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() # asdfasdfoe
dic = {}
res = []
for i in s:
if i not in dic:
dic[i] = s.count(i)
if dic[i] == 1:
res.append(i)
#print(dic)
#print(res)
if min(dic.values()) > 1:
print(-1)
else: # 出现次数等于1
print(res[0])
