faster - longest substring without repeating characters

Solution.java

class Solution {
    public int lengthOfLongestSubstring(String s) {
        int r = 0;
        
        Set<Character> set;
        for(int i=0;i<s.length();i++) {
            set = new HashSet<>();
            int t = 0;
            for(int j=i;j<s.length();j++){
                if(set.contains(s.charAt(j))) break;
                set.add(s.charAt(j));
                // System.out.println(s.substring(i,j+1));
                // System.out.println(set);
                if(set.size() > r) r=set.size();
            }
        }
        return r;
    }
}