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44 lines
1.3 KiB
C
44 lines
1.3 KiB
C
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/* mpz_invert (inv, x, n). Find multiplicative inverse of X in Z(N).
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If X has an inverse, return non-zero and store inverse in INVERSE,
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otherwise, return 0 and put garbage in X.
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Copyright (C) 1996 Free Software Foundation, Inc.
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This file is part of the GNU MP Library.
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The GNU MP Library is free software; you can redistribute it and/or modify
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it under the terms of the GNU Library General Public License as published by
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the Free Software Foundation; either version 2 of the License, or (at your
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option) any later version.
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The GNU MP Library is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
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License for more details.
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You should have received a copy of the GNU Library General Public License
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along with the GNU MP Library; see the file COPYING.LIB. If not, write to
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the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
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MA 02111-1307, USA. */
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#include "gmp.h"
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int
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#if __STDC__
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mpz_invert (mpz_ptr inverse, mpz_srcptr x, mpz_srcptr n)
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#else
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mpz_invert (inverse, x, n)
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mpz_ptr inverse;
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mpz_srcptr x, n;
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#endif
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{
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mpz_t gcd;
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int rv;
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mpz_init (gcd);
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mpz_gcdext (gcd, inverse, (mpz_ptr) 0, x, n);
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rv = gcd->_mp_size == 1 && (gcd->_mp_d)[0] == 1;
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mpz_clear (gcd);
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return rv;
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}
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