leetcode

0 class Solution {

1 public:

2 int firstUniqChar(string s) {

3 vector<int> um(26, 0);

4 for (char c : s)

5 um[c - 'a']++;

6 for (int i = 0; i < s.size(); i++)

7 if (um[s[i] - 'a'] == 1) return i;

8 return -1;

9 }

10 };