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
import sys
s = input()
d = {}
for i in range(len(s)):
d[s[i]] = d.get(s[i],0)+1
min_num = min(d.values())
if min_num>1:
print(-1)
else:
for i in range(len(s)):
if d[s[i]]==1:
print(s[i])
break
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