[Second]Longest Substring Without Repeating Characters

 

    int lengthOfLongestSubstring(string s) {
        // Note: The Solution object is instantiated only once and is reused by each test case.
        int max_len = 0,cur_len = 0;
        int hash[256];
        
        for(int i=0;i<256;i++)
            hash[i] = -1;
        
        for(int i=0;i<s.size();i++)
        {
            if(hash[s[i]]==-1||hash[s[i]]<i-cur_len)
                cur_len++;
            else
                cur_len = i - hash[s[i]];
            hash[s[i]] = i;
            max_len = max(max_len,cur_len);
        }
        
        return max_len;