LeetCode Algorithm Longest Substring Without Repeating Characters

Given a string, find the length of the longest substring without repeating characters.
给一个string，找到最长的子string，其中没有重复的字母。

Examples:

Given “abcabcbb”, the answer is “abc”, which the length is 3.

Given “bbbbb”, the answer is “b”, with the length of 1.

Given “pwwkew”, the answer is “wke”, with the length of 3. Note that the answer must be a substring, “pwke” is a subsequence and not a substring.

class Solution {public:    int lengthOfLongestSubstring(string s) {        if(s.empty()) return 0;//若为空，则返回0        int length = 1;//用来记录最长的长度        for(int i = 0;;i++)//从第一个字母开始        {            int j =length;//字符串长度取现阶段最长的            while(setLength(s.substr(i,j)) == j)//如果不重复，则j加一，循环至出现重复字符。            {                j++;            }            length =length>(j-1)?length:(j-1);//length取最长的            if(i+length > s.size()) break;//如果后续没有超过length的string，则退出循环。        }        return length;            }    inline int setLength(string s)//增加inline依旧排名很low，WTF    {        set<char> set_char;        for(auto ss:s)  set_char.insert(ss);        return set_char.size();    }};