93 lines
2.8 KiB
C
93 lines
2.8 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) 2010, 2011 Sebastian Pancratz
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******************************************************************************/
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#include <stdlib.h>
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#include <stdio.h>
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#include <string.h>
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#include "fmpz_poly_q.h"
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/**
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* \ingroup StringConversions
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*
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* Sets the rational function \c rop to the value specified by the
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* null-terminated string \c s.
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*
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* This method has now already been somewhat improved and is not very tolerant
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* in the handling of malformed input. It expects either legitimate input for
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* an \c fmpz_poly_t element, or two such inputs separated by a <tt>/</tt>
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* only, in which case it is also assumed that the second polynomial is
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* non-zero.
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*
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* The rational function is brought into canonical form by calling
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* #fmpz_poly_q_canonicalize() in this function.
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*
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* Returns \c 0 if the string represents a valid rational function and
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* \c non-zero otherwise.
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*/
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int fmpz_poly_q_set_str(fmpz_poly_q_t rop, const char *s)
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{
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int ans, i, m;
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size_t len;
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char * numstr;
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len = strlen(s);
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for (m = 0; m < len; m++)
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{
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if (s[m] == '/')
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break;
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}
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if (m == len)
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{
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ans = fmpz_poly_set_str(rop->num, s);
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fmpz_poly_set_si(rop->den, 1);
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return ans;
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}
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else
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{
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numstr = flint_malloc(m + 1);
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if (!numstr)
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{
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flint_printf("Exception (fmpz_poly_q_set_str). Memory allocation failed.\n");
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abort();
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}
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for (i = 0; i < m; i++)
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numstr[i] = s[i];
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numstr[i] = '\0';
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ans = fmpz_poly_set_str(rop->num, numstr);
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ans |= fmpz_poly_set_str(rop->den, s + (m + 1));
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if (ans == 0)
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fmpz_poly_q_canonicalise(rop);
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else
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fmpz_poly_q_zero(rop);
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flint_free(numstr);
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return ans;
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}
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}
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