dual_tree_traverser.hpp

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#ifndef MLPACK_CORE_TREE_COVER_TREE_DUAL_TREE_TRAVERSER_HPP
#define MLPACK_CORE_TREE_COVER_TREE_DUAL_TREE_TRAVERSER_HPP

#include <mlpack/prereqs.hpp>
#include <queue>

namespace mlpack {
namespace tree {

template<
    typename MetricType,
    typename StatisticType,
    typename MatType,
    typename RootPointPolicy
>
template<typename RuleType>
class CoverTree<MetricType, StatisticType, MatType, RootPointPolicy>::
    DualTreeTraverser
{
 public:
  DualTreeTraverser(RuleType& rule);

  void Traverse(CoverTree& queryNode, CoverTree& referenceNode);

  size_t NumPrunes() const { return numPrunes; }
  size_t& NumPrunes() { return numPrunes; }

  size_t NumVisited() const { return 0; }
  size_t NumScores() const { return 0; }
  size_t NumBaseCases() const { return 0; }

 private:
  RuleType& rule;

  size_t numPrunes;

  struct DualCoverTreeMapEntry
  {
    CoverTree<MetricType, StatisticType, MatType, RootPointPolicy>*
        referenceNode;
    double score;
    double baseCase;
    typename RuleType::TraversalInfoType traversalInfo;

    bool operator<(const DualCoverTreeMapEntry& other) const
    {
      if (score == other.score)
        return (baseCase < other.baseCase);
      else
        return (score < other.score);
    }
  };

  void Traverse(
      CoverTree& queryNode,
      std::map<int, std::vector<DualCoverTreeMapEntry>,
          std::greater<int>>& referenceMap);

  void PruneMap(
      CoverTree& queryNode,
      std::map<int, std::vector<DualCoverTreeMapEntry>,
          std::greater<int>>& referenceMap,
      std::map<int, std::vector<DualCoverTreeMapEntry>,
          std::greater<int>>& childMap);

  void ReferenceRecursion(
      CoverTree& queryNode,
    std::map<int, std::vector<DualCoverTreeMapEntry>,
        std::greater<int>>& referenceMap);
};

} // namespace tree
} // namespace mlpack

// Include implementation.
#include "dual_tree_traverser_impl.hpp"

#endif