pqc/external/flint-2.4.3/padic/val_fac.c

88 lines
1.9 KiB
C

/*=============================================================================
This file is part of FLINT.
FLINT 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.
FLINT 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 FLINT; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
=============================================================================*/
/******************************************************************************
Copyright (C) 2011, 2012 Sebastian Pancratz
******************************************************************************/
#include "padic.h"
ulong padic_val_fac_ui_2(ulong N)
{
ulong s = 0, t = N;
do
{
t /= 2;
s += t;
}
while (t);
return s;
}
ulong padic_val_fac_ui(ulong N, const fmpz_t prime)
{
if (fmpz_abs_fits_ui(prime))
{
const ulong p = fmpz_get_ui(prime);
ulong s = 0, t = N;
do
{
t /= p;
s += t;
}
while (t);
return s;
}
else
{
return 0;
}
}
void padic_val_fac(fmpz_t rop, const fmpz_t op, const fmpz_t p)
{
fmpz_t s, t;
if (fmpz_sgn(op) < 0)
{
flint_printf("Exception (padic_val_fac). op is negative.\n");
abort();
}
fmpz_init(s);
fmpz_init_set(t, op);
do
{
fmpz_fdiv_q(t, t, p);
fmpz_add(s, s, t);
}
while (!fmpz_is_zero(t));
fmpz_swap(rop, s);
}