701. Insert into a Binary Search Tree

Python

class Solution:
    def insertIntoBST(self, root: Optional[TreeNode], val: int) -> Optional[TreeNode]:
        if not root:
            return TreeNode(val=val)

        if root.val > val:
            root.left = self.insertIntoBST(root.left, val)
        if root.val < val:
            root.right = self.insertIntoBST(root.right, val)

        return root