56 lines
1.7 KiB
C
56 lines
1.7 KiB
C
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/*=============================================================================
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This file is part of FLINT.
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FLINT is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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FLINT is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with FLINT; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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=============================================================================*/
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/******************************************************************************
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Copyright (C) 2011 Fredrik Johansson
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******************************************************************************/
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#include "fmpq_mat.h"
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int
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fmpq_mat_pivot(slong * perm, fmpq_mat_t mat, slong r, slong c)
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{
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slong t, j;
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fmpq * u;
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if (!fmpq_is_zero(fmpq_mat_entry(mat, r, c)))
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return 1;
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for (j = r + 1; j < mat->r; j++)
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{
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if (!fmpq_is_zero(fmpq_mat_entry(mat, j, c)))
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{
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if (perm)
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{
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t = perm[j];
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perm[j] = perm[r];
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perm[r] = t;
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}
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u = mat->rows[j];
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mat->rows[j] = mat->rows[r];
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mat->rows[r] = u;
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return -1;
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}
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}
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return 0;
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}
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