449. 序列化和反序列化二叉搜索树

难度：中等
昨天忘记做了。。。

简单学习一下官方题解
主要是：’ '.join(map(str, arr)) int数组转String，中间有空格隔开
list(map(int, data.split())) String转int数组

class Codec:def serialize(self, root: TreeNode) -> str:arr = []def postOrder(root: TreeNode) -> None:if root is None:returnpostOrder(root.left)postOrder(root.right)arr.append(root.val)postOrder(root)return ' '.join(map(str, arr))def deserialize(self, data: str) -> TreeNode:arr = list(map(int, data.split()))def construct(lower: int, upper: int) -> TreeNode:if arr == [] or arr[-1] < lower or arr[-1] > upper:return Noneval = arr.pop()root = TreeNode(val)root.right = construct(val, upper)root.left = construct(lower, val)return rootreturn construct(-inf, inf)