Update LongestSubstringWithoutRepeatingCharacters.py

Author: assassint2017

Longest Substring Without Repeating Characters/LongestSubstringWithoutRepeatingCharacters.py

@@ -7,15 +7,17 @@ def lengthOfLongestSubstring(self, s):
         :rtype: int
         """
 
-        temp_list = []
-        max_length, length = 0, 0
+        temp_list = []  # 存储子字符串
+        max_length, length = 0, 0  # length跟踪子字符串的长度
 
         for letter in s:
             if letter not in temp_list:
                 length += 1
                 if length > max_length:
                     max_length = length
             else:
+                # 这里由于后边的字符的最大不重复子字符串不可能超过第一个
+                # 所以要从第一个已经的不重复的字符开始计算
                 temp_list = temp_list[temp_list.index(letter) + 1:]
                 length = len(temp_list) + 1
             temp_list.append(letter)