mirror of
https://github.com/bolero-MURAKAMI/Sprout.git
synced 2024-11-29 01:03:45 +00:00
86 lines
3.3 KiB
C++
86 lines
3.3 KiB
C++
/*=============================================================================
|
|
Copyright (c) 2011-2019 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_CXX14_INPLACE_MERGE_HPP
|
|
#define SPROUT_ALGORITHM_CXX14_INPLACE_MERGE_HPP
|
|
|
|
#include <iterator>
|
|
#include <sprout/config.hpp>
|
|
#include <sprout/iterator/distance.hpp>
|
|
#include <sprout/iterator/advance.hpp>
|
|
#include <sprout/algorithm/lower_bound.hpp>
|
|
#include <sprout/algorithm/upper_bound.hpp>
|
|
#include <sprout/algorithm/cxx14/iter_swap.hpp>
|
|
#include <sprout/algorithm/cxx14/rotate.hpp>
|
|
#include HDR_FUNCTIONAL_SSCRISK_CEL_OR_SPROUT
|
|
|
|
namespace sprout {
|
|
namespace detail {
|
|
template<typename BidirectionalIterator, typename Distance, typename Compare>
|
|
inline SPROUT_CXX14_CONSTEXPR void
|
|
inplace_merge(
|
|
BidirectionalIterator first, BidirectionalIterator middle, BidirectionalIterator last,
|
|
Distance len1, Distance len2, Compare comp
|
|
)
|
|
{
|
|
if (len1 == 0 || len2 == 0) {
|
|
return;
|
|
}
|
|
if (len1 + len2 == 2) {
|
|
if (comp(*middle, *first)) {
|
|
sprout::iter_swap(first, middle);
|
|
}
|
|
return;
|
|
}
|
|
BidirectionalIterator first_cut = first;
|
|
BidirectionalIterator second_cut = middle;
|
|
Distance len11 = 0;
|
|
Distance len22 = 0;
|
|
if (len1 > len2) {
|
|
len11 = len1 / 2;
|
|
sprout::advance(first_cut, len11);
|
|
second_cut = sprout::lower_bound(middle, last, *first_cut, comp);
|
|
len22 = sprout::distance(middle, second_cut);
|
|
} else {
|
|
len22 = len2 / 2;
|
|
sprout::advance(second_cut, len22);
|
|
first_cut = sprout::upper_bound(first, middle, *second_cut, comp);
|
|
len11 = sprout::distance(first, first_cut);
|
|
}
|
|
sprout::rotate(first_cut, middle, second_cut);
|
|
BidirectionalIterator new_middle = first_cut;
|
|
sprout::advance(new_middle, sprout::distance(middle, second_cut));
|
|
sprout::detail::inplace_merge(first, first_cut, new_middle, len11, len22, comp);
|
|
sprout::detail::inplace_merge(new_middle, second_cut, last, len1 - len11, len2 - len22, comp);
|
|
}
|
|
} // namespace detail
|
|
//
|
|
// 25.4.4 Merge
|
|
//
|
|
template<typename BidirectionalIterator, typename Compare>
|
|
inline SPROUT_CXX14_CONSTEXPR void
|
|
inplace_merge(BidirectionalIterator first, BidirectionalIterator middle, BidirectionalIterator last, Compare comp) {
|
|
typedef typename std::iterator_traits<BidirectionalIterator>::difference_type difference_type;
|
|
if (first == middle || middle == last) {
|
|
return;
|
|
}
|
|
difference_type const len1 = sprout::distance(first, middle);
|
|
difference_type const len2 = sprout::distance(middle, last);
|
|
sprout::detail::inplace_merge(first, middle, last, len1, len2, comp);
|
|
}
|
|
|
|
template<typename BidirectionalIterator>
|
|
inline SPROUT_CXX14_CONSTEXPR void
|
|
inplace_merge(BidirectionalIterator first, BidirectionalIterator middle, BidirectionalIterator last) {
|
|
sprout::inplace_merge(
|
|
first, middle, last,
|
|
NS_SSCRISK_CEL_OR_SPROUT::less<typename std::iterator_traits<BidirectionalIterator>::value_type>()
|
|
);
|
|
}
|
|
} // namespace sprout
|
|
|
|
#endif // #ifndef SPROUT_ALGORITHM_CXX14_INPLACE_MERGE_HPP
|