これは、PHP でバイナリ ツリーとその操作を構築するために使用したコードです。
<?php
class Node
{
public $data;
public $leftChild;
public $rightChild;
public function __construct($data)
{
$this->data=$data;
$this->leftChild=null;
$this->rightChild=null;
}
public function disp_data()
{
echo $this->data;
}
}//end class Node
class BinaryTree
{
public $root;
//public $s;
public function __construct()
{
$this->root=null;
//$this->s=file_get_contents('store');
}
//function to display the tree
public function display()
{
$this->display_tree($this->root);
}
public function display_tree($local_root)
{
if($local_root==null)
return;
$this->display_tree($local_root->leftChild);
echo $local_root->data."<br/>";
$this->display_tree($local_root->rightChild);
}
// function to insert a new node
public function insert($key)
{
$newnode=new Node($key);
if($this->root==null)
{
$this->root=$newnode;
return;
}
else
{
$parent=$this->root;
$current=$this->root;
while(true)
{
$parent=$current;
//$this->find_order($key,$current->data);
if($key==($this->find_order($key,$current->data)))
{
$current=$current->leftChild;
if($current==null)
{
$parent->leftChild=$newnode;
return;
}//end if2
}//end if1
else
{
$current=$current->rightChild;
if($current==null)
{
$parent->rightChild=$newnode;
return;
} //end if1
} //end else
}//end while loop
}//end else
} //end insert function
//function to search a particular Node
public function find($key)
{
$current=$this->root;
while($current->data!=$key)
{
if($key==$this->find_order($key,$current->data))
{
$current=$current->leftChild;
}
else
{
$current=$current->rightChild;
}
if($current==null)
return(null);
}
return($current->data);
}// end the function to search
public function delete1($key)
{
$current=$this->root;
$parent=$this->root;
$isLeftChild=true;
while($current->data!=$key)
{
$parent=$current;
if($key==($this->find_order($key,$current->data)))
{
$current=$current->leftChild;
$isLeftChild=true;
}
else
{
$current=$current->rightChild;
$isLeftChild=false;
}
if($current==null)
return(null);
}//end while loop
echo "<br/><br/>Node to delete:".$current->data;
//to delete a leaf node
if($current->leftChild==null&&$current->rightChild==null)
{
if($current==$this->root)
$this->root=null;
else if($isLeftChild==true)
{
$parent->leftChild=null;
}
else
{
$parent->rightChild=null;
}
return($current);
}//end if1
//to delete a node having a leftChild
else if($current->rightChild==null)
{
if($current==$this->root)
$this->root=$current->leftChild;
else if($isLeftChild==true)
{
$parent->leftChild=$current->leftChild;
}
else
{
$parent->rightChild=$current->leftChild;
}
return($current);
}//end else if1
//to delete a node having a rightChild
else if($current->leftChild==null)
{
if($current==$this->root)
$this->root=$current->rightChild;
else if($isLeftChild==true)
{
$parent->leftChild=$current->rightChild;
}
else
{
$parent->rightChild=$current->rightChild;
}
return($current);
}
//to delete a node having both childs
else
{
$successor=$this->get_successor($current);
if($current==$this->root)
{
$this->root=$successor;
}
else if($isLeftChild==true)
{
$parent->leftChild=$successor;
}
else
{
$parent->rightChild=$successor;
}
$successor->leftChild=$current->leftChild;
return($current);
}
}//end the function to delete a node
//Function to find the successor node
public function get_successor($delNode)
{
$succParent=$delNode;
$successor=$delNode;
$temp=$delNode->rightChild;
while($temp!=null)
{
$succParent=$successor;
$successor=$temp;
$temp=$temp->leftChild;
}
if($successor!=$delNode->rightChild)
{
$succParent->leftChild=$successor->rightChild;
$successor->rightChild=$delNode->rightChild;
}
return($successor);
}
//function to find the order of two strings
public function find_order($str1,$str2)
{
$str1=strtolower($str1);
$str2=strtolower($str2);
$i=0;
$j=0;
$p1=$str1[i];
$p2=$str2[j];
while(true)
{
if(ord($p1)<ord($p2)||($p1==''&&$p2==''))
{
return($str1);
}
else
{
if(ord($p1)==ord($p2))
{
$p1=$str1[++$i];
$p2=$str2[++$j];
continue;
}
return($str2);
}
}//end while
} //end function find string order
public function is_empty()
{
if($this->root==null)
return(true);
else
return(false);
}
}//end class BinaryTree
?>