Longest Substring Without Repeating Characters

Given a string, find the length of the longest substring without repeating characters.

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 asubstring, "pwke" is a subsequence and not a substring.

class Solution {public:    int lengthOfLongestSubstring(string s)  {if (s.empty() || (0 == s.size())){return 0;}                char T[256] = {0};char T1[256] = {0};int mxl = 0;int lastMxl = 0;for (int i = 0; i < s.size(); i++){                int index = s[i];if (T[index] > 0){    int pos = T[index];for (int j = 0; j < mxl; j++){int tmp = T[T1[j]] - pos;T[T1[j]] = (tmp <= 0) ? 0 : tmp;}for (int j = 0; j < mxl; j++){if ((pos + j) < 256){T1[j] = T1[pos + j];}else{T1[j] = '\0';}}if (mxl > lastMxl){lastMxl = mxl;} mxl = mxl - pos;}T1[mxl++] = s[i];T[index] = mxl;}return (mxl > lastMxl) ? mxl : lastMxl;    }};