java二叉树现实

package test;
public class Tree {  
  
    private int data;// 数据节点  
    private Tree left;// 左子树  
    private Tree right;// 右子树  
 
    public Tree(int data) {  
        this.data = data;  
        this.left = null;  
        this.right = null;  
    }  
 
    /** 
     * 创建二叉树，返回根结点 
     *  
     * @param input 
     * @return 
     */ 
    public static Tree createTree(int[] input) {  
        Tree root = null;  
        Tree temp = null;  
        for (int i = 0; i < input.length; i++) {  
            // 创建根节点  
            if (root == null) {  
                root = temp = new Tree(input[i]);  
            } else {  
                // 回到根结点  
                temp = root;  
                // 添加节点  
                while (temp.data != input[i])
                {  
                    if (input[i] <= temp.data)
                    {  
                        if (temp.left != null)
                        {  
                            temp = temp.left;  
                        }
                        else
                        {  
                            temp.left = new Tree(input[i]);  
                        }  
                    }
                    else
                    {  
                        if (temp.right != null)
                        {  
                            temp = temp.right;  
                        }
                        else
                        {  
                            temp.right = new Tree(input[i]);  
                        }  
                    }  
                }  
            }  
        }  
        return root;  
    }  
 
    /** 
     * 前序遍历 
     *  
     * @param tree 
     */ 
    public static void preOrder(Tree tree) {  
        if (tree != null) {  
            System.out.print(tree.data + " ");  
            preOrder(tree.left);  
            preOrder(tree.right);  
        }  
    }  
 
    /** 
     * 中序遍历 
     *  
     * @param tree 
     */ 
    public static void midOrder(Tree tree) {  
        if (tree != null) {  
            midOrder(tree.left);  
            System.out.print(tree.data + " ");  
            midOrder(tree.right);  
        }  
    }  
 
    /** 
     * 后序遍历 
     *  
     * @param tree 
     */
  
   public static void posOrder(Tree tree) {  
        if (tree != null) {  
            posOrder(tree.left);  
            posOrder(tree.right);  
            System.out.print(tree.data + " ");  
        }  
    }  
 
    /** 
     * @param args 
     */ 
    public static void main(String[] args) {  
        int[] input = { 4, 2, 6, 1, 3, 5, 7 };  
        Tree tree = createTree(input);  
  /*     System.out.print("前序遍历：");  
        preOrder(tree);  */
    /*   System.out.print("/n中序遍历：");  
        midOrder(tree);   */
        System.out.print("/n后序遍历：");  
        posOrder(tree);  
    }  
}