/* 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.graph.dhns.utils.avl; import java.util.Iterator; import org.gephi.utils.collection.avl.ResetableIterator; import org.gephi.graph.dhns.node.AbstractNode; import org.gephi.graph.dhns.node.iterators.AbstractNodeIterator; /** * * @author Mathieu */ public class ViewNodeTree { private AbstractNodeAVLNode root; private int count; public boolean add(AbstractNode item) { AbstractNodeAVLNode p = this.root; if (p == null) { this.root = new AbstractNodeAVLNode(item); } else { while (true) { int c = item.getViewId() - p.item.getViewId(); if (c < 0) { if (p.left != null) { p = p.left; } else { p.left = new AbstractNodeAVLNode(item, p); p.balance--; break; } } else if (c > 0) { if (p.right != null) { p = p.right; } else { p.right = new AbstractNodeAVLNode(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) { AbstractNodeAVLNode 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 { AbstractNodeAVLNode 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) { AbstractNodeAVLNode 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 { AbstractNodeAVLNode 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(AbstractNode item) { return this.remove(item.getViewId()); } public boolean remove(int number) { AbstractNodeAVLNode p = this.root; while (p != null) { int c = number - p.item.getViewId(); if (c < 0) { p = p.left; } else if (c > 0) { p = p.right; } else { AbstractNodeAVLNode 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 { AbstractNodeAVLNode 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) { AbstractNodeAVLNode x = y.right; if (x.balance == -1) { AbstractNodeAVLNode 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) { AbstractNodeAVLNode x = y.left; if (x.balance == 1) { AbstractNodeAVLNode 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(AbstractNode item) { AbstractNodeAVLNode p = this.root; while (p != null) { int c = item.getViewId() - p.item.getViewId(); if (c < 0) { p = p.left; } else if (c > 0) { p = p.right; } else { return true; } } return false; } public AbstractNode get(int number) { AbstractNodeAVLNode p = this.root; while (p != null) { int c = number - p.item.getViewId(); 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 AbstractNodeIterator iterator() { return new AbstractNodeAVLIterator(this); } public int getCount() { return count; } private class AbstractNodeAVLNode { AbstractNodeAVLNode parent; AbstractNodeAVLNode left; AbstractNodeAVLNode right; int balance; AbstractNode item; public AbstractNodeAVLNode(AbstractNode item) { this.item = item; } public AbstractNodeAVLNode(AbstractNode item, AbstractNodeAVLNode parent) { this.item = item; this.parent = parent; } } private class AbstractNodeAVLIterator extends AbstractNodeIterator implements Iterator<AbstractNode>, ResetableIterator { private AbstractNodeAVLNode next; private AbstractNode current; public AbstractNodeAVLIterator() { } public AbstractNodeAVLIterator(AbstractNodeAVLNode node) { this.next = node; goToDownLeft(); } public AbstractNodeAVLIterator(ViewNodeTree tree) { this(tree.root); } public void setNode(ViewNodeTree tree) { this.next = tree.root; goToDownLeft(); } private void goToDownLeft() { if (next != null) { while (next.left != null) { next = next.left; } } } public boolean hasNext() { if (next == null) { return false; } current = this.next.item; if (next.right == null) { while ((next.parent != null) && (next == next.parent.right)) { this.next = this.next.parent; } this.next = this.next.parent; } else { this.next = this.next.right; while (this.next.left != null) { this.next = this.next.left; } } return true; } public AbstractNode next() { return current; } public void remove() { ViewNodeTree.this.remove(current); } } }