Longest Substring Without Repeating Characters

Given a string s, determine the length of the longest substring that contains no repeated characters. This problem can be solved using the sliding window technique where you track the last seen positions of characters.

The mathematical formulation can be expressed as finding the maximum k such that there exists a substring s[i...j] with no duplicate characters, where k = j - i + 1.

For example:

• Input: abcabcbb → Output: 3
• Input: bbbbb → Output: 1
• Input: pwwkew → Output: 3

inputFormat

The input consists of a single line containing a string s composed of English letters and possible symbols. The string may be empty.

outputFormat

Output an integer representing the length of the longest substring of s that does not contain any repeating characters.

abcabcbb

3