LeetCode--387--字符串中的第一个唯一字符

问题描述：

给定一个字符串，找到它的第一个不重复的字符，并返回它的索引。如果不存在，则返回 -1。

案例:

s = "leetcode"
返回 0.

s = "loveleetcode",
返回 2.

方法：

 1 class Solution(object):
 2     def firstUniqChar(self, s):
 3         """
 4         :type s: str
 5         :rtype: int
 6         """
 7         x = "abcdefghijklmnopqrstuvwxyz"
 8         res = []  #res=[s.index[i] for i in x if s.count(i) == 1]
 9         for i in x:
10             if i in s and s.count(i) == 1:
11                 res.append(s.index(i))
12         if len(res):
13             return min(res)
14         return -1

官方：

 1 class Solution(object):
 2     def firstUniqChar(self, s):
 3         """
 4         :type s: str
 5         :rtype: int
 6         """
 7         
 8         if s == '':
 9             return -1
10         
11         l = len(s)
12         tmp = l
13         for i in 'abcdefghijklmnopqrstuvwxyz':
14             start = s.find(i)
15             end = s.rfind(i)
16             if start != -1 and start == end:
17                 tmp = min(tmp, start)
18         if tmp < l:
19             return tmp
20         else:
21             return -1

2018-09-28 16:27:05