703 lines
21 KiB
C++
703 lines
21 KiB
C++
// boost heap: pairing heap
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//
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// Copyright (C) 2010 Tim Blechmann
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//
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// Distributed under the Boost Software License, Version 1.0. (See
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// accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt)
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#ifndef BOOST_HEAP_PAIRING_HEAP_HPP
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#define BOOST_HEAP_PAIRING_HEAP_HPP
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#include <algorithm>
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#include <vector>
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#include <boost/assert.hpp>
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#include <boost/heap/detail/heap_comparison.hpp>
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#include <boost/heap/detail/heap_node.hpp>
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#include <boost/heap/policies.hpp>
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#include <boost/heap/detail/stable_heap.hpp>
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#include <boost/heap/detail/tree_iterator.hpp>
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#ifndef BOOST_DOXYGEN_INVOKED
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#ifdef BOOST_HEAP_SANITYCHECKS
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#define BOOST_HEAP_ASSERT BOOST_ASSERT
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#else
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#define BOOST_HEAP_ASSERT(expression)
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#endif
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#endif
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namespace boost {
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namespace heap {
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namespace detail {
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typedef parameter::parameters<boost::parameter::optional<tag::allocator>,
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boost::parameter::optional<tag::compare>,
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boost::parameter::optional<tag::stable>,
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boost::parameter::optional<tag::constant_time_size>,
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boost::parameter::optional<tag::stability_counter_type>
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> pairing_heap_signature;
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template <typename T, typename Parspec>
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struct make_pairing_heap_base
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{
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static const bool constant_time_size = parameter::binding<Parspec,
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tag::constant_time_size,
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boost::mpl::true_
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>::type::value;
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typedef typename detail::make_heap_base<T, Parspec, constant_time_size>::type base_type;
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typedef typename detail::make_heap_base<T, Parspec, constant_time_size>::allocator_argument allocator_argument;
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typedef typename detail::make_heap_base<T, Parspec, constant_time_size>::compare_argument compare_argument;
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typedef heap_node<typename base_type::internal_type, false> node_type;
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typedef typename allocator_argument::template rebind<node_type>::other allocator_type;
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struct type:
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base_type,
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allocator_type
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{
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type(compare_argument const & arg):
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base_type(arg)
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{}
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#ifdef BOOST_HAS_RVALUE_REFS
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type(type && rhs):
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base_type(std::move(static_cast<base_type&>(rhs))),
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allocator_type(std::move(static_cast<allocator_type&>(rhs)))
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{}
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type & operator=(type && rhs)
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{
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base_type::operator=(std::move(static_cast<base_type&>(rhs)));
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allocator_type::operator=(std::move(static_cast<allocator_type&>(rhs)));
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return *this;
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}
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type & operator=(type const & rhs)
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{
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base_type::operator=(static_cast<base_type const &>(rhs));
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allocator_type::operator=(static_cast<const allocator_type&>(rhs));
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return *this;
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}
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#endif
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};
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};
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}
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/**
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* \class pairing_heap
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* \brief pairing heap
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*
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* Pairing heaps are self-adjusting binary heaps. Although design and implementation are rather simple,
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* the complexity analysis is yet unsolved. For details, consult:
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*
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* Pettie, Seth (2005), "Towards a final analysis of pairing heaps",
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* Proc. 46th Annual IEEE Symposium on Foundations of Computer Science, pp. 174–183
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*
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* The template parameter T is the type to be managed by the container.
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* The user can specify additional options and if no options are provided default options are used.
