/* Copyright (C) 2012 Sebastian Pancratz Copyright (C) 2013 Tom Bachmann (C++ adaptation) This file is part of FLINT. FLINT is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License (LGPL) as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. See . */ /* Demo FLINT program to demonstrate some use of the function fmpz_mod_poly_radix() for radix conversion over $\mathbf{Z}/n \mathbf{Z}$. */ #include #include #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; }