Sprout/sprout/algorithm/find_difference.hpp
2014-01-08 16:48:12 +09:00

122 lines
4.8 KiB
C++

/*=============================================================================
Copyright (c) 2011-2014 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_FIND_DIFFERENCE_HPP
#define SPROUT_ALGORITHM_FIND_DIFFERENCE_HPP
#include <iterator>
#include <type_traits>
#include <sprout/config.hpp>
#include <sprout/iterator/operation.hpp>
#include <sprout/tuple/tuple/tuple.hpp>
#include <sprout/tuple/tuple/get.hpp>
#include <sprout/functional/less.hpp>
#include <sprout/utility/pair/pair.hpp>
namespace sprout {
namespace detail {
template<typename InputIterator1, typename InputIterator2>
inline SPROUT_CONSTEXPR sprout::pair<InputIterator1, InputIterator2>
find_difference_impl_check(
sprout::tuples::tuple<InputIterator1, InputIterator2, bool> const& current,
InputIterator1 last1, InputIterator2 last2
)
{
return sprout::tuples::get<2>(current)
? sprout::pair<InputIterator1, InputIterator2>(
sprout::tuples::get<0>(current),
sprout::tuples::get<1>(current)
)
: sprout::pair<InputIterator1, InputIterator2>(last1, last2)
;
}
template<typename InputIterator1, typename InputIterator2, typename Compare>
inline SPROUT_CONSTEXPR sprout::tuples::tuple<InputIterator1, InputIterator2, bool>
find_difference_impl_1(
sprout::tuples::tuple<InputIterator1, InputIterator2, bool> const& current,
InputIterator1 last1, InputIterator2 last2, Compare comp, typename std::iterator_traits<InputIterator1>::difference_type n
)
{
typedef sprout::tuples::tuple<InputIterator1, InputIterator2, bool> type;
return sprout::tuples::get<2>(current) || sprout::tuples::get<0>(current) == last1 ? current
: n == 1 ? sprout::tuples::get<1>(current) == last2
? type(sprout::tuples::get<0>(current), sprout::tuples::get<1>(current), true)
: comp(*sprout::tuples::get<0>(current), *sprout::tuples::get<1>(current))
? type(sprout::tuples::get<0>(current), sprout::tuples::get<1>(current), true)
: comp(*sprout::tuples::get<1>(current), *sprout::tuples::get<0>(current))
? type(sprout::tuples::get<0>(current), sprout::next(sprout::tuples::get<1>(current)), false)
: type(sprout::next(sprout::tuples::get<0>(current)), sprout::next(sprout::tuples::get<1>(current)), false)
: sprout::detail::find_difference_impl_1(
sprout::detail::find_difference_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, bool>
find_difference_impl(
sprout::tuples::tuple<InputIterator1, InputIterator2, bool> const& current,
InputIterator1 last1, InputIterator2 last2, Compare comp, typename std::iterator_traits<InputIterator1>::difference_type n
)
{
return sprout::tuples::get<2>(current) || sprout::tuples::get<0>(current) == last1 ? current
: sprout::detail::find_difference_impl(
sprout::detail::find_difference_impl_1(
current,
last1, last2, comp, n
),
last1, last2, comp, n * 2
)
;
}
template<typename InputIterator1, typename InputIterator2, typename Compare>
inline SPROUT_CONSTEXPR sprout::pair<InputIterator1, InputIterator2>
find_difference(
InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2, InputIterator2 last2,
Compare comp
)
{
typedef sprout::tuples::tuple<InputIterator1, InputIterator2, bool> type;
return sprout::detail::find_difference_impl_check(
sprout::detail::find_difference_impl(type(first1, first2, false), last1, last2, comp, 1),
last1, last2
);
}
} // namespace detail
//
// find_difference
//
// recursion depth:
// O(log N)
//
template<typename InputIterator1, typename InputIterator2, typename Compare>
inline SPROUT_CONSTEXPR sprout::pair<InputIterator1, InputIterator2>
find_difference(
InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2, InputIterator2 last2,
Compare comp
)
{
return sprout::detail::find_difference(first1, last1, first2, last2, comp);
}
template<typename InputIterator1, typename InputIterator2>
inline SPROUT_CONSTEXPR sprout::pair<InputIterator1, InputIterator2>
find_difference(
InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2, InputIterator2 last2
)
{
return sprout::find_difference(first1, last1, first2, last2, sprout::less<>());
}
} // namespace sprout
#endif // #ifndef SPROUT_ALGORITHM_FIND_DIFFERENCE_HPP