template NodeMap<std::vector<std::pair<int,int> > >
    rInOutLabels1;

    //_intLabels1[v]==i means that vertex v has the i label in
    //_g1 (i is in {0,1,2,..,K-1}, where K is the number of diff. labels)
    M1 &_intLabels1;

    //_intLabels2[v]==i means that vertex v has the i label in
    //_g2 (i is in {0,1,2,..,K-1}, where K is the number of diff. labels)
    M2 &_intLabels2;

    //largest label
    const int maxLabel;

    //lookup tables for manipulating with label class cardinalities
    //after use they have to be reset to 0..0
    std::vector<int> labelTmp1,labelTmp2;

    MappingType _mapping_type;

    //indicates whether the mapping or the labels must be deleted in the ctor
    bool _deallocMappingAfterUse,_deallocLabelsAfterUse;


    //improved cutting function
    template<MappingType MT>
    bool cutByLabels(const typename G1::Node n1,const typename G2::Node n2) {
      for(typename G2::IncEdgeIt e2(_g2,n2); e2!=INVALID; ++e2) {
        const typename G2::Node currNode=_g2.oppositeNode(n2,e2);
        if(_conn[currNode]>0)
          --labelTmp1[_intLabels2[currNode]];
        else if(MT!=SUBGRAPH&&_conn[currNode]==0)
          --labelTmp2[_intLabels2[currNode]];
      }

      bool ret=1;
      if(ret) {
        for(unsigned int i = 0; i < rInOutLabels1[n1].size(); ++i)
          labelTmp1[rInOutLabels1[n1][i].first]+=rInOutLabels1[n1][i].second;

        if(MT!=SUBGRAPH)
          for(unsigned int i = 0; i < rNewLabels1[n1].size(); ++i)
            labelTmp2[rNewLabels1[n1][i].first]+=rNewLabels1[n1][i].second;

        switch(MT) {
        case INDUCED:
          for(unsigned int i = 0; i < rInOutLabels1[n1].size(); ++i)
            if(labelTmp1[rInOutLabels1[n1][i].first]>0) {
              ret=0;
              break;
            }
          if(ret)
            for(unsigned int i = 0; i < rNewLabels1[n1].size(); ++i)
              if(labelTmp2[rNewLabels1[n1][i].first]>0) {
                ret=0;
                break;
              }
          break;
        case SUBGRAPH:
          for(unsigned int i = 0; i < rInOutLabels1[n1].size(); ++i)
            if(labelTmp1[rInOutLabels1[n1][i].first]>0) {
              ret=0;
              break;
            }
          break;
        case ISOMORPH:
          for(unsigned int i = 0; i < rInOutLabels1[n1].size(); ++i)
            if(labelTmp1[rInOutLabels1[n1][i].first]!=0) {
              ret=0;
              break;
            }
          if(ret)
            for(unsigned int i = 0; i < rNewLabels1[n1].size(); ++i)
              if(labelTmp2[rNewLabels1[n1][i].first]!=0) {
                ret=0;
                break;
              }
          break;
        default:
          return false;
        }
        for(unsigned int i = 0; i < rInOutLabels1[n1].size(); ++i)
          labelTmp1[rInOutLabels1[n1][i].first]=0;

        if(MT!=SUBGRAPH)
          for(unsigned int i = 0; i < rNewLabels1[n1].size(); ++i)
            labelTmp2[rNewLabels1[n1][i].first]=0;
      }

      for(typename G2::IncEdgeIt e2(_g2,n2); e2!=INVALID; ++e2) {
        const typename G2::Node currNode=_g2.oppositeNode(n2,e2);
        labelTmp1[_intLabels2[currNode]]=0;
        if(MT!=SUBGRAPH&&_conn[currNode]==0)
          labelTmp2[_intLabels2[currNode]]=0;
      }

      return ret;
    }


    //try to exclude the matching of n1 and n2
    template<MappingType MT>
    bool feas(const typename G1::Node n1,const typename G2::Node n2) {
      if(_intLabels1[n1]!=_intLabels2[n2])
        return 0;

