107 lines
2.8 KiB
C
107 lines
2.8 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) 2012 Sebastian Pancratz
|
|
|
|
******************************************************************************/
|
|
|
|
#include "fmpz_mod_poly.h"
|
|
#include "padic_poly.h"
|
|
|
|
/*
|
|
TODO: Move this bit of code into "padic".
|
|
*/
|
|
static void __padic_reduce(fmpz_t u, slong *v, slong N, const padic_ctx_t ctx)
|
|
{
|
|
if (!fmpz_is_zero(u))
|
|
{
|
|
if (*v < N)
|
|
{
|
|
int alloc;
|
|
fmpz_t pow;
|
|
|
|
alloc = _padic_ctx_pow_ui(pow, N - *v, ctx);
|
|
fmpz_mod(u, u, pow);
|
|
if (alloc)
|
|
fmpz_clear(pow);
|
|
}
|
|
else
|
|
{
|
|
fmpz_zero(u);
|
|
*v = 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
void _padic_poly_compose_pow(fmpz *rop, slong *rval, slong N,
|
|
const fmpz *op, slong val, slong len, slong k,
|
|
const padic_ctx_t ctx)
|
|
{
|
|
if (k == 1)
|
|
{
|
|
if (rop != op)
|
|
{
|
|
_fmpz_vec_set(rop, op, len);
|
|
*rval = val;
|
|
}
|
|
}
|
|
else if (len == 1)
|
|
{
|
|
fmpz_set(rop, op);
|
|
*rval = val;
|
|
|
|
__padic_reduce(rop, rval, N, ctx);
|
|
}
|
|
else
|
|
{
|
|
slong i, j, h;
|
|
|
|
for (i = len - 1, j = (len - 1) * k ; i >= 0; i--, j -= k)
|
|
{
|
|
fmpz_set(rop + j, op + i);
|
|
if (i)
|
|
for (h = 1; h < k; h++)
|
|
fmpz_zero(rop + (j - h));
|
|
}
|
|
*rval = val;
|
|
}
|
|
}
|
|
|
|
void padic_poly_compose_pow(padic_poly_t rop, const padic_poly_t op, slong k,
|
|
const padic_ctx_t ctx)
|
|
{
|
|
const slong len = op->length;
|
|
const slong lenr = (len - 1) * k + 1;
|
|
|
|
if (len == 0)
|
|
{
|
|
padic_poly_zero(rop);
|
|
}
|
|
else
|
|
{
|
|
padic_poly_fit_length(rop, lenr);
|
|
_padic_poly_compose_pow(rop->coeffs, &(rop->val), rop->N,
|
|
op->coeffs, op->val, op->length, k, ctx);
|
|
_padic_poly_set_length(rop, lenr);
|
|
}
|
|
}
|
|
|