81 lines
2.3 KiB
C
81 lines
2.3 KiB
C
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/*=============================================================================
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This file is part of FLINT.
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FLINT is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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FLINT is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with FLINT; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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=============================================================================*/
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/******************************************************************************
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Copyright (C) 2011 Sebastian Pancratz
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******************************************************************************/
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#include <gmp.h>
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#include "flint.h"
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#include "fmpz_mod_poly.h"
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void _fmpz_mod_poly_evaluate_fmpz(fmpz_t res, const fmpz *poly, slong len,
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const fmpz_t a, const fmpz_t p)
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{
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if (len == 0)
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{
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fmpz_zero(res);
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}
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else if (len == 1 || fmpz_is_zero(a))
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{
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fmpz_set(res, poly);
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}
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else
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{
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slong i = len - 1;
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fmpz_t t;
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fmpz_init(t);
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fmpz_set(res, poly + i);
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for (i = len - 2; i >= 0; i--)
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{
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fmpz_mul(t, res, a);
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fmpz_mod(t, t, p);
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fmpz_add(res, poly + i, t);
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}
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fmpz_clear(t);
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if (fmpz_cmpabs(res, p) >= 0)
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fmpz_sub(res, res, p);
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}
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}
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void fmpz_mod_poly_evaluate_fmpz(fmpz_t res,
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const fmpz_mod_poly_t poly, const fmpz_t a)
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{
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if (res == a)
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{
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fmpz_t t;
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fmpz_init(t);
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_fmpz_mod_poly_evaluate_fmpz(t, poly->coeffs, poly->length,
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a, &(poly->p));
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fmpz_swap(res, t);
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fmpz_clear(t);
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}
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else
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{
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_fmpz_mod_poly_evaluate_fmpz(res, poly->coeffs, poly->length,
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a, &(poly->p));
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}
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}
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