get_lead_term()

const gbvector * gbvectorHeap::get_lead_term

(

)

Definition at line 1551 of file gbring.cpp.

{
  int lead_so_far = -1;
  for (int i = 0; i <= top_of_heap; i++)
    {
      if (heap[i] == nullptr) continue;
      if (lead_so_far < 0)
        {
          lead_so_far = i;
          continue;
        }
      int cmp = GR->gbvector_compare(F, heap[lead_so_far], heap[i]);
      if (cmp == GT) continue;
      if (cmp == LT)
        {
          lead_so_far = i;
          continue;
        }
      // At this point we have equality
      K->add_to(heap[lead_so_far]->coeff, heap[i]->coeff);
      gbvector *tmp = heap[i];
      heap[i] = tmp->next;
      tmp->next = nullptr;
      GR->gbvector_remove(tmp);
 
      if (K->is_zero(heap[lead_so_far]->coeff))
        {
          // Remove, and start over
          tmp = heap[lead_so_far];
          heap[lead_so_far] = tmp->next;
          tmp->next = nullptr;
          GR->gbvector_remove(tmp);
          lead_so_far = -1;
          i = -1;
        }
    }
  mLead = lead_so_far;
  if (lead_so_far < 0) return nullptr;
  gbvector *result = heap[lead_so_far];
  return result;
}

References F, GR, GT, heap, K, LT, mLead, gbvector::next, result(), and top_of_heap.

Referenced by gb2_comp::gb_geo_reduce(), GB_comp::gb_geo_reduce(), GBinhom_comp::gb_geo_reduce(), GBKernelComputation::geo_reduce(), MarkedGB::geo_remainder(), and remove_lead_term().