mirror of
https://github.com/bolero-MURAKAMI/Sprout.git
synced 2025-07-04 14:14:09 +00:00
fix recursion depth: is_heap, is_heap_until
This commit is contained in:
parent
0201107eec
commit
86f68671a1
5 changed files with 232 additions and 21 deletions
|
@ -1,42 +1,70 @@
|
|||
#ifndef SPROUT_ALGORITHM_IS_HEAP_UNTIL_HPP
|
||||
#define SPROUT_ALGORITHM_IS_HEAP_UNTIL_HPP
|
||||
|
||||
#include <cstddef>
|
||||
#include <iterator>
|
||||
#include <sprout/config.hpp>
|
||||
#include <sprout/iterator/operation.hpp>
|
||||
#include HDR_ITERATOR_SSCRISK_CEL_OR_SPROUT
|
||||
#include HDR_FUNCTIONAL_SSCRISK_CEL_OR_SPROUT
|
||||
|
||||
namespace sprout {
|
||||
// Copyright (C) 2011 RiSK (sscrisk)
|
||||
|
||||
namespace detail {
|
||||
template<typename RandomAccessIterator, typename Compare>
|
||||
inline SPROUT_CONSTEXPR typename std::iterator_traits<RandomAccessIterator>::difference_type
|
||||
is_heap_until_impl(
|
||||
RandomAccessIterator it, Compare comp,
|
||||
typename std::iterator_traits<RandomAccessIterator>::difference_type first, typename std::iterator_traits<RandomAccessIterator>::difference_type last,
|
||||
typename std::iterator_traits<RandomAccessIterator>::difference_type pivot, typename std::iterator_traits<RandomAccessIterator>::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<typename RandomAccessIterator, typename Compare>
|
||||
inline SPROUT_CONSTEXPR RandomAccessIterator
|
||||
is_heap_until_impl(
|
||||
RandomAccessIterator first, RandomAccessIterator last, Compare comp,
|
||||
std::size_t n
|
||||
typename std::iterator_traits<RandomAccessIterator>::difference_type size
|
||||
)
|
||||
{
|
||||
return sprout::next(first, n) == last || !comp(first[n], first[(n - 1) / 2]) ? sprout::next(first, n)
|
||||
: sprout::detail::is_heap_until_impl(first, last, comp, n + 1)
|
||||
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
|
||||
template<typename RandomAccessIterator>
|
||||
inline SPROUT_CONSTEXPR RandomAccessIterator
|
||||
is_heap_until(RandomAccessIterator first, RandomAccessIterator last) {
|
||||
return sprout::is_heap_until(first, last, NS_SSCRISK_CEL_OR_SPROUT::less<decltype(*first)>());
|
||||
}
|
||||
|
||||
//
|
||||
// recursion depth:
|
||||
// O(log N)
|
||||
//
|
||||
template<typename RandomAccessIterator, typename Compare>
|
||||
inline SPROUT_CONSTEXPR RandomAccessIterator
|
||||
is_heap_until(RandomAccessIterator first, RandomAccessIterator last, Compare comp) {
|
||||
return NS_SSCRISK_CEL_OR_SPROUT::distance(first, last) < 2 ? last
|
||||
: sprout::detail::is_heap_until_impl(first, last, comp, 1)
|
||||
;
|
||||
return sprout::detail::is_heap_until_impl(
|
||||
first, last, comp,
|
||||
NS_SSCRISK_CEL_OR_SPROUT::distance(first, last)
|
||||
);
|
||||
}
|
||||
|
||||
template<typename RandomAccessIterator>
|
||||
inline SPROUT_CONSTEXPR RandomAccessIterator
|
||||
is_heap_until(RandomAccessIterator first, RandomAccessIterator last) {
|
||||
return sprout::is_heap_until(
|
||||
first, last,
|
||||
NS_SSCRISK_CEL_OR_SPROUT::less<typename std::iterator_traits<RandomAccessIterator>::value_type>()
|
||||
);
|
||||
}
|
||||
} // namespace sprout
|
||||
|
||||
|
|
Loading…
Add table
Add a link
Reference in a new issue