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- //
- //=======================================================================
- // Copyright 1997, 1998, 1999, 2000 University of Notre Dame.
- // Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek
- //
- // 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 BOOST_MUTABLE_QUEUE_HPP
- #define BOOST_MUTABLE_QUEUE_HPP
- #include <vector>
- #include <algorithm>
- #include <functional>
- #include <boost/property_map/property_map.hpp>
- #include <boost/pending/mutable_heap.hpp>
- #include <boost/pending/is_heap.hpp>
- #include <boost/graph/detail/array_binary_tree.hpp>
- #include <iterator>
- namespace boost
- {
- // The mutable queue whose elements are indexed
- //
- // This adaptor provides a special kind of priority queue that has
- // and update operation. This allows the ordering of the items to
- // change. After the ordering criteria for item x changes, one must
- // call the Q.update(x)
- //
- // In order to efficiently find x in the queue, a functor must be
- // provided to map value_type to a unique ID, which the
- // mutable_queue will then use to map to the location of the
- // item. The ID's generated must be between 0 and N, where N is the
- // value passed to the constructor of mutable_queue
- template < class IndexedType,
- class RandomAccessContainer = std::vector< IndexedType >,
- class Comp = std::less< typename RandomAccessContainer::value_type >,
- class ID = identity_property_map >
- class mutable_queue
- {
- public:
- typedef IndexedType value_type;
- typedef typename RandomAccessContainer::size_type size_type;
- protected:
- typedef typename RandomAccessContainer::iterator iterator;
- #if !defined BOOST_NO_STD_ITERATOR_TRAITS
- typedef array_binary_tree_node< iterator, ID > Node;
- #else
- typedef array_binary_tree_node< iterator, value_type, ID > Node;
- #endif
- typedef compare_array_node< RandomAccessContainer, Comp > Compare;
- typedef std::vector< size_type > IndexArray;
- public:
- typedef Compare value_compare;
- typedef ID id_generator;
- mutable_queue(size_type n, const Comp& x, const ID& _id)
- : index_array(n), comp(x), id(_id)
- {
- c.reserve(n);
- }
- template < class ForwardIterator >
- mutable_queue(ForwardIterator first, ForwardIterator last, const Comp& x,
- const ID& _id)
- : index_array(std::distance(first, last)), comp(x), id(_id)
- {
- while (first != last)
- {
- push(*first);
- ++first;
- }
- }
- bool empty() const { return c.empty(); }
- void pop()
- {
- value_type tmp = c.back();
- c.back() = c.front();
- c.front() = tmp;
- size_type id_f = get(id, c.back());
- size_type id_b = get(id, tmp);
- size_type i = index_array[id_b];
- index_array[id_b] = index_array[id_f];
- index_array[id_f] = i;
- c.pop_back();
- Node node(c.begin(), c.end(), c.begin(), id);
- down_heap(node, comp, index_array);
- }
- void push(const IndexedType& x)
- {
- c.push_back(x);
- /*set index-array*/
- index_array[get(id, x)] = c.size() - 1;
- Node node(c.begin(), c.end(), c.end() - 1, id);
- up_heap(node, comp, index_array);
- }
- void update(const IndexedType& x)
- {
- size_type current_pos = index_array[get(id, x)];
- c[current_pos] = x;
- Node node(c.begin(), c.end(), c.begin() + current_pos, id);
- update_heap(node, comp, index_array);
- }
- value_type& front() { return c.front(); }
- value_type& top() { return c.front(); }
- const value_type& front() const { return c.front(); }
- const value_type& top() const { return c.front(); }
- size_type size() const { return c.size(); }
- void clear() { c.clear(); }
- #if 0
- // dwa 2003/7/11 - I don't know what compiler is supposed to
- // be able to compile this, but is_heap is not standard!!
- bool test() {
- return std::is_heap(c.begin(), c.end(), Comp());
- }
- #endif
- protected:
- IndexArray index_array;
- Compare comp;
- RandomAccessContainer c;
- ID id;
- };
- }
- #endif // BOOST_MUTABLE_QUEUE_HPP
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