support_counter/SupportCounterLookupEdge.hpp

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#ifndef SupportCounterLookupEdge_HPP
#define SupportCounterLookupEdge_HPP

#include "common.hpp"
#include <vector>
#include "apriori/bodon/Leaf.hpp"
//#include <iterator>   //for test

namespace Bodon
{
   template <class TRIE>
   class SupportCounterLookupEdge
   {
      protected:
         typedef Leaf LEAF;
      public:
         SupportCounterLookupEdge( ){}

         void updateCounters(
            TRIE& main_trie, const std::vector<item_t>& transaction,
            item_t candidate_size, const counter_t counter_incr)
         {
            if( candidate_size <= transaction.size() )
               findCandidates( 
                  &main_trie, transaction.end()-candidate_size+1, 
                  transaction.begin(), candidate_size,
                  counter_incr );
         }

      protected:
         void findCandidates( TRIE* subtrie,
            std::vector<item_t>::const_iterator it_basket_upper_bound,
            std::vector<item_t>::const_iterator it_basket, 
            item_t step_to_candidate,
            const counter_t counter_incr );
   };

   template <class TRIE> void 
   SupportCounterLookupEdge<TRIE>::findCandidates( 
      TRIE* subtrie, std::vector<item_t>::const_iterator it_basket_upper_bound,
      std::vector<item_t>::const_iterator it_basket, 
      item_t step_to_candidate, const counter_t counter_incr )
   {
      --step_to_candidate;
      void* subsubtrie;
      if( step_to_candidate ) 
      {
         while( it_basket != it_basket_upper_bound )
         {
            if( subtrie->edgelist.lookup(*it_basket, subsubtrie) )
            {
               ++it_basket;
               if(subsubtrie)
                  findCandidates( static_cast<TRIE*>(subsubtrie),
                                  it_basket_upper_bound + 1, it_basket, 
                                  step_to_candidate, counter_incr );
            }
            else
               break;
         }
      }
      else
      {
         while( it_basket != it_basket_upper_bound )
         {
            if( subtrie->edgelist.lookup(*it_basket, subsubtrie) )
            {
               ++it_basket;
               if(subsubtrie)
                  static_cast<LEAF*>(subsubtrie)
                     ->increaseCounter( counter_incr);
            }
            else
               break;
         }
      }
   }
}
#endif

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