construct_pairs()

int F4SPairSet::construct_pairs ( bool remove_disjoints )

private

Definition at line 246 of file f4-spairs.cpp.

{
  if (gb.size() == 0) return 0;
 
  VP.reset();
  PS.reset();
  gbelem *me = gb[gb.size() - 1];
  int me_component = static_cast<int>(M->get_component(me->f.monoms));
 
  std::vector<std::vector<pre_spair *>> bins;
 
  mtbb::tick_count t0 {mtbb::tick_count::now()};
  
  // Loop through each element of gb, and create the pre_spair
  for (int i = 0; i < gb.size() - 1; i++)
    {
      if (gb[i]->minlevel == ELEM_NON_MIN_GB) continue;
      if (me_component != M->get_component(gb[i]->f.monoms)) continue;
      pre_spair *p = create_pre_spair(i);
      insert_pre_spair(bins, p);
    }
 
  mtbb::tick_count t1 {mtbb::tick_count::now()};
  mPrePairsSeconds += (t1-t0).seconds();  

  // Now minimalize the set //
  MonomialLookupTable *montab = new MonomialLookupTable(M->n_vars());
 
  PreSPairSorter C;
  int n_new_pairs = 0;
  for (int i = 0; i < bins.size(); i++)
    {
      if (bins[i].size() == 0) continue;
      // First sort the monomials of this degree
 
      std::stable_sort(bins[i].begin(), bins[i].end(), C);
 
      // Loop through each degree and potentially insert...
      auto first = bins[i].begin();
      auto next = first;
      auto end = bins[i].end();
      for (; first != end; first = next)
        {
          next = first + 1;
          pre_spair *chosen = *first;
          while (next != end)
            {
              pre_spair *p = *next;
              if (!varpower_monomials::is_equal(chosen->quot, p->quot)) break;
              next++;
            }
          /* At this point: [first,next) is the range of equal monomials */
 
          int32_t junk;
          bool inideal = montab->find_one_divisor_vp(0, chosen->quot, junk);
          if (!inideal)
            {
              // MES: Maybe choose another of the equal monomials...
              montab->insert_minimal_vp(0, chosen->quot, 0);
              // The following condition is that gcd is not one
              if (!remove_disjoints || !chosen->are_disjoint)
                {
                  insert_spair(chosen, INTSIZE(gb) - 1);
                  n_new_pairs++;
                }
            }
        }
    }
  delete montab;
  mtbb::tick_count t2 {mtbb::tick_count::now()};
  mMinimizePairsSeconds += (t2-t1).seconds();
 
  return n_new_pairs;
}

References pre_spair::are_disjoint, begin(), create_pre_spair(), ELEM_NON_MIN_GB, end(), gbelem::f, F4MonomialLookupTableT< Key >::find_one_divisor_vp(), gb, F4MonomialLookupTableT< Key >::insert_minimal_vp(), insert_pre_spair(), insert_spair(), INTSIZE, ExponentList< long, false >::is_equal(), M, mMinimizePairsSeconds, GBF4Polynomial::monoms, mPrePairsSeconds, p, PS, pre_spair::quot, seconds(), and VP.

Referenced by find_new_pairs().