Longest_Sub_string_without_Repeat_Characters_BruteForce

Longest_Sub_string_without_Repeat_Characters_BruteForce.cpp

class Solution {
public:
    bool isAllUnique(string &s, int start, int end)
    {
        unordered_set<char> hash;
        for(int i = start; i <= end; i++)
        {
            if(hash.find(s[i]) != hash.end())
                return false;
            hash.insert(s[i]);
        }
        return true;
    }
    int lengthOfLongestSubstring(string s) {
        int len = s.size();
        int maxLen = s.empty()? 0 : 1;
        for(int i = 0; i < len; i++)
        {
            for(int j = i + 1; j< len; j++)
            {
                if(isAllUnique(s, i, j)) 
                    maxLen = max(j - i + 1, maxLen);
            }
        }
        return maxLen;
    }
};