二叉树镜像

package Struct;

public class TreeNode {
    public int val = 0;
    public TreeNode left = null;
    public TreeNode right = null;

    public TreeNode(int val) {
        this.val = val;
    }

    @Override
    public String toString() {
        return "TreeNode [val=" + val + ", left=" + left + ", right=" + right + "]";
    }
}
 
package offer;

import Struct.TreeNode;

/**
 * 
 * 二叉树的镜像定义：源二叉树 
            8
           /  
          6   10
         /   / 
        5  7 9  11
        镜像二叉树
            8
           /  
          10   6
         /   / 
        11 9 7   5
 * @author 爱不会绝迹
 *
 */
public class Problem08 {
    /**
     * 
     * 镜像二叉树
     * @param root
     */
    public static void Mirror(TreeNode root) {
        if(root!=null){
            TreeNode tmp = root.left;
            root.left = root.right;
            root.right = tmp;
            Mirror(root.left);
            Mirror(root.right);
        }
    }
    
    private static int index = -1;
    public static void main(String[] args) {
        Integer[] array = {8,6,5,null,null,7,null,null,10,9,null,null,11,null,null};
        TreeNode tree = createBinTree(array);
//        inOrder(tree);
//        postOrder(tree);
        Mirror(tree);
        preOrder(tree);
    }
    private static TreeNode createBinTree(Integer[] array) {
        TreeNode tree = null;
        if(index < array.length-1 && array[++index]!=null){
            tree = new TreeNode(array[index]);
            tree.left = createBinTree(array);
            tree.right = createBinTree(array);
        }
        return tree;
    }
    private static void preOrder(TreeNode root){
        if(root!=null){
            System.out.print(root.val+" ");
            preOrder(root.left);
            preOrder(root.right);
        }
    }
    
    private static void inOrder(TreeNode root){
        if(root!=null){
            preOrder(root.left);
            System.out.print(root.val+" ");
            preOrder(root.right);
        }
    }
    
    private static void postOrder(TreeNode root){
        if(root!=null){
            preOrder(root.left);
            preOrder(root.right);
            System.out.print(root.val+" ");
        }
    }
}