Problem Solving Series — Day 1 The String Problem That Taught Me About Sets in JavaScript

Strings • Sets • Sliding Window • Beginner Developer Journey I realized that learning syntax alone doesn’t make someone a programmer — real programming is about thinking, logic, and solving problems. That’s why I’m starting this Problem Solving Series, inspired by a conversation with my friend Bala yesterday (you can read that story here: https://dev.to/buddingdeveloper/i-blinked-when-my-friend-asked-this-question-39k4 Problem Solving Series Every day I will pick one problem, try to understand it, think about the logic, and share the learning.Some problems will be easy.Some will be confusing.Some might break my brain. But the goal is simple: Learn to think like a programmer, not just write code. And today is Day 1. Today’s Problem The problem looks simple at first glance. You are given a string. Your task is to find the longest substring that contains no repeating characters. Example string: pwwkew We need to find the longest continuous group of characters where no character repeats. P