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

102 lines
3.0 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) 2010 Sebastian Pancratz
******************************************************************************/
#include <gmp.h>
#include "flint.h"
#include "fmpz.h"
#include "fmpz_vec.h"
#include "fmpq_poly.h"
int _fmpq_poly_cmp(const fmpz * lpoly, const fmpz_t lden,
const fmpz * rpoly, const fmpz_t rden, slong len)
{
int ans;
slong i = len - 1;
fmpz_t lcoeff, rcoeff;
if (fmpz_equal(lden, rden))
{
while (i && fmpz_equal(lpoly + i, rpoly + i))
i--;
ans = fmpz_cmp(lpoly + i, rpoly + i);
}
else if (*lden == WORD(1)) /* Here rden exceeds 1 */
{
fmpz_init(lcoeff);
fmpz_mul(lcoeff, lpoly + i, rden);
while (i && fmpz_equal(lcoeff, rpoly + i))
fmpz_mul(lcoeff, lpoly + (--i), rden);
ans = fmpz_cmp(lcoeff, rpoly + i);
fmpz_clear(lcoeff);
}
else if (*rden == WORD(1)) /* Here lden exceeds 1 */
{
fmpz_init(rcoeff);
fmpz_mul(rcoeff, rpoly + i, lden);
while (i && fmpz_equal(rcoeff, lpoly + i))
fmpz_mul(rcoeff, rpoly + (--i), lden);
ans = fmpz_cmp(lpoly + i, rcoeff);
fmpz_clear(rcoeff);
}
else /* Here both lden, rden exceed 1 */
{
fmpz_init(lcoeff);
fmpz_init(rcoeff);
fmpz_mul(lcoeff, lpoly + i, rden);
fmpz_mul(rcoeff, rpoly + i, lden);
while (i && fmpz_equal(lcoeff, rcoeff))
{
i--;
fmpz_mul(lcoeff, lpoly + i, rden);
fmpz_mul(rcoeff, rpoly + i, lden);
}
ans = fmpz_cmp(lcoeff, rcoeff);
fmpz_clear(lcoeff);
fmpz_clear(rcoeff);
}
return ans;
}
int fmpq_poly_cmp(const fmpq_poly_t left, const fmpq_poly_t right)
{
slong len1, len2;
if (left == right)
return 0;
len1 = left->length;
len2 = right->length;
if (len1 < len2)
return -1;
else if (len1 > len2)
return 1;
else if (len1 == 0)
return 0;
else
return _fmpq_poly_cmp(left->coeffs, left->den, right->coeffs, right->den, len1);
}