Python代码

class Solution:
    def serialize(self, root):
        if not root:
            return "None"
        return str(root.val) + ',' + self.serialize(root.left) + ',' + self.serialize(root.right)

    def deserialize(self, data):
        self.i = -1
        data = data.split(',')
        return self.dfs(data)

    def dfs(self,data):
        if self.i >= len(data):
            return
        self.i += 1
        root = None
        if data[self.i] != "None":
            root = TreeNode(int(data[self.i]))
            root.left = self.dfs(data)
            root.right = self.dfs(data)
        return root