0387.cpp (262B)
1 class Solution { 2 public: 3 int firstUniqChar(string s) { 4 vector<int> um(26, 0); 5 for (char c : s) 6 um[c - 'a']++; 7 for (int i = 0; i < s.size(); i++) 8 if (um[s[i] - 'a'] == 1) return i; 9 return -1; 10 } 11 };