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101 lines
2.9 KiB
101 lines
2.9 KiB
/***************************************************************************
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* Copyright (C) 2004-2005 by Daniel Clarke *
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* daniel.jc@gmail.com *
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* *
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* This program is free software; you can redistribute it and/or modify *
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* it under the terms of the GNU General Public License as published by *
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* the Free Software Foundation; either version 2 of the License, or *
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* (at your option) any later version. *
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* *
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* This program is distributed in the hope that it will be useful, *
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* but WITHOUT ANY WARRANTY; without even the implied warranty of *
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
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* GNU General Public License for more details. *
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* *
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* You should have received a copy of the GNU General Public License *
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* along with this program; if not, write to the *
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* Free Software Foundation, Inc., *
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. *
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***************************************************************************/
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#include "traverser.h"
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#include "pic14.h"
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Traverser::Traverser(BTreeNode *root)
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{
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m_root = root;
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m_current = root;
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}
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Traverser::~Traverser()
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{
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}
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BTreeNode * Traverser::start()
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{
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/* To find the start we will iterate, or possibly recurse
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down the tree, each time turning down the node that has children,
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if they both have no children we have reached the end and it shouldn't
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really matter which we pick (check this algorithm) */
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BTreeNode *n = m_root;
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bool found = false;
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while(!found)
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{
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if( !n->hasChildren() ) found = true;
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else
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{
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if( !n->left()->hasChildren() )
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{
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if( !n->right()->hasChildren() ) found = true;
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n = n->right();
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}
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else n = n->left();
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}
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}
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//if(n->parent()) m_current = n->parent();
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//else m_current = n;
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m_current = n;
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return m_current;
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}
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BTreeNode * Traverser::next()
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{
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// a.t.m we will just take the next thing to be the parent.
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if( m_current != m_root ) m_current = m_current->parent();
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return m_current;
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}
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bool Traverser::onLeftBranch()
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{
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return current()->parent()->left() == current();
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}
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BTreeNode * Traverser::oppositeNode()
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{
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if ( onLeftBranch() )
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return current()->parent()->right();
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else
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return current()->parent()->left();
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}
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void Traverser::descendLeftwardToTerminal()
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{
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bool done = false;
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while(!done)
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{
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if( !current()->hasChildren() ) return;
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else
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{
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m_current = current()->left();
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}
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}
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}
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void Traverser::moveToParent()
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{
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if(current()->parent()) m_current = current()->parent();
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}
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