mirror of
https://github.com/bolero-MURAKAMI/Sprout
synced 2024-11-12 21:09:01 +00:00
108 lines
4.1 KiB
C++
108 lines
4.1 KiB
C++
/*=============================================================================
|
|
Copyright (c) 2011-2013 Bolero MURAKAMI
|
|
https://github.com/bolero-MURAKAMI/Sprout
|
|
|
|
Distributed under the Boost Software License, Version 1.0. (See accompanying
|
|
file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
|
|
=============================================================================*/
|
|
#ifndef SPROUT_ALGORITHM_IS_PARTITIONED_HPP
|
|
#define SPROUT_ALGORITHM_IS_PARTITIONED_HPP
|
|
|
|
#include <iterator>
|
|
#include <type_traits>
|
|
#include <sprout/config.hpp>
|
|
#include <sprout/iterator/operation.hpp>
|
|
#include <sprout/iterator/type_traits/category.hpp>
|
|
#include <sprout/utility/pair/pair.hpp>
|
|
#include <sprout/algorithm/none_of.hpp>
|
|
#include <sprout/algorithm/find_if_not.hpp>
|
|
|
|
namespace sprout {
|
|
namespace detail {
|
|
template<typename RandomAccessIterator, typename Predicate>
|
|
inline SPROUT_CONSTEXPR bool
|
|
is_partitioned_impl_ra(RandomAccessIterator first, RandomAccessIterator last, Predicate pred) {
|
|
return first == last ? true
|
|
: sprout::none_of(sprout::next(first), last, pred)
|
|
;
|
|
}
|
|
template<typename RandomAccessIterator, typename Predicate>
|
|
inline SPROUT_CONSTEXPR typename std::enable_if<
|
|
sprout::is_constant_distance_iterator<RandomAccessIterator>::value,
|
|
bool
|
|
>::type
|
|
is_partitioned(
|
|
RandomAccessIterator first, RandomAccessIterator last, Predicate pred,
|
|
std::random_access_iterator_tag*
|
|
)
|
|
{
|
|
return sprout::detail::is_partitioned_impl_ra(
|
|
sprout::find_if_not(first, last, pred),
|
|
last, pred
|
|
);
|
|
}
|
|
|
|
template<typename InputIterator, typename Predicate>
|
|
inline SPROUT_CONSTEXPR sprout::pair<InputIterator, typename std::iterator_traits<InputIterator>::difference_type>
|
|
is_partitioned_impl_1(
|
|
sprout::pair<InputIterator, typename std::iterator_traits<InputIterator>::difference_type> const& current,
|
|
InputIterator last, Predicate pred, typename std::iterator_traits<InputIterator>::difference_type n
|
|
)
|
|
{
|
|
typedef sprout::pair<InputIterator, typename std::iterator_traits<InputIterator>::difference_type> type;
|
|
return current.second > 1 || current.first == last ? current
|
|
: n == 1 ? current.second == 0
|
|
? pred(*current.first) ? type(sprout::next(current.first), 0) : type(sprout::next(current.first), 1)
|
|
: !pred(*current.first) ? type(sprout::next(current.first), 1) : type(current.first, 2)
|
|
: sprout::detail::is_partitioned_impl_1(
|
|
sprout::detail::is_partitioned_impl_1(
|
|
current,
|
|
last, pred, n / 2
|
|
),
|
|
last, pred, n - n / 2
|
|
)
|
|
;
|
|
}
|
|
template<typename InputIterator, typename Predicate>
|
|
inline SPROUT_CONSTEXPR sprout::pair<InputIterator, typename std::iterator_traits<InputIterator>::difference_type>
|
|
is_partitioned_impl(
|
|
sprout::pair<InputIterator, typename std::iterator_traits<InputIterator>::difference_type> const& current,
|
|
InputIterator last, Predicate pred, typename std::iterator_traits<InputIterator>::difference_type n
|
|
)
|
|
{
|
|
return current.second > 1 || current.first == last ? current
|
|
: sprout::detail::is_partitioned_impl(
|
|
sprout::detail::is_partitioned_impl_1(
|
|
current,
|
|
last, pred, n
|
|
),
|
|
last, pred, n * 2
|
|
)
|
|
;
|
|
}
|
|
template<typename InputIterator, typename Predicate>
|
|
inline SPROUT_CONSTEXPR bool
|
|
is_partitioned(
|
|
InputIterator first, InputIterator last, Predicate pred,
|
|
std::input_iterator_tag*
|
|
)
|
|
{
|
|
typedef sprout::pair<InputIterator, typename std::iterator_traits<InputIterator>::difference_type> type;
|
|
return sprout::detail::is_partitioned_impl(type(first, 0), last, pred, 1).second <= 1;
|
|
}
|
|
} // namespace detail
|
|
|
|
// 25.3.13 Partitions
|
|
//
|
|
// recursion depth:
|
|
// O(log N)
|
|
//
|
|
template<typename InputIterator, typename Predicate>
|
|
inline SPROUT_CONSTEXPR bool
|
|
is_partitioned(InputIterator first, InputIterator last, Predicate pred) {
|
|
typedef typename std::iterator_traits<InputIterator>::iterator_category* category;
|
|
return sprout::detail::is_partitioned(first, last, pred, category());
|
|
}
|
|
} // namespace sprout
|
|
|
|
#endif // #ifndef SPROUT_ALGORITHM_IS_PARTITIONED_HPP
|