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

Example 1:

• Input: s = “abcabcbb”
• Output: 3
• Explanation: The answer is “abc”, with the length of 3.

Example 2:

• Input: s = “bbbbb”
• Output: 1
• Explanation: The answer is “b”, with the length of 1.

Example 3:

• Input: s = “pwwkew”
• Output: 3
• Explanation: 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 * 104
• s consists of English letters, digits, symbols and spaces.