LongestSubstringWithoutRepeatingCharacters.java

public int lengthOfLongestSubstring(String s) {
        if(s==null || s.length()==0)
         return 0;
         
        int max = Integer.MIN_VALUE;
        for (int i = 0; i < s.length(); i++) {
            int []charIndex = new int[127];
            charIndex[s.charAt(i)]++;
            int count = 1;
            for (int j = i+1; j < s.length(); j++) {
                char c = s.charAt(j);
                int charCount = charIndex[c];
                if(charCount>=1){
                    break;
                }else{
                    charIndex[c]++;
                    count++;
                }
            }
            max = Math.max(max,count);
        }
         return max;
    }