PHP implementation Clues two fork tree and Binary tree traversal method detailed clues binary tree pre-sequence clue binary tree First order clue binary

In this paper, we describe the clue of PHP implementation two fork tree and binary tree traversal method. Share to everyone for your reference, as follows:

<?php  require ' bitree.php ';  $str = ' ko#be8#tr### #acy ##### ';  $tree = new Bitree ($STR);  $tree->createthreadtree ();  echo $tree->threadlist (). "\ n"; traverse the lead from the first node two tree  echo $tree->threadlistreserv (); reverse traverse?> from the last node.

bitree.php:

<? /** * PHP Implementation two fork tree * * @author Zhaojiangwei * @since 2011/10/25 10:32 *//Node class node{Private $data = NULL    ;    Private $left = NULL;    Private $right = NULL;    Private $lTag = 0;    Private $rTag = 0;    Public Function Node ($data = False) {$this->data = $data;    }//I do not like to use the Magic method public Function GetData () {return $this->data;    The Public Function SetData ($data) {$this->data = $data;    } public Function GetLeft () {return $this->left;    The Public Function Setleft ($left) {$this->left = $left;    } public Function GetRight () {return $this->right;    The Public Function Setright ($right) {$this->right = $right;    } public Function Getltag () {return $this->ltag;    The Public Function Setltag ($tag) {$this->ltag = $tag;    } public Function Getrtag () {return $this->rtag;    The Public Function Setrtag ($tag) {$this->rtag = $tag; }}//Lead two fork tree classes class Bitree{Private $datas = null;//the string to import; Private $root = NULL; root node private $leafCount = 0;//leaf node number private $headNode = NULL; Clue two fork Tree's head node private $preNode = null;//traversal of a threaded binary tree when saving the previous traversed node public function Bitree ($datas) {Is_array ($datas) | |      Datas = Str_split ($datas);      $this->datas = $datas;      $this->backupdata = $this->datas;    $this->createtree (TRUE); }//Pre-sequence traversal create tree//$root determine if you want to create a root node public function createtree ($root = FALSE) {if (Emptyempty ($this->datas)) r      Eturn NULL;      $first = Array_shift ($this->datas);      if ($first = = ' # ') {return NULL;        }else{$node = new node ($first);        $root && $this->root = $node;        $node->setleft ($this->createtree ());        $node->setright ($this->createtree ());      return $node;      }}//Returns the number of leaf nodes of the binary tree public Function Getleafcount () {$this->figureleafcount ($this->root);    return $this->leafcount; } Private FunCtion Figureleafcount ($node) {if ($node = = NULL) return false;      if ($this->checkempty ($node)) {$this->leafcount + +;        }else{$this->figureleafcount ($node->getleft ());      $this->figureleafcount ($node->getright ()); }}//Determine if the node is a leaf node private function checkempty ($node) {if ($node->getleft () = = NULL && $node->ge      Tright () = = NULL) {return true;    } return false;    }//Returns the binary tree depth public function getdepth () {return $this->traversdepth ($this->root);      }//Traversal to find the binary tree depth public function traversdepth ($node) {if ($node = = NULL) {return 0;      } $u = $this->traversdepth ($node->getleft ()) + 1;      $v = $this->traversdepth ($node->getright ()) + 1; return $u > $v?    $u: $v; }//Returns the traversal result, in the form of a string//$order is returned in the form of a traversal, before the public function getList ($order = ' front ') {if ($this->root = = NULL      ) return NULL;      $nodeList = Array (); Switch ($oRder) {case "front": $this->frontlist ($this->root, $nodeList);        Break          Case "Middle": $this->middlelist ($this->root, $nodeList);        Break          Case "Last": $this->lastlist ($this->root, $nodeList);        Break          Default: $this->frontlist ($this->root, $nodeList);      Break    } return implode ($nodeList);      }//Create thread two fork tree public Function Createthreadtree () {$this->headnode = new Node ();      $this->prenode = & $this->headnode;      $this->headnode->setltag (0);      $this->headnode->setleft ($this->root);      $this->headnode->setrtag (1);      $this->threadtraverse ($this->root);      $this->prenode->setright ($this->headnode);      $this->prenode->setrtag (1);    $this->headnode->setright ($this->prenode); }//threaded binary tree Private function Threadtraverse ($node) {if ($node! = NULL) {if ($node,GetLeft () = = NULL) {$node->setltag (1);        $node->setleft ($this->prenode);        }else{$this->threadtraverse ($node->getleft ()); if ($this->prenode! = $this->headnode && $this->prenode->getright () = = NULL) {$this-&          Gt;prenode->setrtag (1);        $this->prenode->setright ($node);      } $this->prenode = & $node;//Note the reference $this->threadtraverse ($node->getright ());      }}//From the first node traversing the sequence clue two fork tree public Function threadlist () {$arr = array (); for ($node = $this->getfirstthreadnode ($this->root); $node! = $this->headnode; $node = $this->getnextnode ($      node) {$arr [] = $node->getdata ();    } return implode ($arr);      }//reverse-traverse the sequence thread from the tail node two fork tree public Function Threadlistreserv () {$arr = array (); for ($node = $this->headnode->getright (); $node! = $this->headnode; $node = $this->getprenode ($node)) {$ arr[] = $node-&Gt;getdata ();    } return implode ($arr); }//Returns a node's predecessor public Function Getprenode ($node) {if ($node->getltag () = = 1) {return $node->getleft (      );      }else{return $this->getlastthreadnode ($node->getleft ()); }}//Returns the subsequent public function Getnextnode ($node) {if ($node->getrtag () = = 1) of a node {return $node->ge      Tright ();      }else{return $this->getfirstthreadnode ($node->getright ()); }}//Returns the first node of the sequence clue two fork in public function Getfirstthreadnode ($node) {while ($node->getltag () = = 0) {$no      de = $node->getleft ();    } return $node; }//Returns the last node of the sequence clue two fork tree public Function Getlastthreadnode ($node) {while ($node->getrtag () = = 0) {$node =      $node->getright ();    } return $node; }//Pre-order traversal private Function Frontlist ($node, & $nodeList) {if ($node!== NULL) {$nodeList [] = $node-&gt        ; GetData (); $this->frontlist ($node->getleft(), $nodeList);      $this->frontlist ($node->getright (), $nodeList); }}//Sequence traversal private function middlelist ($node, & $nodeList) {if ($node! = NULL) {$this->middleli        St ($node->getleft (), $nodeList);        $nodeList [] = $node->getdata ();      $this->middlelist ($node->getright (), $nodeList); }}//post-traversal private function Lastlist ($node, & $nodeList) {if ($node! = NULL) {$this->lastlist ($        Node->getleft (), $nodeList);        $this->lastlist ($node->getright (), $nodeList);      $nodeList [] = $node->getdata ();    }} Public Function GetData () {return $this->data;    } public Function Getroot () {return $this->root; }}?>

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