def sortedArrayToBSTRecu(self, num, start, end):
        if start == end:
            return None
        mid = start + (end - start) / 2
        node = TreeNode(num[mid])
        node.left = self.sortedArrayToBSTRecu(num, start, mid)
        node.right = self.sortedArrayToBSTRecu(num, mid + 1, end)
        return node
dataset/ETHPy150Open kamyu104/LeetCode/Python/convert-sorted-array-to-binary-search-tree.py/Solution.sortedArrayToBSTRecu/original