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
/*
Copyright (C) 2010 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 "fmpz.h"
#include "fmpz_mat.h"
int
fmpz_mat_solve_fflu(fmpz_mat_t X, fmpz_t den,
const fmpz_mat_t A, const fmpz_mat_t B)
{
fmpz_mat_t LU;
slong dim, *perm;
int result;
if (fmpz_mat_is_empty(A) || fmpz_mat_is_empty(B))
{
fmpz_one(den);
return 1;
}
dim = fmpz_mat_nrows(A);
perm = _perm_init(dim);
fmpz_mat_init_set(LU, A);
result = (fmpz_mat_fflu(LU, den, perm, LU, 1) == dim);
if (result)
{
fmpz_mat_solve_fflu_precomp(X, perm, LU, B);
if (_perm_parity(perm, dim))
{
fmpz_neg(den, den);
fmpz_mat_neg(X, X);
}
} else
fmpz_zero(den);
_perm_clear(perm);
fmpz_mat_clear(LU);
return result;
}