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*
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* The container supports the following options:
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* - \c boost::heap::compare<>, defaults to \c compare<std::less<T> >
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* - \c boost::heap::stable<>, defaults to \c stable<false>
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* - \c boost::heap::stability_counter_type<>, defaults to \c stability_counter_type<boost::uintmax_t>
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* - \c boost::heap::allocator<>, defaults to \c allocator<std::allocator<T> >
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* - \c boost::heap::constant_time_size<>, defaults to \c constant_time_size<true>
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*
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*
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*/
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#ifdef BOOST_DOXYGEN_INVOKED
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template<class T, class ...Options>
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#else
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template <typename T,
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class A0 = boost::parameter::void_,
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class A1 = boost::parameter::void_,
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class A2 = boost::parameter::void_,
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class A3 = boost::parameter::void_,
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class A4 = boost::parameter::void_
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>
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#endif
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class pairing_heap:
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private detail::make_pairing_heap_base<T,
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typename detail::pairing_heap_signature::bind<A0, A1, A2, A3, A4>::type
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>::type
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{
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typedef typename detail::pairing_heap_signature::bind<A0, A1, A2, A3, A4>::type bound_args;
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typedef detail::make_pairing_heap_base<T, bound_args> base_maker;
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typedef typename base_maker::type super_t;
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typedef typename super_t::internal_type internal_type;
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typedef typename super_t::size_holder_type size_holder;
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typedef typename base_maker::allocator_argument allocator_argument;
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private:
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template <typename Heap1, typename Heap2>
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friend struct heap_merge_emulate;
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#ifndef BOOST_DOXYGEN_INVOKED
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struct implementation_defined:
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detail::extract_allocator_types<typename base_maker::allocator_argument>
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{
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typedef T value_type;
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typedef typename detail::extract_allocator_types<typename base_maker::allocator_argument>::size_type size_type;
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typedef typename detail::extract_allocator_types<typename base_maker::allocator_argument>::reference reference;
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typedef typename base_maker::compare_argument value_compare;
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typedef typename base_maker::allocator_type allocator_type;
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typedef typename allocator_type::pointer node_pointer;
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typedef typename allocator_type::const_pointer const_node_pointer;
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typedef detail::heap_node_list node_list_type;
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typedef typename node_list_type::iterator node_list_iterator;
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typedef typename node_list_type::const_iterator node_list_const_iterator;
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typedef typename base_maker::node_type node;
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typedef detail::value_extractor<value_type, internal_type, super_t> value_extractor;
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typedef typename super_t::internal_compare internal_compare;
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typedef detail::node_handle<node_pointer, super_t, reference> handle_type;
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typedef detail::tree_iterator<node,
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const value_type,
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allocator_type,
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value_extractor,
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detail::pointer_to_reference<node>,
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false,
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false,
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value_compare
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> iterator;
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typedef iterator const_iterator;
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typedef detail::tree_iterator<node,
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const value_type,
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allocator_type,
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value_extractor,
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detail::pointer_to_reference<node>,
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false,
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true,
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value_compare
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> ordered_iterator;
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};
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typedef typename implementation_defined::node node;
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typedef typename implementation_defined::node_pointer node_pointer;
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typedef typename implementation_defined::node_list_type node_list_type;
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typedef typename implementation_defined::node_list_iterator node_list_iterator;
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typedef typename implementation_defined::node_list_const_iterator node_list_const_iterator;
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typedef typename implementation_defined::internal_compare internal_compare;
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typedef boost::intrusive::list<detail::heap_node_base<true>,
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boost::intrusive::constant_time_size<false>
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> node_child_list;
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#endif
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public:
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typedef T value_type;
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typedef typename implementation_defined::size_type size_type;
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typedef typename implementation_defined::difference_type difference_type;
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typedef typename implementation_defined::value_compare value_compare;
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typedef typename implementation_defined::allocator_type allocator_type;
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typedef typename implementation_defined::reference reference;
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typedef typename implementation_defined::const_reference const_reference;
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typedef typename implementation_defined::pointer pointer;
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typedef typename implementation_defined::const_pointer const_pointer;
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/// \copydoc boost::heap::priority_queue::iterator
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typedef typename implementation_defined::iterator iterator;
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typedef typename implementation_defined::const_iterator const_iterator;
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typedef typename implementation_defined::ordered_iterator ordered_iterator;
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typedef typename implementation_defined::handle_type handle_type;
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static const bool constant_time_size = super_t::constant_time_size;
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static const bool has_ordered_iterators = true;
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static const bool is_mergable = true;
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static const bool is_stable = detail::extract_stable<bound_args>::value;
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static const bool has_reserve = false;
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/// \copydoc boost::heap::priority_queue::priority_queue(value_compare const &)
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explicit pairing_heap(value_compare const & cmp = value_compare()):
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super_t(cmp), root(NULL)
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{}
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/// \copydoc boost::heap::priority_queue::priority_queue(priority_queue const &)
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pairing_heap(pairing_heap const & rhs):
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super_t(rhs), root(NULL)
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{
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if (rhs.empty())
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return;
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clone_tree(rhs);
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size_holder::set_size(rhs.get_size());
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}
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#ifdef BOOST_HAS_RVALUE_REFS
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/// \copydoc boost::heap::priority_queue::priority_queue(priority_queue &&)
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pairing_heap(pairing_heap && rhs):