      for(typename G1::IncEdgeIt e1(_g1,n1); e1!=INVALID; ++e1) {
        const typename G1::Node& currNode=_g1.oppositeNode(n1,e1);
        if(_mapping[currNode]!=INVALID)
          --_conn[_mapping[currNode]];
      }

      bool isIso=1;
      for(typename G2::IncEdgeIt e2(_g2,n2); e2!=INVALID; ++e2) {
        int& connCurrNode = _conn[_g2.oppositeNode(n2,e2)];
        if(connCurrNode<-1)
          ++connCurrNode;
        else if(MT!=SUBGRAPH&&connCurrNode==-1) {
          isIso=0;
          break;
        }
      }

      if(isIso)
        for(typename G1::IncEdgeIt e1(_g1,n1); e1!=INVALID; ++e1) {
          const typename G2::Node& currNodePair =
            _mapping[_g1.oppositeNode(n1,e1)];
          int& connCurrNodePair=_conn[currNodePair];
          if(currNodePair!=INVALID&&connCurrNodePair!=-1) {
            switch(MT){
            case INDUCED:
            case ISOMORPH:
              isIso=0;
              break;
            case SUBGRAPH:
              if(connCurrNodePair<-1)
                isIso=0;
              break;
            }
            connCurrNodePair=-1;
          }
        }
      else
        for(typename G1::IncEdgeIt e1(_g1,n1); e1!=INVALID; ++e1) {
          const typename G2::Node currNode=_mapping[_g1.oppositeNode(n1,e1)];
          if(currNode!=INVALID/*&&_conn[currNode]!=-1*/)
            _conn[currNode]=-1;
        }

      return isIso&&cutByLabels<MT>(n1,n2);
    }


    //matches n1 and n2
    void addPair(const typename G1::Node n1,const typename G2::Node n2) {
      _conn[n2]=-1;
      _mapping.set(n1,n2);
      for(typename G2::IncEdgeIt e2(_g2,n2); e2!=INVALID; ++e2) {
        int& currConn = _conn[_g2.oppositeNode(n2,e2)];
        if(currConn!=-1)
          ++currConn;
      }
    }


    //dematches n1 and n2
    void subPair(const typename G1::Node n1,const typename G2::Node n2) {
      _conn[n2]=0;
      _mapping.set(n1,INVALID);
      for(typename G2::IncEdgeIt e2(_g2,n2); e2!=INVALID; ++e2){
        int& currConn = _conn[_g2.oppositeNode(n2,e2)];
        if(currConn>0)
          --currConn;
        else if(currConn==-1)
          ++_conn[n2];
      }
    }


    void processBFSLevel(typename G1::Node source,unsigned int& orderIndex,
                         typename G1::template NodeMap<int>& dm1,
                         typename G1::template NodeMap<bool>& added) {
      order[orderIndex]=source;
      added[source]=1;

      unsigned int endPosOfLevel=orderIndex,
        startPosOfLevel=orderIndex,
        lastAdded=orderIndex;

      typename G1::template NodeMap<int> currConn(_g1,0);

      while(orderIndex<=lastAdded){
        typename G1::Node currNode = order[orderIndex];
        for(typename G1::IncEdgeIt e(_g1,currNode); e!=INVALID; ++e) {
          typename G1::Node n = _g1.oppositeNode(currNode,e);
          if(!added[n]) {
            order[++lastAdded]=n;
            added[n]=1;
          }
        }
        if(orderIndex>endPosOfLevel){
          for(unsigned int j = startPosOfLevel; j <= endPosOfLevel; ++j) {
            int minInd=j;
            for(unsigned int i = j+1; i <= endPosOfLevel; ++i)
              if(currConn[order[i]]>currConn[order[minInd]]||
                 (currConn[order[i]]==currConn[order[minInd]]&&
                  (dm1[order[i]]>dm1[order[minInd]]||
                   (dm1[order[i]]==dm1[order[minInd]]&&
                    labelTmp1[_intLabels1[order[minInd]]]>
                    labelTmp1[_intLabels1[order[i]]]))))
                minInd=i;

            --labelTmp1[_intLabels1[order[minInd]]];
            for(typename G1::IncEdgeIt e(_g1,order[minInd]); e!=INVALID; ++e)
              ++currConn[_g1.oppositeNode(order[minInd],e)];
            std::swap(order[j],order[minInd]);
          }
          startPosOfLevel=endPosOfLevel+1;
          endPosOfLevel=lastAdded;
        }
        ++orderIndex;
      }
    }


