88 lines
2.5 KiB
C
88 lines
2.5 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 William Hart
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******************************************************************************/
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#include <gmp.h>
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#include <stdlib.h>
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#include "flint.h"
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#include "fmpz.h"
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#include "fmpz_poly.h"
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int _fmpz_poly_divides(fmpz * q, const fmpz * a,
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slong len1, const fmpz * b, slong len2)
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{
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fmpz * r = _fmpz_vec_init(len1);
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_fmpz_poly_divrem(q, r, a, len1, b, len2);
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FMPZ_VEC_NORM(r, len1);
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_fmpz_vec_clear(r, len1);
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return (len1 == 0);
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}
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int fmpz_poly_divides(fmpz_poly_t q, const fmpz_poly_t a, const fmpz_poly_t b)
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{
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if (fmpz_poly_is_zero(b))
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{
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flint_printf("Exception (fmpz_poly_divides). Division by zero.\n");
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abort();
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}
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if (fmpz_poly_is_zero(a))
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{
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fmpz_poly_zero(q);
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return 1;
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}
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if (a->length < b->length)
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{
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return 0;
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}
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{
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const slong lenQ = a->length - b->length + 1;
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int res;
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if (q == a || q == b)
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{
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fmpz_poly_t t;
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fmpz_poly_init2(t, lenQ);
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res = _fmpz_poly_divides(t->coeffs, a->coeffs, a->length, b->coeffs, b->length);
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_fmpz_poly_set_length(t, lenQ);
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_fmpz_poly_normalise(t);
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fmpz_poly_swap(q, t);
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fmpz_poly_clear(t);
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}
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else
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{
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fmpz_poly_fit_length(q, lenQ);
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res = _fmpz_poly_divides(q->coeffs, a->coeffs, a->length, b->coeffs, b->length);
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_fmpz_poly_set_length(q, lenQ);
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_fmpz_poly_normalise(q);
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}
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return res;
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}
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}
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