arb/dlog/1modpe.c
2016-10-08 22:45:58 +02:00

47 lines
1.5 KiB
C

/*=============================================================================
This file is part of ARB.
ARB is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
ARB is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with ARB; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
=============================================================================*/
/******************************************************************************
Copyright (C) 2016 Pascal Molin
******************************************************************************/
#include "dlog.h"
/* assume b = 1 mod p, not checked */
ulong
dlog_1modpe(const dlog_1modpe_t t, ulong b)
{
padic_t px;
fmpz_t ix;
ulong ux;
padic_init(px);
fmpz_init(ix);
padic_set_ui(px, b, t->ctx);
padic_log(px, px, t->ctx);
padic_mul(px, px, t->invlog, t->ctx);
padic_get_fmpz(ix, px, t->ctx);
ux = fmpz_get_ui(ix);
padic_clear(px);
fmpz_clear(ix);
return ux;
}