Sprout/sprout/algorithm/fixed/random_swap.hpp
bolero-MURAKAMI 8cd36c14bd add bozo_sort
2012-07-25 23:10:01 +09:00

100 lines
3.2 KiB
C++

#ifndef SPROUT_ALGORITHM_FIXED_RANDOM_SWAP_HPP
#define SPROUT_ALGORITHM_FIXED_RANDOM_SWAP_HPP
#include <cstddef>
#include <sprout/config.hpp>
#include <sprout/array.hpp>
#include <sprout/container/traits.hpp>
#include <sprout/container/functions.hpp>
#include <sprout/iterator/operation.hpp>
#include <sprout/utility/forward.hpp>
#include <sprout/algorithm/fixed/result_of.hpp>
#include <sprout/algorithm/fixed/swap_element.hpp>
#include <sprout/random/uniform_int_distribution.hpp>
namespace sprout {
namespace fixed {
namespace detail {
template<typename Random>
inline SPROUT_CONSTEXPR sprout::array<std::ptrdiff_t, 2> make_random_swap_indexes_2(
Random const& rnd,
std::ptrdiff_t i0
)
{
return sprout::array<std::ptrdiff_t, 2>{{i0, rnd.result()}};
}
template<typename Random>
inline SPROUT_CONSTEXPR sprout::array<std::ptrdiff_t, 2> make_random_swap_indexes_1(
Random const& rnd
)
{
return sprout::fixed::detail::make_random_swap_indexes_2(
rnd(),
rnd.result()
);
}
template<typename UniformRandomNumberGenerator>
inline SPROUT_CONSTEXPR sprout::array<std::ptrdiff_t, 2> make_random_swap_indexes(
std::ptrdiff_t n,
UniformRandomNumberGenerator&& g
)
{
return n > 1
? sprout::fixed::detail::make_random_swap_indexes_1(
sprout::random::uniform_int_distribution<std::ptrdiff_t>(0, n - 1)(sprout::forward<UniformRandomNumberGenerator>(g))
)
: sprout::array<std::ptrdiff_t, 2>{{}}
;
}
template<typename Container, typename RandomSwapped>
inline SPROUT_CONSTEXPR typename sprout::fixed::result_of::algorithm<Container>::type random_swap_impl_1(
Container const& cont,
RandomSwapped const& random_swapped
)
{
return random_swapped[0] == random_swapped[1]
? sprout::deep_copy(cont)
: sprout::fixed::swap_element(
cont,
sprout::next(sprout::begin(cont), random_swapped[0]),
sprout::next(sprout::begin(cont), random_swapped[1])
)
;
}
template<typename Container, typename UniformRandomNumberGenerator>
inline SPROUT_CONSTEXPR typename sprout::fixed::result_of::algorithm<Container>::type random_swap_impl(
Container const& cont,
UniformRandomNumberGenerator&& g,
typename sprout::container_traits<Container>::size_type size
)
{
return sprout::fixed::detail::random_swap_impl_1(
cont,
sprout::fixed::detail::make_random_swap_indexes(
size,
sprout::forward<UniformRandomNumberGenerator>(g)
)
);
}
} // namespace detail
//
// random_swap
//
template<typename Container, typename UniformRandomNumberGenerator>
inline SPROUT_CONSTEXPR typename sprout::fixed::result_of::algorithm<Container>::type random_swap(
Container const& cont,
UniformRandomNumberGenerator&& g
)
{
return sprout::fixed::detail::random_swap_impl(
cont,
sprout::forward<UniformRandomNumberGenerator>(g),
sprout::size(cont)
);
}
} // namespace fixed
using sprout::fixed::random_swap;
} // namespace sprout
#endif // #ifndef SPROUT_ALGORITHM_FIXED_RANDOM_SWAP_HPP