ALL: Add flint

external/flint-2.4.3/examples/multi_crt.c

@@ -0,0 +1,103 @@
+/*=============================================================================
+
+    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 balanced 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;
+    fmpz_t x, y;
+
+    /* Data needed by multi CRT functions */
+    fmpz_comb_t comb;
+    fmpz_comb_temp_t comb_temp;
+
+    mp_limb_t * primes;
+    mp_limb_t * residues;
+
+    slong num_primes;
+
+    if (argc != 3)
+    {
+        flint_printf("Syntax: crt <integer> <num_primes>\n");
+        return EXIT_FAILURE;
+    }
+
+    num_primes = atoi(argv[2]);
+
+    if (num_primes < 1)
+    {
+        flint_printf("Requires num_primes >= 1\n");
+        return EXIT_FAILURE;
+    }
+
+    fmpz_init(x);
+    fmpz_init(y);
+
+    fmpz_set_str(x, argv[1], 10);
+
+    primes = flint_malloc(num_primes * sizeof(mp_limb_t));
+    residues = flint_malloc(num_primes * sizeof(mp_limb_t));
+
+    primes[0] = 2;
+    for (i = 1; i < num_primes; i++)
+        primes[i] = n_nextprime(primes[i-1], 0);
+
+    fmpz_comb_init(comb, primes, num_primes);
+    fmpz_comb_temp_init(comb_temp, comb);
+
+    /* Reduce modulo all primes */
+    fmpz_multi_mod_ui(residues, x, comb, comb_temp);
+
+    /* Reconstruct */
+    fmpz_multi_CRT_ui(y, residues, comb, comb_temp, 1);
+
+    for (i = 0; i < num_primes; i++)
+        flint_printf("residue mod %wu = %wu\n", primes[i], residues[i]);
+
+    flint_printf("reconstruction = ");
+    fmpz_print(y);
+    flint_printf("\n");
+
+    fmpz_clear(x);
+    fmpz_clear(y);
+
+    fmpz_comb_temp_clear(comb_temp);
+    fmpz_comb_clear(comb);
+
+    flint_free(residues);
+    flint_free(primes);
+
+    return EXIT_SUCCESS;
+}