19、哈希表-JZTXT

1、字符串中的第一个唯一字符

public class FirstUniqChar {

    public int firstUniqChar(String s) {
        int[] freq = new int[26];

        for (int i = 0; i < s.length(); i++) freq[s.charAt(i) - 'a']++;

        for (int i = 0; i < s.length(); i++) {
            if (freq[s.charAt(i) - 'a'] == 1) return i;
        }

        return -1;
    }
}