mirror of
https://github.com/bolero-MURAKAMI/Sprout
synced 2024-11-12 21:09:01 +00:00
77 lines
2.8 KiB
C++
77 lines
2.8 KiB
C++
/*=============================================================================
|
|
Copyright (c) 2011-2018 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_HEAP_UNTIL_HPP
|
|
#define SPROUT_ALGORITHM_IS_HEAP_UNTIL_HPP
|
|
|
|
#include <iterator>
|
|
#include <sprout/config.hpp>
|
|
#include <sprout/iterator/operation.hpp>
|
|
#include HDR_FUNCTIONAL_SSCRISK_CEL_OR_SPROUT
|
|
|
|
namespace sprout {
|
|
namespace detail {
|
|
template<typename RandomAccessIterator, typename Compare>
|
|
inline SPROUT_CONSTEXPR typename std::iterator_traits<RandomAccessIterator>::difference_type
|
|
is_heap_until_impl(
|
|
RandomAccessIterator const& it, Compare comp,
|
|
typename std::iterator_traits<RandomAccessIterator>::difference_type first, typename std::iterator_traits<RandomAccessIterator>::difference_type last,
|
|
typename std::iterator_traits<RandomAccessIterator>::difference_type pivot, typename std::iterator_traits<RandomAccessIterator>::difference_type found
|
|
)
|
|
{
|
|
return found != first ? found
|
|
: pivot == 0 ? (!comp(it[first], it[(first - 1) / 2]) ? first : last)
|
|
: sprout::detail::is_heap_until_impl(
|
|
it, comp, first + pivot, last,
|
|
((last - first) - pivot) / 2,
|
|
sprout::detail::is_heap_until_impl(
|
|
it, comp, first, first + pivot,
|
|
pivot / 2,
|
|
first
|
|
)
|
|
)
|
|
;
|
|
}
|
|
|
|
template<typename RandomAccessIterator, typename Compare>
|
|
inline SPROUT_CONSTEXPR RandomAccessIterator
|
|
is_heap_until_impl(
|
|
RandomAccessIterator const& first, RandomAccessIterator const& last, Compare comp,
|
|
typename std::iterator_traits<RandomAccessIterator>::difference_type size
|
|
)
|
|
{
|
|
return size < 2 ? last
|
|
: sprout::next(first, sprout::detail::is_heap_until_impl(first, comp, 1, size, (size - 1) / 2, 1))
|
|
;
|
|
}
|
|
} // namespace detail
|
|
|
|
// 25.4.6.5 is_heap
|
|
//
|
|
// recursion depth:
|
|
// O(log N)
|
|
//
|
|
template<typename RandomAccessIterator, typename Compare>
|
|
inline SPROUT_CONSTEXPR RandomAccessIterator
|
|
is_heap_until(RandomAccessIterator first, RandomAccessIterator last, Compare comp) {
|
|
return sprout::detail::is_heap_until_impl(
|
|
first, last, comp,
|
|
sprout::distance(first, last)
|
|
);
|
|
}
|
|
|
|
template<typename RandomAccessIterator>
|
|
inline SPROUT_CONSTEXPR RandomAccessIterator
|
|
is_heap_until(RandomAccessIterator first, RandomAccessIterator last) {
|
|
return sprout::is_heap_until(
|
|
first, last,
|
|
NS_SSCRISK_CEL_OR_SPROUT::less<typename std::iterator_traits<RandomAccessIterator>::value_type>()
|
|
);
|
|
}
|
|
} // namespace sprout
|
|
|
|
#endif // #ifndef SPROUT_ALGORITHM_IS_HEAP_UNTIL_HPP
|