#include "arb_poly.h"
#include "gr_poly.h"
void
_arb_poly_compose(arb_ptr res,
arb_srcptr poly1, slong len1,
arb_srcptr poly2, slong len2, slong prec)
{
gr_ctx_t ctx;
gr_ctx_init_real_arb(ctx, prec);
if (_gr_poly_compose(res, poly1, len1, poly2, len2, ctx) != GR_SUCCESS)
_arb_vec_indeterminate(res, (len1 - 1) * (len2 - 1) + 1);
}
void arb_poly_compose(arb_poly_t res,
const arb_poly_t poly1, const arb_poly_t poly2, slong prec)
{
const slong len1 = poly1->length;
const slong len2 = poly2->length;
if (len1 == 0)
{
arb_poly_zero(res);
}
else if (len1 == 1 || len2 == 0)
{
arb_poly_set_arb(res, poly1->coeffs);
}
else
{
const slong lenr = (len1 - 1) * (len2 - 1) + 1;
if (res != poly1 && res != poly2)
{
arb_poly_fit_length(res, lenr);
_arb_poly_compose(res->coeffs, poly1->coeffs, len1,
poly2->coeffs, len2, prec);
}
else
{
arb_poly_t t;
arb_poly_init2(t, lenr);
_arb_poly_compose(t->coeffs, poly1->coeffs, len1,
poly2->coeffs, len2, prec);
arb_poly_swap(res, t);
arb_poly_clear(t);
}
_arb_poly_set_length(res, lenr);
_arb_poly_normalise(res);
}
}