每日一题力扣387
给定一个字符串,找到它的第一个不重复的字符,并返回它的索引。如果不存在,则返回 -1
错解:
理解错题意了
class Solution: def firstUniqChar(self, s: str) -> int: for i in range(len(s)): for j in range(i+1,len(s)): if s[i]!=s[j]: return i
正解:
class Solution: def firstUniqChar(self, s: str) -> int: d=dict() for i in s: d[i]=d.get(i,0) +1 for idx,x in enumerate(s): if d[x]==1: return idx return -1