167 lines
No EOL
2.8 KiB
PHP
167 lines
No EOL
2.8 KiB
PHP
<?php
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/*
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* Doubly Linked List
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*
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* This list is linked to an avl tree for searching purpose!
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*/
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class DLL {
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private $first;
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private $last;
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private $size;
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private $avl;
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function DLL() {
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$this->avl = new AVLTree();
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$this->first = null;
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$this->last = null;
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$this->size = 0;
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}
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function getIterator() {
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return new NodeIterator($this->first);
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}
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final function getSize() {
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return $this->size;
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}
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final function isEmpty() {
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return ($this->size == 0);
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}
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function getFirst() {
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return $this->first;
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}
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function getLast() {
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return $this->last;
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}
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function addNode($data,$before = null) { // add a node
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if($this->findNode($data->getID()) != null) {
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return false;
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}
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$n = new DLLnode($data);
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if($before == null) {
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//insert as last
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if($this->last != null) {
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$this->last->setChild($n);
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}
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$n->setParent($this->last);
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$this->last = $n;
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}
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else {
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//insert before
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$b = $this->findNode($before);
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if($b != null) {
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if($b == $this->first) {
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$this->first = $n;
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}
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$tmp = $b->getParent();
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$b->setParent($n);
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$n->setChild($b);
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if($tmp != null) {
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$tmp->setChild($n);
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}
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}
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else {
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$this->addNode($data);
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return null;
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}
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}
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if($this->first == null) {
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$this->first = $n;
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}
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$this->avl->insert($n); // pass on to avl tree
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$this->size++;
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return null;
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}
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function removeNode($id) { // remove a node
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#$this->avl->inorder();
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$n = $this->findNode($id);
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if($n != null) {
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$p = $n->getParent();
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$c = $n->getChild();
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if($c != null) {
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$c->setParent($p);
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if($p != null) {
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$p->setChild($c);
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}
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}
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else {
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if($p != null) {
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$p->setChild(null);
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}
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$this->last = $p;
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}
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if($p == null) {
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if($c != null) {
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$c->setParent(null);
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$this->first = $c;
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}
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else {
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$this->first = null;
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}
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}
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$this->avl->remove($id); // pass on to avl tree
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$this->size--;
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}
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}
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function findNode($id) {
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return $this->avl->find($id);
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}
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}
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/*
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* List nodes
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*/
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class DLLnode {
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private $parent;
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private $child;
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public $data;
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function DLLNode($d) {
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$this->parent = null;
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$this->child = null;
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$this->data = $d; // actual data
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}
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final function getParent() {
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return $this->parent;
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}
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final function setParent($p) {
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$this->parent = $p;
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}
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final function getChild() {
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return $this->child;
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}
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final function setChild($c) {
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$this->child = $c;
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}
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final function getIterator() {
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return new NodeIterator($this);
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}
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function getID() {
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return $this->data->getID();
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}
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}
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?>
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