leetcode 3: long substring without duplicates : java solution

LeetCode Problem 3, "Longest Substring Without Repeating Characters," asks for the length of the longest substring from a given string that does not contain any repeated characters. To solve it, you can use a sliding window technique with two pointers to dynamically adjust the window's size. As you iterate through the string, you maintain a set or hash map to track characters in the current window and update your pointers accordingly. This approach ensures an optimal O(n) time complexity by preventing a full scan for each starting point. The problem tests your ability to implement efficient string manipulation techniques and understand hashing mechanisms.