Sprout/sprout/algorithm/is_permutation.hpp
2016-02-25 18:48:28 +09:00

236 lines
9.7 KiB
C++

/*=============================================================================
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_PERMUTATION_HPP
#define SPROUT_ALGORITHM_IS_PERMUTATION_HPP
#include <iterator>
#include <type_traits>
#include <sprout/config.hpp>
#include <sprout/iterator/operation.hpp>
#include <sprout/iterator/type_traits/common.hpp>
#include <sprout/utility/pair/pair.hpp>
#include <sprout/functional/equal_to.hpp>
#include <sprout/functional/bind2nd.hpp>
#include <sprout/algorithm/count_if.hpp>
#include <sprout/algorithm/find_if.hpp>
#include <sprout/algorithm/mismatch.hpp>
namespace sprout {
namespace detail {
template<typename Difference, typename ForwardIterator, typename BinaryPredicate>
inline SPROUT_CONSTEXPR bool
is_permutation_impl_check(Difference count, ForwardIterator first, ForwardIterator last, BinaryPredicate pred)
{
return count != 0 && sprout::count_if(sprout::next(first), last, sprout::bind2nd(pred, *first)) + 1 == count;
}
template<typename RandomAccessIterator1, typename RandomAccessIterator2, typename BinaryPredicate>
inline SPROUT_CONSTEXPR bool
is_permutation_impl_ra(
RandomAccessIterator1 first1, RandomAccessIterator1 last1,
RandomAccessIterator2 first2, RandomAccessIterator2 last2,
BinaryPredicate pred, RandomAccessIterator1 current,
typename std::iterator_traits<RandomAccessIterator1>::difference_type size
)
{
return size == 1 ? sprout::find_if(first1, current, sprout::bind2nd(pred, *current)) != current
|| sprout::detail::is_permutation_impl_check(
sprout::count_if(first2, last2, sprout::bind2nd(pred, *current)),
current, last1, pred
)
: sprout::detail::is_permutation_impl_ra(
first1, last1, first2, last2,
pred, current, size / 2
)
&& sprout::detail::is_permutation_impl_ra(
first1, last1, first2, last2,
pred, sprout::next(current, size / 2), size - size / 2
)
;
}
template<typename RandomAccessIterator1, typename RandomAccessIterator2, typename BinaryPredicate>
inline SPROUT_CONSTEXPR typename std::enable_if<
sprout::is_constant_distance_iterator<RandomAccessIterator1>::value && sprout::is_constant_distance_iterator<RandomAccessIterator2>::value,
bool
>::type
is_permutation(
sprout::pair<RandomAccessIterator1, RandomAccessIterator2> first, RandomAccessIterator1 last1, BinaryPredicate pred,
std::random_access_iterator_tag*
)
{
return first.first == last1
|| sprout::detail::is_permutation_impl_ra(
first.first, last1, first.second, sprout::next(first.second, sprout::distance(first.first, last1)),
pred, first.first, sprout::distance(first.first, last1)
)
;
}
template<typename ForwardIterator1, typename ForwardIterator2, typename BinaryPredicate>
inline SPROUT_CONSTEXPR sprout::pair<ForwardIterator1, bool>
is_permutation_impl_1(
sprout::pair<ForwardIterator1, bool> const& current,
ForwardIterator1 first1, ForwardIterator1 last1, ForwardIterator2 first2, ForwardIterator2 last2,
BinaryPredicate pred, typename std::iterator_traits<ForwardIterator1>::difference_type n
)
{
typedef sprout::pair<ForwardIterator1, bool> type;
return !current.second || current.first == last1 ? current
: n == 1 ? sprout::find_if(first1, current.first, sprout::bind2nd(pred, *current.first)) != current.first
|| sprout::detail::is_permutation_impl_check(
sprout::count_if(first2, last2, sprout::bind2nd(pred, *current.first)),
current.first, last1, pred
)
? type(sprout::next(current.first), true)
: type(current.first, false)
: sprout::detail::is_permutation_impl_1(
sprout::detail::is_permutation_impl_1(
current,
first1, last1, first2, last2, pred, n / 2
),
first1, last1, first2, last2, pred, n - n / 2
)
;
}
template<typename ForwardIterator1, typename ForwardIterator2, typename BinaryPredicate>
inline SPROUT_CONSTEXPR bool
is_permutation_impl(
ForwardIterator1 first1, ForwardIterator1 last1, ForwardIterator2 first2,
BinaryPredicate pred, typename std::iterator_traits<ForwardIterator1>::difference_type size
)
{
typedef sprout::pair<ForwardIterator1, bool> type;
return sprout::detail::is_permutation_impl_1(
type(first1, true),
first1, last1, first2, sprout::next(first2, size),
pred, size
).second
;
}
template<typename ForwardIterator1, typename ForwardIterator2, typename BinaryPredicate>
inline SPROUT_CONSTEXPR bool
is_permutation(
sprout::pair<ForwardIterator1, ForwardIterator2> first, ForwardIterator1 last1, BinaryPredicate pred,
