-//$$CDS-header$$
+/*
+ This file is a part of libcds - Concurrent Data Structures library
-#ifndef __CDS_OPT_PERMUTATION_H
-#define __CDS_OPT_PERMUTATION_H
+ (C) Copyright Maxim Khizhinsky (libcds.dev@gmail.com) 2006-2017
+
+ Source code repo: http://github.com/khizmax/libcds/
+ Download: http://sourceforge.net/projects/libcds/files/
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+
+ * Redistributions of source code must retain the above copyright notice, this
+ list of conditions and the following disclaimer.
+
+ * Redistributions in binary form must reproduce the above copyright notice,
+ this list of conditions and the following disclaimer in the documentation
+ and/or other materials provided with the distribution.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#ifndef CDSLIB_OPT_PERMUTATION_H
+#define CDSLIB_OPT_PERMUTATION_H
+
+#include <cstdlib> // rand, srand
+#include <random>
+#include <algorithm> // std::shuffle
+#include <numeric> // std::iota
#include <cds/opt/options.h>
-#include <stdlib.h> // rand, srand
-#include <algorithm> // random_shuffle
namespace cds { namespace opt {
};
\endcode
- Usage example:
+ <b>Usage example</b>
+
The permutation generator is intended for <tt>do {} while</tt> loop:
\code
permutation_generator gen( 16 );
do {
int i = gen;
//...
- } while ( gen.next() );
+ } while ( gen.next());
// Get other permutation
gen.reset();
do {
int i = gen;
//...
- } while ( gen.next() );
+ } while ( gen.next());
\endcode
The following \p Generator defined:
- - opt::v::random_permutation
- - opt::v::random2_permutation
- - opt::v::random_shuffle_permutation
- - opt::v::skew_permutation
+ - \p opt::v::random_permutation
+ - \p opt::v::random2_permutation
+ - \p opt::v::random_shuffle_permutation
+ - \p opt::v::skew_permutation
*/
template <typename Generator>
struct permutation_generator {
/// Permutation generator of arbitrary length based on \p rand()
/**
- The class is suitable for opt::permutation_generator option.
+ The class is suitable for \p opt::permutation_generator option.
The generator calculates <tt>n = rand()</tt> and produces the sequence
<tt>[n % nLen, (n + 1) % nLen, ..., (n + nLen - 1) % nLen]</tt>.
random_permutation( size_t nLength )
: m_nCur(0)
, m_nStart(0)
- , m_nMod( integer_type(nLength) )
+ , m_nMod( integer_type(nLength))
{
reset();
}
/// Resets the generator to produce new sequence
void reset()
{
- m_nCur = m_nStart = integer_type( rand() ) % m_nMod;
+ m_nCur = m_nStart = integer_type( std::rand()) % m_nMod;
}
};
/// Permutation generator of power-of-2 length based on \p rand()
/**
- The class is suitable for opt::permutation_generator option.
+ The class is suitable for \p opt::permutation_generator option.
The generator calculates <tt>n = rand()</tt> and produces the sequence
<tt>[n % nLen, (n + 1) % nLen, ..., (n + nLen - 1) % nLen]</tt>.
/// Resets the generator to produce new sequence
void reset()
{
- m_nCur = m_nStart = integer_type( rand() ) & m_nMask;
+ m_nCur = m_nStart = integer_type( std::rand()) & m_nMask;
}
};
- /// Permutation generator based on \p std::random_shuffle
+ /// Permutation generator based on \p std::shuffle
/**
- The class is suitable for opt::permutation_generator option.
+ The class is suitable for \p opt::permutation_generator option.
- The generator produces a permutation of [0, nLen) sequence.
+ The generator produces a permutation of <tt>[0, nLen)</tt> sequence.
The generator instance allocates a memory block.
- \p Int template argument specifies the type of generated value, it should be any integer.
+ Template parameters:
+ - \p Int - specifies the type of generated value, it should be any integer.
+ - \p RandomGenerator - random generator, default is \p std::mt19937
+ - \p RandomDevice - random device, default is \p std::random_device
*/
- template <typename Int=int>
+ template <typename Int=int, class RandomGenerator = std::mt19937, class RandomDevice = std::random_device >
class random_shuffle_permutation
{
public:
- typedef Int integer_type; ///< Type of generated value
+ typedef Int integer_type; ///< Type of generated value
+ typedef RandomGenerator random_generator; ///< random generator
+ typedef RandomDevice random_device; ///< random device
protected:
//@cond
public:
/// Initializes the generator of arbitrary length \p nLength
random_shuffle_permutation( size_t nLength )
- : m_pCur( null_ptr<integer_type *>() )
+ : m_pCur( nullptr )
{
m_pFirst = new integer_type[nLength];
m_pLast = m_pFirst + nLength;
- for ( integer_type i = 0; i < static_cast<integer_type>(nLength); ++i )
- m_pFirst[i] = i;
+ std::iota(m_pFirst, m_pLast, integer_type{0} );
reset();
}
/// Resets the generator to produce new sequence
void reset()
{
- std::random_shuffle( m_pFirst, m_pLast );
+ std::shuffle( m_pFirst, m_pLast, random_generator{ random_device{}() });
m_pCur = m_pFirst;
}
};
<tt>int(Generator) + nOffset</tt>
where \p Generator - a permutation generator.
- The class is suitable for opt::permutation_generator option
+ The class is suitable for \p opt::permutation_generator option
if the goal sequence should be a permutation of <tt>[nOffset, nOffset + nLength)</tt>
*/
template <typename Generator>
}} // namespace cds::opt
-#endif // #ifndef __CDS_OPT_PERMUTATION_H
+#endif // #ifndef CDSLIB_OPT_PERMUTATION_H
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