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/*
Copyright (C) 2022 Fredrik Johansson
This file is part of FLINT.
FLINT 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 3 of the License, or
(at your option) any later version. See <https://www.gnu.org/licenses/>.
*/
#include "gr_poly.h"
/* FIXME: this may inappropriately return GR_DOMAIN for nonconstant
polynomials non-integral domains. See AbstractAlgebra. */
int
gr_poly_inv(gr_poly_t res,
const gr_poly_t poly, gr_ctx_t ctx)
{
if (poly->length == 0)
{
if (gr_ctx_is_zero_ring(ctx) == T_TRUE)
return gr_poly_zero(res, ctx);
else
return GR_DOMAIN;
}
else if (poly->length == 1)
{
int status;
gr_poly_fit_length(res, 1, ctx);
status = gr_inv(res->coeffs, poly->coeffs, ctx);
_gr_poly_set_length(res, 1, ctx);
_gr_poly_normalise(res, ctx);
return status;
}
else
{
return GR_DOMAIN;
}
}