Python - Faster than 100% -  In order traversal, using stack solution - Easy
\nclass Solution:\n    def kthSmallest(self, root: TreeNode, k: int) -> int:\n        stack = []\n        res = []\n        while stack or root:\n            wh
```\nclass Solution:\n    def kthSmallest(self, root: TreeNode, k: int) -> int:\n        stack = []\n        res = []\n        while stack or root:\n            while root:\n                stack.append(root)\n                root = root.left\n            root = stack.pop()\n            res.append(root)\n            root = root.right\n        return res[k-1].val\n```
['Python', 'Python3']