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

65 lines
1.9 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 Sebastian Pancratz
******************************************************************************/
#include <gmp.h>
#include "flint.h"
#include "fmpz.h"
#include "fmpz_vec.h"
#include "fmpq_poly.h"
void fmpq_poly_get_slice(fmpq_poly_t rop, const fmpq_poly_t op, slong i, slong j)
{
i = FLINT_MAX(i, 0);
j = FLINT_MIN(j, op->length);
if (i < j)
{
slong k;
if (rop == op)
{
for (k = 0; k < i; k++)
fmpz_zero(rop->coeffs + k);
for (k = j; k < rop->length; k++)
fmpz_zero(rop->coeffs + k);
fmpq_poly_canonicalise(rop);
}
else
{
fmpq_poly_fit_length(rop, j);
_fmpq_poly_set_length(rop, j);
_fmpz_vec_set(rop->coeffs + i, op->coeffs + i, j - i);
fmpz_set(rop->den, op->den);
fmpq_poly_canonicalise(rop);
}
}
else
{
fmpq_poly_zero(rop);
}
}