ceph/src/boost/boost/compute/algorithm/is_permutation.hpp

   1 //---------------------------------------------------------------------------//
   2 // Copyright (c) 2014 Roshan <thisisroshansmail@gmail.com>
   3 //
   4 // Distributed under the Boost Software License, Version 1.0
   5 // See accompanying file LICENSE_1_0.txt or copy at
   6 // http://www.boost.org/LICENSE_1_0.txt
   7 //
   8 // See http://boostorg.github.com/compute for more information.
   9 //---------------------------------------------------------------------------//
  10
  11 #ifndef BOOST_COMPUTE_ALGORITHM_IS_PERMUTATION_HPP
  12 #define BOOST_COMPUTE_ALGORITHM_IS_PERMUTATION_HPP
  13
  14 #include <iterator>
  15
  16 #include <boost/static_assert.hpp>
  17
  18 #include <boost/compute/system.hpp>
  19 #include <boost/compute/command_queue.hpp>
  20 #include <boost/compute/container/vector.hpp>
  21 #include <boost/compute/detail/iterator_range_size.hpp>
  22 #include <boost/compute/algorithm/equal.hpp>
  23 #include <boost/compute/algorithm/sort.hpp>
  24 #include <boost/compute/type_traits/is_device_iterator.hpp>
  25
  26 namespace boost {
  27 namespace compute {
  28
  29 ///
  30 /// \brief Permutation checking algorithm
  31 ///
  32 /// Checks if the range [first1, last1) can be permuted into the
  33 /// range [first2, last2)
  34 /// \return True, if it can be permuted. False, otherwise.
  35 ///
  36 /// \param first1 Iterator pointing to start of first range
  37 /// \param last1 Iterator pointing to end of first range
  38 /// \param first2 Iterator pointing to start of second range
  39 /// \param last2 Iterator pointing to end of second range
  40 /// \param queue Queue on which to execute
  41 ///
  42 /// Space complexity: \Omega(distance(\p first1, \p last1) + distance(\p first2, \p last2))
  43 template<class InputIterator1, class InputIterator2>
  44 inline bool is_permutation(InputIterator1 first1,
  45                            InputIterator1 last1,
  46                            InputIterator2 first2,
  47                            InputIterator2 last2,
  48                            command_queue &queue = system::default_queue())
  49 {
  50     BOOST_STATIC_ASSERT(is_device_iterator<InputIterator1>::value);
  51     BOOST_STATIC_ASSERT(is_device_iterator<InputIterator2>::value);
  52     typedef typename std::iterator_traits<InputIterator1>::value_type value_type1;
  53     typedef typename std::iterator_traits<InputIterator2>::value_type value_type2;
  54
  55     size_t count1 = detail::iterator_range_size(first1, last1);
  56     size_t count2 = detail::iterator_range_size(first2, last2);
  57
  58     if(count1 != count2) return false;
  59
  60     vector<value_type1> temp1(first1, last1, queue);
  61     vector<value_type2> temp2(first2, last2, queue);
  62
  63     sort(temp1.begin(), temp1.end(), queue);
  64     sort(temp2.begin(), temp2.end(), queue);
  65
  66     return equal(temp1.begin(), temp1.end(),
  67                  temp2.begin(), queue);
  68 }
  69
  70 } // end compute namespace
  71 } // end boost namespace
  72
  73 #endif // BOOST_COMPUTE_ALGORITHM_IS_PERMUTATION_HPP