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super_t(std::move(rhs)), root(rhs.root)
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{
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rhs.root = NULL;
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}
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/// \copydoc boost::heap::priority_queue::operator=(priority_queue &&)
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pairing_heap & operator=(pairing_heap && rhs)
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{
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super_t::operator=(std::move(rhs));
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root = rhs.root;
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rhs.root = NULL;
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return *this;
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}
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#endif
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/// \copydoc boost::heap::priority_queue::operator=(priority_queue const & rhs)
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pairing_heap & operator=(pairing_heap const & rhs)
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{
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clear();
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size_holder::set_size(rhs.get_size());
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static_cast<super_t&>(*this) = rhs;
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clone_tree(rhs);
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return *this;
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}
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~pairing_heap(void)
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{
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while (!empty())
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pop();
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}
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/// \copydoc boost::heap::priority_queue::empty
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bool empty(void) const
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{
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return root == NULL;
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}
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/// \copydoc boost::heap::binomial_heap::size
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size_type size(void) const
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{
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if (constant_time_size)
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return size_holder::get_size();
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if (root == NULL)
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return 0;
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else
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return detail::count_nodes(root);
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}
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/// \copydoc boost::heap::priority_queue::max_size
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size_type max_size(void) const
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{
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return allocator_type::max_size();
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}
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/// \copydoc boost::heap::priority_queue::clear
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void clear(void)
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{
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if (empty())
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return;
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root->template clear_subtree<allocator_type>(*this);
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root->~node();
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allocator_type::deallocate(root, 1);
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root = NULL;
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size_holder::set_size(0);
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}
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/// \copydoc boost::heap::priority_queue::get_allocator
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allocator_type get_allocator(void) const
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{
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return *this;
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}
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/// \copydoc boost::heap::priority_queue::swap
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void swap(pairing_heap & rhs)
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{
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super_t::swap(rhs);
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std::swap(root, rhs.root);
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}
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/// \copydoc boost::heap::priority_queue::top
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const_reference top(void) const
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{
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BOOST_ASSERT(!empty());
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return super_t::get_value(root->value);
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}
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/**
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* \b Effects: Adds a new element to the priority queue. Returns handle to element
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*
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* \cond
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* \b Complexity: \f$2^2log(log(N))\f$ (amortized).
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* \endcond
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*
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* \b Complexity: 2**2*log(log(N)) (amortized).
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*
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* */
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handle_type push(value_type const & v)
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{
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size_holder::increment();
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node_pointer n = allocator_type::allocate(1);
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new(n) node(super_t::make_node(v));
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merge_node(n);
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return handle_type(n);
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}
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#if defined(BOOST_HAS_RVALUE_REFS) && !defined(BOOST_NO_VARIADIC_TEMPLATES)
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/**
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* \b Effects: Adds a new element to the priority queue. The element is directly constructed in-place. Returns handle to element.
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*
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* \cond
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* \b Complexity: \f$2^2log(log(N))\f$ (amortized).
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* \endcond
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*
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* \b Complexity: 2**2*log(log(N)) (amortized).
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*
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* */
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template <class... Args>
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handle_type emplace(Args&&... args)
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{
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size_holder::increment();
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node_pointer n = allocator_type::allocate(1);
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new(n) node(super_t::make_node(std::forward<T>(args)...));
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merge_node(n);
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return handle_type(n);
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}
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#endif
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/**
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* \b Effects: Removes the top element from the priority queue.
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*
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* \b Complexity: Logarithmic (amortized).
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*
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* */
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void pop(void)
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{
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BOOST_ASSERT(!empty());
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erase(handle_type(root));
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}
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/**
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* \b Effects: Assigns \c v to the element handled by \c handle & updates the priority queue.
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*
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* \cond
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* \b Complexity: \f$2^2log(log(N))\f$ (amortized).
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* \endcond
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*
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* \b Complexity: 2**2*log(log(N)) (amortized).
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*
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* */
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void update (handle_type handle, const_reference v)
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{
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handle.node_->value = super_t::make_node(v);
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update(handle);
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}
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/**
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* \b Effects: Updates the heap after the element handled by \c handle has been changed.
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*
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* \cond
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* \b Complexity: \f$2^2log(log(N))\f$ (amortized).
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* \endcond
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*
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* \b Complexity: 2**2*log(log(N)) (amortized).
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*
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* \b Note: If this is not called, after a handle has been updated, the behavior of the data structure is undefined!
