pqc/external/flint-2.4.3/fmpz_poly_q/evaluate.c

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2014-05-18 22:03:37 +00:00
/*=============================================================================
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) 2010, 2011 Sebastian Pancratz
******************************************************************************/
#include "fmpz_poly_q.h"
int fmpz_poly_q_evaluate(mpq_t rop, const fmpz_poly_q_t f, const mpq_t a)
{
if (flint_mpz_cmp_si(mpq_denref(a), 1)) /* a is not an integer */
{
mpq_t mpqnum, mpqden;
mpq_init(mpqden);
fmpz_poly_evaluate_mpq(mpqden, f->den, a);
if (mpq_sgn(mpqden) == 0)
{
mpq_clear(mpqden);
return 1;
}
mpq_init(mpqnum);
fmpz_poly_evaluate_mpq(mpqnum, f->num, a);
mpq_div(rop, mpqnum, mpqden);
mpq_clear(mpqnum);
mpq_clear(mpqden);
return 0;
}
else /* a is an integer */
{
fmpz_t num, den, a2;
fmpz_init(num);
fmpz_init(den);
fmpz_init(a2);
fmpz_set_mpz(a2, mpq_numref(a));
fmpz_poly_evaluate_fmpz(den, f->den, a2);
if (fmpz_is_zero(den))
{
fmpz_clear(a2);
fmpz_clear(num);
fmpz_clear(den);
return 1;
}
fmpz_poly_evaluate_fmpz(num, f->num, a2);
fmpz_get_mpz(mpq_numref(rop), num);
fmpz_get_mpz(mpq_denref(rop), den);
mpq_canonicalize(rop);
fmpz_clear(a2);
fmpz_clear(num);
fmpz_clear(den);
return 0;
}
}