pqc/external/flint-2.4.3/examples/radix.cpp
2014-05-24 23:16:06 +02:00

95 lines
2.7 KiB
C++

/*=============================================================================
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) 2012 Sebastian Pancratz
Copyright (C) 2013 Tom Bachmann (C++ adaptation)
******************************************************************************/
/*
Demo FLINT program to demonstrate some use of the
function fmpz_mod_poly_radix() for radix conversion
over $\mathbf{Z}/n \mathbf{Z}$.
*/
#include <cstdio>
#include <ctime>
#include "fmpz_mod_polyxx.h"
using namespace std;
using namespace flint;
int main(void)
{
const slong n = 12376;
const slong N = n / 26;
frandxx state;
fmpzxx m(17);
m = m.pow(26u);
fmpz_mod_polyxx A(m), B(m);
A.set_coeff(3, 5);
A.set_coeff(4, 4);
B.set_coeff(0, 1);
B.set_coeff(2, 1);
B.set_coeff(3, 5);
B.set_coeff(4, 1);
B.set_coeff(5, 5);
B.set_coeff(8, 8);
B.set_coeff(9, 8);
B.set_coeff(10, 5);
B.set_coeff(12, 6);
B.set_coeff(13, 1);
fmpz_mod_polyxx r(A.pow(3u) * fmpzxx(4) + B.pow(2u) * fmpzxx(27));
fmpz_mod_poly_vecxx b(N + 1, m);
fmpz_mod_polyxx t = fmpz_mod_polyxx::randtest(m, state, n + 1);
flint_printf("Radix conversion\n");
flint_printf("----------------\n");
flint_printf(" Degree of the radix: %wd\n", r.degree());
flint_printf(" Bit size of the modulus: %wd\n", (slong) bits(r.modulus()));
flint_printf(" Degree of the input: %wd\n", t.degree());
clock_t c0 = clock();
fmpz_mod_poly_radixxx S(r, n + 1);
clock_t c1 = clock();
double c = (double) (c1 - c0) / CLOCKS_PER_SEC;
flint_printf(" Precomputation: %fs\n", c);
c0 = clock();
b = t.radix(S);
c1 = clock();
c = (double) (c1 - c0) / CLOCKS_PER_SEC;
flint_printf(" Conversion: %fs\n", c);
return 0;
}