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Annotation of OpenXM_contrib/gmp/mpz/invert.c, Revision 1.1.1.1

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: }