Given a string s, find the length of the longest substring without repeating characters.
Examples
Example 1
Input: s = "abcabcbb"
Output: 3
The answer is "abc", with the length of 3.
Example 2
Input: s = "bbbbb"
Output: 1
The answer is "b", with the length of 1.
Example 3
Input: s = "pwwkew"
Output: 3
The answer is "wke", with the length of 3. Notice that the answer must be a substring, "pwke" is a subsequence and not a substring.
Constraints
0 <= s.length <= 5 * 10⁴sconsists of English letters, digits, symbols, and spaces.