]>
Commit | Line | Data |
---|---|---|
7c673cae FG |
1 | // |
2 | //======================================================================= | |
3 | // Copyright 1997, 1998, 1999, 2000 University of Notre Dame. | |
4 | // Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek | |
5 | // | |
6 | // Distributed under the Boost Software License, Version 1.0. (See | |
7 | // accompanying file LICENSE_1_0.txt or copy at | |
8 | // http://www.boost.org/LICENSE_1_0.txt) | |
9 | //======================================================================= | |
10 | // | |
11 | #ifndef BOOST_GRAPH_DETAIL_MUTABLE_HEAP_H | |
12 | #define BOOST_GRAPH_DETAIL_MUTABLE_HEAP_H | |
13 | ||
14 | /* | |
15 | There are a few things wrong with this set of functions. | |
16 | ||
17 | ExternalData should be removed, it is not part of the core | |
18 | algorithm. It can be handled inside the tree nodes. | |
19 | ||
20 | The swap() should be replaced by assignment since its use is causing | |
21 | the number of memory references to double. | |
22 | ||
23 | The min_element should be replaced by a fixed length loop | |
24 | (fixed at d for d-heaps). | |
25 | ||
26 | The member functions of TreeNode should be changed to global | |
27 | functions. | |
28 | ||
29 | These functions will be replaced by those in heap_tree.h | |
30 | ||
31 | */ | |
32 | ||
33 | namespace boost { | |
34 | ||
35 | template <class TreeNode, class Compare, class ExternalData> | |
36 | inline TreeNode up_heap(TreeNode x, const Compare& comp, ExternalData& edata) { | |
37 | while (x.has_parent() && comp(x, x.parent())) | |
38 | x.swap(x.parent(), edata); | |
39 | return x; | |
40 | } | |
41 | ||
42 | template <class TreeNode, class Compare, class ExternalData> | |
43 | inline TreeNode down_heap(TreeNode x, const Compare& comp, ExternalData& edata) { | |
44 | while (x.children().size() > 0) { | |
45 | typename TreeNode::children_type::iterator | |
46 | child_iter = std::min_element(x.children().begin(), | |
47 | x.children().end(), | |
48 | comp); | |
49 | if (comp(*child_iter, x)) | |
50 | x.swap(*child_iter, edata); | |
51 | else | |
52 | break; | |
53 | } | |
54 | return x; | |
55 | } | |
56 | ||
57 | template <class TreeNode, class Compare, class ExternalData> | |
58 | inline void update_heap(TreeNode x, const Compare& comp, ExternalData& edata) { | |
59 | x = down_heap(x, comp, edata); | |
60 | (void)up_heap(x, comp, edata); | |
61 | } | |
62 | ||
63 | } | |
64 | #endif |