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