feat(problem): 更新0108.将有序数组转换为二叉搜索树。添加了Python递归的精简版，自身调用

problems/0108.将有序数组转换为二叉搜索树.md

@@ -334,6 +334,18 @@ class Solution:
         return root
 
 ```
+递归 精简(自身调用)
+```python
+class Solution:
+    def sortedArrayToBST(self, nums: List[int]) -> Optional[TreeNode]:
+        if not nums:
+            return
+        mid = len(nums) // 2
+        root = TreeNode(nums[mid])
+        root.left = self.sortedArrayToBST(nums[:mid])
+        root.right = self.sortedArrayToBST(nums[mid + 1 :])
+        return root
+```
 
 迭代法
 ```python