Chris@16: //
Chris@16: //=======================================================================
Chris@16: // Copyright 1997, 1998, 1999, 2000 University of Notre Dame.
Chris@16: // Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek
Chris@16: //
Chris@16: // Distributed under the Boost Software License, Version 1.0. (See
Chris@16: // accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: //=======================================================================
Chris@16: //
Chris@16: #ifndef BOOST_GRAPH_DETAIL_MUTABLE_HEAP_H
Chris@16: #define BOOST_GRAPH_DETAIL_MUTABLE_HEAP_H
Chris@16: 
Chris@16: /*
Chris@16:   There are a few things wrong with this set of functions.
Chris@16: 
Chris@16:   ExternalData should be removed, it is not part of the core
Chris@16:   algorithm. It can be handled inside the tree nodes.
Chris@16: 
Chris@16:   The swap() should be replaced by assignment since its use is causing
Chris@16:   the number of memory references to double.
Chris@16: 
Chris@16:   The min_element should be replaced by a fixed length loop
Chris@16:   (fixed at d for d-heaps).
Chris@16: 
Chris@16:   The member functions of TreeNode should be changed to global
Chris@16:   functions.
Chris@16: 
Chris@16:   These functions will be replaced by those in heap_tree.h
Chris@16: 
Chris@16:  */
Chris@16: 
Chris@16: namespace boost {
Chris@16: 
Chris@16:   template <class TreeNode, class Compare, class ExternalData>
Chris@16:   inline TreeNode up_heap(TreeNode x, const Compare& comp, ExternalData& edata) {
Chris@16:     while (x.has_parent() && comp(x, x.parent()))
Chris@16:       x.swap(x.parent(), edata);
Chris@16:     return x;
Chris@16:   }
Chris@16: 
Chris@16:   template <class TreeNode, class Compare, class ExternalData>
Chris@16:   inline TreeNode down_heap(TreeNode x, const Compare& comp, ExternalData& edata) {
Chris@16:     while (x.children().size() > 0) {
Chris@16:       typename TreeNode::children_type::iterator 
Chris@16:         child_iter = std::min_element(x.children().begin(),
Chris@16:                                       x.children().end(), 
Chris@16:                                       comp);
Chris@16:       if (comp(*child_iter, x))
Chris@16:         x.swap(*child_iter, edata);
Chris@16:       else
Chris@16:         break;
Chris@16:     }
Chris@16:     return x;
Chris@16:   }
Chris@16: 
Chris@16:   template <class TreeNode, class Compare, class ExternalData>
Chris@16:   inline void update_heap(TreeNode x, const Compare& comp, ExternalData& edata) {
Chris@16:     x = down_heap(x, comp, edata);
Chris@16:     (void)up_heap(x, comp, edata);
Chris@16:   }
Chris@16: 
Chris@16: }
Chris@16: #endif