#include "gr_vec.h"
#include "gr_poly.h"
int
_gr_poly_sub(gr_ptr res, gr_srcptr poly1, slong len1,
gr_srcptr poly2, slong len2, gr_ctx_t ctx)
{
slong sz;
int status;
slong min = FLINT_MIN(len1, len2);
status = _gr_vec_sub(res, poly1, poly2, min, ctx);
if (len1 > min)
{
sz = ctx->sizeof_elem;
status |= _gr_vec_set(GR_ENTRY(res, min, sz), GR_ENTRY(poly1, min, sz), len1 - min, ctx);
}
if (len2 > min)
{
sz = ctx->sizeof_elem;
status |= _gr_vec_neg(GR_ENTRY(res, min, sz), GR_ENTRY(poly2, min, sz), len2 - min, ctx);
}
return status;
}
int
gr_poly_sub(gr_poly_t res, const gr_poly_t poly1, const gr_poly_t poly2, gr_ctx_t ctx)
{
int status;
slong max = FLINT_MAX(poly1->length, poly2->length);
FLINT_ASSERT(poly1->length == 0 || gr_is_zero(gr_poly_coeff_srcptr(poly1, poly1->length - 1, ctx), ctx) != T_TRUE);
FLINT_ASSERT(poly2->length == 0 || gr_is_zero(gr_poly_coeff_srcptr(poly2, poly2->length - 1, ctx), ctx) != T_TRUE);
gr_poly_fit_length(res, max, ctx);
status = _gr_poly_sub(res->coeffs, poly1->coeffs, poly1->length, poly2->coeffs, poly2->length, ctx);
_gr_poly_set_length(res, max, ctx);
_gr_poly_normalise(res, ctx);
return status;
}