/*
Copyright 2008-2010 Gephi
Authors : Mathieu Bastian <mathieu.bastian@gephi.org>
Website : http://www.gephi.org
This file is part of Gephi.
DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
Copyright 2011 Gephi Consortium. All rights reserved.
The contents of this file are subject to the terms of either the GNU
General Public License Version 3 only ("GPL") or the Common
Development and Distribution License("CDDL") (collectively, the
"License"). You may not use this file except in compliance with the
License. You can obtain a copy of the License at
http://gephi.org/about/legal/license-notice/
or /cddl-1.0.txt and /gpl-3.0.txt. See the License for the
specific language governing permissions and limitations under the
License. When distributing the software, include this License Header
Notice in each file and include the License files at
/cddl-1.0.txt and /gpl-3.0.txt. If applicable, add the following below the
License Header, with the fields enclosed by brackets [] replaced by
your own identifying information:
"Portions Copyrighted [year] [name of copyright owner]"
If you wish your version of this file to be governed by only the CDDL
or only the GPL Version 3, indicate your decision by adding
"[Contributor] elects to include this software in this distribution
under the [CDDL or GPL Version 3] license." If you do not indicate a
single choice of license, a recipient has the option to distribute
your version of this file under either the CDDL, the GPL Version 3 or
to extend the choice of license to its licensees as provided above.
However, if you add GPL Version 3 code and therefore, elected the GPL
Version 3 license, then the option applies only if the new code is
made subject to such option by the copyright holder.
Contributor(s):
Portions Copyrighted 2011 Gephi Consortium.
*/
package org.gephi.utils.collection.avl;
import java.lang.reflect.Array;
import java.util.Iterator;
/**
* Special type of AVL tree which possess a {@link AVLItemAccessor}. It allows to configure the indexes returned
* by the tree nodes
*
* @author Mathieu Bastian
* @param <Item> The type of Object in the tree
*/
public class ParamAVLTree<Item> implements Iterable<Item> {
protected ParamAVLNode<Item> root;
protected int count;
private AVLItemAccessor<Item> accessor;
public ParamAVLTree(AVLItemAccessor<Item> accessor) {
this.accessor = accessor;
}
public ParamAVLTree() {
}
public boolean add(Item item) {
ParamAVLNode<Item> p = this.root;
if (p == null) {
this.root = new ParamAVLNode(item);
} else {
while (true) {
int c = accessor.getNumber(item) - accessor.getNumber(p.item);
if (c < 0) {
if (p.left != null) {
p = p.left;
} else {
p.left = new ParamAVLNode(item, p);
p.balance--;
break;
}
} else if (c > 0) {
if (p.right != null) {
p = p.right;
} else {
p.right = new ParamAVLNode(item, p);
p.balance++;
break;
}
} else {
return false;
}
}
while ((p.balance != 0) && (p.parent != null)) {
if (p.parent.left == p) {
p.parent.balance--;
} else {
p.parent.balance++;
}
p = p.parent;
if (p.balance == -2) {
ParamAVLNode x = p.left;
if (x.balance == -1) {
x.parent = p.parent;
if (p.parent == null) {
this.root = x;
} else {
if (p.parent.left == p) {
p.parent.left = x;
} else {
p.parent.right = x;
}
}
p.left = x.right;
if (p.left != null) {
p.left.parent = p;
}
x.right = p;
p.parent = x;
x.balance = 0;
p.balance = 0;
} else {
ParamAVLNode w = x.right;
w.parent = p.parent;
if (p.parent == null) {
