701. 二叉搜索树中的插入操作(Medium)

class Solution:
    def insertIntoBST(self, root: TreeNode, val: int) -> TreeNode:
        def search(root, val):
            if not root: return TreeNode(val)
            if val > root.val:
                root.right = search(root.right, val)
            else:
                root.left = search(root.left, val)
            return root 
        return search(root, val)