51 lines
1.5 KiB
C
51 lines
1.5 KiB
C
/*=============================================================================
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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 Sebastian Pancratz
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Copyright (C) 2011 Fredrik Johansson
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******************************************************************************/
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#include "perm.h"
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#include "flint.h"
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#include "ulong_extras.h"
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int _perm_randtest(slong *vec, slong n, flint_rand_t state)
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{
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slong i, j, t;
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int parity = 0;
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for (i = 0; i < n; i++)
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vec[i] = i;
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for (i = n - 1; i > 0; i--)
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{
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j = n_randint(state, i + 1);
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parity ^= (i != j);
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t = vec[i];
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vec[i] = vec[j];
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vec[j] = t;
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}
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return parity;
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}
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