pqc/external/flint-2.4.3/nmod_poly/test/t-resultant.c
2014-05-24 23:16:06 +02:00

129 lines
3.8 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) 2011 Sebastian Pancratz
******************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <gmp.h>
#include "flint.h"
#include "nmod_poly.h"
#include "ulong_extras.h"
int
main(void)
{
int i, result;
FLINT_TEST_INIT(state);
flint_printf("resultant....");
fflush(stdout);
/* Check res(f, g) == (-1)^(deg f deg g) res(g, f) */
for (i = 0; i < 100 * flint_test_multiplier(); i++)
{
nmod_poly_t f, g;
mp_limb_t x, y;
mp_limb_t n;
do n = n_randtest_not_zero(state);
while (!n_is_probabprime(n));
nmod_poly_init(f, n);
nmod_poly_init(g, n);
nmod_poly_randtest(f, state, n_randint(state, 200));
nmod_poly_randtest(g, state, n_randint(state, 200));
x = nmod_poly_resultant(f, g);
y = nmod_poly_resultant(g, f);
if ((nmod_poly_degree(f) * nmod_poly_degree(g)) % 2)
y = nmod_neg(y, f->mod);
result = (x == y);
if (!result)
{
flint_printf("FAIL (res(f, g) == (-1)^(deg f deg g) res(g, f)):\n");
nmod_poly_print(f), flint_printf("\n\n");
nmod_poly_print(g), flint_printf("\n\n");
flint_printf("x = %wu\n", x);
flint_printf("y = %wu\n", y);
flint_printf("n = %wu\n", n);
abort();
}
nmod_poly_clear(f);
nmod_poly_clear(g);
}
/* Check res(f h, g) == res(f, g) res(h, g) */
for (i = 0; i < 50 * flint_test_multiplier(); i++)
{
nmod_poly_t f, g, h;
mp_limb_t x, y, z;
mp_limb_t n;
do n = n_randtest_not_zero(state);
while (!n_is_probabprime(n));
nmod_poly_init(f, n);
nmod_poly_init(g, n);
nmod_poly_init(h, n);
nmod_poly_randtest(f, state, n_randint(state, 200));
nmod_poly_randtest(g, state, n_randint(state, 200));
nmod_poly_randtest(h, state, n_randint(state, 200));
y = nmod_poly_resultant(f, g);
z = nmod_poly_resultant(h, g);
y = nmod_mul(y, z, f->mod);
nmod_poly_mul(f, f, h);
x = nmod_poly_resultant(f, g);
result = (x == y);
if (!result)
{
flint_printf("FAIL (res(f h, g) == res(f, g) res(h, g)):\n");
nmod_poly_print(f), flint_printf("\n\n");
nmod_poly_print(g), flint_printf("\n\n");
nmod_poly_print(h), flint_printf("\n\n");
flint_printf("x = %wu\n", x);
flint_printf("y = %wu\n", y);
flint_printf("z = %wd\n", z);
flint_printf("n = %wu\n", n);
abort();
}
nmod_poly_clear(f);
nmod_poly_clear(g);
nmod_poly_clear(h);
}
FLINT_TEST_CLEANUP(state);
flint_printf("PASS\n");
return 0;
}