92 lines
2.7 KiB
C
92 lines
2.7 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 "padic_poly.h"
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void _padic_poly_mul(fmpz *rop, slong *rval, slong N,
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const fmpz *op1, slong val1, slong len1,
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const fmpz *op2, slong val2, slong len2,
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const padic_ctx_t ctx)
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{
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fmpz_t pow;
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int alloc;
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*rval = val1 + val2;
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alloc = _padic_ctx_pow_ui(pow, N - *rval, ctx);
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_fmpz_poly_mul(rop, op1, len1, op2, len2);
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_fmpz_vec_scalar_mod_fmpz(rop, rop, len1 + len2 - 1, pow);
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if (alloc)
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fmpz_clear(pow);
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}
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void padic_poly_mul(padic_poly_t f,
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const padic_poly_t g, const padic_poly_t h,
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const padic_ctx_t ctx)
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{
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const slong lenG = g->length;
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const slong lenH = h->length;
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const slong lenF = lenG + lenH - 1;
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if (lenG == 0 || lenH == 0 || g->val + h->val >= f->N)
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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;
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if (f == g || f == h)
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{
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t = _fmpz_vec_init(lenF);
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}
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else
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{
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padic_poly_fit_length(f, lenF);
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t = f->coeffs;
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}
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if (lenG >= lenH)
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_padic_poly_mul(t, &(f->val), f->N, g->coeffs, g->val, lenG,
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h->coeffs, h->val, lenH, ctx);
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else
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_padic_poly_mul(t, &(f->val), f->N, h->coeffs, h->val, lenH,
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g->coeffs, g->val, lenG, ctx);
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if (f == g || f == h)
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{
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_fmpz_vec_clear(f->coeffs, f->alloc);
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f->coeffs = t;
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f->alloc = lenF;
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}
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_padic_poly_set_length(f, lenF);
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_padic_poly_normalise(f);
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}
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}
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