序列化二叉树

题目：

请实现两个函数，分别用来序列化和反序列化二叉树

解答：

 1 public class Solution {
 2     public int index = -1;
 3 
 4     String Serialize(TreeNode root) {
 5         StringBuilder s = new StringBuilder();
 6 
 7         if(root == null){
 8             s.append("#,");
 9             return s.toString();
10         }
11 
12         s.append(root.val+",");
13         s.append(Serialize(root.left));
14         s.append(Serialize(root.right));
15         
16         return s.toString();
17     }
18 
19     TreeNode Deserialize(String str) {
20         index++;
21         String[] DLRseq = str.split(",");
22         TreeNode leave = null;
23         if(!DLRseq[index].equals("#")){
24             leave = new TreeNode(Integer.valueOf(DLRseq[index]));
25             leave.left = Deserialize(str);
26             leave.right = Deserialize(str);
27         }
28         return leave;
29     }  
30 }