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//        MueLu: A package for multigrid based preconditioning
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#ifndef MUELU_ISOLATEDNODEAGGREGATIONALGORITHM_KOKKOS_DECL_HPP
#define MUELU_ISOLATEDNODEAGGREGATIONALGORITHM_KOKKOS_DECL_HPP

#include "MueLu_ConfigDefs.hpp"
#ifdef HAVE_MUELU_KOKKOS_REFACTOR

#include <KokkosCompat_ClassicNodeAPI_Wrapper.hpp>

#include "MueLu_IsolatedNodeAggregationAlgorithm_kokkos_fwd.hpp"

#include "MueLu_Aggregates_kokkos_fwd.hpp"
#include "MueLu_AggregationAlgorithmBase_kokkos.hpp"
#include "MueLu_FactoryBase_fwd.hpp"
#include "MueLu_LWGraph_kokkos.hpp"

namespace MueLu {
  /*!
    @class IsolatedNodeAggregationAlgorithm class.
    @brief Ignores isolated nodes during aggregation. Marks the node to be "aggregated" without adding real aggregates for them.

    @ingroup Aggregation

    ### Idea ###
    The isolated node aggregation algorithm loops over all non-aggregated nodes
    (with a state different than aggregated or ignored) which have only themselves
    as neighbor node. The state of these "isolated" nodes is then set to ignored such
    that they are not considered in the aggregation. This aggregation algorithm should
    run as one of the last aggregation algorithms in the aggregation method.

    ### Comments ###
    Only nodes with state different than READY or AGGREGATED are changed to IGNORED.
    After that, all nodes should have the state AGGREGATED or IGNORED.

  */

  template <class LocalOrdinal = int,
            class GlobalOrdinal = LocalOrdinal,
            class Node = KokkosClassic::DefaultNode::DefaultNodeType>
  class IsolatedNodeAggregationAlgorithm_kokkos :
    public MueLu::AggregationAlgorithmBase_kokkos<LocalOrdinal,GlobalOrdinal,Node> {
#undef MUELU_ISOLATEDNODEAGGREGATIONALGORITHM_KOKKOS_SHORT
#include "MueLu_UseShortNamesOrdinal.hpp"

  public:
    //! @name Constructors/Destructors.
    //@{

    //! Constructor.
    IsolatedNodeAggregationAlgorithm_kokkos(const RCP<const FactoryBase>& graphFact = Teuchos::null) { }

    //! Destructor.
    virtual ~IsolatedNodeAggregationAlgorithm_kokkos() { }

    //@}


    //! @name Aggregation methods.
    //@{

    /*! @brief Local aggregation. */

    void BuildAggregates(const ParameterList& params, const LWGraph_kokkos& graph, Aggregates_kokkos& aggregates, std::vector<unsigned>& aggStat, LO& numNonAggregatedNodes) const;
    //@}

    std::string description() const { return "Phase - (isolated)"; }

  }; //class MaxLinkAggregationAlgorithm

} //namespace MueLu

#define MUELU_ISOLATEDNODEAGGREGATIONALGORITHM_KOKKOS_SHORT
#endif // HAVE_MUELU_KOKKOS_REFACTOR
#endif // MUELU_ISOLATEDNODEAGGREGATIONALGORITHM_DECL_HPP
