pqc/external/flint-2.4.3/fmpz_poly/derivative.c
2014-05-24 23:16:06 +02:00

54 lines
1.7 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, 2010 Sebastian Pancratz
******************************************************************************/
#include <gmp.h>
#include "flint.h"
#include "fmpz.h"
#include "fmpz_poly.h"
void _fmpz_poly_derivative(fmpz * rpoly, const fmpz * poly, slong len)
{
slong i;
for (i = 1; i < len; i++)
fmpz_mul_ui(rpoly + (i - 1), poly + i, i);
}
void fmpz_poly_derivative(fmpz_poly_t res, const fmpz_poly_t poly)
{
const slong len = poly->length;
if (len < 2)
{
fmpz_poly_zero(res);
}
else
{
fmpz_poly_fit_length(res, len - 1);
_fmpz_poly_derivative(res->coeffs, poly->coeffs, len);
_fmpz_poly_set_length(res, len - 1);
}
}