Today's Challenge

https://leetcode.com/problems/first-unique-character-in-a-string/

First Unique Character in a String - LeetCode

한동안 hard만 나오더니 요즘은 easy 가 가끔 나오네 ㅎㅎ
문제를 좀 잘 못봤음.. 결국 hash 개념으로 접근하면 쉽게 풀림

class Solution:
    def firstUniqChar(self, s: str) -> int:        
        cnt = collections.Counter(s)
        
        for i, ch in enumerate(s):
            if cnt[ch] == 1:
                return i
        
        return -1