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