mirror of
https://github.com/bolero-MURAKAMI/Sprout
synced 2024-11-12 21:09:01 +00:00
120 lines
4.8 KiB
C++
120 lines
4.8 KiB
C++
/*=============================================================================
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Copyright (c) 2011-2016 Bolero MURAKAMI
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https://github.com/bolero-MURAKAMI/Sprout
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Distributed under the Boost Software License, Version 1.0. (See accompanying
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file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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=============================================================================*/
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#ifndef SPROUT_ALGORITHM_FIND_INTERSECTION_HPP
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#define SPROUT_ALGORITHM_FIND_INTERSECTION_HPP
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#include <iterator>
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#include <type_traits>
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#include <sprout/config.hpp>
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#include <sprout/iterator/operation.hpp>
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#include <sprout/tuple/tuple/tuple.hpp>
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#include <sprout/tuple/tuple/get.hpp>
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#include <sprout/functional/less.hpp>
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#include <sprout/utility/pair/pair.hpp>
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namespace sprout {
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namespace detail {
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template<typename InputIterator1, typename InputIterator2>
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inline SPROUT_CONSTEXPR sprout::pair<InputIterator1, InputIterator2>
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find_intersection_impl_check(
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sprout::tuples::tuple<InputIterator1, InputIterator2, bool> const& current,
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InputIterator1 last1, InputIterator2 last2
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)
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{
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return sprout::tuples::get<2>(current)
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? sprout::pair<InputIterator1, InputIterator2>(
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sprout::tuples::get<0>(current),
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sprout::tuples::get<1>(current)
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)
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: sprout::pair<InputIterator1, InputIterator2>(last1, last2)
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;
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}
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template<typename InputIterator1, typename InputIterator2, typename Compare>
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inline SPROUT_CONSTEXPR sprout::tuples::tuple<InputIterator1, InputIterator2, bool>
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find_intersection_impl_1(
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sprout::tuples::tuple<InputIterator1, InputIterator2, bool> const& current,
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InputIterator1 last1, InputIterator2 last2, Compare comp, typename std::iterator_traits<InputIterator1>::difference_type n
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)
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{
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typedef sprout::tuples::tuple<InputIterator1, InputIterator2, bool> type;
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return sprout::tuples::get<2>(current) || sprout::tuples::get<0>(current) == last1 || sprout::tuples::get<1>(current) == last2 ? current
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: n == 1 ? comp(*sprout::tuples::get<0>(current), *sprout::tuples::get<1>(current))
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? type(sprout::next(sprout::tuples::get<0>(current)), sprout::tuples::get<1>(current), false)
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: comp(*sprout::tuples::get<1>(current), *sprout::tuples::get<0>(current))
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? type(sprout::tuples::get<0>(current), sprout::next(sprout::tuples::get<1>(current)), false)
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: type(sprout::tuples::get<0>(current), sprout::tuples::get<1>(current), true)
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: sprout::detail::find_intersection_impl_1(
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sprout::detail::find_intersection_impl_1(
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current,
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last1, last2, comp, n / 2
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),
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last1, last2, comp, n - n / 2
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)
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;
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}
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template<typename InputIterator1, typename InputIterator2, typename Compare>
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inline SPROUT_CONSTEXPR sprout::tuples::tuple<InputIterator1, InputIterator2, bool>
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find_intersection_impl(
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sprout::tuples::tuple<InputIterator1, InputIterator2, bool> const& current,
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InputIterator1 last1, InputIterator2 last2, Compare comp, typename std::iterator_traits<InputIterator1>::difference_type n
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)
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{
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return sprout::tuples::get<2>(current) || sprout::tuples::get<0>(current) == last1 || sprout::tuples::get<1>(current) == last2 ? current
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: sprout::detail::find_intersection_impl(
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sprout::detail::find_intersection_impl_1(
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current,
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last1, last2, comp, n
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),
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last1, last2, comp, n * 2
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)
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;
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}
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template<typename InputIterator1, typename InputIterator2, typename Compare>
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inline SPROUT_CONSTEXPR sprout::pair<InputIterator1, InputIterator2>
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find_intersection(
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InputIterator1 first1, InputIterator1 last1,
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InputIterator2 first2, InputIterator2 last2,
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Compare comp
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)
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{
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typedef sprout::tuples::tuple<InputIterator1, InputIterator2, bool> type;
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return sprout::detail::find_intersection_impl_check(
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sprout::detail::find_intersection_impl(type(first1, first2, false), last1, last2, comp, 1),
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last1, last2
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);
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}
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} // namespace detail
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//
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// find_intersection
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//
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// recursion depth:
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// O(log N)
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//
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template<typename InputIterator1, typename InputIterator2, typename Compare>
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inline SPROUT_CONSTEXPR sprout::pair<InputIterator1, InputIterator2>
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find_intersection(
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InputIterator1 first1, InputIterator1 last1,
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InputIterator2 first2, InputIterator2 last2,
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Compare comp
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)
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{
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return sprout::detail::find_intersection(first1, last1, first2, last2, comp);
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}
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template<typename InputIterator1, typename InputIterator2>
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inline SPROUT_CONSTEXPR sprout::pair<InputIterator1, InputIterator2>
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find_intersection(
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InputIterator1 first1, InputIterator1 last1,
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InputIterator2 first2, InputIterator2 last2
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)
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{
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return sprout::find_intersection(first1, last1, first2, last2, sprout::less<>());
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}
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} // namespace sprout
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#endif // #ifndef SPROUT_ALGORITHM_FIND_INTERSECTION_HPP
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