65 lines
2.0 KiB
C
65 lines
2.0 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, 2012 Sebastian Pancratz
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******************************************************************************/
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#include "fmpz_mod_poly.h"
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#include "padic_poly.h"
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void padic_poly_neg(padic_poly_t f, const padic_poly_t g,
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const padic_ctx_t ctx)
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{
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const slong len = g->length;
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if (len == 0 || g->val >= padic_poly_prec(f))
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{
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padic_poly_zero(f);
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}
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else
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{
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fmpz_t pow;
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int alloc;
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padic_poly_fit_length(f, len);
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_padic_poly_set_length(f, len);
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f->val = g->val;
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alloc = _padic_ctx_pow_ui(pow, padic_poly_prec(f) - f->val, ctx);
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if (padic_poly_prec(f) >= padic_poly_prec(g)) /* No reduction */
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{
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_fmpz_mod_poly_neg(f->coeffs, g->coeffs, len, pow);
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}
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else /* Reduction necessary? */
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{
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_fmpz_vec_scalar_mod_fmpz(f->coeffs, g->coeffs, len, pow);
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_fmpz_mod_poly_neg(f->coeffs, f->coeffs, len, pow);
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_padic_poly_normalise(f);
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}
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if (alloc)
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fmpz_clear(pow);
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}
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}
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