387. First Unique Character in a String
Given a string s, find the first non-repeating character in it and return its index . If it does not exist, return -1.
Example 1:
Input: s = "leetcode" Output: 0
Example 2:
Input: s = "loveleetcode" Output: 2
Example 3:
Input: s = "aabb" Output: -1
Constraints:
- 1 <= s.length <= 10
<sup>5</sup> - s consists of only lowercase English letters.
Python:
class Solution(object):
def firstUniqChar(self, s):
"""
:type s: str
:rtype: int
"""