cgal/Partition_2/include/CGAL/Rotation_tree_2.C

140 lines
3.7 KiB
C

// Copyright (c) 2000 Max-Planck-Institute Saarbruecken (Germany).
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org); you may redistribute it under
// the terms of the Q Public License version 1.0.
// See the file LICENSE.QPL distributed with CGAL.
//
// Licensees holding a valid commercial license may use this file in
// accordance with the commercial license agreement provided with the software.
//
// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
//
// $Source$
// $Revision$ $Date$
// $Name$
//
// Author(s) : Susan Hert <hert@mpi-sb.mpg.de>
#include <iostream>
namespace CGAL {
// makes *p the rightmost child of *q
template<class Traits>
void Rotation_tree_2<Traits>::set_rightmost_child(Self_iterator p,
Self_iterator q)
{
CGAL_assertion(q != this->end());
if (p != this->end())
{
(*p).clear_right_sibling();
if (rightmost_child(q) != this->end())
{
(*p).set_left_sibling(rightmost_child(q));
(*rightmost_child(q)).set_right_sibling(p);
}
else
(*p).clear_left_sibling();
(*p).set_parent(q);
(*q).set_rightmost_child(p);
}
else
{
(*q).clear_rightmost_child();
}
}
// makes *p the left sibling of *q
template <class Traits>
void Rotation_tree_2<Traits>::set_left_sibling(Self_iterator p,
Self_iterator q)
{
if (q == this->end()) return;
if (p != this->end())
{
if (left_sibling(q) != this->end())
{
(*left_sibling(q)).set_right_sibling(p);
(*p).set_left_sibling(left_sibling(q));
}
else
(*p).clear_left_sibling();
(*q).set_left_sibling(p);
(*p).set_right_sibling(q);
set_parent(parent(q),p);
}
else
{
if (left_sibling(q) != this->end())
(*(*q).left_sibling()).clear_right_sibling();
(*q).clear_left_sibling();
}
}
// makes p the right sibling of q
template <class Traits>
void Rotation_tree_2<Traits>::set_right_sibling(Self_iterator p,
Self_iterator q)
{
if (q == this->end()) return;
if (p != this->end())
{
if (right_sibling(q) != this->end())
{
(*right_sibling(q)).set_left_sibling(p);
(*p).set_right_sibling(right_sibling(q));
}
else
(*p).clear_right_sibling();
(*q).set_right_sibling(p);
(*p).set_left_sibling(q);
set_parent(parent(q),p);
}
else
{
if (right_sibling(q) != this->end())
(*right_sibling(q)).clear_left_sibling();
(*q).clear_right_sibling();
}
}
// NOTE: this function does not actually remove the node p from the
// list; it only reorganizes the pointers so this node is not
// in the tree structure anymore
template <class Traits>
void Rotation_tree_2<Traits>::erase(Self_iterator p)
{
CGAL_assertion((*p).is_a_leaf());
Self_iterator s;
s = right_sibling(p);
if (s != this->end())
set_left_sibling(left_sibling(p),s);
s = left_sibling(p);
if (s != this->end())
set_right_sibling(right_sibling(p),s);
s = parent(p);
// if p was the rightmost child of its parent, then set its left
// sibling as the new rightmost child
if (rightmost_child(s) == p)
set_rightmost_child(left_sibling(p),s);
}
template <class Traits>
std::ostream& operator<<(std::ostream& os, const Rotation_tree_2<Traits>& tree)
{
typename Rotation_tree_2<Traits>::const_iterator it;
for (it = tree.begin(); it != tree.end(); it++)
os << *it << " " << std::endl;
return os;
}
}