Sprout/sprout/algorithm/fixed/prev_permutation.hpp
2013-08-12 00:09:40 +09:00

120 lines
4.9 KiB
C++

/*=============================================================================
Copyright (c) 2011-2013 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_FIXED_PREV_PERMUTATION_HPP
#define SPROUT_ALGORITHM_FIXED_PREV_PERMUTATION_HPP
#include <sprout/config.hpp>
#include <sprout/container/traits.hpp>
#include <sprout/container/functions.hpp>
#include <sprout/iterator/operation.hpp>
#include <sprout/algorithm/fixed/result_of.hpp>
#include <sprout/algorithm/fixed/swap_element.hpp>
#include <sprout/algorithm/fixed/reverse_copy.hpp>
#include <sprout/algorithm/fixed/reverse.hpp>
#include <sprout/sub_array/sub_array.hpp>
#include <sprout/utility/pair/pair.hpp>
#include HDR_FUNCTIONAL_SSCRISK_CEL_OR_SPROUT
namespace sprout {
namespace fixed {
namespace detail {
template<typename Result, typename Container, typename Difference>
inline SPROUT_CONSTEXPR Result
prev_permutation_impl_4(Container const& cont, Difference d) {
return Result(
sprout::get_internal(sprout::fixed::reverse(sprout::sub_array<Container const&>(cont, d, sprout::size(cont)))),
true
);
}
template<typename Result, typename Container, typename Compare, typename BidirectionalIterator>
inline SPROUT_CONSTEXPR Result
prev_permutation_impl_3(
Container const& cont, Compare comp,
BidirectionalIterator first, BidirectionalIterator last,
BidirectionalIterator i, BidirectionalIterator ii, BidirectionalIterator j
)
{
return !comp(*sprout::prev(j), *i) ? sprout::fixed::detail::prev_permutation_impl_3<Result>(
cont, comp, first, last,
i, ii, sprout::prev(j)
)
: sprout::fixed::detail::prev_permutation_impl_4<Result>(
sprout::fixed::swap_element(cont, i, sprout::prev(j)),
sprout::distance(first, ii)
)
;
}
template<typename Result, typename Container, typename Compare, typename BidirectionalIterator>
inline SPROUT_CONSTEXPR Result
prev_permutation_impl_2(
Container const& cont, Compare comp,
BidirectionalIterator first, BidirectionalIterator last,
BidirectionalIterator i, BidirectionalIterator ii
)
{
return comp(*ii, *i) ? sprout::fixed::detail::prev_permutation_impl_3<Result>(
cont, comp, first, last,
i, ii, last
)
: i == first ? Result(sprout::fixed::reverse_copy(first, last, cont), false)
: sprout::fixed::detail::prev_permutation_impl_2<Result>(
cont, comp, first, last,
sprout::prev(i), i
)
;
}
template<typename Result, typename Container, typename Compare, typename BidirectionalIterator>
inline SPROUT_CONSTEXPR Result
prev_permutation_impl_1(Container const& cont, Compare comp, BidirectionalIterator first, BidirectionalIterator last, BidirectionalIterator i) {
return i == last ? Result(sprout::deep_copy(cont), false)
: sprout::fixed::detail::prev_permutation_impl_2<Result>(
cont, comp, first, last,
sprout::prev(last, 2), sprout::prev(last)
)
;
}
template<typename Result, typename Container, typename Compare, typename BidirectionalIterator>
inline SPROUT_CONSTEXPR Result
prev_permutation_impl(Container const& cont, Compare comp, BidirectionalIterator first, BidirectionalIterator last) {
return first == last ? Result(sprout::deep_copy(cont), false)
: sprout::fixed::detail::prev_permutation_impl_1<Result>(
cont, comp, first, last,
sprout::next(first)
);
}
} // namespace detail
//
// prev_permutation
//
template<typename Container, typename Compare>
inline SPROUT_CONSTEXPR sprout::pair<typename sprout::fixed::result_of::algorithm<Container>::type, bool>
prev_permutation(Container const& cont, Compare comp) {
typedef sprout::pair<typename sprout::fixed::result_of::algorithm<Container>::type, bool> type;
return sprout::fixed::detail::prev_permutation_impl<type>(
cont, comp,
sprout::begin(cont), sprout::end(cont)
);
}
//
// prev_permutation
//
template<typename Container>
inline SPROUT_CONSTEXPR sprout::pair<typename sprout::fixed::result_of::algorithm<Container>::type, bool>
prev_permutation(Container const& cont) {
typedef sprout::pair<typename sprout::fixed::result_of::algorithm<Container>::type, bool> type;
return sprout::fixed::detail::prev_permutation_impl<type>(
cont, NS_SSCRISK_CEL_OR_SPROUT::less<typename sprout::container_traits<Container>::value_type>(),
sprout::begin(cont), sprout::end(cont)
);
}
} // namespace fixed
using sprout::fixed::prev_permutation;
} // namespace sprout
#endif // #ifndef SPROUT_ALGORITHM_FIXED_PREV_PERMUTATION_HPP