79 lines
2.1 KiB
C
79 lines
2.1 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 Fredrik Johansson
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******************************************************************************/
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/*
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Demo FLINT program for incremental multimodular reduction and
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reconstruction using the Chinese Remainder Theorem.
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*/
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#include <stdlib.h>
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#include <stdio.h>
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#include "flint.h"
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#include "fmpz.h"
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#include "ulong_extras.h"
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int main(int argc, char* argv[])
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{
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slong i, bit_bound;
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mp_limb_t prime, res;
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fmpz_t x, y, prod;
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if (argc != 2)
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{
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flint_printf("Syntax: crt <integer>\n");
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return EXIT_FAILURE;
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}
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fmpz_init(x);
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fmpz_init(y);
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fmpz_init(prod);
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fmpz_set_str(x, argv[1], 10);
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bit_bound = fmpz_bits(x) + 2;
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fmpz_zero(y);
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fmpz_one(prod);
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prime = 0;
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for (i = 0; fmpz_bits(prod) < bit_bound; i++)
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{
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prime = n_nextprime(prime, 0);
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res = fmpz_fdiv_ui(x, prime);
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fmpz_CRT_ui(y, y, prod, res, prime, 1);
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flint_printf("residue mod %wu = %wu; reconstruction = ", prime, res);
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fmpz_print(y);
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flint_printf("\n");
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fmpz_mul_ui(prod, prod, prime);
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}
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fmpz_clear(x);
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fmpz_clear(y);
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fmpz_clear(prod);
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return EXIT_SUCCESS;
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}
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