    //we will find pairs for the nodes of g1 in this order
    void setOrder(){
      for(typename G2::NodeIt n2(_g2); n2!=INVALID; ++n2)
        ++labelTmp1[_intLabels2[n2]];

      //       OutDegMap<G1> dm1(_g1);
      typename G1::template NodeMap<int> dm1(_g1,0);
      for(typename G1::EdgeIt e(_g1); e!=INVALID; ++e) {
        ++dm1[_g1.u(e)];
        ++dm1[_g1.v(e)];
      }

      typename G1::template NodeMap<bool> added(_g1,0);
      unsigned int orderIndex=0;

      for(typename G1::NodeIt n(_g1); n!=INVALID;) {
        if(!added[n]){
          typename G1::Node minNode = n;
          for(typename G1::NodeIt n1(_g1,minNode); n1!=INVALID; ++n1)
            if(!added[n1] &&
               (labelTmp1[_intLabels1[minNode]]>
                labelTmp1[_intLabels1[n1]]||(dm1[minNode]<dm1[n1]&&
                                             labelTmp1[_intLabels1[minNode]]==
                                             labelTmp1[_intLabels1[n1]])))
              minNode=n1;
          processBFSLevel(minNode,orderIndex,dm1,added);
        }
        else
          ++n;
      }
      for(unsigned int i = 0; i < labelTmp1.size(); ++i)
        labelTmp1[i]=0;
    }


    template<MappingType MT>
    bool extMatch(){
      while(_depth>=0) {
        //there is no node in g1, which has not pair in g2.
        if(_depth==static_cast<int>(order.size())) {
          --_depth;
          return true;
        }
        typename G1::Node& nodeOfDepth = order[_depth];
        const typename G2::Node& pairOfNodeOfDepth = _mapping[nodeOfDepth];
        typename G2::IncEdgeIt &edgeItOfDepth = currEdgeIts[_depth];
        //the node of g2, which neighbours are the candidates for
        //the pair of order[_depth]
        typename G2::Node currPNode;
        if(edgeItOfDepth==INVALID){
          typename G1::IncEdgeIt fstMatchedE(_g1,nodeOfDepth);
          //if _mapping[order[_depth]]!=INVALID, we dont need
          //fstMatchedE
          if(pairOfNodeOfDepth==INVALID)
            for(; fstMatchedE!=INVALID &&
                  _mapping[_g1.oppositeNode(nodeOfDepth,
                                            fstMatchedE)]==INVALID;
                ++fstMatchedE); //find fstMatchedE, it could be preprocessed
          if(fstMatchedE==INVALID||pairOfNodeOfDepth!=INVALID) {
            //We found no covered neighbours, this means
            //the graph is not connected(or _depth==0).  Each
            //uncovered(and there are some other properties due
            //to the spec. problem types) node of g2 is
            //candidate.  We can read the iterator of the last
            //tried node from the match if it is not the first
            //try(match[nodeOfDepth]!=INVALID)
            typename G2::NodeIt n2(_g2);
            //if it's not the first try
            if(pairOfNodeOfDepth!=INVALID) {
              n2=++typename G2::NodeIt(_g2,pairOfNodeOfDepth);
              subPair(nodeOfDepth,pairOfNodeOfDepth);
            }
            for(; n2!=INVALID; ++n2)
              if(MT!=SUBGRAPH) {
                if(_conn[n2]==0&&feas<MT>(nodeOfDepth,n2))
                  break;
              }
              else if(_conn[n2]>=0&&feas<MT>(nodeOfDepth,n2))
                break;
            // n2 is the next candidate
            if(n2!=INVALID) {
              addPair(nodeOfDepth,n2);
              ++_depth;
            }
            else // there are no more candidates
              --_depth;
            continue;
          }
          else{
            currPNode=_mapping[_g1.oppositeNode(nodeOfDepth,
                                                fstMatchedE)];
            edgeItOfDepth=typename G2::IncEdgeIt(_g2,currPNode);
          }
        }
        else{
          currPNode=_g2.oppositeNode(pairOfNodeOfDepth,
                                     edgeItOfDepth);
          subPair(nodeOfDepth,pairOfNodeOfDepth);
          ++edgeItOfDepth;
        }
        for(; edgeItOfDepth!=INVALID; ++edgeItOfDepth) {
          const typename G2::Node currNode =
            _g2.oppositeNode(currPNode, edgeItOfDepth);
          if(_conn[currNode]>0&&feas<MT>(nodeOfDepth,currNode)) {
            addPair(nodeOfDepth,currNode);
            break;
          }
        }
        edgeItOfDepth==INVALID?--_depth:++_depth;
      }
      return false;
    }

