subtract_in_place()

void M2::ARingTower::subtract_in_place ( int level, ARingPolynomial & f, const ARingPolynomial g ) const

private

Definition at line 374 of file aring-tower.cpp.

{
  if (g == nullptr) return;
  if (f == nullptr)
    {
      f = copy(level, g);
      negate_in_place(level, f);
      return;
    }
  int fdeg = f->deg;
  int gdeg = g->deg;
 
  increase_capacity(g->deg, f);
  if (level == 0)
    for (int i = 0; i <= gdeg; i++)
      mBaseRing.subtract(f->coeffs[i], f->coeffs[i], g->coeffs[i]);
  else
    for (int i = 0; i <= gdeg; i++)
      subtract_in_place(level - 1, f->polys[i], g->polys[i]);
 
  if (gdeg > fdeg)
    f->deg = gdeg;
  else if (gdeg == fdeg)
    reset_degree(f);
}

References M2::ARingPolynomialStruct::coeffs, copy(), M2::ARingPolynomialStruct::deg, increase_capacity(), mBaseRing, negate_in_place(), M2::ARingPolynomialStruct::polys, reset_degree(), and subtract_in_place().

Referenced by subtract(), and subtract_in_place().