77 lines
2.1 KiB
C
77 lines
2.1 KiB
C
/*=============================================================================
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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.h"
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slong * _padic_lifts_exps(slong *n, slong N)
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{
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slong *a, i;
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*n = FLINT_CLOG2(N) + 1;
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a = flint_malloc((*n) * sizeof(slong));
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for (a[i = 0] = N; a[i] > 1; i++)
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a[i + 1] = (a[i] + 1) / 2;
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return a;
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}
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void _padic_lifts_pows(fmpz *pow, const slong *a, slong n, const fmpz_t p)
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{
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if (n == 1)
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{
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fmpz_set(pow + 0, p);
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}
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else /* n > 1 */
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{
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slong i = n - 1;
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fmpz_t t = {WORD(1)};
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fmpz_set(pow + i, p);
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for (i--; i >= 1; i--)
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{
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if (a[i] & WORD(1))
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{
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fmpz_mul(pow + i, t, pow + (i + 1));
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fmpz_mul(t, t, t);
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}
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else
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{
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fmpz_mul(t, t, pow + (i + 1));
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fmpz_mul(pow + i, pow + (i + 1), pow + (i + 1));
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}
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}
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{
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if (a[i] & WORD(1))
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fmpz_mul(pow + i, t, pow + (i + 1));
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else
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fmpz_mul(pow + i, pow + (i + 1), pow + (i + 1));
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}
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fmpz_clear(t);
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}
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}
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