二叉树

package cn.edu.ujn.nk;
 
import java.util.Stack;
 
/**
 * 二叉树的链式存储
 * @author WWX
 */  
public class BinaryTree {  
     
    private TreeNode root=null;  
      
    public BinaryTree(){  
        root=new TreeNode(1,"rootNode(A)");  
    }  
      
    /**
     * 创建一棵二叉树
     * <pre> 
     *           A
     *     B          C
     *  D     E            F
     *  </pre> 
     * @param root
     * @author WWX
     */  
    public void createBinTree(TreeNode root){  
        TreeNode newNodeB = new TreeNode(2,"B");  
        TreeNode newNodeC = new TreeNode(3,"C");  
        TreeNode newNodeD = new TreeNode(4,"D");  
        TreeNode newNodeE = new TreeNode(5,"E");  
        TreeNode newNodeF = new TreeNode(6,"F");  
        root.leftChild=newNodeB;  
        root.rightChild=newNodeC;  
        root.leftChild.leftChild=newNodeD;  
        root.leftChild.rightChild=newNodeE;  
        root.rightChild.rightChild=newNodeF;  
    }  
      
    public boolean isEmpty(){  
        return root==null;  
    }  
  
    //树的高度  
    public int height(){  
        return height(root);  
    }  
      
    //节点个数  
    public int size(){  
        return size(root);  
    }  
      
    private int height(TreeNode subTree){  
        if(subTree == null)  
            return 0;	// 递归结束：空树高度为0
        else{
            int i = height(subTree.leftChild);
            int j = height(subTree.rightChild);
            return (i < j) ? (j + 1) : (i + 1);
        }
    }
      
    private int size(TreeNode subTree){  
        if(subTree == null){
            return 0;  
        }else{  
            return 1 + size(subTree.leftChild) + size(subTree.rightChild);  
        }  
    }  
      
    //返回双亲结点  
    public TreeNode parent(TreeNode element){  
        return (root == null|| root == element) ? null : parent(root, element);
    }
      
    public TreeNode parent(TreeNode subTree,TreeNode element){  
        if(subTree == null)  
            return null;  
        if(subTree.leftChild == element || subTree.rightChild == element)
            //返回父结点地址  
            return subTree;  
        TreeNode p;
        // 先在左子树中找，如果左子树中没有找到，才到右子树去找  
        if((p = parent(subTree.leftChild, element)) != null)
            //递归在左子树中搜索  
            return p;  
        else  
            //递归在右子树中搜索  
            return parent(subTree.rightChild, element);  
    }  
      
    public TreeNode getLeftChildNode(TreeNode element){  
        return (element != null) ? element.leftChild : null;  
    }  
      
    public TreeNode getRightChildNode(TreeNode element){  
        return (element != null) ? element.rightChild : null;  
    }  
      
    public TreeNode getRoot(){  
        return root;
    }  
      
    //在释放某个结点时，该结点的左右子树都已经释放，  
    //所以应该采用后续遍历，当访问某个结点时将该结点的存储空间释放  
    public void destroy(TreeNode subTree){  
        //删除根为subTree的子树  
        if(subTree!=null){  
            //删除左子树  
            destroy(subTree.leftChild);  
            //删除右子树  
            destroy(subTree.rightChild);  
            //删除根结点  
            subTree=null;  
        }  
    }  
      
    public void traverse(TreeNode subTree){  
        System.out.println("key:"+subTree.key+"--name:"+subTree.data);;  
        traverse(subTree.leftChild);  
        traverse(subTree.rightChild);  
    }  
      
    //前序遍历  
    public void preOrder(TreeNode subTree){  
        if(subTree!=null){  
            visted(subTree);  
            preOrder(subTree.leftChild);  
            preOrder(subTree.rightChild);  
        }  
    }  
      
    //中序遍历  
    public void inOrder(TreeNode subTree){  
        if(subTree!=null){  
            inOrder(subTree.leftChild);  
            visted(subTree);  
            inOrder(subTree.rightChild);  
        }  
    }  
      
