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fix recursion depth O(logN): some algorithms

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This commit is contained in:
bolero-MURAKAMI 2013-01-03 17:01:50 +09:00
parent 28697ee7a8
commit 5019f6aa96
162 changed files with 3600 additions and 1659 deletions
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58
sprout/algorithm/count.hpp
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@ -2,9 +2,11 @@
#define SPROUT_ALGORITHM_COUNT_HPP
#include <iterator>
#include <type_traits>
#include <sprout/config.hpp>
#include <sprout/iterator/operation.hpp>
#include HDR_ITERATOR_SSCRISK_CEL_OR_SPROUT
#include <sprout/iterator/type_traits/is_iterator.hpp>
#include <sprout/utility/pair.hpp>
namespace sprout {
namespace detail {
@ -22,28 +24,60 @@ namespace sprout {
)
+ sprout::detail::count_impl_ra(
sprout::next(first, pivot), last, value,
(NS_SSCRISK_CEL_OR_SPROUT::distance(first, last) - pivot) / 2
(sprout::distance(first, last) - pivot) / 2
)
;
}
template<typename RandomAccessIterator, typename T>
inline SPROUT_CONSTEXPR typename std::iterator_traits<RandomAccessIterator>::difference_type
inline SPROUT_CONSTEXPR typename std::enable_if<
sprout::is_constant_distance_iterator<RandomAccessIterator>::value,
typename std::iterator_traits<RandomAccessIterator>::difference_type
>::type
count(
RandomAccessIterator first, RandomAccessIterator last, T const& value,
std::random_access_iterator_tag*
)
{
return first == last ? 0
: sprout::detail::count_impl_ra(first, last, value, NS_SSCRISK_CEL_OR_SPROUT::distance(first, last) / 2)
: sprout::detail::count_impl_ra(first, last, value, sprout::distance(first, last) / 2)
;
}
// Copyright (C) 2011 RiSK (sscrisk)
template<typename InputIterator, typename T>
inline SPROUT_CONSTEXPR typename std::iterator_traits<InputIterator>::difference_type
count_impl(InputIterator first, InputIterator last, T const& value) {
return first == last ? 0
: (*first == value ? 1 : 0) + sprout::detail::count_impl(sprout::next(first), last, value)
inline SPROUT_CONSTEXPR sprout::pair<InputIterator, typename std::iterator_traits<InputIterator>::difference_type>
count_impl_1(
sprout::pair<InputIterator, typename std::iterator_traits<InputIterator>::difference_type> const& current,
InputIterator last, T const& value, typename std::iterator_traits<InputIterator>::difference_type n
)
{
typedef sprout::pair<InputIterator, typename std::iterator_traits<InputIterator>::difference_type> type;
return current.first == last ? current
: n == 1 ? type(sprout::next(current.first), current.second + (*current.first == value ? 1 : 0))
: sprout::detail::count_impl_1(
sprout::detail::count_impl_1(
current,
last, value, n / 2
),
last, value, n - n / 2
)
;
}
template<typename InputIterator, typename T>
inline SPROUT_CONSTEXPR sprout::pair<InputIterator, typename std::iterator_traits<InputIterator>::difference_type>
count_impl(
sprout::pair<InputIterator, typename std::iterator_traits<InputIterator>::difference_type> const& current,
InputIterator last, T const& value, typename std::iterator_traits<InputIterator>::difference_type n
)
{
typedef sprout::pair<InputIterator, typename std::iterator_traits<InputIterator>::difference_type> type;
return current.first == last ? current
: sprout::detail::count_impl(
sprout::detail::count_impl_1(
current,
last, value, n
),
last, value, n * 2
)
;
}
template<typename InputIterator, typename T>
@ -53,15 +87,15 @@ namespace sprout {
void*
)
{
return sprout::detail::count_impl(first, last, value);
typedef sprout::pair<InputIterator, typename std::iterator_traits<InputIterator>::difference_type> type;
return sprout::detail::count_impl(type(first, 0), last, value, 1).second;
}
} //namespace detail
// 25.2.9 Count
//
// recursion depth:
// [first, last) is RandomAccessIterator -> O(log N)
// otherwise -> O(N)
// O(log N)
//
template<typename InputIterator, typename T>
inline SPROUT_CONSTEXPR typename std::iterator_traits<InputIterator>::difference_type