67 lines
2.3 KiB
C
67 lines
2.3 KiB
C
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// Copyright (c) 1997
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// Utrecht University (The Netherlands),
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// ETH Zurich (Switzerland),
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// INRIA Sophia-Antipolis (France),
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// Max-Planck-Institute Saarbruecken (Germany),
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// and Tel-Aviv University (Israel). All rights reserved.
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//
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// This file is part of CGAL (www.cgal.org); you can redistribute it and/or
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// modify it under the terms of the GNU Lesser General Public License as
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// published by the Free Software Foundation; either version 3 of the License,
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// 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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// SPDX-License-Identifier: LGPL-3.0+
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//
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//
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// Author(s) : Lutz Kettner <kettner@inf.ethz.ch>
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#ifndef CGAL_RANDOM_SELECTION_H
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#define CGAL_RANDOM_SELECTION_H 1
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#include <cstddef>
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#include <iterator>
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#include <CGAL/Random.h>
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namespace CGAL {
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template <class RandomAccessIterator, class Size, class OutputIterator,
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class Random>
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OutputIterator random_selection( RandomAccessIterator first,
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RandomAccessIterator last,
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Size n,
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OutputIterator result,
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Random& rnd)
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// choose a random item from the range [`first',`last') and write it
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// to `result', each item from the range with equal probability.
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// Repeat this n times, thus writing n items to `result'. A single
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// random number is needed from `rnd' for each item. Returns the
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// value of `result' after inserting the n items.
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{
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std::ptrdiff_t m = last - first;
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for ( Size i = 0; i < n; i++) {
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*result++ = first[ rnd(m)];
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}
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return result;
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}
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template <class RandomAccessIterator, class Size, class OutputIterator>
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OutputIterator random_selection( RandomAccessIterator first,
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RandomAccessIterator last,
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Size n,
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OutputIterator result)
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{
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return random_selection( first, last, n, result, get_default_random());
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}
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} //namespace CGAL
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#endif // CGAL_RANDOM_SELECTION_H //
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