Update 0109._convert_sorted_list_to_binary_search_tree.md

docs/Leetcode_Solutions/Python/0109._convert_sorted_list_to_binary_search_tree.md

-### 109. Convert Sorted List to Binary Search Tree
+# 109. Convert Sorted List to Binary Search Tree
 
+**<font color=orange>难度: Medium</font>**
 
+## 刷题内容
 
-题目:
-<https://leetcode.com/problems/convert-sorted-list-to-binary-search-tree/>
+> 原题连接
 
+* https://leetcode.com/problems/convert-sorted-list-to-binary-search-tree/
 
-难度:
+> 内容描述
 
-Medium
+```
+Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST.
+
+For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the two subtrees of every node never differ by more than 1.
+
+Example:
+
+Given the sorted linked list: [-10,-3,0,5,9],
+
+One possible answer is: [0,-3,9,-10,null,5], which represents the following height balanced BST:
+
+      0
+     / \
+   -3   9
+   /   /
+ -10  5
+```
+
+## 解题方案
 
-思路：
+> 思路 1
+******- 时间复杂度: O(N)******- 空间复杂度: O(N)******
 
 跟第 108 题一样