ALL: Add flint

external/flint-2.4.3/examples/crt.cpp

@@ -0,0 +1,68 @@
+/*=============================================================================
+
+    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
+    Copyright (C) 2013 Tom Bachmann (C++ adaptation)
+
+******************************************************************************/
+
+/*
+    Demo FLINT program for incremental multimodular reduction and
+    reconstruction using the Chinese Remainder Theorem.
+*/
+
+#include <iostream>
+#include "fmpzxx.h"
+#include "ulong_extras.h"
+
+using namespace flint;
+
+int main(int argc, char* argv[])
+{
+    if (argc != 2)
+    {
+        flint_printf("Syntax: crt <integer>\n");
+        return EXIT_FAILURE;
+    }
+    
+    fmpzxx x(argv[1]);
+    slong bit_bound = bits(x) + 2;
+
+    fmpzxx y(0);
+    fmpzxx prod(1);
+
+    mp_limb_t prime = 0;
+    for (unsigned i = 0; bits(prod) < bit_bound; i++)
+    {
+        prime = n_nextprime(prime, 0);
+
+        ulong res = (x % prime).to<ulong>();
+        y = y.CRT(prod, res, prime, true);
+
+        std::cout << "residue mod " << prime << " = " << res;
+        std::cout << "; reconstruction = " << y << '\n';
+
+        prod *= prime;
+    }
+
+    return 0;
+}
+