3. Longest Substring Without Repeating Characters.cpp

class Solution {
public:
    int lengthOfLongestSubstring(string s) {
        if(s.length()==0)
        {
            return 0;
        }
        if(s.length()==1)
        {
            return 1;
        }
        
        int maxL = 0;
        bool visited[256] = {false};
        int left = 0,right = 0;

        for(;right<s.length();right++)
        {
            if(visited[s[right]]==false)
            {
                visited[s[right]] = true;
            }
            else
            {
                maxL = max(maxL,(right-left));
                while(left<right)
                {
                    if(s[left]!=s[right])
                    {
                        visited[s[left]] = false;
                        left++;
                    }
                    else
                    {
                        left++;
                        break;
                    }
                }
            }
        }

        maxL = max(maxL,(right-left));
        return maxL;
    }
};