pqc/external/flint-2.4.3/nmod_mat/trace.c

48 lines
1.4 KiB
C

/*=============================================================================
This file is part of FLINT.
FLINT is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
FLINT is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with FLINT; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
=============================================================================*/
/******************************************************************************
Copyright (C) 2011 Fredrik Johansson
******************************************************************************/
#include <stdlib.h>
#include <gmp.h>
#include "flint.h"
#include "nmod_mat.h"
#include "nmod_vec.h"
mp_limb_t
nmod_mat_trace(const nmod_mat_t mat)
{
mp_limb_t t;
slong i, n = nmod_mat_nrows(mat);
if (n == 0)
return 0;
t = nmod_mat_entry(mat, 0, 0);
for (i = 1; i < n; i++)
t = nmod_add(t, nmod_mat_entry(mat, i, i), mat->mod);
return t;
}