Given a string s, find the length of the longest substring without repeating characters.
/*
* Given a string s, find the length of the longest substring without repeating characters.
* Input: s = "abcabcbb"
* Output: 3
* Explantion: the answer is "abc", with the length of 3.
* Input: s = "pwwkew"
* Output: 3
* Explantion: the answer is "wke", with the length of 3.
*/
public int LeetCode_3( string s)
{
int start = 0, end = 1, ans = 0, c = 0;
string buf = "",s2 = "";
for (int i = 0; i < s.Length; i++)
{
buf = s.Substring(start, end-start);
if(end < s.Length)
{
s2 = s.Substring(end, 1);
c = buf.IndexOf(s2);
if (c != -1)
{
start = start + (c+1);
}
end++;
}
if (ans < (end - start))
{
ans = end - start;
}
}
return ans;
}