// | |
//======================================================================= | |
// 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 |