    //calc. the lookup table for cutting the searchtree
    void setRNew1tRInOut1t(){
      typename G1::template NodeMap<int> tmp(_g1,0);
      for(unsigned int i=0; i<order.size(); ++i) {
        tmp[order[i]]=-1;
        for(typename G1::IncEdgeIt e1(_g1,order[i]); e1!=INVALID; ++e1) {
          const typename G1::Node currNode=_g1.oppositeNode(order[i],e1);
          if(tmp[currNode]>0)
            ++labelTmp1[_intLabels1[currNode]];
          else if(tmp[currNode]==0)
            ++labelTmp2[_intLabels1[currNode]];
        }
        //labelTmp1[i]=number of neightbours with label i in set rInOut
        //labelTmp2[i]=number of neightbours with label i in set rNew
        for(typename G1::IncEdgeIt e1(_g1,order[i]); e1!=INVALID; ++e1) {
          const int& currIntLabel = _intLabels1[_g1.oppositeNode(order[i],e1)];
          if(labelTmp1[currIntLabel]>0) {
            rInOutLabels1[order[i]]
              .push_back(std::make_pair(currIntLabel,
                                        labelTmp1[currIntLabel]));
            labelTmp1[currIntLabel]=0;
          }
          else if(labelTmp2[currIntLabel]>0) {
            rNewLabels1[order[i]].
              push_back(std::make_pair(currIntLabel,labelTmp2[currIntLabel]));
            labelTmp2[currIntLabel]=0;
          }
        }

        for(typename G1::IncEdgeIt e1(_g1,order[i]); e1!=INVALID; ++e1) {
          int& tmpCurrNode=tmp[_g1.oppositeNode(order[i],e1)];
          if(tmpCurrNode!=-1)
            ++tmpCurrNode;
        }
      }
    }

    int getMaxLabel() const{
      int m=-1;
      for(typename G1::NodeIt n1(_g1); n1!=INVALID; ++n1) {
        const int& currIntLabel = _intLabels1[n1];
        if(currIntLabel>m)
          m=currIntLabel;
      }
      for(typename G2::NodeIt n2(_g2); n2!=INVALID; ++n2) {
        const int& currIntLabel = _intLabels2[n2];
        if(currIntLabel>m)
          m=currIntLabel;
      }
      return m;
    }

  public:
    ///Constructor

    ///Constructor.
    ///\param g1 The graph to be embedded.
    ///\param g2 The graph \e g1 will be embedded into.
    ///\param m The type of the NodeMap storing the mapping.
    ///By default, it is G1::NodeMap<G2::Node>
    ///\param intLabel1 The NodeMap storing the integer node labels of G1.
    ///The labels must be the numbers {0,1,2,..,K-1}, where K is the number of
    ///different labels.
    ///\param intLabel1 The NodeMap storing the integer node labels of G2.
    ///The labels must be the numbers {0,1,2,..,K-1}, where K is the number of
    ///different labels.
    Vf2pp(const G1 &g1, const G2 &g2,M &m, M1 &intLabels1, M2 &intLabels2) :
      _depth(0), _conn(g2,0), _mapping(m), order(countNodes(g1),INVALID),
      currEdgeIts(countNodes(g1),INVALID), _g1(g1), _g2(g2), rNewLabels1(_g1),
      rInOutLabels1(_g1), _intLabels1(intLabels1) ,_intLabels2(intLabels2),
      maxLabel(getMaxLabel()), labelTmp1(maxLabel+1),labelTmp2(maxLabel+1),
      _mapping_type(SUBGRAPH), _deallocMappingAfterUse(0),
      _deallocLabelsAfterUse(0)
    {
      setOrder();
      setRNew1tRInOut1t();

      //reset mapping
      for(typename G1::NodeIt n(g1);n!=INVALID;++n)
        m[n]=INVALID;
    }

    ///Destructor

    ///Destructor.
    ///
    ~Vf2pp()
    {
      if(_deallocMappingAfterUse)
        delete &_mapping;
      if(_deallocLabelsAfterUse) {
        delete &_intLabels1;
        delete &_intLabels2;
      }
    }

    ///Returns the current mapping type.

