PHP Cashing Balanced binary tree (AVL tree)

PHP Implements Balanced binary tree (AVL tree)

 
  Deletenode (' n ');(non-balanced tree can be deleted, balance tree not write delete operation)    Print_r ($tree->gettree ());?>

bstorder.php

 data = $data;            $this->left = $left;            $this->right = $right;        $this-&GT;BF = $BF;        } public Function GETBF () {return $this->bf;        The Public Function SETBF ($BF) {$this-&GT;BF = $BF;        } public Function GetData () {return $this->data;        The Public Function SetData ($data) {$this->data = $data;        } public Function &getleft () {return $this->left;        } public Function &getright () {return $this->right;        The Public Function Setleft ($left) {$this->left = $left;        The Public Function Setright ($right) {$this->right = $right;        }} class bst{private $head;//head node private $data;//Initial input data, array form, such as Array (' A ', ' B ');         private $tag;//The previous node set at lookup (invalid, useless)//$BST: Whether to create the AVL tree 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->in               Sertbfnode ($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-&GT;GETBF ()) {case 0: $node-&GT;SETBF (                            1);                        return TRUE; Case 1: $this->rightrotate ($noDE);                        return FALSE;                            Case-1: $node-&GT;SETBF (0);                    return FALSE; }}elseif ($node->getdata () < $value) {if (! $this->insertbfnode ($node->getrigh                    T (), $value)) {return FALSE; } switch ($node-&GT;GETBF ()) {case 0: $node-&GT;SETBF (                            -1);                        return TRUE;                            Case 1: $node-&GT;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-&GT;GETBF ()) {Case 1: $left = & $right->getleft ();                            Switch ($left-&GT;GETBF ()) {case-1: $right-&GT;SETBF (0);                            $node-&GT;SETBF (1);                        Break                            Case 0: $right-&GT;SETBF (0);                            $node-&GT;SETBF (0);                        Break Case 1: $right-&GT;SETBF (-1);                            $node-&GT;SETBF (0);                    Break                    } $left-&GT;SETBF (0);                    $this->excuteright ($right);                    $this->excuteleft ($node);                                    Break                    Case-1: $node-&GT;SETBF (0);                    $right-&GT;SETBF (0);                    $this->excuteleft ($node);            Break            }} Private Function Rightrotate (& $node) {$left = & $node->getleft ();                    Switch ($left-&GT;GETBF ()) {case-1: $right = & $left->getright ();                            Switch ($right-&GT;GETBF ()) {case-1: $left-&GT;SETBF (1);                            $node-&GT;SETBF (0);                        Break                   Case 0: $left-&GT;SETBF (0);         $node-&GT;SETBF (0);                          Break                            Case 1: $left-&GT;SETBF (0);                            $node-&GT;SETBF (-1);                    Break                     } $right-&GT;SETBF (0);                    $this->excuteleft ($left);                    $this->excuteright ($node);                Break                    Case 1: $node-&GT;SETBF (0);                    $left-&GT;SETBF (0);                    $this->excuteright ($node);            Break }} Public Function Createbst () {foreach ($this->data as $value) {$this->inse            Rtnode ($value);            }}//$pre: If the node is not found, returns the pre-value 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 No            De ($key);                }else{$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; }}?>

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