题解 | #第一个只出现一次的字符#

#
# 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
#
# 
# @param str string字符串 
# @return int整型
#
class Solution:
    def FirstNotRepeatingChar(self , str: str) -> int:
        if len(str) == 1:
            return -1
        hash = dict()
        for i in str:
            if i in hash.keys():
                hash[i] += 1
            else:
                hash[i] = 1
        for key,value in hash.items():
            if value == 1:
                return str.index(key)
        return -1