gcd()

TowerPolynomial DPoly::gcd	(	int	level,
		const TowerPolynomial	f,
		const TowerPolynomial	g )

Definition at line 1126 of file dpoly.cpp.

{
  TowerPolynomial F = copy(level, f);
  TowerPolynomial G = copy(level, g);
  if (G == nullptr)
    {
      G = F;
      F = nullptr;
    }
  for (;;)
    {
#ifdef DEBUGGCD
      printf("G = %s\n", to_string(level, G));
#endif
      make_monic(level, G);
      if (G == nullptr) return nullptr;  // failed
 
#ifdef DEBUGGCD
      printf("monic G = %s\n", to_string(level, G));
      printf("F       = %s\n", to_string(level, F));
#endif
 
      remainder(level, F, G);  // modifies F
      if (F == nullptr) return G;
 
#ifdef DEBUGGCD
      printf("F mod G     = %s\n", to_string(level, F));
#endif
 
      swap_poly(F, G);
    }
}

References copy(), G, make_monic(), remainder(), swap_poly(), and to_string().