Ever felt like you're repeating yourself? Well, strings shouldn’t either! 🧵 In this coding challenge, your mission is to find the longest section of a given string where no character appears more than once . It sounds simple, but it’s a classic puzzle that makes you think about efficiency, memory, and clever iteration. What you’ll practice: Looping through strings in smart ways Tracking characters you’ve already seen (hint: sets or maps are your friends!) Sliding window technique—a super useful tool for many problems Writing clean, fast code without nested loops if possible Example to get you started: "abcabccc" → "abc" (length 3) "defggft" → "defg" (length 4) Think about: What if the string is empty? Should case matter? (usually yes, unless stated otherwise) How can you avoid starting over from scratch each time? It’s a perfect problem to level up your Java skills and get comfortable with more advanced string manipulation. Give it a t...