mirror of
https://github.com/bolero-MURAKAMI/Sprout.git
synced 2024-11-14 10:39:05 +00:00
73 lines
2.7 KiB
C++
73 lines
2.7 KiB
C++
#ifndef SPROUT_DETAIL_ALGORITHM_LEXICOGRAPHICAL_COMPARE_HPP
|
|
#define SPROUT_DETAIL_ALGORITHM_LEXICOGRAPHICAL_COMPARE_HPP
|
|
|
|
#include <sprout/config.hpp>
|
|
#include <sprout/utility/pair/pair.hpp>
|
|
#include <sprout/iterator/next.hpp>
|
|
|
|
namespace sprout {
|
|
namespace detail {
|
|
template<typename RandomAccessIterator1, typename RandomAccessIterator2, typename Compare>
|
|
inline SPROUT_CONSTEXPR int
|
|
lexicographical_compare_impl_ra(
|
|
RandomAccessIterator1 first1, RandomAccessIterator2 first2, Compare comp,
|
|
typename std::iterator_traits<RandomAccessIterator1>::difference_type size,
|
|
int found
|
|
)
|
|
{
|
|
return found != 2 ? found
|
|
: size == 1 ? comp(*first1, *first2) ? -1 : comp(*first2, *first1) ? 1 : 2
|
|
: sprout::detail::lexicographical_compare_impl_ra(
|
|
sprout::next(first1, size / 2), sprout::next(first2, size / 2), comp, size - size / 2,
|
|
sprout::detail::lexicographical_compare_impl_ra(
|
|
first1, first2, comp, size / 2,
|
|
2
|
|
)
|
|
)
|
|
;
|
|
}
|
|
|
|
template<typename InputIterator1, typename InputIterator2, typename Compare>
|
|
inline SPROUT_CONSTEXPR sprout::pair<InputIterator1, InputIterator2>
|
|
lexicographical_compare_impl_1(
|
|
sprout::pair<InputIterator1, InputIterator2> const& current,
|
|
InputIterator1 last1, InputIterator2 last2, Compare comp,
|
|
typename std::iterator_traits<InputIterator1>::difference_type n
|
|
)
|
|
{
|
|
typedef sprout::pair<InputIterator1, InputIterator2> type;
|
|
return current.second == last2 || current.first == last1 ? current
|
|
: n == 1 ? comp(*current.first, *current.second) ? type(last1, current.second)
|
|
: comp(*current.second, *current.first) ? type(current.first, last2)
|
|
: type(sprout::next(current.first), sprout::next(current.second))
|
|
: sprout::detail::lexicographical_compare_impl_1(
|
|
sprout::detail::lexicographical_compare_impl_1(
|
|
current,
|
|
last1, last2, comp, n / 2
|
|
),
|
|
last1, last2, comp, n - n / 2
|
|
)
|
|
;
|
|
}
|
|
template<typename InputIterator1, typename InputIterator2, typename Compare>
|
|
inline SPROUT_CONSTEXPR sprout::pair<InputIterator1, InputIterator2>
|
|
lexicographical_compare_impl(
|
|
sprout::pair<InputIterator1, InputIterator2> const& current,
|
|
InputIterator1 last1, InputIterator2 last2, Compare comp,
|
|
typename std::iterator_traits<InputIterator1>::difference_type n
|
|
)
|
|
{
|
|
return current.second == last2 || current.first == last1 ? current
|
|
: sprout::detail::lexicographical_compare_impl(
|
|
sprout::detail::lexicographical_compare_impl_1(
|
|
current,
|
|
last1, last2, comp, n
|
|
),
|
|
last1, last2, comp, n * 2
|
|
)
|
|
;
|
|
}
|
|
} // namespace detail
|
|
} // namespace sprout
|
|
|
|
#endif /* #ifndef SPROUT_DETAIL_ALGORITHM_LEXICOGRAPHICAL_COMPARE_HPP */
|