Update 167._two_sum_ii_-_input_array_is_sorted.md

Author: 0xkookoo

docs/Leetcode_Solutions/Python/167._two_sum_ii_-_input_array_is_sorted.md

@@ -1,19 +1,38 @@
-### 167. Two Sum II - Input array is sorted
+# 167. Two Sum II - Input array is sorted
 
+**<font color=red>难度: Easy</font>**
 
+## 刷题内容
 
-题目:
-<https://leetcode.com/problems/two-sum-ii-input-array-is-sorted/>
+> 原题连接
 
+* https://leetcode.com/problems/two-sum-ii-input-array-is-sorted/description/
 
-难度:
-Medium
+> 内容描述
 
+```
+
+Given an array of integers that is already sorted in ascending order, find two numbers such that they add up to a specific target number.
+
+The function twoSum should return indices of the two numbers such that they add up to the target, where index1 must be less than index2.
+
+Note:
+
+Your returned answers (both index1 and index2) are not zero-based.
+You may assume that each input would have exactly one solution and you may not use the same element twice.
+Example:
+
+Input: numbers = [2,7,11,15], target = 9
+Output: [1,2]
+Explanation: The sum of 2 and 7 is 9. Therefore index1 = 1, index2 = 2.
+```
 
-思路：
+## 解题方案
 
+> 思路 1
+******- 时间复杂度: O(lgN)******- 空间复杂度: O(1)******
 
-双指针
+二分法+双指针，beats 86.15%
 
 ```python
 class Solution(object):
@@ -27,9 +46,8 @@ class Solution(object):
         while l < r:
             if numbers[l] + numbers[r] == target:
                 return [l+1, r+1]
-            elif numbers[l] + numbers[r] > target:
-                r -= 1
-            else:
+            elif numbers[l] + numbers[r] < target:
                 l += 1
-
+            else:
+                r -= 1
 ```