    ///Returns the current mapping type.
    ///
    MappingType mappingType() const
    {
      return _mapping_type;
    }

    ///Sets the mapping type

    ///Sets the mapping type.
    ///
    ///The mapping type is set to \ref SUBGRAPH by default.
    ///
    ///\sa See \ref MappingType for the possible values.
    void mappingType(MappingType m_type)
    {
      _mapping_type = m_type;
    }

    ///Finds a mapping.

    ///This method finds a mapping from g1 into g2 according to the mapping
    ///type set by \ref mappingType(MappingType) "mappingType()".
    ///
    ///By subsequent calls, it returns all possible mappings one-by-one.
    ///
    ///\retval true if a mapping is found.
    ///\retval false if there is no (more) mapping.
    bool find()
    {
      switch(_mapping_type)
        {
        case SUBGRAPH:
          return extMatch<SUBGRAPH>();
        case INDUCED:
          return extMatch<INDUCED>();
        case ISOMORPH:
          return extMatch<ISOMORPH>();
        default:
          return false;
        }
    }
  };

  template<typename G1, typename G2>
  class Vf2ppWizardBase {
  protected:
    typedef G1 Graph1;
    typedef G2 Graph2;

    const G1 &_g1;
    const G2 &_g2;

    MappingType _mapping_type;

    typedef typename G1::template NodeMap<typename G2::Node> Mapping;
    bool _local_mapping;
    void *_mapping;
    void createMapping() {
      _mapping = new Mapping(_g1);
    }

    bool _local_nodeLabels;
    typedef typename G1::template NodeMap<int> NodeLabels1;
    typedef typename G2::template NodeMap<int> NodeLabels2;
    void *_nodeLabels1, *_nodeLabels2;
    void createNodeLabels() {
      _nodeLabels1 = new NodeLabels1(_g1,0);
      _nodeLabels2 = new NodeLabels2(_g2,0);
    }

    Vf2ppWizardBase(const G1 &g1,const G2 &g2)
      : _g1(g1), _g2(g2), _mapping_type(SUBGRAPH),
        _local_mapping(1), _local_nodeLabels(1) { }
  };


  /// \brief Auxiliary class for the function-type interface of %VF2
  /// Plus Plus algorithm.
  ///
  /// This auxiliary class implements the named parameters of
  /// \ref vf2pp() "function-type interface" of \ref Vf2pp algorithm.
  ///
  /// \warning This class is not to be used directly.
  ///
  /// \tparam TR The traits class that defines various types used by the
  /// algorithm.
  template<typename TR>
  class Vf2ppWizard : public TR {
    typedef TR Base;
    typedef typename TR::Graph1 Graph1;
    typedef typename TR::Graph2 Graph2;
    typedef typename TR::Mapping Mapping;
    typedef typename TR::NodeLabels1 NodeLabels1;
    typedef typename TR::NodeLabels2 NodeLabels2;

    using TR::_g1;
    using TR::_g2;
    using TR::_mapping_type;
    using TR::_mapping;
    using TR::_nodeLabels1;
    using TR::_nodeLabels2;

  public:
    ///Constructor
    Vf2ppWizard(const Graph1 &g1,const Graph2 &g2) : Base(g1,g2) { }

    ///Copy constructor
    Vf2ppWizard(const Base &b) : Base(b) {}


    template<typename T>
    struct SetMappingBase : public Base {
      typedef T Mapping;
      SetMappingBase(const Base &b) : Base(b) { }
    };

