Java Two fork tree implementation code

 Public classTree {PrivateTreeNode root =NULL;  PublicTree () {root=NewTreeNode (1, "A"); }        Private classTreeNode {Private intkey; PrivateString data; Private Booleanisvisted; PrivateTreeNode Leftchild; PrivateTreeNode Rightchild;  PublicTreeNode (intkey, String data) {             This. Key =key;  This. data =data;  This. Leftchild =NULL;  This. Rightchild =NULL;  This. isvisted =false; }    }    /*** Create a binary tree * A * B C * D E F * createbintree: (). * @authorWei Jian *@paramRoot*/     Public voidcreatebintree (TreeNode root) {TreeNode Newnodeb=NewTreeNode (2, "B"); TreeNode Newnodec=NewTreeNode (3, "C"); TreeNode newnoded=NewTreeNode (4, "D"); TreeNode Newnodee=NewTreeNode (5, "E"); TreeNode Newnodef=NewTreeNode (6, "F"); Root.leftchild=Newnodeb; Root.rightchild=Newnodec;//newnodec.rightchild = newnodef;//newnodeb.leftchild = newnoded;//newnodeb.rightchild = Newnodee;Root.rightChild.rightChild =Newnodef; Root.leftChild.leftChild=newnoded; Root.leftChild.rightChild=Newnodee; }         Public BooleanIsEmpty () {returnRoot = =NULL; }    //height of the tree     Public intheight () {returnheight (root); }    //Number of nodes     Public intsize () {returnsize (root); }        Private intheight (TreeNode subtree) {if(Subtree = =NULL)            return0; inti =height (subtree.leftchild); intj =height (subtree.rightchild); returnI < J? J + 1:i + 1; }        Private intsize (TreeNode subtree) {if(Subtree = =NULL)            return0; return1 + size (subtree.leftchild) +size (subtree.rightchild); }    //Return parent Node     PublicTreeNode Parent (TreeNode element) {return(Root = =NULL|| Root = =Element)?NULL: Parent (root, Element); }         PublicTreeNode Parent (TreeNode subtree, TreeNode element) {if(Subtree = =NULL)            return NULL; if(Subtree.leftchild = = Element | | subtree.rightchild = =Element) {            //returns the parent node address            returnsubtree;        } TreeNode p; //look in the left subtree first, and if not found in the left dial hand tree, look in the right subtree        if(p = parent (subtree.leftchild, Element))! =NULL)            returnP//recursive left subtree search        Else            returnparent (subtree.rightchild, Element); }         PublicTreeNode Getleftchildnode (TreeNode element) {returnElement! =NULL? Element.leftchild:NULL; }         PublicTreeNode Getrightchildnode (TreeNode element) {returnElement! =NULL? Element.rightchild:NULL; }         PublicTreeNode Getroot () {returnRoot; }        //when a node is freed, the left and right subtrees of that node are released,//Therefore, a subsequent traversal should be used to release the storage space of the node when a node is accessed     Public voidDistroy (TreeNode subtree) {//Delete a subtree with the root of subtree        if(Subtree! =NULL) {            //Delete left subtreeDistroy (Subtree.leftchild); //Delete Right sub-treeDistroy (Subtree.rightchild); //Delete root nodesubtree =NULL; }    }         Public voidTraverse (TreeNode subtree) {System.out.println ("Key:" + Subtree.key + "--name:" +subtree.data);        Traverse (Subtree.leftchild);    Traverse (Subtree.rightchild); }    //Pre-sequence traversal     Public voidPerorder (TreeNode subtree) {if(Subtree! =NULL) {visted (subtree);            Perorder (Subtree.leftchild);        Perorder (Subtree.rightchild); }    }    //Middle Sequence Traversal     Public voidinorder (TreeNode subtree) {if(Subtree! =NULL) {perorder (subtree.leftchild);            visted (subtree);        Perorder (Subtree.rightchild); }    }    //Post-post traversal     Public voidpostorder (TreeNode subtree) {if(Subtree! =NULL) {perorder (subtree.leftchild);            Perorder (Subtree.rightchild);        visted (subtree); }    }    //Mirror symmetry of the two-fork tree     Public voidMirror (TreeNode subtree) {if(Subtree = =NULL)            return; TreeNode node=NewTreeNode (Subtree.key, subtree.data); Node.leftchild=Subtree.leftchild; Subtree.leftchild=Subtree.rightchild; Subtree.rightchild=Node.leftchild;        Mirror (Subtree.leftchild);    Mirror (Subtree.rightchild); }         Public voidvisted (TreeNode subtree) {subtree.isvisted=true; System.out.println ("Key:" + Subtree.key + "---data:" +subtree.data); }    //Test     Public Static voidMain (string[] args) {Tree bt=NewTree ();                Bt.createbintree (Bt.root); System.out.println (Bt.size ()+ "---size"); System.out.println (Bt.height ()+ "---height"); System.out.println ("************** Pre-order traversal ************");        Bt.perorder (Bt.root); System.out.println ("************ Mirror symmetry * * pre-sequence traversal ************");        Bt.mirror (Bt.root); Bt.perorder (bt.root);//System.out.println ("************** in sequence traversal ************");//Bt.inorder (bt.root);//        //System.out.println ("************** post-Traversal ************");//Bt.postorder (bt.root);    }    }

Java Two fork tree implementation code