pqc/external/flint-2.4.3/fmpz_mod_poly/randtest.c

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2014-05-18 22:03:37 +00:00
/*=============================================================================
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
Copyright (C) 2009 William Hart
Copyright (C) 2013 Mike Hansen
******************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <gmp.h>
#include "flint.h"
#include "fmpz.h"
#include "fmpz_mod_poly.h"
void
fmpz_mod_poly_randtest(fmpz_mod_poly_t f, flint_rand_t state, slong len)
{
slong i;
fmpz_mod_poly_fit_length(f, len);
for (i = 0; i < len; i++)
fmpz_randm(f->coeffs + i, state, &(f->p));
_fmpz_mod_poly_set_length(f, len);
_fmpz_mod_poly_normalise(f);
}
void
fmpz_mod_poly_randtest_monic(fmpz_mod_poly_t f, flint_rand_t state, slong len)
{
slong i;
fmpz_mod_poly_fit_length(f, len);
for (i = 0; i < len - 1; i++)
fmpz_randm(f->coeffs + i, state, &(f->p));
fmpz_one(f->coeffs + len - 1);
_fmpz_mod_poly_set_length(f, len);
}
void
fmpz_mod_poly_randtest_irreducible(fmpz_mod_poly_t f,
flint_rand_t state, slong len)
{
if (len == 0)
{
flint_printf("Exception (fmpz_mod_poly_randtest_irreducible). len == 0.\n");
abort();
}
fmpz_mod_poly_randtest(f, state, len);
while (fmpz_mod_poly_is_zero(f) || !fmpz_mod_poly_is_irreducible(f))
fmpz_mod_poly_randtest(f, state, len);
}
void
fmpz_mod_poly_randtest_monic_irreducible(fmpz_mod_poly_t f,
flint_rand_t state, slong len)
{
if (len == 0)
{
flint_printf("Exception (fmpz_mod_poly_randtest_monic_irreducible). len == 0.\n");
abort();
}
fmpz_mod_poly_randtest_monic(f, state, len);
while (fmpz_mod_poly_is_zero(f) || !fmpz_mod_poly_is_irreducible(f))
fmpz_mod_poly_randtest_monic(f, state, len);
}
void
fmpz_mod_poly_randtest_not_zero(fmpz_mod_poly_t f,
flint_rand_t state, slong len)
{
if (len == 0)
{
flint_printf("Exception (fmpz_mod_poly_randtest_not_zero). len == 0.\n");
abort();
}
fmpz_mod_poly_randtest(f, state, len);
while (fmpz_mod_poly_is_zero(f))
fmpz_mod_poly_randtest(f, state, len);
}
void
fmpz_mod_poly_randtest_trinomial(fmpz_mod_poly_t poly, flint_rand_t state, slong len)
{
ulong k;
fmpz_mod_poly_fit_length(poly, len);
_fmpz_vec_zero(poly->coeffs, len);
fmpz_randm(poly->coeffs, state, &(poly->p));
k = (n_randtest(state) % (len - 2)) + 1;
fmpz_randm(poly->coeffs + k, state, &(poly->p));
fmpz_one(poly->coeffs + len - 1);
_fmpz_mod_poly_set_length(poly, len);
}
void
fmpz_mod_poly_randtest_pentomial(fmpz_mod_poly_t poly, flint_rand_t state, slong len)
{
fmpz_mod_poly_fit_length(poly, len);
_fmpz_vec_zero(poly->coeffs, len);
fmpz_randm(poly->coeffs, state, &(poly->p));
fmpz_randm(poly->coeffs + 1, state, &(poly->p));
fmpz_randm(poly->coeffs + 2, state, &(poly->p));
fmpz_randm(poly->coeffs + 3, state, &(poly->p));
fmpz_one(poly->coeffs + len - 1);
_fmpz_mod_poly_set_length(poly, len);
}
int
fmpz_mod_poly_randtest_trinomial_irreducible(fmpz_mod_poly_t poly, flint_rand_t state,
slong len, slong max_attempts)
{
slong i = 0;
while (max_attempts == 0 || i < max_attempts)
{
fmpz_mod_poly_randtest_trinomial(poly, state, len);
if (!fmpz_mod_poly_is_zero(poly) && fmpz_mod_poly_is_irreducible(poly))
{
return 1;
}
i++;
}
return 0;
}
int
fmpz_mod_poly_randtest_pentomial_irreducible(fmpz_mod_poly_t poly, flint_rand_t state,
slong len, slong max_attempts)
{
slong i = 0;
while (max_attempts == 0 || i < max_attempts)
{
fmpz_mod_poly_randtest_pentomial(poly, state, len);
if (!fmpz_mod_poly_is_zero(poly) && fmpz_mod_poly_is_irreducible(poly))
{
return 1;
}
i++;
}
return 0;
}
void
fmpz_mod_poly_randtest_sparse_irreducible(fmpz_mod_poly_t poly, flint_rand_t state, slong len)
{
if (len < 3)
{
fmpz_mod_poly_randtest_monic_irreducible(poly, state, len);
return;
}
/* Try trinomials */
if (fmpz_mod_poly_randtest_trinomial_irreducible(poly, state, len, 2*len))
return;
if (len < 5)
{
fmpz_mod_poly_randtest_monic_irreducible(poly, state, len);
return;
}
/* Try pentomials */
if (fmpz_mod_poly_randtest_pentomial_irreducible(poly, state, len, 2*len))
return;
/* Give up */
fmpz_mod_poly_randtest_monic_irreducible(poly, state, len);
}