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