This is RBTree.m in view mode; [Download] [Up]
/* Implementation for Objective-C Red-Black Tree collection object
Copyright (C) 1993 Free Software Foundation, Inc.
Written by: R. Andrew McCallum <mccallum@cs.rochester.edu>
Dept. of Computer Science, U. of Rochester, Rochester, NY 14627
This file is part of the GNU Objective-C Collection library.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free
Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <coll/RBTree.h>
#include <coll/IndexedCollectionPrivate.h>
#include <coll/RBTreeNode.h>
#define NODE_IS_RED(NODE) ([NODE isRed])
#define NODE_IS_BLACK(NODE) (![NODE isRed])
/* sentinal */
static id nilRBNode;
@implementation RBTree
+ initialize
{
if (self == [RBTree class])
{
[self setVersion:-1]; /* alpha release */
nilRBNode = [[RBTreeNode alloc] init];
[nilRBNode setBlack];
}
return self;
}
- nilNode
{
return nilRBNode;
}
- sortAddElement: (elt)newElement byCalling: (int(*)(elt,elt))aFunc
{
id y;
[super sortAddElement:newElement byCalling:aFunc];
[newElement.id_u setRed];
while (newElement.id_u != _contents_root
&& [[newElement.id_u parentNode] isRed])
{
if ([newElement.id_u parentNode] ==
[[[newElement.id_u parentNode] parentNode] leftNode])
{
y = [[[newElement.id_u parentNode] parentNode] leftNode];
if ([y isRed])
{
[[newElement.id_u parentNode] setBlack];
[y setBlack];
[[[newElement.id_u parentNode] parentNode] setRed];
newElement.id_u = [[newElement.id_u parentNode] parentNode];
}
else
{
if (newElement.id_u == [[newElement.id_u parentNode] rightNode])
{
newElement.id_u = [newElement.id_u parentNode];
[self leftRotateAroundNode:newElement.id_u];
}
[[newElement.id_u parentNode] setBlack];
[[[newElement.id_u parentNode] parentNode] setRed];
[self rightRotateAroundNode:
[[newElement.id_u parentNode] parentNode]];
}
}
else
{
y = [[[newElement.id_u parentNode] parentNode] rightNode];
if ([y isRed])
{
[[newElement.id_u parentNode] setBlack];
[y setBlack];
[[[newElement.id_u parentNode] parentNode] setRed];
newElement.id_u = [[newElement.id_u parentNode] parentNode];
}
else
{
if (newElement.id_u == [[newElement.id_u parentNode] leftNode])
{
newElement.id_u = [newElement.id_u parentNode];
[self rightRotateAroundNode:newElement.id_u];
}
[[newElement.id_u parentNode] setBlack];
[[[newElement.id_u parentNode] parentNode] setRed];
[self leftRotateAroundNode:
[[newElement.id_u parentNode] parentNode]];
}
}
}
[_contents_root setBlack];
return self;
}
- _RBTreeDeleteFixup: x
{
id w;
while (x != _contents_root && NODE_IS_BLACK(x))
{
if (NODE_IS_LEFTCHILD(x))
{
w = [[x parentNode] rightNode];
if (NODE_IS_RED(w))
{
[w setBlack];
[[x parentNode] setRed];
[self leftRotateAroundNode:[x parentNode]];
w = [[x parentNode] rightNode];
}
if (NODE_IS_BLACK([w leftNode]) && NODE_IS_BLACK([w rightNode]))
{
[w setRed];
x = [x parentNode];
}
else
{
if (NODE_IS_BLACK([w rightNode]))
{
[[w leftNode] setBlack];
[w setRed];
[self rightRotateAroundNode:w];
w = [[x parentNode] rightNode];
}
if (NODE_IS_BLACK([x parentNode]))
[w setBlack];
else
[w setRed];
[[x parentNode] setBlack];
[[w rightNode] setBlack];
[self leftRotateAroundNode:[x parentNode]];
x = _contents_root;
}
}
else
{
w = [[x parentNode] leftNode];
if (NODE_IS_RED(w))
{
[w setBlack];
[[x parentNode] setRed];
[self rightRotateAroundNode:[x parentNode]];
w = [[x parentNode] leftNode];
}
if (NODE_IS_BLACK([w rightNode]) && NODE_IS_BLACK([w leftNode]))
{
[w setRed];
x = [x parentNode];
}
else
{
if (NODE_IS_BLACK([w leftNode]))
{
[[w rightNode] setBlack];
[w setRed];
[self leftRotateAroundNode:w];
w = [[x parentNode] leftNode];
}
if (NODE_IS_BLACK([x parentNode]))
[w setBlack];
else
[w setRed];
[[x parentNode] setBlack];
[[w leftNode] setBlack];
[self rightRotateAroundNode:[x parentNode]];
x = _contents_root;
}
}
}
[x setBlack];
return self;
}
- (elt) removeElement: (elt)oldElement
{
id x, y;
if ([oldElement.id_u leftNode] == [self nilNode]
|| [oldElement.id_u rightNode] == [self nilNode])
y = oldElement.id_u;
else
y = [self successorOfElement:oldElement].id_u;
if ([y leftNode] != [self nilNode])
x = [y leftNode];
else
x = [y rightNode];
[x setParentNode:[y parentNode]];
if ([y parentNode] == [self nilNode])
_contents_root = x;
else
{
if (y == [[y parentNode] leftNode])
[[y parentNode] setLeftNode:x];
else
[[y parentNode] setRightNode:x];
}
if (y != oldElement.id_u)
{
/* put y in the place of oldElement.id_u */
[y setParentNode:[oldElement.id_u parentNode]];
[y setLeftNode:[oldElement.id_u leftNode]];
[y setRightNode:[oldElement.id_u rightNode]];
if (oldElement.id_u == [[oldElement.id_u parentNode] leftNode])
[[oldElement.id_u parentNode] setLeftNode:y];
else
[[oldElement.id_u parentNode] setRightNode:oldElement.id_u];
[[oldElement.id_u leftNode] setParentNode:y];
[[oldElement.id_u rightNode] setParentNode:y];
}
if (NODE_IS_BLACK(y))
[self _RBTreeDeleteFixup:x];
[oldElement.id_u setRightNode:[self nilNode]];
[oldElement.id_u setLeftNode:[self nilNode]];
[oldElement.id_u setParentNode:[self nilNode]];
_count--;
return oldElement;
}
/* Override methods that could violate assumptions of RBTree structure.
Perhaps I shouldn't DISALLOW this, let users have the power to do
whatever they want. I mention this in the QUESTIONS section of the
TODO file. */
/***
Or perhaps instead of calling INSERTION_ERROR we could fix up the RB
property of the tree.
- insertElement: (elt)newElement before: (elt)oldElement
{
INSERTION_ERROR();
return self;
}
- insertElement: (elt)newElement after: (elt)oldElement
{
INSERTION_ERROR();
return self;
}
- insertElement: (elt)newElement atIndex: (unsigned)index
{
INSERTION_ERROR();
return self;
}
- appendElement: (elt)newElement
{
INSERTION_ERROR();
return self;
}
****/
@end
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.