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* */
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void update (handle_type handle)
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{
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node_pointer n = handle.node_;
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n->unlink();
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if (!n->children.empty())
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n = merge_nodes(n, merge_node_list(n->children));
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if (n != root)
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merge_node(n);
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}
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/**
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* \b Effects: Assigns \c v to the element handled by \c handle & updates the priority queue.
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*
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* \cond
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* \b Complexity: \f$2^2log(log(N))\f$ (amortized).
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* \endcond
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*
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* \b Complexity: 2**2*log(log(N)) (amortized).
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*
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* \b Note: The new value is expected to be greater than the current one
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* */
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void increase (handle_type handle, const_reference v)
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{
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update(handle, v);
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}
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/**
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* \b Effects: Updates the heap after the element handled by \c handle has been changed.
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*
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* \cond
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* \b Complexity: \f$2^2log(log(N))\f$ (amortized).
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* \endcond
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*
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* \b Complexity: 2**2*log(log(N)) (amortized).
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*
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* \b Note: If this is not called, after a handle has been updated, the behavior of the data structure is undefined!
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* */
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void increase (handle_type handle)
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{
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update(handle);
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}
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/**
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* \b Effects: Assigns \c v to the element handled by \c handle & updates the priority queue.
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*
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* \cond
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* \b Complexity: \f$2^2log(log(N))\f$ (amortized).
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* \endcond
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*
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* \b Complexity: 2**2*log(log(N)) (amortized).
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*
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* \b Note: The new value is expected to be less than the current one
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* */
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void decrease (handle_type handle, const_reference v)
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{
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update(handle, v);
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}
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/**
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* \b Effects: Updates the heap after the element handled by \c handle has been changed.
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*
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* \cond
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* \b Complexity: \f$2^2log(log(N))\f$ (amortized).
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* \endcond
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*
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* \b Complexity: 2**2*log(log(N)) (amortized).
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*
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* \b Note: The new value is expected to be less than the current one. If this is not called, after a handle has been updated, the behavior of the data structure is undefined!
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* */
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void decrease (handle_type handle)
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{
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update(handle);
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}
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/**
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* \b Effects: Removes the element handled by \c handle from the priority_queue.
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*
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* \cond
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* \b Complexity: \f$2^2log(log(N))\f$ (amortized).
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* \endcond
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*
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* \b Complexity: 2**2*log(log(N)) (amortized).
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* */
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void erase(handle_type handle)
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{
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node_pointer n = handle.node_;
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if (n != root) {
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n->unlink();
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if (!n->children.empty())
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merge_node(merge_node_list(n->children));
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} else {
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if (!n->children.empty())
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root = merge_node_list(n->children);
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else
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root = NULL;
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}
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size_holder::decrement();
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n->~node();
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allocator_type::deallocate(n, 1);
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}
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/// \copydoc boost::heap::priority_queue::begin
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iterator begin(void) const
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{
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return iterator(root, super_t::value_comp());
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}
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/// \copydoc boost::heap::priority_queue::end
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iterator end(void) const
|
||
{
|
||
return iterator();
|
||
}
|
||
|
||
/// \copydoc boost::heap::fibonacci_heap::ordered_begin
|
||
ordered_iterator ordered_begin(void) const
|
||
{
|
||
return ordered_iterator(root, super_t::value_comp());
|
||
}
|
||
|
||
/// \copydoc boost::heap::fibonacci_heap::ordered_begin
|
||
ordered_iterator ordered_end(void) const
|
||
{
|
||
return ordered_iterator(NULL, super_t::value_comp());
|
||
}
|
||
|
||
|
||
/// \copydoc boost::heap::d_ary_heap_mutable::s_handle_from_iterator
|
||
static handle_type s_handle_from_iterator(iterator const & it)
|
||
{
|
||
return super_t::s_handle_from_iterator(&*it);
|
||
}
|
||
|
||
/**
|
||
* \b Effects: Merge all elements from rhs into this
|
||
*
|
||
* \cond
|
||
* \b Complexity: \f$2^2log(log(N))\f$ (amortized).
|
||
* \endcond
|
||
*
|
||
* \b Complexity: 2**2*log(log(N)) (amortized).
