mirror of
https://github.com/vale981/arb
synced 2025-03-05 09:21:38 -05:00
54 lines
1.3 KiB
C
54 lines
1.3 KiB
C
/*
|
|
Copyright (C) 2008, 2009 William Hart
|
|
Copyright (C) 2010 Sebastian Pancratz
|
|
Copyright (C) 2013 Fredrik Johansson
|
|
|
|
This file is part of Arb.
|
|
|
|
Arb is free software: you can redistribute it and/or modify it under
|
|
the terms of the GNU Lesser General Public License (LGPL) as published
|
|
by the Free Software Foundation; either version 2.1 of the License, or
|
|
(at your option) any later version. See <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#include "arb_poly.h"
|
|
|
|
void
|
|
_arb_poly_shift_right(arb_ptr res, arb_srcptr poly, slong len, slong n)
|
|
{
|
|
slong i;
|
|
|
|
/* Copy in forward order to avoid writing over unshifted coefficients */
|
|
if (res != poly)
|
|
{
|
|
for (i = 0; i < len - n; i++)
|
|
arb_set(res + i, poly + n + i);
|
|
}
|
|
else
|
|
{
|
|
for (i = 0; i < len - n; i++)
|
|
arb_swap(res + i, res + n + i);
|
|
}
|
|
|
|
}
|
|
|
|
void
|
|
arb_poly_shift_right(arb_poly_t res, const arb_poly_t poly, slong n)
|
|
{
|
|
if (n == 0)
|
|
{
|
|
arb_poly_set(res, poly);
|
|
return;
|
|
}
|
|
|
|
if (poly->length <= n)
|
|
{
|
|
arb_poly_zero(res);
|
|
return;
|
|
}
|
|
|
|
arb_poly_fit_length(res, poly->length - n);
|
|
_arb_poly_shift_right(res->coeffs, poly->coeffs, poly->length, n);
|
|
_arb_poly_set_length(res, poly->length - n);
|
|
}
|
|
|