index_of_var()

int DPoly::index_of_var	(	int	level,
		const TowerPolynomial	f ) const

Definition at line 1456 of file dpoly.cpp.

{
  if (f == nullptr or level < 0 or f->deg >= 2) return -1;
  if (level == 0)
    {
      if (f->deg == 0) return -1;
      // At this point, degree is 1.
      if (f->arr.ints[0] == 0 and f->arr.ints[1] == 1)
        return 0;
      else
        return -1;
    }
  else
    {
      if (f->arr.polys[0] == nullptr and is_one(level - 1, f->arr.polys[1]))
        return level;
      if (f->deg == 1) return -1;
      return index_of_var(level - 1, f->arr.polys[0]);
    }
}

References index_of_var(), and is_one().

Referenced by index_of_var().