combine()

MonomialView newf4::MonomialView::combine ( const MonomialView & left, const MonomialView & right, bool copyLeft, bool copyRight, std::function< int(int, int)> , MemoryBlock & block )

static

Definition at line 6 of file MonomialView.cpp.

{
    auto rng = block.allocateArray<MonomialInt>(left.size() + right.size() - 1);
    MonomialView result(rng.first);
 
    auto leftIt = left.begin();
    auto rightIt = right.begin();
    auto leftEnd = left.end();
    auto rightEnd = right.end();
    auto resultIt = result.begin();
 
    while (true)
    {
       if (leftIt == leftEnd)
       {
     // take from right and increment right and result
     if (useRight)
     {
       std::copy(rightIt.loc(),rightEnd.loc(),resultIt.loc());
       resultIt += ((rightEnd.loc() - rightIt.loc()) >> 1);
     }
     break;
       }
       if (rightIt == rightEnd)
       {
         // take from left and increment left and result
     if (useLeft)
     {
        std::copy(leftIt.loc(),leftEnd.loc(),resultIt.loc());
        resultIt += ((leftEnd.loc() - leftIt.loc()) >> 1);
     }
     break;
       }
       if (leftIt.var() < rightIt.var())
       {
      // take from left and increment left and result
      std::copy(leftIt.loc(), leftIt.loc() + 2, resultIt.loc());
      ++resultIt;
      ++leftIt;
       }
       else if (leftIt.var() > rightIt.var())
       {
      // take from right and increment right and result
      std::copy(rightIt.loc(), rightIt.loc() + 2, resultIt.loc());
      ++resultIt;
      ++rightIt;
       }
       else
       {
      // take maximum and increment both
      resultIt.loc()[0] = leftIt.var();
      auto temp = bothFunc(leftIt.power(), rightIt.power());
      if (temp > 0) // if we actually need this variable, store power and increment result
      {
        resultIt.loc()[1] = bothFunc(leftIt.power(), rightIt.power());
        ++resultIt;
      }
      ++leftIt;
      ++rightIt;
       }
    }
    block.shrinkLastAllocate(rng.first, rng.second, resultIt.loc());
    *rng.first = resultIt.loc() - rng.first;
    return result;
}

References MemoryBlock::allocateArray(), begin(), end(), MonomialView(), result(), rng(), MemoryBlock::shrinkLastAllocate(), and size().

Referenced by lcm(), product(), and quotient().