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

171 lines
5.1 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) 2011, 2012 Sebastian Pancratz
******************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include "long_extras.h"
#include "ulong_extras.h"
#include "padic_poly.h"
int
main(void)
{
int i, result;
padic_ctx_t ctx;
fmpz_t p;
slong N;
FLINT_TEST_INIT(state);
flint_printf("inv_series... ");
fflush(stdout);
/* Check aliasing */
for (i = 0; i < 1000; i++)
{
padic_poly_t a, b, c;
slong n;
fmpz_init_set_ui(p, n_randtest_prime(state, 0));
N = n_randint(state, PADIC_TEST_PREC_MAX - PADIC_TEST_PREC_MIN)
+ PADIC_TEST_PREC_MIN;
padic_ctx_init(ctx, p, FLINT_MAX(0, N-10), FLINT_MAX(0, N+10), PADIC_SERIES);
padic_poly_init2(a, 0, N);
padic_poly_init2(b, 0, N);
padic_poly_init2(c, 0, N);
padic_poly_randtest(a, state, n_randint(state, 100) + 1, ctx);
if (fmpz_is_zero(a->coeffs))
{
fmpz_randtest_not_zero(a->coeffs, state, 20);
fmpz_remove(a->coeffs, a->coeffs, p);
padic_poly_reduce(a, ctx);
} else
fmpz_remove(a->coeffs, a->coeffs, p);
padic_poly_set(b, a, ctx);
n = n_randint(state, 100) + 1;
padic_poly_inv_series(c, b, n, ctx);
padic_poly_inv_series(b, b, n, ctx);
result = (padic_poly_equal(b, c) && padic_poly_is_reduced(b, ctx));
if (!result)
{
flint_printf("FAIL:\n");
flint_printf("a = "), padic_poly_print(a, ctx), flint_printf("\n\n");
flint_printf("b = "), padic_poly_print(b, ctx), flint_printf("\n\n");
flint_printf("c = "), padic_poly_print(c, ctx), flint_printf("\n\n");
abort();
}
padic_poly_clear(a);
padic_poly_clear(b);
padic_poly_clear(c);
padic_ctx_clear(ctx);
fmpz_clear(p);
}
/*
Check correctness:
If ord_p(a) = v then we can compute b = a^{-1} mod p^N
and we will have a b = 1 mod p^{N-|v|}. Thus, require
that N - |v| > 0.
*/
for (i = 0; i < 1000; i++)
{
padic_poly_t a, b, c;
slong n, N2;
fmpz_init_set_ui(p, n_randtest_prime(state, 0));
N = n_randint(state, PADIC_TEST_PREC_MAX - 1) + 1;
padic_ctx_init(ctx, p, FLINT_MAX(0, N-10), FLINT_MAX(0, N+10), PADIC_SERIES);
padic_poly_init2(a, 0, N);
padic_poly_init2(b, 0, N);
{
slong i, len = n_randint(state, 10) + 1;
int alloc;
fmpz_t pow;
padic_poly_fit_length(a, len);
_padic_poly_set_length(a, len);
a->val = n_randint(state, N);
if (n_randint(state, 2))
a->val = - a->val;
alloc = _padic_ctx_pow_ui(pow, N - a->val, ctx);
for (i = 0; i < len; i++)
fmpz_randm(a->coeffs + i, state, pow);
while (fmpz_is_zero(a->coeffs))
fmpz_randm(a->coeffs, state, pow);
fmpz_remove(a->coeffs, a->coeffs, p);
_padic_poly_normalise(a);
if (alloc)
fmpz_clear(pow);
}
n = n_randint(state, 100) + 1;
N2 = N - FLINT_ABS(a->val);
padic_poly_init2(c, 0, N2);
padic_poly_inv_series(b, a, n, ctx);
padic_poly_mul(c, a, b, ctx);
padic_poly_truncate(c, n, p);
result = (padic_poly_is_one(c) && padic_poly_is_reduced(b, ctx));
if (!result)
{
flint_printf("FAIL:\n");
flint_printf("a = "), padic_poly_print(a, ctx), flint_printf("\n\n");
flint_printf("b = "), padic_poly_print(b, ctx), flint_printf("\n\n");
flint_printf("c = "), padic_poly_print(c, ctx), flint_printf("\n\n");
flint_printf("N = %wd\n", N);
flint_printf("N2 = %wd\n", N2);
abort();
}
padic_poly_clear(a);
padic_poly_clear(b);
padic_poly_clear(c);
padic_ctx_clear(ctx);
fmpz_clear(p);
}
FLINT_TEST_CLEANUP(state);
flint_printf("PASS\n");
return EXIT_SUCCESS;
}