std::forward_iterator_tag*
)
{
return first.first == last1
|| sprout::detail::is_permutation_impl(
first.first, last1, first.second, pred, sprout::distance(first.first, last1)
)
;
}
} // namespace detail
// 25.2.12 Is permutation
//
// recursion depth:
// O(log N)
//
template<typename ForwardIterator1, typename ForwardIterator2, typename BinaryPredicate>
inline SPROUT_CONSTEXPR bool
is_permutation(ForwardIterator1 first1, ForwardIterator1 last1, ForwardIterator2 first2, BinaryPredicate pred) {
typedef typename sprout::common_iterator_category<ForwardIterator1, ForwardIterator2>::type* category;
return sprout::detail::is_permutation(sprout::mismatch(first1, last1, first2, pred), last1, pred, category());
}
template<typename ForwardIterator1, typename ForwardIterator2>
inline SPROUT_CONSTEXPR bool
is_permutation(ForwardIterator1 first1, ForwardIterator1 last1, ForwardIterator2 first2) {
return sprout::is_permutation(first1, last1, first2, sprout::equal_to<>());
}
namespace detail {
template<typename RandomAccessIterator1, typename RandomAccessIterator2, typename BinaryPredicate>
inline SPROUT_CONSTEXPR bool
is_permutation_impl_ra_1(
sprout::pair<RandomAccessIterator1, RandomAccessIterator2> first,
RandomAccessIterator1 last1, RandomAccessIterator2 last2, BinaryPredicate pred
)
{
return first.first == last1
|| sprout::detail::is_permutation_impl_ra(
first.first, last1, first.second, last2,
pred, first.first, sprout::distance(first.first, last1)
)
;
}
template<typename RandomAccessIterator1, typename RandomAccessIterator2, typename BinaryPredicate>
inline SPROUT_CONSTEXPR typename std::enable_if<
sprout::is_constant_distance_iterator<RandomAccessIterator1>::value && sprout::is_constant_distance_iterator<RandomAccessIterator2>::value,
bool
>::type
is_permutation(
RandomAccessIterator1 first1, RandomAccessIterator1 last1, RandomAccessIterator2 first2, RandomAccessIterator2 last2, BinaryPredicate pred,
std::random_access_iterator_tag*
)
{
return sprout::distance(first1, last1) == sprout::distance(first2, last2)
&& sprout::detail::is_permutation_impl_ra_1(
sprout::mismatch(first1, last1, first2, last2, pred),
last1, last2, pred)
;
}
template<typename ForwardIterator1, typename ForwardIterator2, typename BinaryPredicate, typename Difference1, typename Difference2>
inline SPROUT_CONSTEXPR bool
is_permutation_impl_3(
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2, BinaryPredicate pred,
Difference1 size1, Difference2 size2
)
{
typedef sprout::pair<ForwardIterator1, bool> type;
return size1 == size2
&& sprout::detail::is_permutation_impl_1(
type(first1, true), first1, last1, first2, last2,
pred, size1
).second
;
}
template<typename ForwardIterator1, typename ForwardIterator2, typename BinaryPredicate>
inline SPROUT_CONSTEXPR bool
is_permutation_impl_2(
sprout::pair<ForwardIterator1, ForwardIterator2> first,
ForwardIterator1 last1, ForwardIterator2 last2, BinaryPredicate pred
)
{
return sprout::detail::is_permutation_impl_3(
first.first, last1, first.second, last2, pred,
sprout::distance(first.first, last1), sprout::distance(first.second, last2)
)
;
}
template<typename ForwardIterator1, typename ForwardIterator2, typename BinaryPredicate>
inline SPROUT_CONSTEXPR bool
is_permutation(
ForwardIterator1 first1, ForwardIterator1 last1, ForwardIterator2 first2, ForwardIterator2 last2, BinaryPredicate pred,
std::forward_iterator_tag*
)
{
return sprout::detail::is_permutation_impl_2(
sprout::mismatch(first1, last1, first2, last2, pred),
last1, last2, pred);
}
} // namespace detail
// 25.2.12 Is permutation
//
// recursion depth:
// O(log N)
//
template<typename ForwardIterator1, typename ForwardIterator2, typename BinaryPredicate>
inline SPROUT_CONSTEXPR bool
is_permutation(ForwardIterator1 first1, ForwardIterator1 last1, ForwardIterator2 first2, ForwardIterator2 last2, BinaryPredicate pred) {
typedef typename sprout::common_iterator_category<ForwardIterator1, ForwardIterator2>::type* category;
return sprout::detail::is_permutation(first1, last1, first2, last2, pred, category());
}
template<typename ForwardIterator1, typename ForwardIterator2>
inline SPROUT_CONSTEXPR bool
is_permutation(ForwardIterator1 first1, ForwardIterator1 last1, ForwardIterator2 first2, ForwardIterator2 last2) {
return sprout::is_permutation(first1, last1, first2, last2, sprout::equal_to<>());
}
} // namespace sprout
#endif // #ifndef SPROUT_ALGORITHM_IS_PERMUTATION_HPP