_fmpz_mod_poly_hgcd
#include <flint/fmpz_mod_poly.h>slong _fmpz_mod_poly_hgcd(fmpz ** M, slong * lenM, fmpz * A, slong * lenA, fmpz * B, slong * lenB, const fmpz * a, slong lena, const fmpz * b, slong lenb, const fmpz_mod_ctx_t ctx)sourceOne step of the half-GCD algorithm (_gr_poly_hgcd): for \mathit{lena} > \mathit{lenb} > 0, computes the 2 \times 2 matrix M (the entries M[0], ..., M[3] with lengths lenM[0], ..., lenM[3], each with space for lena coefficients) and the two consecutive remainders A, B of the Euclidean remainder sequence of (a, b) that straddle half the degree of a, such that (A, B)^T = \sigma M^{-1} (a, b)^T, and returns the sign \sigma = \pm 1. A and B need space for lena and lenb coefficients; their lengths are returned in *lenA, *lenB. See Half-GCD.
The FLINT team, “_fmpz_mod_poly_hgcd (fmpz_mod_poly.h),” FLINT: Fast Library for Number Theory, documentation, version 3.7.0-dev, 2026. https://flintlib.org/doc/fmpz_mod_poly/_fmpz_mod_poly_hgcd.html (generated 2026-10-20).
@misc{flint-doc-fmpz-mod-poly-fmpz-mod-poly-hgcd,
author = {{The FLINT team}},
title = {{\_fmpz\_mod\_poly\_hgcd (fmpz\_mod\_poly.h)}},
howpublished = {FLINT: Fast Library for Number Theory, documentation, version 3.7.0-dev},
year = {2026},
url = {https://flintlib.org/doc/fmpz_mod_poly/_fmpz_mod_poly_hgcd.html},
note = {Generated 2026-10-20}
}