    //后续遍历  
    public void postOrder(TreeNode subTree) {  
        if (subTree != null) {  
            postOrder(subTree.leftChild);  
            postOrder(subTree.rightChild);  
            visted(subTree);  
        }  
    }  
      
    //前序遍历的非递归实现  
    public void nonRecPreOrder(TreeNode p){  
        Stack<TreeNode> stack=new Stack<TreeNode>();  
        TreeNode node=p;  
        while(node!=null||stack.size()>0){  
            while(node!=null){  
                visted(node);  
                stack.push(node);  
                node=node.leftChild;  
            }  
            while(stack.size()>0){  
                node=stack.pop();  
                node=node.rightChild;  
            }   
        }  
    }  
      
    //中序遍历的非递归实现  
    public void nonRecInOrder(TreeNode p){  
        Stack<TreeNode> stack =new Stack<BinaryTree.TreeNode>();  
        TreeNode node =p;  
        while(node!=null||stack.size()>0){  
            //存在左子树  
            while(node!=null){  
                stack.push(node);  
                node=node.leftChild;  
            }  
            //栈非空  
            if(stack.size()>0){  
                node=stack.pop();  
                visted(node);  
                node=node.rightChild;  
            }  
        }  
    }  
      
    //后序遍历的非递归实现  
    public void noRecPostOrder(TreeNode p){  
        Stack<TreeNode> stack=new Stack<BinaryTree.TreeNode>();  
        TreeNode node =p;  
        while(p!=null){  
            //左子树入栈  
            for(;p.leftChild!=null;p=p.leftChild){  
                stack.push(p);  
            }  
            //当前结点无右子树或右子树已经输出  
            while(p!=null&&(p.rightChild==null||p.rightChild==node)){  
                visted(p);  
                //纪录上一个已输出结点  
                node =p;  
                if(stack.empty())  
                    return;  
                p=stack.pop();  
            }  
            //处理右子树  
            stack.push(p);  
            p=p.rightChild;  
        }  
    }  
    public void visted(TreeNode subTree){  
        subTree.isVisted=true;  
        System.out.println("key:"+subTree.key+"--name:"+subTree.data);;  
    }
    /**
     * 二叉树的节点数据结构
     * @author WWX
     */  
    private class  TreeNode{
        private int key = 0;
        private String data = null;  
        private boolean isVisted = false;
        private TreeNode leftChild = null;
        private TreeNode rightChild = null;  
          
        public TreeNode(){}  
          
        /**
         * @param key  层序编码
         * @param data 数据域
         */  
        public TreeNode(int key,String data){  
            this.key = key;  
            this.data = data;  
            this.leftChild = null;  
            this.rightChild = null;  
        }  
    }  
      
    //测试  
    public static void main(String[] args) {  
        BinaryTree bt = new BinaryTree();  
        bt.createBinTree(bt.root);  
        System.out.println("the size of the tree is " + bt.size());  
        System.out.println("the height of the tree is " + bt.height());  
          
        System.out.println("***递归实现****(前序遍历)[ABDECF]遍历*****************");  
        bt.preOrder(bt.root);  
          
        System.out.println("***递归实现****(中序遍历)[DBEACF]遍历*****************");  
        bt.inOrder(bt.root);  
         
        System.out.println("***递归实现****(后序遍历)[DEBFCA]遍历*****************");  
        bt.postOrder(bt.root);  
          
        System.out.println("***非递归实现****(前序遍历)[ABDECF]遍历*****************");  
        bt.nonRecPreOrder(bt.root);  
          
        System.out.println("***非递归实现****(中序遍历)[DBEACF]遍历*****************");  
        bt.nonRecInOrder(bt.root);  
          
        System.out.println("***非递归实现****(后序遍历)[DEBFCA]遍历*****************");  
        bt.noRecPostOrder(bt.root);  
    }  
}