Update Python codes.

codes/python/chapter_computational_complexity/leetcode_two_sum.py

@@ -11,6 +11,7 @@ from include import *
 """ 方法一：暴力枚举 """
 class SolutionBruteForce:
     def twoSum(self, nums: List[int], target: int) -> List[int]:
+        # 两层循环，时间复杂度 O(n^2)
         for i in range(len(nums) - 1):
             for j in range(i + 1, len(nums)):
                 if nums[i] + nums[j] == target:
@@ -20,7 +21,9 @@ class SolutionBruteForce:
 """ 方法二：辅助哈希表 """
 class SolutionHashMap:
     def twoSum(self, nums: List[int], target: int) -> List[int]:
+        # 辅助哈希表，空间复杂度 O(n)
         dic = {}
+        # 单层循环，时间复杂度 O(n)
         for i in range(len(nums)):
             if target - nums[i] in dic:
                 return dic[target - nums[i]], i