214 lines
6.2 KiB
C
214 lines
6.2 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) 2011 William Hart
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Copyright (C) 2011 Sebastian Pancratz
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******************************************************************************/
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#include <stdio.h>
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#include <stdlib.h>
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#include <gmp.h>
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#include "flint.h"
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#include "fmpz.h"
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#include "fmpz_poly.h"
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#include "nmod_poly.h"
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#include "ulong_extras.h"
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int
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main(void)
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{
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int i, result;
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FLINT_TEST_INIT(state);
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flint_printf("hensel_lift....");
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fflush(stdout);
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/* We check that lifting local factors of F_poly yields factors */
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for (i = 0; i < 100 * flint_test_multiplier(); i++)
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{
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fmpz_poly_t F_poly, F_poly2, F_poly3, A, B, G, H,
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A_out, B_out, G_out, H_out, Prod_1, Prod_2;
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nmod_poly_t a, b, d, g, h, prod;
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fmpz_t p, p1, big_P, p1_2, big_P_2;
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slong bits, length, nbits, n, exp, part_exp;
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bits = n_randint(state, 200) + 1;
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nbits = n_randint(state, FLINT_BITS - 6) + 6;
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fmpz_init(p);
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fmpz_init(p1);
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fmpz_init(big_P);
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fmpz_init(p1_2);
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fmpz_init(big_P_2);
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fmpz_poly_init(F_poly);
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fmpz_poly_init(F_poly2);
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fmpz_poly_init(F_poly3);
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fmpz_poly_init(Prod_1);
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fmpz_poly_init(Prod_2);
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fmpz_poly_init(A);
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fmpz_poly_init(B);
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fmpz_poly_init(G);
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fmpz_poly_init(H);
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fmpz_poly_init(A_out);
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fmpz_poly_init(B_out);
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fmpz_poly_init(G_out);
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fmpz_poly_init(H_out);
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n = n_randprime(state, nbits, 0);
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exp = bits/(FLINT_BIT_COUNT(n) - 1) + 1;
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part_exp = n_randint(state, exp);
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nmod_poly_init(g, n);
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nmod_poly_init(h, n);
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nmod_poly_init(a, n);
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nmod_poly_init(b, n);
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nmod_poly_init(d, n);
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nmod_poly_init(prod, n);
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do {
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length = n_randint(state, 200) + 2;
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do { fmpz_poly_randtest(F_poly2, state, length, bits); }
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while (F_poly2->length < 2);
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fmpz_set_ui(F_poly2->coeffs, n_randbits(state, FLINT_MIN(bits, FLINT_BITS - 2)));
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fmpz_set_ui(F_poly2->coeffs + F_poly2->length - 1, 1);
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length = n_randint(state, 200) + 2;
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do { fmpz_poly_randtest(F_poly3, state, length, bits); }
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while (F_poly3->length < 2);
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fmpz_set_ui(F_poly3->coeffs, n_randbits(state, FLINT_MIN(bits, FLINT_BITS - 2)));
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fmpz_set_ui(F_poly3->coeffs + F_poly3->length - 1, 1);
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fmpz_poly_mul(F_poly, F_poly2, F_poly3);
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fmpz_poly_get_nmod_poly(prod, F_poly);
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} while (!nmod_poly_is_squarefree(prod));
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fmpz_poly_get_nmod_poly(g, F_poly2);
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fmpz_poly_get_nmod_poly(h, F_poly3);
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nmod_poly_xgcd(d, a, b, g, h);
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nmod_poly_clear(prod);
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nmod_poly_clear(d);
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fmpz_poly_set_nmod_poly(A, a);
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fmpz_poly_set_nmod_poly(B, b);
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fmpz_poly_set_nmod_poly(G, g);
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fmpz_poly_set_nmod_poly(H, h);
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fmpz_set_ui(p, n);
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fmpz_set_ui(p1, n);
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fmpz_set_ui(big_P, n);
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fmpz_set_ui(p1_2, n);
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fmpz_set_ui(big_P_2, n);
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part_exp = 1;
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while (part_exp < exp)
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{
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fmpz_set(p, big_P);
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fmpz_set_ui(p1, n);
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fmpz_set_ui(big_P, n);
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if (exp - part_exp <= part_exp)
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{
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fmpz_pow_ui(p1, p1, exp - part_exp);
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fmpz_pow_ui(big_P, big_P, exp);
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part_exp = exp;
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}
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else
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{
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fmpz_set(p1, p);
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fmpz_pow_ui(big_P, big_P, 2*part_exp);
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part_exp = 2*part_exp;
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}
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fmpz_poly_hensel_lift(G_out, H_out, A_out, B_out, F_poly,
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G, H, A, B, p, p1);
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fmpz_poly_set(G, G_out);
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fmpz_poly_set(H, H_out);
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fmpz_poly_set(A, A_out);
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fmpz_poly_set(B, B_out);
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}
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fmpz_poly_mul(Prod_1, A, G);
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fmpz_poly_mul(Prod_2, B, H);
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fmpz_poly_add(Prod_1, Prod_1, Prod_2);
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fmpz_poly_scalar_smod_fmpz(Prod_1, Prod_1, big_P);
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result = (Prod_1->length == 1 && fmpz_is_one(Prod_1->coeffs));
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if (!result)
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{
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flint_printf("FAIL:\n");
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flint_printf("length = %wd, bits = %wd, n = %wd, exp = %wd\n", length, bits, n, exp);
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fmpz_poly_print(F_poly); flint_printf("\n\n");
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fmpz_poly_print(F_poly2); flint_printf("\n\n");
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fmpz_poly_print(F_poly3); flint_printf("\n\n");
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fmpz_poly_print(Prod_1); flint_printf("\n\n");
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abort();
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}
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nmod_poly_clear(g);
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nmod_poly_clear(h);
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nmod_poly_clear(a);
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nmod_poly_clear(b);
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fmpz_poly_clear(Prod_1);
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fmpz_poly_clear(Prod_2);
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fmpz_poly_clear(A);
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fmpz_poly_clear(B);
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fmpz_poly_clear(G);
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fmpz_poly_clear(H);
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fmpz_poly_clear(A_out);
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fmpz_poly_clear(B_out);
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fmpz_poly_clear(G_out);
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fmpz_poly_clear(H_out);
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fmpz_clear(p);
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fmpz_clear(p1);
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fmpz_clear(big_P);
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fmpz_clear(p1_2);
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fmpz_clear(big_P_2);
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fmpz_poly_clear(F_poly3);
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fmpz_poly_clear(F_poly2);
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fmpz_poly_clear(F_poly);
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}
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FLINT_TEST_CLEANUP(state);
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flint_printf("PASS\n");
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return 0;
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}
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