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:
        # write code here
        dic = dict()
        for i in str:
            if i not in dic:
                dic[i] = 1
            elif i in dic:
                dic[i] += 1
        for k,v in dic.items():
            if v == 1:
                return str.index(k)
        return -1