leetcode3-Longest Substring Without Repeating Characters

class Solution {
     public int lengthOfLongestSubstring(String s) {
        if (s== null || s.length() == 0){
            return 0;
        }
        int max = 0;
        int temp = 0;
        char c[] = s.toCharArray();
        for(int i = 0;i set = new HashSet();
            temp = 0;
            for(int j = i;j