剑指offer_61

public class TreeNode {
    int val = 0;
    TreeNode left = null;
    TreeNode right = null;
    public TreeNode(int val) {
        this.val = val;
    }
}
*/
public class  {
    
    String Serialize(TreeNode root) {
        StringBuffer sb = new StringBuffer();
        if(root == null){
            sb.append("#,");
            return sb.toString();
        }
        sb.append(root.val + ",");
        sb.append(Serialize(root.left));
  		sb.append(Serialize(root.right));
        
        return sb.toString();
    }
    
    private int index;
    private TreeNode DeserializeHelper(String []strings){
        ++index;
        TreeNode node = null;
        if(!strings[index].equals("#")){
            node = new TreeNode(Integer.valueOf(strings[index]));
            node.left = DeserializeHelper(strings);
            node.right = DeserializeHelper(strings);
        }
        return node;
    }
    
    TreeNode Deserialize(String str) {
        index = -1;
        String []strings = str.split(",");
        return DeserializeHelper(strings);
  	}
    
}