this.root = w;
} else {
if (p.parent.left == p) {
p.parent.left = w;
} else {
p.parent.right = w;
}
}
x.right = w.left;
if (x.right != null) {
x.right.parent = x;
}
p.left = w.right;
if (p.left != null) {
p.left.parent = p;
}
w.left = x;
w.right = p;
x.parent = w;
p.parent = w;
if (w.balance == -1) {
x.balance = 0;
p.balance = 1;
} else if (w.balance == 0) {
x.balance = 0;
p.balance = 0;
} else // w.balance == 1
{
x.balance = -1;
p.balance = 0;
}
w.balance = 0;
}
break;
} else if (p.balance == 2) {
ParamAVLNode x = p.right;
if (x.balance == 1) {
x.parent = p.parent;
if (p.parent == null) {
this.root = x;
} else {
if (p.parent.left == p) {
p.parent.left = x;
} else {
p.parent.right = x;
}
}
p.right = x.left;
if (p.right != null) {
p.right.parent = p;
}
x.left = p;
p.parent = x;
x.balance = 0;
p.balance = 0;
} else {
ParamAVLNode w = x.left;
w.parent = p.parent;
if (p.parent == null) {
this.root = w;
} else {
if (p.parent.left == p) {
p.parent.left = w;
} else {
p.parent.right = w;
}
}
x.left = w.right;
if (x.left != null) {
x.left.parent = x;
}
p.right = w.left;
if (p.right != null) {
p.right.parent = p;
}
w.right = x;
w.left = p;
x.parent = w;
p.parent = w;
if (w.balance == 1) {
x.balance = 0;
p.balance = -1;
} else if (w.balance == 0) {
x.balance = 0;
p.balance = 0;
} else // w.balance == -1
{
x.balance = 1;
p.balance = 0;
}
w.balance = 0;
}
break;
}
}
}
this.count++;
return true;
}
public boolean remove(Item item) {
ParamAVLNode<Item> p = this.root;
while (p != null) {
int c = accessor.getNumber(item) - accessor.getNumber(p.item);
if (c < 0) {
p = p.left;
} else if (c > 0) {
p = p.right;
} else {
ParamAVLNode y; // node from which rebalancing begins
int choice = 0; //0:Done 1:Left 2:Right
if (p.right == null) // Case 1: p has no right child
{
if (p.left != null) {
p.left.parent = p.parent;
}
if (p.parent == null) {
this.root = p.left;
count--;
return true;
}
if (p == p.parent.left) {
p.parent.left = p.left;
y = p.parent;
choice = 1;
// goto LeftDelete;
} else {
p.parent.right = p.left;
y = p.parent;
choice = 2;
//goto RightDelete;
}
} else if (p.right.left == null) // Case 2: p's right child has no left child
{
if (p.left != null) {
p.left.parent = p.right;
p.right.left = p.left;
}
p.right.balance = p.balance;
p.right.parent = p.parent;
if (p.parent == null) {
this.root = p.right;
} else {
if (p == p.parent.left) {
p.parent.left = p.right;
} else {
p.parent.right = p.right;
}
}
y = p.right;
choice = 2;
//goto RightDelete;
} else // Case 3: p's right child has a left child
{
ParamAVLNode s = p.right.left;
while (s.left != null) {
s = s.left;
}
if (p.left != null) {
p.left.parent = s;
s.left = p.left;
}
s.parent.left = s.right;
if (s.right != null) {
s.right.parent = s.parent;
}
p.right.parent = s;
s.right = p.right;
y = s.parent; // for rebalacing, must be set before we change s.parent
s.balance = p.balance;
s.parent = p.parent;
if (p.parent == null) {
this.root = s;
} else {
if (p == p.parent.left) {
p.parent.left = s;
} else {
p.parent.right = s;
}
}
choice = 1;
// goto LeftDelete;
}
// rebalancing begins
while (choice != 0) {
if (choice == 1) {
//LeftDelete:
y.balance++;
if (y.balance == 1) {
//goto Done;
choice = 0;
} else if (y.balance == 2) {
ParamAVLNode x = y.right;
if (x.balance == -1) {
ParamAVLNode w = x.left;
w.parent = y.parent;
if (y.parent == null) {
this.root = w;
} else {
if (y.parent.left == y) {
y.parent.left = w;
} else {
y.parent.right = w;
}
