leetcode 387. First Unique Character in a String

public class Solution { public int firstUniqChar(String s) { int[] alphabet = new int[26]; for(char c: s.toCharArray()) alphabet[c-'a'] ++; for (int i=0;i<s.length(); i++) if (alphabet[s.charAt(i) - 'a'] == 1) return i; return -1; } }