74 lines
2.1 KiB
C
74 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) 2010 Sebastian Pancratz
|
||
|
|
|
||
|
|
******************************************************************************/
|
||
|
|
|
||
|
|
#include <gmp.h>
|
||
|
|
#include "flint.h"
|
||
|
|
#include "fmpz.h"
|
||
|
|
#include "fmpz_vec.h"
|
||
|
|
#include "fmpz_poly.h"
|
||
|
|
#include "fmpq_poly.h"
|
||
|
|
|
||
|
|
int _fmpz_poly_is_squarefree(const fmpz * poly, slong len)
|
||
|
|
{
|
||
|
|
if (len < 3)
|
||
|
|
{
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
else if (len == 3)
|
||
|
|
{
|
||
|
|
int ans;
|
||
|
|
fmpz_t lhs, rhs;
|
||
|
|
fmpz_init(lhs);
|
||
|
|
fmpz_init(rhs);
|
||
|
|
|
||
|
|
fmpz_mul(lhs, poly + 1, poly + 1);
|
||
|
|
fmpz_mul(rhs, poly, poly + 2);
|
||
|
|
fmpz_mul_ui(rhs, rhs, 4);
|
||
|
|
|
||
|
|
ans = !fmpz_equal(lhs, rhs);
|
||
|
|
fmpz_clear(lhs);
|
||
|
|
fmpz_clear(rhs);
|
||
|
|
return ans;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
int ans;
|
||
|
|
fmpz * w = _fmpz_vec_init(2 * len);
|
||
|
|
|
||
|
|
_fmpz_poly_derivative(w, poly, len);
|
||
|
|
_fmpz_poly_gcd(w + len, poly, len, w, len - WORD(1));
|
||
|
|
ans = _fmpz_vec_is_zero(w + len + 1, len - 2);
|
||
|
|
|
||
|
|
_fmpz_vec_clear(w, 2 * len);
|
||
|
|
return ans;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
int fmpz_poly_is_squarefree(const fmpz_poly_t poly)
|
||
|
|
{
|
||
|
|
return _fmpz_poly_is_squarefree(poly->coeffs, poly->length);
|
||
|
|
}
|
||
|
|
|