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Annotation of OpenXM_contrib/gmp/mpz/invert.c, Revision 1.1

1.1     ! maekawa     1: /* mpz_invert (inv, x, n).  Find multiplicative inverse of X in Z(N).
        !             2:    If X has an inverse, return non-zero and store inverse in INVERSE,
        !             3:    otherwise, return 0 and put garbage in X.
        !             4:
        !             5: Copyright (C) 1996 Free Software Foundation, Inc.
        !             6:
        !             7: This file is part of the GNU MP Library.
        !             8:
        !             9: The GNU MP Library is free software; you can redistribute it and/or modify
        !            10: it under the terms of the GNU Library General Public License as published by
        !            11: the Free Software Foundation; either version 2 of the License, or (at your
        !            12: option) any later version.
        !            13:
        !            14: The GNU MP Library is distributed in the hope that it will be useful, but
        !            15: WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
        !            16: or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
        !            17: License for more details.
        !            18:
        !            19: You should have received a copy of the GNU Library General Public License
        !            20: along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
        !            21: the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
        !            22: MA 02111-1307, USA. */
        !            23:
        !            24: #include "gmp.h"
        !            25:
        !            26: int
        !            27: #if __STDC__
        !            28: mpz_invert (mpz_ptr inverse, mpz_srcptr x, mpz_srcptr n)
        !            29: #else
        !            30: mpz_invert (inverse, x, n)
        !            31:      mpz_ptr inverse;
        !            32:      mpz_srcptr x, n;
        !            33: #endif
        !            34: {
        !            35:   mpz_t gcd;
        !            36:   int rv;
        !            37:
        !            38:   mpz_init (gcd);
        !            39:   mpz_gcdext (gcd, inverse, (mpz_ptr) 0, x, n);
        !            40:   rv = gcd->_mp_size == 1 && (gcd->_mp_d)[0] == 1;
        !            41:   mpz_clear (gcd);
        !            42:   return rv;
        !            43: }