    ///\brief \ref named-templ-param "Named parameter" for setting
    ///the mapping.
    ///
    ///\ref named-templ-param "Named parameter" function for setting
    ///the map that stores the found embedding.
    template<typename T>
    Vf2ppWizard< SetMappingBase<T> > mapping(const T &t) {
      Base::_mapping=reinterpret_cast<void*>(const_cast<T*>(&t));
      Base::_local_mapping = 0;
      return Vf2ppWizard<SetMappingBase<T> >(*this);
    }

    template<typename NL1, typename NL2>
    struct SetNodeLabelsBase : public Base {
      typedef NL1 NodeLabels1;
      typedef NL2 NodeLabels2;
      SetNodeLabelsBase(const Base &b) : Base(b) { }
    };

    ///\brief \ref named-templ-param "Named parameter" for setting the
    ///node labels.
    ///
    ///\ref named-templ-param "Named parameter" function for setting
    ///the node labels.
    ///
    ///\param nodeLabels1 A \ref concepts::ReadMap "readable node map"
    ///of g1 with integer value. In case of K different labels, the labels
    ///must be the {0,1,..,K-1} numbers.
    ///\param nodeLabels2 A \ref concepts::ReadMap "readable node map"
    ///of g2 with integer value. In case of K different labels, the labels
    ///must be the {0,1,..,K-1} numbers.
    template<typename NL1, typename NL2>
    Vf2ppWizard< SetNodeLabelsBase<NL1,NL2> >
    nodeLabels(const NL1 &nodeLabels1, const NL2 &nodeLabels2) {
      Base::_local_nodeLabels = 0;
      Base::_nodeLabels1=
        reinterpret_cast<void*>(const_cast<NL1*>(&nodeLabels1));
      Base::_nodeLabels2=
        reinterpret_cast<void*>(const_cast<NL2*>(&nodeLabels2));
      return Vf2ppWizard<SetNodeLabelsBase<NL1,NL2> >
        (SetNodeLabelsBase<NL1,NL2>(*this));
    }


    ///\brief \ref named-templ-param "Named parameter" for setting
    ///the mapping type.
    ///
    ///\ref named-templ-param "Named parameter" for setting
    ///the mapping type.
    ///
    ///The mapping type is set to \ref SUBGRAPH by default.
    ///
    ///\sa See \ref MappingType for the possible values.
    Vf2ppWizard<Base> &mappingType(MappingType m_type) {
      _mapping_type = m_type;
      return *this;
    }

    ///\brief \ref named-templ-param "Named parameter" for setting
    ///the mapping type to \ref INDUCED.
    ///
    ///\ref named-templ-param "Named parameter" for setting
    ///the mapping type to \ref INDUCED.
    Vf2ppWizard<Base> &induced() {
      _mapping_type = INDUCED;
      return *this;
    }

    ///\brief \ref named-templ-param "Named parameter" for setting
    ///the mapping type to \ref ISOMORPH.
    ///
    ///\ref named-templ-param "Named parameter" for setting
    ///the mapping type to \ref ISOMORPH.
    Vf2ppWizard<Base> &iso() {
      _mapping_type = ISOMORPH;
      return *this;
    }

    ///Runs the %VF2 Plus Plus algorithm.

    ///This method runs the VF2 Plus Plus algorithm.
    ///
    ///\retval true if a mapping is found.
    ///\retval false if there is no mapping.
    bool run() {
      if(Base::_local_mapping)
        Base::createMapping();
      if(Base::_local_nodeLabels)
        Base::createNodeLabels();

      Vf2pp<Graph1, Graph2, Mapping, NodeLabels1, NodeLabels2 >
        alg(_g1, _g2, *reinterpret_cast<Mapping*>(_mapping),
            *reinterpret_cast<NodeLabels1*>(_nodeLabels1),
            *reinterpret_cast<NodeLabels2*>(_nodeLabels2));

      alg.mappingType(_mapping_type);

      const bool ret = alg.find();

      if(Base::_local_nodeLabels) {
        delete reinterpret_cast<NodeLabels1*>(_nodeLabels1);
        delete reinterpret_cast<NodeLabels2*>(_nodeLabels2);
      }
      if(Base::_local_mapping)
        delete reinterpret_cast<Mapping*>(_mapping);

      return ret;
    }

    ///Get a pointer to the generated Vf2pp object.

