449. Serialize and Deserialize BST**

Serialization is the process of converting a data structure or object into a sequence of bits so that it can be stored in a file or memory buffer, or transmitted across a network connection link to be reconstructed later in the same or another computer environment.

Design an algorithm to serialize and deserialize a binary search tree. There is no restriction on how your serialization/deserialization algorithm should work. You just need to ensure that a binary search tree can be serialized
to a string and this string can be deserialized to the original tree structure.

The encoded string should be as compact as possible.

Note: Do not use class member/global/static variables to store states. Your serialize and deserialize algorithms should be stateless.

public class Codec {

// Encodes a tree to a single string.
public String serialize(TreeNode root) {

if(root==null) return "#!";
String res = root.val + "!";
res += serialize(root.left);
res += serialize(root.right);
return res;

}

// Decodes your encoded data to tree.
public TreeNode deserialize(String data) {
String[] string = data.split("!");
LinkedList<String> list = new LinkedList<>();
for(String s : string){
list.add(s);
}
return reconstruct(list);
}
private TreeNode reconstruct(Queue<String> queue){
String val = queue.poll();
if(val.equals("#")) return null;
TreeNode head = new TreeNode(Integer.valueOf(val));
head.left = reconstruct(queue);
head.right = reconstruct(queue);
return head;

}
}