88 lines
2.5 KiB
C
88 lines
2.5 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 <gmp.h>
|
||
|
|
#include <stdlib.h>
|
||
|
|
#include "flint.h"
|
||
|
|
#include "fmpz.h"
|
||
|
|
#include "fmpz_poly.h"
|
||
|
|
|
||
|
|
int _fmpz_poly_divides(fmpz * q, const fmpz * a,
|
||
|
|
slong len1, const fmpz * b, slong len2)
|
||
|
|
{
|
||
|
|
fmpz * r = _fmpz_vec_init(len1);
|
||
|
|
|
||
|
|
_fmpz_poly_divrem(q, r, a, len1, b, len2);
|
||
|
|
|
||
|
|
FMPZ_VEC_NORM(r, len1);
|
||
|
|
|
||
|
|
_fmpz_vec_clear(r, len1);
|
||
|
|
|
||
|
|
return (len1 == 0);
|
||
|
|
}
|
||
|
|
|
||
|
|
int fmpz_poly_divides(fmpz_poly_t q, const fmpz_poly_t a, const fmpz_poly_t b)
|
||
|
|
{
|
||
|
|
if (fmpz_poly_is_zero(b))
|
||
|
|
{
|
||
|
|
flint_printf("Exception (fmpz_poly_divides). Division by zero.\n");
|
||
|
|
abort();
|
||
|
|
}
|
||
|
|
if (fmpz_poly_is_zero(a))
|
||
|
|
{
|
||
|
|
fmpz_poly_zero(q);
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
if (a->length < b->length)
|
||
|
|
{
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
{
|
||
|
|
const slong lenQ = a->length - b->length + 1;
|
||
|
|
int res;
|
||
|
|
|
||
|
|
if (q == a || q == b)
|
||
|
|
{
|
||
|
|
fmpz_poly_t t;
|
||
|
|
|
||
|
|
fmpz_poly_init2(t, lenQ);
|
||
|
|
res = _fmpz_poly_divides(t->coeffs, a->coeffs, a->length, b->coeffs, b->length);
|
||
|
|
_fmpz_poly_set_length(t, lenQ);
|
||
|
|
_fmpz_poly_normalise(t);
|
||
|
|
fmpz_poly_swap(q, t);
|
||
|
|
fmpz_poly_clear(t);
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
fmpz_poly_fit_length(q, lenQ);
|
||
|
|
res = _fmpz_poly_divides(q->coeffs, a->coeffs, a->length, b->coeffs, b->length);
|
||
|
|
_fmpz_poly_set_length(q, lenQ);
|
||
|
|
_fmpz_poly_normalise(q);
|
||
|
|
}
|
||
|
|
return res;
|
||
|
|
}
|
||
|
|
}
|