Sprout/sprout/algorithm/fixed/next_permutation.hpp
2012-07-25 14:27:01 +09:00

103 lines
4.2 KiB
C++

#ifndef SPROUT_ALGORITHM_FIXED_NEXT_PERMUTATION_HPP
#define SPROUT_ALGORITHM_FIXED_NEXT_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.hpp>
#include <sprout/sub_array.hpp>
#include <sprout/utility/pair.hpp>
#include HDR_FUNCTIONAL_SSCRISK_CEL_OR_SPROUT
#include HDR_ITERATOR_SSCRISK_CEL_OR_SPROUT
namespace sprout {
namespace fixed {
namespace detail {
template<typename Result, typename Container, typename Difference>
inline SPROUT_CONSTEXPR Result
next_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 Iterator>
inline SPROUT_CONSTEXPR Result
next_permutation_impl_3(Container const& cont, Compare comp, Iterator first, Iterator last, Iterator i, Iterator ii, Iterator j) {
return !comp(*i, *sprout::prev(j)) ? sprout::fixed::detail::next_permutation_impl_3<Result>(
cont, comp, first, last,
i, ii, sprout::prev(j)
)
: sprout::fixed::detail::next_permutation_impl_4<Result>(
sprout::fixed::swap_element(cont, i, sprout::prev(j)),
NS_SSCRISK_CEL_OR_SPROUT::distance(first, ii)
)
;
}
template<typename Result, typename Container, typename Compare, typename Iterator>
inline SPROUT_CONSTEXPR Result
next_permutation_impl_2(Container const& cont, Compare comp, Iterator first, Iterator last, Iterator i, Iterator ii) {
return comp(*i, *ii) ? sprout::fixed::detail::next_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::next_permutation_impl_2<Result>(
cont, comp, first, last,
sprout::prev(i), i
)
;
}
template<typename Result, typename Container, typename Compare, typename Iterator>
inline SPROUT_CONSTEXPR Result
next_permutation_impl_1(Container const& cont, Compare comp, Iterator first, Iterator last, Iterator i) {
return i == last ? Result(sprout::deep_copy(cont), false)
: sprout::fixed::detail::next_permutation_impl_2<Result>(
cont, comp, first, last,
sprout::prev(last, 2), sprout::prev(last)
)
;
}
template<typename Result, typename Container, typename Compare, typename Iterator>
inline SPROUT_CONSTEXPR Result
next_permutation_impl(Container const& cont, Compare comp, Iterator first, Iterator last) {
return first == last ? Result(sprout::deep_copy(cont), false)
: sprout::fixed::detail::next_permutation_impl_1<Result>(
cont, comp, first, last,
sprout::next(first)
);
}
} // namespace detail
//
// next_permutation
//
template<typename Container, typename Compare>
inline SPROUT_CONSTEXPR sprout::pair<typename sprout::fixed::result_of::algorithm<Container>::type, bool>
next_permutation(Container const& cont, Compare comp) {
typedef sprout::pair<typename sprout::fixed::result_of::algorithm<Container>::type, bool> type;
return sprout::fixed::detail::next_permutation_impl<type>(
cont, comp,
sprout::begin(cont), sprout::end(cont)
);
}
//
// next_permutation
//
template<typename Container>
inline SPROUT_CONSTEXPR sprout::pair<typename sprout::fixed::result_of::algorithm<Container>::type, bool>
next_permutation(Container const& cont) {
typedef sprout::pair<typename sprout::fixed::result_of::algorithm<Container>::type, bool> type;
return sprout::fixed::detail::next_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::next_permutation;
} // namespace sprout
#endif // #ifndef SPROUT_ALGORITHM_FIXED_NEXT_PERMUTATION_HPP