剑指offer——二叉树的镜像

 1 /**
 2 public class TreeNode {
 3     int val = 0;
 4     TreeNode left = null;
 5     TreeNode right = null;
 6  
 7     public TreeNode(int val) {
 8         this.val = val;
 9     }
10 }
11 */
12 public class Solution {
13     public void Mirror(TreeNode root) {
14         if(root==null){
15             return;
16         }
17         if(root.left==null && root.right==null){
18             return;
19         }
20         TreeNode node=null;
21         node=root.left;
22         root.left=root.right;
23         root.right=node;
24         if(root.left!=null){
25             Mirror(root.left);
26         }
27         if(root.right!=null){
28             Mirror(root.right);
29         } 
30     }
31 }