110 lines
2.9 KiB
C
110 lines
2.9 KiB
C
/*=============================================================================
|
|
|
|
This file is part of FLINT.
|
|
|
|
FLINT is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 2 of the License, or
|
|
(at your option) any later version.
|
|
|
|
FLINT is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with FLINT; if not, write to the Free Software
|
|
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
|
|
|
|
=============================================================================*/
|
|
/******************************************************************************
|
|
|
|
Copyright (C) 2011 William Hart
|
|
|
|
******************************************************************************/
|
|
|
|
#include <stdlib.h>
|
|
#include <gmp.h>
|
|
#include "flint.h"
|
|
#include "nmod_vec.h"
|
|
#include "nmod_poly.h"
|
|
#include "ulong_extras.h"
|
|
|
|
void
|
|
_nmod_poly_div_series(mp_ptr Q, mp_srcptr A, mp_srcptr B,
|
|
slong n, nmod_t mod)
|
|
{
|
|
mp_ptr Binv = _nmod_vec_init(n);
|
|
|
|
_nmod_poly_inv_series(Binv, B, n, mod);
|
|
_nmod_poly_mullow(Q, Binv, n, A, n, n, mod);
|
|
|
|
_nmod_vec_clear(Binv);
|
|
}
|
|
|
|
void
|
|
nmod_poly_div_series(nmod_poly_t Q, const nmod_poly_t A,
|
|
const nmod_poly_t B, slong n)
|
|
{
|
|
mp_ptr A_coeffs, B_coeffs, Q_coeffs;
|
|
nmod_poly_t t1;
|
|
slong Alen, Blen;
|
|
|
|
Blen = B->length;
|
|
|
|
if (n == 0 || Blen == 0 || B->coeffs[0] == 0)
|
|
{
|
|
flint_printf("Exception (nmod_poly_div_series). Division by zero.\n");
|
|
abort();
|
|
}
|
|
|
|
Alen = A->length;
|
|
|
|
if (Alen < n)
|
|
{
|
|
A_coeffs = _nmod_vec_init(n);
|
|
flint_mpn_copyi(A_coeffs, A->coeffs, Alen);
|
|
flint_mpn_zero(A_coeffs + Alen, n - Alen);
|
|
}
|
|
else
|
|
A_coeffs = A->coeffs;
|
|
|
|
if (Blen < n)
|
|
{
|
|
B_coeffs = _nmod_vec_init(n);
|
|
flint_mpn_copyi(B_coeffs, B->coeffs, Blen);
|
|
flint_mpn_zero(B_coeffs + Blen, n - Blen);
|
|
}
|
|
else
|
|
B_coeffs = B->coeffs;
|
|
|
|
if ((Q == A || Q == B) && Q->length >= n)
|
|
{
|
|
nmod_poly_init2(t1, Q->mod.n, n);
|
|
Q_coeffs = t1->coeffs;
|
|
}
|
|
else
|
|
{
|
|
nmod_poly_fit_length(Q, n);
|
|
Q_coeffs = Q->coeffs;
|
|
}
|
|
|
|
_nmod_poly_div_series(Q_coeffs, A_coeffs, B_coeffs, n, Q->mod);
|
|
|
|
if ((Q == A || Q == B) && Q->length >= n)
|
|
{
|
|
nmod_poly_swap(Q, t1);
|
|
nmod_poly_clear(t1);
|
|
}
|
|
|
|
Q->length = n;
|
|
|
|
if (Alen < n)
|
|
_nmod_vec_clear(A_coeffs);
|
|
|
|
if (Blen < n)
|
|
_nmod_vec_clear(B_coeffs);
|
|
|
|
_nmod_poly_normalise(Q);
|
|
}
|