}
x.left = w.right;
if (x.left != null) {
x.left.parent = x;
}
y.right = w.left;
if (y.right != null) {
y.right.parent = y;
}
w.right = x;
w.left = y;
x.parent = w;
y.parent = w;
if (w.balance == 1) {
x.balance = 0;
y.balance = -1;
} else if (w.balance == 0) {
x.balance = 0;
y.balance = 0;
} else // w.balance == -1
{
x.balance = 1;
y.balance = 0;
}
w.balance = 0;
y = w; // for next iteration
} else {
x.parent = y.parent;
if (y.parent != null) {
if (y.parent.left == y) {
y.parent.left = x;
} else {
y.parent.right = x;
}
} else {
this.root = x;
}
y.right = x.left;
if (y.right != null) {
y.right.parent = y;
}
x.left = y;
y.parent = x;
if (x.balance == 0) {
x.balance = -1;
y.balance = 1;
//goto Done
choice = 0;
} else {
x.balance = 0;
y.balance = 0;
y = x; // for next iteration
}
}
}
} else if (choice == 2) {
//goto LoopTest;
//RightDelete:
y.balance--;
if (y.balance == -1) {
choice = 0;
//goto Done;
} else if (y.balance == -2) {
ParamAVLNode x = y.left;
if (x.balance == 1) {
ParamAVLNode w = x.right;
w.parent = y.parent;
if (y.parent == null) {
this.root = w;
} else {
if (y.parent.left == y) {
y.parent.left = w;
} else {
y.parent.right = w;
}
}
x.right = w.left;
if (x.right != null) {
x.right.parent = x;
}
y.left = w.right;
if (y.left != null) {
y.left.parent = y;
}
w.left = x;
w.right = y;
x.parent = w;
y.parent = w;
if (w.balance == -1) {
x.balance = 0;
y.balance = 1;
} else if (w.balance == 0) {
x.balance = 0;
y.balance = 0;
} else // w.balance == 1
{
x.balance = -1;
y.balance = 0;
}
w.balance = 0;
y = w; // for next iteration
} else {
x.parent = y.parent;
if (y.parent != null) {
if (y.parent.left == y) {
y.parent.left = x;
} else {
y.parent.right = x;
}
} else {
this.root = x;
}
y.left = x.right;
if (y.left != null) {
y.left.parent = y;
}
x.right = y;
y.parent = x;
if (x.balance == 0) {
x.balance = 1;
y.balance = -1;
choice = 0;
//goto Done;
} else {
x.balance = 0;
y.balance = 0;
y = x; // for next iteration
}
}
}
}
if (choice == 0) {
this.count--;
return true;
}
//LoopTest: {
if (y.parent != null) {
if (y == y.parent.left) {
y = y.parent;
choice = 1;
// goto LeftDelete;
} else {
y = y.parent;
choice = 2;
//goto RightDelete;
}
} else {
//Done
this.count--;
return true;
}
}
}
}
return false;
}
public boolean contains(Item item) {
ParamAVLNode<Item> p = this.root;
while (p != null) {
int c = accessor.getNumber(item) - accessor.getNumber(p.item);
if (c < 0) {
p = p.left;
} else if (c > 0) {
p = p.right;
} else {
return true;
}
}
return false;
}
public Item getItem(int number) {
ParamAVLNode<Item> p = this.root;
while (p != null) {
int c = number - accessor.getNumber(p.item);
if (c < 0) {
p = p.left;
} else if (c > 0) {
p = p.right;
} else {
return p.item;
}
}
return null;
}
public void clear() {
this.root = null;
this.count = 0;
}
public Iterator<Item> iterator() {
return new ParamAVLIterator(this);
}
public int getCount() {
return count;
}
public boolean isEmpty() {
return count==0;
}
public AVLItemAccessor<Item> getAccessor() {
return accessor;
}
public void setAccessor(AVLItemAccessor<Item> accessor) {
this.accessor = accessor;
}
public Item[] toArray(Item[] array) {
Item[] result = (Item[]) java.lang.reflect.Array.newInstance(array.getClass().getComponentType(), count);
if(count==0)
return result;
ParamAVLIterator<Item> itr = new ParamAVLIterator<Item>(root);
for (int i = 0; itr.hasNext(); i++) {
Item item = itr.next();
result[i] = item;
}
return result;
}
}