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
http://www.nowcoder.com/practice/e896d0f82f1246a3aa7b232ce38029d4
遍历两次字符串
from collections import defaultdict
while True:
try:
s = input()
d = defaultdict(int)
for c in s:
d[c] += 1
flag = False
for c in s:
if d[c] == 1:
flag = True
print(c)
break
if flag == False:
print(-1)
except:
break
