157 lines
4.4 KiB
C
157 lines
4.4 KiB
C
/*=============================================================================
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This file is part of FLINT.
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FLINT is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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FLINT is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with FLINT; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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=============================================================================*/
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/******************************************************************************
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Copyright (C) 2010 William Hart
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Copyright (C) 2013 Mike Hansen
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******************************************************************************/
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#include <gmp.h>
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#include <stdlib.h>
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#include "flint.h"
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#include "ulong_extras.h"
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#include "nmod_poly.h"
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void
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nmod_poly_randtest(nmod_poly_t poly, flint_rand_t state, slong len)
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{
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nmod_poly_fit_length(poly, len);
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_nmod_vec_randtest(poly->coeffs, state, len, poly->mod);
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poly->length = len;
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_nmod_poly_normalise(poly);
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}
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void
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nmod_poly_randtest_monic(nmod_poly_t poly, flint_rand_t state, slong len)
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{
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nmod_poly_fit_length(poly, len);
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_nmod_vec_randtest(poly->coeffs, state, len - 1, poly->mod);
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poly->coeffs[len - 1] = 1;
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poly->length = len;
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}
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void
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nmod_poly_randtest_irreducible(nmod_poly_t poly, flint_rand_t state, slong len)
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{
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do {
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nmod_poly_randtest(poly, state, len);
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} while (nmod_poly_is_zero(poly) || !(nmod_poly_is_irreducible(poly)));
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}
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void
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nmod_poly_randtest_monic_irreducible(nmod_poly_t poly, flint_rand_t state, slong len)
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{
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do {
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nmod_poly_randtest_monic(poly, state, len);
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} while (nmod_poly_is_zero(poly) || !(nmod_poly_is_irreducible(poly)));
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}
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void
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nmod_poly_randtest_trinomial(nmod_poly_t poly, flint_rand_t state, slong len)
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{
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ulong k;
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nmod_poly_fit_length(poly, len);
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_nmod_vec_zero(poly->coeffs, len);
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poly->coeffs[0] = n_randtest(state) % poly->mod.n;
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poly->coeffs[len - 1] = 1;
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k = (n_randtest(state) % (len - 2)) + 1;
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poly->coeffs[k] = n_randtest(state) % poly->mod.n;
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_nmod_poly_set_length(poly, len);
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}
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void
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nmod_poly_randtest_pentomial(nmod_poly_t poly, flint_rand_t state, slong len)
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{
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nmod_poly_fit_length(poly, len);
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_nmod_vec_zero(poly->coeffs, len);
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poly->coeffs[0] = n_randtest(state) % poly->mod.n;
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poly->coeffs[1] = n_randtest(state) % poly->mod.n;
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poly->coeffs[2] = n_randtest(state) % poly->mod.n;
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poly->coeffs[3] = n_randtest(state) % poly->mod.n;
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poly->coeffs[len - 1] = 1;
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_nmod_poly_set_length(poly, len);
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}
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int
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nmod_poly_randtest_trinomial_irreducible(nmod_poly_t poly, flint_rand_t state,
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slong len, slong max_attempts)
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{
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slong i = 0;
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while (max_attempts == 0 || i < max_attempts)
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{
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nmod_poly_randtest_trinomial(poly, state, len);
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if (!nmod_poly_is_zero(poly) && nmod_poly_is_irreducible(poly))
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{
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return 1;
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}
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i++;
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}
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return 0;
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}
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int
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nmod_poly_randtest_pentomial_irreducible(nmod_poly_t poly, flint_rand_t state,
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slong len, slong max_attempts)
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{
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slong i = 0;
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while (max_attempts == 0 || i < max_attempts)
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{
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nmod_poly_randtest_pentomial(poly, state, len);
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if (!nmod_poly_is_zero(poly) && nmod_poly_is_irreducible(poly))
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{
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return 1;
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}
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i++;
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}
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return 0;
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}
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void
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nmod_poly_randtest_sparse_irreducible(nmod_poly_t poly, flint_rand_t state, slong len)
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{
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if (len < 3)
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{
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nmod_poly_randtest_monic_irreducible(poly, state, len);
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return;
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}
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/* Try trinomials */
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if (nmod_poly_randtest_trinomial_irreducible(poly, state, len, 2*len))
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return;
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if (len < 5)
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{
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nmod_poly_randtest_monic_irreducible(poly, state, len);
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return;
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}
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/* Try pentomials */
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if (nmod_poly_randtest_pentomial_irreducible(poly, state, len, 2*len))
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return;
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/* Give up */
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nmod_poly_randtest_monic_irreducible(poly, state, len);
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}
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