In this tutorial, we solve one of the most frequently asked coding interview questions: finding the length of the longest substring without repeating characters. We start by understanding the problem statement, followed by a detailed explanation of the sliding window technique. You will learn how to use two pointers, left and right, along with a dictionary to track characters and dynamically adjust the window to keep track of unique characters.
We walk through a real example step-by-step, breaking down the logic so every concept is clear. Then, we implement the complete Python solution and test it with sample inputs. By the end of this tutorial, you will understand what a substring is, how to identify duplicates in a sliding window, how to use a dictionary to track character indices, and how to write efficient Python code for this problem. This approach will help you optimize your solution and prepare for technical interviews.
