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

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/*=============================================================================
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_DETAIL_ALGORITHM_SEARCH_ONE_REV_HPP
#define SPROUT_DETAIL_ALGORITHM_SEARCH_ONE_REV_HPP
#include <iterator>
#include <sprout/config.hpp>
#include <sprout/iterator/operation.hpp>
#include <sprout/functional/equal_to.hpp>
#include <sprout/tuple/tuple/tuple.hpp>
#include <sprout/tuple/tuple/get.hpp>
#include <sprout/utility/pair/pair.hpp>
namespace sprout {
namespace detail {
template<typename BidirectionalIterator1, typename BidirectionalIterator2, typename BinaryPredicate>
inline SPROUT_CONSTEXPR sprout::tuples::tuple<BidirectionalIterator1, BidirectionalIterator2, bool>
search_one_rev_impl_1(
sprout::tuples::tuple<BidirectionalIterator1, BidirectionalIterator2, bool> const& current,
BidirectionalIterator1 first1, BidirectionalIterator2 first2, BinaryPredicate pred,
typename std::iterator_traits<BidirectionalIterator1>::difference_type n
)
{
typedef sprout::tuples::tuple<BidirectionalIterator1, BidirectionalIterator2, bool> type;
return sprout::tuples::get<2>(current) ? current
: sprout::tuples::get<1>(current) == first2 ? type(sprout::tuples::get<0>(current), first2, true)
: sprout::tuples::get<0>(current) == first1 ? type(first1, sprout::tuples::get<1>(current), true)
: n == 1 ? pred(*sprout::prev(sprout::tuples::get<0>(current)), *sprout::prev(sprout::tuples::get<1>(current)))
? type(sprout::prev(sprout::tuples::get<0>(current)), sprout::prev(sprout::tuples::get<1>(current)), false)
: type(sprout::tuples::get<0>(current), sprout::tuples::get<1>(current), true)
: sprout::detail::search_one_rev_impl_1(
sprout::detail::search_one_rev_impl_1(
current,
first1, first2, pred, n / 2
),
first1, first2, pred, n - n / 2
)
;
}
template<typename BidirectionalIterator1, typename BidirectionalIterator2, typename BinaryPredicate>
inline SPROUT_CONSTEXPR sprout::tuples::tuple<BidirectionalIterator1, BidirectionalIterator2, bool>
search_one_rev_impl(
sprout::tuples::tuple<BidirectionalIterator1, BidirectionalIterator2, bool> const& current,
BidirectionalIterator1 first1, BidirectionalIterator2 first2, BinaryPredicate pred,
typename std::iterator_traits<BidirectionalIterator1>::difference_type n
)
{
typedef sprout::tuples::tuple<BidirectionalIterator1, BidirectionalIterator2, bool> type;
return sprout::tuples::get<2>(current) ? current
: sprout::tuples::get<1>(current) == first2 ? type(sprout::tuples::get<0>(current), first2, true)
: sprout::tuples::get<0>(current) == first1 ? type(first1, sprout::tuples::get<1>(current), true)
: sprout::detail::search_one_rev_impl(
sprout::detail::search_one_rev_impl_1(
current,
first1, first2, pred, n
),
first1, first2, pred, n * 2
)
;
}
template<typename BidirectionalIterator1, typename BidirectionalIterator2>
inline SPROUT_CONSTEXPR sprout::pair<BidirectionalIterator1, bool>
search_one_rev_check(
sprout::tuples::tuple<BidirectionalIterator1, BidirectionalIterator2, bool> const& result,
BidirectionalIterator1 first1, BidirectionalIterator1 last1, BidirectionalIterator2 first2
)
{
typedef sprout::pair<BidirectionalIterator1, bool> type;
return sprout::tuples::get<1>(result) == first2 ? type(sprout::tuples::get<0>(result), false)
: type(last1, sprout::tuples::get<0>(result) == first1)
;
}
//
// search_one_rev
//
// recursion depth:
// O(log(N1+N2))
//
template<typename BidirectionalIterator1, typename BidirectionalIterator2, typename BinaryPredicate>
inline SPROUT_CONSTEXPR sprout::pair<BidirectionalIterator1, bool>
search_one_rev(
BidirectionalIterator1 first1, BidirectionalIterator1 last1,
BidirectionalIterator2 first2, BidirectionalIterator2 last2, BinaryPredicate pred
)
{
typedef sprout::tuples::tuple<BidirectionalIterator1, BidirectionalIterator2, bool> type;
return sprout::detail::search_one_rev_check(
sprout::detail::search_one_rev_impl(type(last1, last2, false), first1, first2, pred, 1),
first1, last1, first2);
}
template<typename BidirectionalIterator1, typename BidirectionalIterator2>
inline SPROUT_CONSTEXPR sprout::pair<BidirectionalIterator1, bool>
search_one_rev(
BidirectionalIterator1 first1, BidirectionalIterator1 last1,
BidirectionalIterator2 first2, BidirectionalIterator2 last2
)
{
return sprout::detail::search_one_rev(first1, last1, first2, last2, sprout::equal_to<>());
}
} // namespace detail
} // namespace sprout
#endif // #ifndef SPROUT_DETAIL_ALGORITHM_SEARCH_ONE_REV_HPP