Serialization is 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 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. Example 1: Input: root = [2,1,3] Output: [2,1,3] Example 2: Input: root = [] Output: [] Constraints: The number of nodes in the tree is in the range [0, 104]. 0 <= Node.val <= 104 The input tree is guaranteed to be a binary search tree.