1 class Solution {
2 public:
3 int lengthOfLongestSubstring(string s) {
4 vector<int> signs(256, -1);
5 int max_length = 0;
6 int last_valid = -1;
7 for (size_t i = 0; i < s.size(); ++i){
8 char c = s[i];
9 int last_occ = signs[c];
10 if (last_occ < last_valid){
11 last_occ = last_valid;
12 }
13 if (last_occ > last_valid){
14 last_valid = last_occ;
15 }
16 int length = i - last_occ;
17 if (length > max_length){
18 max_length = length;
19 }
20
21 signs[c] = i;
22 }
23 if (max_length == 0){
24 max_length = s.size();
25 }
26 return max_length;
27 }
28 };
