Sprout/sprout/detail/algorithm/set_overlap_count.hpp
2013-01-03 17:01:50 +09:00

95 lines
4.1 KiB
C++

#ifndef SPROUT_DETAIL_ALGORITHM_SET_OVERLAP_COUNT_HPP
#define SPROUT_DETAIL_ALGORITHM_SET_OVERLAP_COUNT_HPP
#include <iterator>
#include <sprout/config.hpp>
#include <sprout/iterator/operation.hpp>
#include <sprout/iterator/type_traits/is_iterator.hpp>
#include <sprout/iterator/type_traits/common.hpp>
#include <sprout/tuple/tuple.hpp>
#include <sprout/functional/less.hpp>
namespace sprout {
namespace detail {
template<typename InputIterator1, typename InputIterator2, typename Compare>
inline SPROUT_CONSTEXPR sprout::tuples::tuple<InputIterator1, InputIterator2, typename std::iterator_traits<InputIterator1>::difference_type>
set_overlap_count_impl_1(
sprout::tuples::tuple<InputIterator1, InputIterator2, typename std::iterator_traits<InputIterator1>::difference_type> const& current,
InputIterator1 last1, InputIterator2 last2, Compare comp, typename std::iterator_traits<InputIterator1>::difference_type n
)
{
typedef sprout::tuples::tuple<InputIterator1, InputIterator2, typename std::iterator_traits<InputIterator1>::difference_type> type;
return sprout::tuples::get<0>(current) == last1 || sprout::tuples::get<1>(current) == last2 ? current
: n == 1 ? comp(*sprout::tuples::get<0>(current), *sprout::tuples::get<1>(current)) ? type(
sprout::next(sprout::tuples::get<0>(current)), sprout::tuples::get<1>(current),
sprout::tuples::get<2>(current)
)
: comp(*sprout::tuples::get<1>(current), *sprout::tuples::get<0>(current)) ? type(
sprout::tuples::get<0>(current), sprout::next(sprout::tuples::get<1>(current)),
sprout::tuples::get<2>(current)
)
: type(
sprout::next(sprout::tuples::get<0>(current)), sprout::next(sprout::tuples::get<1>(current)),
sprout::tuples::get<2>(current) + 1
)
: sprout::detail::set_overlap_count_impl_1(
sprout::detail::set_overlap_count_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::tuples::tuple<InputIterator1, InputIterator2, typename std::iterator_traits<InputIterator1>::difference_type>
set_overlap_count_impl(
sprout::tuples::tuple<InputIterator1, InputIterator2, typename std::iterator_traits<InputIterator1>::difference_type> const& current,
InputIterator1 last1, InputIterator2 last2, Compare comp, typename std::iterator_traits<InputIterator1>::difference_type n
)
{
typedef sprout::tuples::tuple<InputIterator1, InputIterator2, typename std::iterator_traits<InputIterator1>::difference_type> type;
return sprout::tuples::get<0>(current) == last1 || sprout::tuples::get<1>(current) == last2 ? current
: sprout::detail::set_overlap_count_impl(
sprout::detail::set_overlap_count_impl_1(
current,
last1, last2, comp, n
),
last1, last2, comp, n * 2
)
;
}
//
// set_overlap_count
//
// recursion depth:
// O(log N)
//
template<typename InputIterator1, typename InputIterator2, typename Compare>
inline SPROUT_CONSTEXPR typename std::iterator_traits<InputIterator1>::difference_type
set_overlap_count(
InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2, InputIterator2 last2,
Compare comp
)
{
typedef sprout::tuples::tuple<InputIterator1, InputIterator2, typename std::iterator_traits<InputIterator1>::difference_type> type;
return sprout::tuples::get<2>(
sprout::detail::set_overlap_count_impl(type(first1, first2, 0), last1, last2, comp, 1)
);
}
template<typename InputIterator1, typename InputIterator2>
inline SPROUT_CONSTEXPR typename std::iterator_traits<InputIterator1>::difference_type
set_overlap_count(
InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2, InputIterator2 last2
)
{
return sprout::detail::set_overlap_count(first1, last1, first2, last2, sprout::less<>());
}
} // namespace detail
} // namespace sprout
#endif // #ifndef SPROUT_DETAIL_ALGORITHM_SET_OVERLAP_COUNT_HPP