/*============================================================================= Copyright (c) 2011-2016 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_IS_HEAP_UNTIL_HPP #define SPROUT_ALGORITHM_IS_HEAP_UNTIL_HPP #include #include #include #include HDR_FUNCTIONAL_SSCRISK_CEL_OR_SPROUT namespace sprout { namespace detail { template inline SPROUT_CONSTEXPR typename std::iterator_traits::difference_type is_heap_until_impl( RandomAccessIterator const& it, Compare comp, typename std::iterator_traits::difference_type first, typename std::iterator_traits::difference_type last, typename std::iterator_traits::difference_type pivot, typename std::iterator_traits::difference_type found ) { return found != first ? found : pivot == 0 ? (!comp(it[first], it[(first - 1) / 2]) ? first : last) : sprout::detail::is_heap_until_impl( it, comp, first + pivot, last, ((last - first) - pivot) / 2, sprout::detail::is_heap_until_impl( it, comp, first, first + pivot, pivot / 2, first ) ) ; } template inline SPROUT_CONSTEXPR RandomAccessIterator is_heap_until_impl( RandomAccessIterator const& first, RandomAccessIterator const& last, Compare comp, typename std::iterator_traits::difference_type size ) { return size < 2 ? last : sprout::next(first, sprout::detail::is_heap_until_impl(first, comp, 1, size, (size - 1) / 2, 1)) ; } } // namespace detail // 25.4.6.5 is_heap // // recursion depth: // O(log N) // template inline SPROUT_CONSTEXPR RandomAccessIterator is_heap_until(RandomAccessIterator first, RandomAccessIterator last, Compare comp) { return sprout::detail::is_heap_until_impl( first, last, comp, sprout::distance(first, last) ); } template inline SPROUT_CONSTEXPR RandomAccessIterator is_heap_until(RandomAccessIterator first, RandomAccessIterator last) { return sprout::is_heap_until( first, last, NS_SSCRISK_CEL_OR_SPROUT::less::value_type>() ); } } // namespace sprout #endif // #ifndef SPROUT_ALGORITHM_IS_HEAP_UNTIL_HPP