String - 58. Length of Last Word

class Solution {

    /*public int firstUniqChar(String s) {
        if (s == null || s.length() == 0) return -1;
        
        HashMap<Character, Integer> count = new HashMap<Character, Integer>();
        for (int i = 0; i <s.length(); i++) {
            char c =  s.charAt(i);
            count.put(c, count.getOrDefault(c, 0) + 1);
        }
        
        for (int i = 0; i <s.length(); i++) {
            if (count.get(s.charAt(i)) == 1) return i;
        }
        
        return -1;
    }*/
    
    public int firstUniqChar(String s) {
        if (s == null || s.length() == 0) return -1;
        
        int res = Integer.MAX_VALUE;
        for (char c = 'a'; c <= 'z'; c++) {
            if (s.indexOf(c) == -1) continue;
            
            if (s.indexOf(c) == s.lastIndexOf(c)) 
                res = Math.min(res, s.indexOf(c));
        }
        
        return res == Integer.MAX_VALUE ? -1 : res;
    }
}