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