387. First Unique Character in a String

Given a string, find the first non-repeating character in it and return it's index. If it doesn't exist, return -1.

Examples:

s = "leetcode" return 0.

s = "loveleetcode", return 2. Note: You may assume the string contain only lowercase letters.

思路：count（） 代码:python3

class Solution(object):
    def firstUniqChar(self, s):
        """
        :type s: str
        :rtype: int
        """
        arr=[]
        for index,i in enumerate(s):
            if i in arr:
                pass
            else:
                arr.append(i)
                if s.count(i)==1:
                    return index
        return -1