1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
/*
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 "perm.h"
#include "gr.h"
#include "gr_mat.h"
int
gr_mat_det_fflu(gr_ptr res, const gr_mat_t A, gr_ctx_t ctx)
{
slong * P;
gr_mat_t T;
slong n, rank;
int status;
n = gr_mat_nrows(A, ctx);
if (n != gr_mat_ncols(A, ctx))
return GR_DOMAIN;
if (n == 0)
return gr_one(res, ctx);
P = _perm_init(n);
gr_mat_init(T, n, n, ctx);
status = gr_mat_fflu(&rank, P, T, res, A, 1, ctx);
if (status == GR_SUCCESS)
{
if (rank == 0)
{
status |= gr_zero(res, ctx);
}
else
{
if (_perm_parity(P, n))
status |= gr_neg(res, res, ctx);
}
}
else
{
status |= GR_UNABLE;
}
gr_mat_clear(T, ctx);
_perm_clear(P);
return status;
}