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> up_heap(TreeNode x,const Compare & comp,ExternalData & edata)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> down_heap(TreeNode x,const Compare & comp,ExternalData & edata)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> update_heap(TreeNode x,const Compare & comp,ExternalData & edata)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 65