    ///Gives a pointer to the generated Vf2pp object.
    ///
    ///\return Pointer to the generated Vf2pp object.
    ///\warning Don't forget to delete the referred Vf2pp object after use.
    Vf2pp<Graph1, Graph2, Mapping, NodeLabels1, NodeLabels2 >*
    getPtrToVf2ppObject(){
      if(Base::_local_mapping)
        Base::createMapping();
      if(Base::_local_nodeLabels)
        Base::createNodeLabels();

      Vf2pp<Graph1, Graph2, Mapping, NodeLabels1, NodeLabels2 >* ptr =
        new Vf2pp<Graph1, Graph2, Mapping, NodeLabels1, NodeLabels2>
        (_g1, _g2, *reinterpret_cast<Mapping*>(_mapping),
         *reinterpret_cast<NodeLabels1*>(_nodeLabels1),
         *reinterpret_cast<NodeLabels2*>(_nodeLabels2));
      ptr->mappingType(_mapping_type);
      if(Base::_local_mapping)
        ptr->_deallocMappingAfterUse=true;
      if(Base::_local_nodeLabels)
        ptr->_deallocLabelMapsAfterUse=true;

      return ptr;
    }

    ///Counts the number of mappings.

    ///This method counts the number of mappings.
    ///
    /// \return The number of mappings.
    int count() {
      if(Base::_local_mapping)
        Base::createMapping();
      if(Base::_local_nodeLabels)
        Base::createNodeLabels();

      Vf2pp<Graph1, Graph2, Mapping, NodeLabels1, NodeLabels2>
        alg(_g1, _g2, *reinterpret_cast<Mapping*>(_mapping),
            *reinterpret_cast<NodeLabels1*>(_nodeLabels1),
            *reinterpret_cast<NodeLabels2*>(_nodeLabels2));

      alg.mappingType(_mapping_type);

      int ret = 0;
      while(alg.find())
        ++ret;

      if(Base::_local_nodeLabels) {
        delete reinterpret_cast<NodeLabels1*>(_nodeLabels1);
        delete reinterpret_cast<NodeLabels2*>(_nodeLabels2);
      }
      if(Base::_local_mapping)
        delete reinterpret_cast<Mapping*>(_mapping);

      return ret;
    }
  };


  ///Function-type interface for VF2 Plus Plus algorithm.

  /// \ingroup graph_isomorphism
  ///Function-type interface for VF2 Plus Plus algorithm.
  ///
  ///This function has several \ref named-func-param "named parameters"
  ///declared as the members of class \ref Vf2ppWizard.
  ///The following examples show how to use these parameters.
  ///\code
  ///  ListGraph::NodeMap<ListGraph::Node> m(g);
  ///  // Find an embedding of graph g1 into graph g2
  ///  vf2pp(g1,g2).mapping(m).run();
  ///
  ///  // Check whether graphs g1 and g2 are isomorphic
  ///  bool is_iso = vf2pp(g1,g2).iso().run();
  ///
  ///  // Count the number of isomorphisms
  ///  int num_isos = vf2pp(g1,g2).iso().count();
  ///
  ///  // Iterate through all the induced subgraph mappings
  ///  //of graph g1 into g2 using the labels c1 and c2
  ///  auto* myVf2pp = vf2pp(g1,g2).mapping(m).nodeLabels(c1,c2)
  ///  .induced().getPtrToVf2Object();
  ///  while(myVf2pp->find()){
  ///    //process the current mapping m
  ///  }
  ///  delete myVf22pp;
  ///\endcode
  ///\warning Don't forget to put the \ref Vf2ppWizard::run() "run()",
  ///\ref Vf2ppWizard::count() "count()" or
  ///the \ref Vf2ppWizard::getPtrToVf2ppObject() "getPtrToVf2ppObject()"
  ///to the end of the expression.
  ///\sa Vf2ppWizard
  ///\sa Vf2pp
  template<class G1, class G2>
  Vf2ppWizard<Vf2ppWizardBase<G1,G2> > vf2pp(const G1 &g1, const G2 &g2) {
    return Vf2ppWizard<Vf2ppWizardBase<G1,G2> >(g1,g2);
  }

}

#endif