1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
/*
Copyright (C) 2017 Vincent Delecroix
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 "fmpz.h"
#include "fmpz_poly.h"
void fmpz_poly_squarefree_part(fmpz_poly_t res, const fmpz_poly_t poly)
{
if (poly->length == 0)
{
fmpz_poly_zero(res);
}
else if (poly->length == 1)
{
fmpz_poly_one(res);
}
else
{
fmpz_poly_t der, gcd;
fmpz_poly_init(der);
fmpz_poly_init(gcd);
fmpz_poly_derivative(der, poly);
fmpz_poly_gcd(gcd, poly, der);
fmpz_poly_divexact(res, poly, gcd);
if (res->length && fmpz_sgn(res->coeffs + res->length - 1) < 0)
fmpz_poly_neg(res, res);
fmpz_poly_clear(der);
fmpz_poly_clear(gcd);
}
}