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/*
Copyright (C) 2011 Fredrik Johansson
This file is part of FLINT.
FLINT is free software: you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License (LGPL) as published
by the Free Software Foundation; either version 3 of the License, or
(at your option) any later version. See <https://www.gnu.org/licenses/>.
*/
#include "mpn_extras.h"
#include "nmod_poly.h"
#include "nmod_poly_factor.h"
int
_nmod_poly_is_squarefree(nn_srcptr f, slong len, nmod_t mod)
{
nn_ptr fd, g;
slong dlen;
int res;
if (len <= 2)
return len != 0;
fd = flint_malloc(sizeof(ulong) * 2 * (len - 1));
g = fd + len - 1;
_nmod_poly_derivative(fd, f, len, mod);
dlen = len - 1;
MPN_NORM(fd, dlen);
if (dlen)
res = (_nmod_poly_gcd(g, f, len, fd, dlen, mod) == 1);
else
res = 0; /* gcd(f, 0) = f, and len(f) > 2 */
flint_free(fd);
return res;
}
int
nmod_poly_is_squarefree(const nmod_poly_t f)
{
return _nmod_poly_is_squarefree(f->coeffs, f->length, f->mod);
}