Leetcode #387 First Unique Character in a String

Description

Given a string, find the first non-repeating character in it and return it’s index. If it doesn’t exist, return -1.

Example

s = “leetcode”

return 0.

s = “loveleetcode”,

return 2.

Note:

You may assume the string contain only lowercase letters.

Code

class Solution(object):
def firstUniqChar(self, s):
"""
:type s: str
:rtype: int
"""
cnt = dict()
for i in s:
cnt[i] = cnt.get(i, 0) + 1
for i,x in enumerate(s):
if cnt[x] == 1:
return i
else:
return -1