题解 | #找出字符串中第一个只出现一次的字符#
找出字符串中第一个只出现一次的字符
https://www.nowcoder.com/practice/e896d0f82f1246a3aa7b232ce38029d4
s = input() dic = {} res = 0 flag = 0 for i in range(len(s)): if s[i] in dic: dic[s[i]] += 1 else: dic[s[i]] = 1 for key,value in dic.items(): if value == 1: print(key) flag = 1 break if flag == 0: print('-1')