LeetCode_3. Longest Substring Without Repeating Characters.cpp

class Solution {
public:
    int lengthOfLongestSubstring(string s) {
        int i, j;
        int maxLen=0;
        int maxIndex=0;
        int sLen = s.length();
        int substringLen=0;

        for(i=0; i<sLen; i++){
            bool check[256] = {false};
            substringLen = 1;
            check[s[i]] = true;
            for(j=i+1; j<sLen; j++){
                if(!check[s[j]]){ // character not exit yet
                    check[s[j]] = true;
                    substringLen++;
                }
                else
                    break;
            }
            if(substringLen>maxLen){
                maxLen = substringLen;
                maxIndex = i;
            }
        }
        return maxLen;
    }
};

Need consider several cases, "", "c", others ascii characters.