71 lines
2.1 KiB
C
71 lines
2.1 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 Sebastian Pancratz
|
||
|
|
|
||
|
|
******************************************************************************/
|
||
|
|
|
||
|
|
#include <gmp.h>
|
||
|
|
#include "flint.h"
|
||
|
|
#include "fmpz.h"
|
||
|
|
#include "fmpz_poly.h"
|
||
|
|
#include "fmpz_mod_poly.h"
|
||
|
|
|
||
|
|
void _fmpz_mod_poly_derivative(fmpz *res, const fmpz *poly, slong len,
|
||
|
|
const fmpz_t p)
|
||
|
|
{
|
||
|
|
slong j, k = 1;
|
||
|
|
|
||
|
|
for (j = 1; j < len; j++)
|
||
|
|
{
|
||
|
|
if (k == 0)
|
||
|
|
fmpz_zero(res + (j - 1));
|
||
|
|
else if (k == 1)
|
||
|
|
fmpz_set(res + (j - 1), poly + j);
|
||
|
|
else
|
||
|
|
{
|
||
|
|
fmpz_mul_ui(res + (j - 1), poly + j, k);
|
||
|
|
fmpz_mod(res + (j - 1), res + (j - 1), p);
|
||
|
|
}
|
||
|
|
|
||
|
|
if (fmpz_equal_ui(p, ++k))
|
||
|
|
k = 0;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
void fmpz_mod_poly_derivative(fmpz_mod_poly_t res, const fmpz_mod_poly_t poly)
|
||
|
|
{
|
||
|
|
const slong len = poly->length;
|
||
|
|
|
||
|
|
if (len < 2)
|
||
|
|
{
|
||
|
|
fmpz_mod_poly_zero(res);
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
fmpz_mod_poly_fit_length(res, len - 1);
|
||
|
|
_fmpz_mod_poly_derivative(res->coeffs, poly->coeffs, len, &(res->p));
|
||
|
|
_fmpz_mod_poly_set_length(res, len - 1);
|
||
|
|
_fmpz_mod_poly_normalise(res);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|