// | |
//======================================================================= | |
// 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_GRAPH_DETAIL_MUTABLE_HEAP_H | |
#define BOOST_GRAPH_DETAIL_MUTABLE_HEAP_H | |
/* | |
There are a few things wrong with this set of functions. | |
ExternalData should be removed, it is not part of the core | |
algorithm. It can be handled inside the tree nodes. | |
The swap() should be replaced by assignment since its use is causing | |
the number of memory references to double. | |
The min_element should be replaced by a fixed length loop | |
(fixed at d for d-heaps). | |
The member functions of TreeNode should be changed to global | |
functions. | |
These functions will be replaced by those in heap_tree.h | |
*/ | |
namespace boost { | |
template <class TreeNode, class Compare, class ExternalData> | |
inline TreeNode up_heap(TreeNode x, const Compare& comp, ExternalData& edata) { | |
while (x.has_parent() && comp(x, x.parent())) | |
x.swap(x.parent(), edata); | |
return x; | |
} | |
template <class TreeNode, class Compare, class ExternalData> | |
inline TreeNode down_heap(TreeNode x, const Compare& comp, ExternalData& edata) { | |
while (x.children().size() > 0) { | |
typename TreeNode::children_type::iterator | |
child_iter = std::min_element(x.children().begin(), | |
x.children().end(), | |
comp); | |
if (comp(*child_iter, x)) | |
x.swap(*child_iter, edata); | |
else | |
break; | |
} | |
return x; | |
} | |
template <class TreeNode, class Compare, class ExternalData> | |
inline void update_heap(TreeNode x, const Compare& comp, ExternalData& edata) { | |
x = down_heap(x, comp, edata); | |
(void)up_heap(x, comp, edata); | |
} | |
} | |
#endif |