Longest Substring No Repeats

Implement a function lengthOfLongestSubstring that takes a string and returns the length of the longest substring without repeating characters.

Input:

• A single string s (may contain spaces, letters, digits, or symbols)

Output:

• An integer representing the length of the longest substring without repeating characters

Example Inputs & Outputs

// Example 1:
Input: "abcabcbb"
Output: 3  // "abc"

// Example 2:
Input: "bbbbb"
Output: 1  // "b"

// Example 3:
Input: "pwwkew"
Output: 3  // "wke"

// Example 4:
Input: ""
Output: 0

// Example 5:
Input: "aab"
Output: 2  // "ab"

Constraints & Edge Cases

• Input string may be empty
• Input string can contain any printable characters
• Repeated characters may appear consecutively or at intervals
• Result must be calculated in optimal time (O(n))