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/*
Copyright (C) 2011 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 "nmod_poly.h"
#include "nmod_poly_mat.h"
#include "perm.h"
int
nmod_poly_mat_solve_fflu(nmod_poly_mat_t X, nmod_poly_t den,
const nmod_poly_mat_t A, const nmod_poly_mat_t B)
{
nmod_poly_mat_t LU;
slong dim, *perm;
int result;
if (nmod_poly_mat_is_empty(B))
{
nmod_poly_one(den);
return 1;
}
dim = nmod_poly_mat_nrows(A);
perm = _perm_init(dim);
nmod_poly_mat_init_set(LU, A);
result = (nmod_poly_mat_fflu(LU, den, perm, LU, 1) == dim);
if (result)
{
nmod_poly_mat_solve_fflu_precomp(X, perm, LU, B);
if (_perm_parity(perm, dim))
{
nmod_poly_neg(den, den);
nmod_poly_mat_neg(X, X);
}
} else
nmod_poly_zero(den);
_perm_clear(perm);
nmod_poly_mat_clear(LU);
return result;
}