require 'bstOrder.php';

$test = range(1, 10);

//$test = array(3,9,1,4,8,5,7,6,2,10);

$tree = new Bst($test, true);

//$tree->deleteNode('30');(非平衡树可删除,平衡树的没写删除操作)

print_r($tree->getTree());

?>

bstOrder.php

/**

* PHP实现二叉排序树

* @author zhaojiangwei

* @since 2011/11/16 16:29

*

*/

class Node{

private $data;

private $left;

private $right;

private $bf;//平衡度

public function Node($data = NULL, $bf = 0, $left = NULL, $right = NULL){

$this->data = $data;

$this->left = $left;

$this->right = $right;

$this->bf = $bf;

}

public function getBf(){

return $this->bf;

}

public function setBf($bf){

$this->bf = $bf;

}

public function getData(){

return $this->data;

}

public function setData($data){

$this->data = $data;

}

public function &getLeft(){

return $this->left;

}

public function &getRight(){

return $this->right;

}

public function setLeft($left){

$this->left = $left;

}

public function setRight($right){

$this->right = $right;

}

}

class Bst{

private $head;//头结点

private $data;//初始输入的数据,为数组形式,如array('a','b');

private $tag;//查找时设置的前一结点(已无效,没用)

//$bst:是否创建AVL树

public function Bst($data, $bst = FALSE){

$this->data = $data;

$this->head = NULL;

if(!$bst){

$this->createBst();

}else{

$this->createBfBst();

}

}

public function createBfBst(){

foreach($this->data as $value){

$this->insertBfNode($this->head, $value);

}

}

private function insertBfNode(&$node, $value){

if($node == NULL){

$node = new Node($value, 0);

return TRUE;

}else{

if($node->getData() > $value){

if(!$this->insertBfNode($node->getLeft(), $value)){

return FALSE;

}

switch($node->getBf()){

case 0:

$node->setBf(1);

return TRUE;

case 1:

$this->rightRotate($node);

return FALSE;

case -1:

$node->setBf(0);

return FALSE;

}

}elseif($node->getData() < $value){

if(!$this->insertBfNode($node->getRight(), $value)){

return FALSE;

}

switch($node->getBf()){

case 0:

$node->setBf(-1);

return TRUE;

case 1:

$node->setBf(0);

return FALSE;

case -1:

$this->leftRotate($node);

return FALSE;

}

}else{

return FAlse;

}

}

}

private function excuteLeft(&$node){

$temp = $node;

$node = $node->getRight();

$temp->setRight($node->getLeft());

$node->setLeft($temp);

}

private function excuteRight(&$node){

$temp = $node;

$node = $node->getLeft();

$temp->setLeft($node->getRight());

$node->setRight($temp);

}

private function leftRotate(&$node){

$right = &$node->getRight();

switch($right->getBf()){

case 1:

$left = &$right->getLeft();

switch($left->getBf()){

case -1:

$right->setBf(0);

$node->setBf(1);

break;

case 0:

$right->setBf(0);

$node->setBf(0);

break;

case 1:

$right->setBf(-1);

$node->setBf(0);

break;

}

$left->setBf(0);

$this->excuteRight($right);

$this->excuteLeft($node);

break;

case -1:

$node->setBf(0);

$right->setBf(0);

$this->excuteLeft($node);

break;

}

}

private function rightRotate(&$node){

$left = &$node->getLeft();

switch($left->getBf()){

case -1:

$right = &$left->getRight();

switch($right->getBf()){

case -1:

$left->setBf(1);

$node->setBf(0);

break;

case 0:

$left->setBf(0);

$node->setBf(0);

break;

case 1:

$left->setBf(0);

$node->setBf(-1);

break;

}

$right->setBf(0);

$this->excuteLeft($left);

$this->excuteRight($node);

break;

case 1:

$node->setBf(0);

$left->setBf(0);

$this->excuteRight($node);

break;

}

}

public function createBst(){

foreach($this->data as $value){

$this->insertNode($value);

}

}

//$pre:如果找不到该结点,是否返回前值

public function &searchBst(& $node, $key, $pre = FALSE){

if($node == NULL){

if($pre){

return $this->tag;

}else{

return FALSE;

}

}

if($key > $node->getData()){

$this->tag = $node;

return $this->searchBst($node->getRight(), $key, $pre);

}elseif($key < $node->getData()){

$this->tag = $node;

return $this->searchBst($node->getLeft(), $key, $pre);

}else{

return $node;

}

}

public function insertNode($key){

if(!$this->head){

$this->head = new Node($key);

}else{

$pre = $this->searchBst($this->head, $key, TRUE);

$node = new Node($key);

if($pre->getData() > $key){

$pre->setLeft($node);

}else{

$pre->setRight($node);

}

}

}

public function deleteNode($key){

$node = &$this->searchBst($this->head, $key);

if(!$node){

return FALSE;

}

if($node->getLeft() == NULL){

$node = $node->getRight();

}elseif($node->getRight() == NULL){

$node = $node->getLeft();

}else{

$leftBig = &$this->searchLeftBig($node);

$node->setData($leftBig->getData());

if($leftBig->getLeft()){

$leftBig = $leftBig->getLeft();

}

}

}

private function &searchLeftBig(& $key){

$result = &$key->getLeft();

while($result){

if($result->getRight() == NULL){

return $result;

}

$result = &$result->getRight();

}

}

public function getTree(){

return $this->head;

}

}

?>