support_counter/SupportCounterMerge.hpp

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#ifndef SupportCounterMerge_HPP
#define SupportCounterMerge_HPP

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




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

         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 
   SupportCounterMerge<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;
      typename TRIE::iterator it_edge(subtrie->edgelist.begin());
      if( step_to_candidate ) 
      {
         while( it_edge != subtrie->edgelist.end() && 
                it_basket != it_basket_upper_bound )
         {
            if( (*it_edge).first < *it_basket) ++it_edge;
            else if( (*it_edge).first > *it_basket) ++it_basket;
            else
            {
               ++it_basket;
               findCandidates( static_cast<TRIE*>((*it_edge).second),
                               it_basket_upper_bound + 1, it_basket, 
                               step_to_candidate, counter_incr);
               ++it_edge;
            }
         }
      }
      else
      {
         while( it_edge != subtrie->edgelist.end() && 
                it_basket != it_basket_upper_bound )
         {
            if( (*it_edge).first < *it_basket) ++it_edge;
            else if( (*it_edge).first > *it_basket) ++it_basket;
            else
            {
               ++it_basket;
               static_cast<LEAF*>((*it_edge).second)
                     ->increaseCounter( counter_incr);
               ++it_edge;
            }
         }
      }
   }
}
#endif

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