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 a substring, "pwke"

 1 public class Solution {
 2     public int LengthOfLongestSubstring(string s) {
 3         int i = 0, j = 0, curMax = 0;
 4         
 5         var dict = new Dictionary<char, int>();
 6         
 7         while (j < s.Length)
 8         {
 9             if
 
 (dict.ContainsKey(s[j]))
10             {
11                 var index = dict[s[j]];
12                 while (i <= index)
13                 {
14                     dict.Remove(s[i]);
15                     i++;
16                 }                            
17             }
18             else
 

19             {
20                 curMax = Math.Max(curMax, j - i + 1);
21             }
22             
23             dict[s[j]] = j;
24             j++;
25         }
26         
27         return curMax;
28     }
29 }

Leetcode 3: Longest Substring Without Repeating Characters