84 lines
2.7 KiB
C
84 lines
2.7 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) 2012 Lina Kulakova
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******************************************************************************/
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#include <math.h>
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#include "fmpz_mod_poly.h"
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void
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fmpz_mod_poly_factor_kaltofen_shoup(fmpz_mod_poly_factor_t res,
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const fmpz_mod_poly_t poly)
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{
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fmpz_mod_poly_t v;
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fmpz_mod_poly_factor_t sq_free, dist_deg;
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slong i, j, k, l, res_num, dist_deg_num;
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slong *degs;
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fmpz_mod_poly_init(v, &poly->p);
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fmpz_mod_poly_make_monic(v, poly);
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if (poly->length <= 2)
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{
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fmpz_mod_poly_factor_insert (res, v, 1);
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fmpz_mod_poly_clear (v);
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return;
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}
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if (!(degs = flint_malloc(fmpz_mod_poly_degree(poly) * sizeof(slong))))
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{
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flint_printf("Exception (fmpz_mod_poly_factor_kaltofen_shoup): \n");
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flint_printf("Not enough memory.\n");
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abort();
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}
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/* compute squarefree factorisation */
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fmpz_mod_poly_factor_init(sq_free);
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fmpz_mod_poly_factor_squarefree(sq_free, v);
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/* compute distinct-degree factorisation */
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fmpz_mod_poly_factor_init(dist_deg);
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for (i = 0; i < sq_free->num; i++)
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{
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dist_deg_num = dist_deg->num;
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fmpz_mod_poly_factor_distinct_deg(dist_deg, sq_free->poly + i, °s);
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/* compute equal-degree factorisation */
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for (j = dist_deg_num, l = 0; j < dist_deg->num; j++, l++)
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{
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res_num = res->num;
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fmpz_mod_poly_factor_equal_deg(res, dist_deg->poly + j, degs[l]);
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for (k = res_num; k < res->num; k++)
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res->exp[k] = fmpz_mod_poly_remove(v, res->poly + k);
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}
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}
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flint_free(degs);
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fmpz_mod_poly_clear(v);
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fmpz_mod_poly_factor_clear(dist_deg);
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fmpz_mod_poly_factor_clear(sq_free);
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}
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