|
||
*
|
||
* */
|
||
void merge(pairing_heap & rhs)
|
||
{
|
||
if (rhs.empty())
|
||
return;
|
||
|
||
merge_node(rhs.root);
|
||
|
||
size_holder::add(rhs.get_size());
|
||
rhs.set_size(0);
|
||
rhs.root = NULL;
|
||
|
||
super_t::set_stability_count(std::max(super_t::get_stability_count(),
|
||
rhs.get_stability_count()));
|
||
rhs.set_stability_count(0);
|
||
}
|
||
|
||
/// \copydoc boost::heap::priority_queue::value_comp
|
||
value_compare const & value_comp(void) const
|
||
{
|
||
return super_t::value_comp();
|
||
}
|
||
|
||
/// \copydoc boost::heap::priority_queue::operator<(HeapType const & rhs) const
|
||
template <typename HeapType>
|
||
bool operator<(HeapType const & rhs) const
|
||
{
|
||
return detail::heap_compare(*this, rhs);
|
||
}
|
||
|
||
/// \copydoc boost::heap::priority_queue::operator>(HeapType const & rhs) const
|
||
template <typename HeapType>
|
||
bool operator>(HeapType const & rhs) const
|
||
{
|
||
return detail::heap_compare(rhs, *this);
|
||
}
|
||
|
||
/// \copydoc boost::heap::priority_queue::operator>=(HeapType const & rhs) const
|
||
template <typename HeapType>
|
||
bool operator>=(HeapType const & rhs) const
|
||
{
|
||
return !operator<(rhs);
|
||
}
|
||
|
||
/// \copydoc boost::heap::priority_queue::operator<=(HeapType const & rhs) const
|
||
template <typename HeapType>
|
||
bool operator<=(HeapType const & rhs) const
|
||
{
|
||
return !operator>(rhs);
|
||
}
|
||
|
||
/// \copydoc boost::heap::priority_queue::operator==(HeapType const & rhs) const
|
||
template <typename HeapType>
|
||
bool operator==(HeapType const & rhs) const
|
||
{
|
||
return detail::heap_equality(*this, rhs);
|
||
}
|
||
|
||
/// \copydoc boost::heap::priority_queue::operator!=(HeapType const & rhs) const
|
||
template <typename HeapType>
|
||
bool operator!=(HeapType const & rhs) const
|
||
{
|
||
return !(*this == rhs);
|
||
}
|
||
|
||
private:
|
||
#if !defined(BOOST_DOXYGEN_INVOKED)
|
||
void clone_tree(pairing_heap const & rhs)
|
||
{
|
||
BOOST_HEAP_ASSERT(root == NULL);
|
||
if (rhs.empty())
|
||
return;
|
||
|
||
root = allocator_type::allocate(1);
|
||
|
||
new(root) node(static_cast<node const &>(*rhs.root), static_cast<allocator_type&>(*this));
|
||
}
|
||
|
||
void merge_node(node_pointer other)
|
||
{
|
||
BOOST_HEAP_ASSERT(other);
|
||
if (root != NULL)
|
||
root = merge_nodes(root, other);
|
||
else
|
||
root = other;
|
||
}
|
||
|
||
node_pointer merge_node_list(node_child_list & children)
|
||
{
|
||
assert(!children.empty());
|
||
node_pointer merged = merge_first_pair(children);
|
||
if (children.empty())
|
||
return merged;
|
||
|
||
node_child_list node_list;
|
||
node_list.push_back(*merged);
|
||
|
||
do {
|
||
node_pointer next_merged = merge_first_pair(children);
|
||
node_list.push_back(*next_merged);
|
||
} while (!children.empty());
|
||
|
||
return merge_node_list(node_list);
|
||
}
|
||
|
||
node_pointer merge_first_pair(node_child_list & children)
|
||
{
|
||
assert(!children.empty());
|
||
node_pointer first_child = static_cast<node_pointer>(&children.front());
|
||
children.pop_front();
|
||
if (children.empty())
|
||
return first_child;
|
||
|
||
node_pointer second_child = static_cast<node_pointer>(&children.front());
|
||
children.pop_front();
|
||
|
||
return merge_nodes(first_child, second_child);
|
||
}
|
||
|
||
node_pointer merge_nodes(node_pointer node1, node_pointer node2)
|
||
{
|
||
if (super_t::operator()(node1->value, node2->value))
|
||
std::swap(node1, node2);
|
||
|
||
node2->unlink();
|
||
node1->children.push_front(*node2);
|
||
return node1;
|
||
}
|
||
|
||
node_pointer root;
|
||
#endif
|
||
};
|
||
|
||
|
||
} /* namespace heap */
|
||
} /* namespace boost */
|
||
|
||
#undef BOOST_HEAP_ASSERT
|
||
#endif /* BOOST_HEAP_PAIRING_HEAP_HPP */
|