mirror of https://github.com/CGAL/cgal
55 lines
1.6 KiB
C++
55 lines
1.6 KiB
C++
// Copyright (c) 2012 GeometryFactory (France). All rights reserved.
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// All rights reserved.
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//
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// This file is part of CGAL (www.cgal.org).
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// You can redistribute it and/or modify it under the terms of the GNU
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// General Public License as published by the Free Software Foundation,
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// either version 3 of the License, or (at your option) any later version.
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//
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// Licensees holding a valid commercial license may use this file in
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// accordance with the commercial license agreement provided with the software.
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//
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// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
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// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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//
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// $URL:
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// $Id:
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//
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//
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#ifndef CGAL_RANDOM_SHUFFLE_H
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#define CGAL_RANDOM_SHUFFLE_H
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// needed for iter_swap
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#include <algorithm>
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#include <CGAL/config.h>
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namespace CGAL {
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// a random_shuffle that does not vary across different stdlib
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// implementation and thus reliably reproduces the same result when
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// called with the same seed.
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// only the 3 argument version is provided.
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// this is implementation found in the gcc 4.6.2 release
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template<typename RandomAccessIterator, typename RandomNumberGenerator>
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void
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random_shuffle(RandomAccessIterator first, RandomAccessIterator last,
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#if !defined CGAL_CFG_NO_CPP0X_RVALUE_REFERENCE
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RandomNumberGenerator&& rand)
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#else
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RandomNumberGenerator& rand)
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#endif
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{
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if (first == last) return;
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for (RandomAccessIterator i = first + 1; i != last; ++i)
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std::iter_swap(i, first + rand((i - first) + 1));
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}
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} // CGAL
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#endif /* CGAL_RANDOM_SHUFFLE_H */
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