Java Sliding Window Solution for Longest Substring Without Repeating Characters

🚀 DSA Learning Journey | Day 9 | Java Solved “125. Valid Palindrome.” 💡 Key Idea: Used Two Pointers while ignoring non-alphanumeric characters and comparing characters in a case-insensitive way. ⚙ Implementation • Language: Java • Time Complexity: O(n) • Space Complexity: O(1) 📚 Learning how two-pointer technique simplifies string validation problems. #Java #DSA #LeetCode #ProblemSolving #TwoPointers #JavaDeveloper

💻 Practicing Binary to Decimal Conversion using Java Today I worked on converting a binary number into its decimal equivalent using logic and iteration. 🔍 Key Learnings: Understanding how binary digits map to powers of 2 Strengthening loop and mathematical logic Improving problem-solving skills step by step Instead of just memorizing, I focused on understanding the logic deeply and practicing with different inputs. 📌 Example: Binary: 1010 → Decimal: 10 Consistency + Practice = Progress 🚀 #Java #DSA #CodingJourney #Programming #100DaysOfCode #LearnToCode #ProblemSolving #DeveloperJourney #CodingPractice #TechSkills

🚀 100 Days Java + DSA Challenge | Day 2 Today’s focus was on strengthening my programming fundamentals by covering: 🔹 Operators in Java (Arithmetic, Relational, Logical, Assignment) 🔹 Conditional Statements (if, if-else, nested if, switch) Understanding how operators work and how decisions are made in code is essential for building strong logic. These concepts are the backbone of problem-solving in Data Structures and Algorithms. 💡 Practiced writing multiple programs using conditions and improved my logical thinking step by step. Consistency is the key — small progress every day leads to big results. #100DaysOfCode #Java #DSA #LearningJourney #Coding #SoftwareDevelopment

💻 Built a Diamond Pattern in Java using pure logic and nested loops. While practicing DSA fundamentals, I implemented this pattern by understanding how spaces and stars align in each row. This helped me strengthen my control over loops, conditions, and pattern-based problem solving. 📌 Key Learning: Breaking a complex pattern into smaller logical steps makes it much easier to implement. Consistency in solving such problems is what builds strong programming logic. #Java #DSA #Programming #CodingJourney #ProblemSolving #LogicBuilding #Developers #Learning #100DaysOfCode

🚀 Day 16/45 – Understanding Abstraction in Java On Day 16 of my Java learning journey, I explored Abstraction, one of the core principles of Object-Oriented Programming. Abstraction focuses on hiding implementation details and showing only the essential functionality to the user. 📚 What I Learned Today Today I learned: ✔ What abstraction is and why it is important ✔ How to use abstract classes in Java ✔ Understanding abstract methods (methods without body) ✔ How abstraction works with inheritance 💻 Practice Work To apply my learning, I implemented: • An animal example using abstract class • A shape example demonstrating abstraction 🎯 Key Takeaway Abstraction helps simplify complex systems by hiding unnecessary details and focusing on what is important. It plays a key role in building clean and scalable applications. Step by step, I am gaining a deeper understanding of OOP concepts. #Java #Programming #LearningInPublic #CodingJourney #SoftwareDevelopment #OOP

Today I implemented Array Reversal in Java using the Two-Pointer Technique! 🔄 Logic: ∙ Set left = 0 and right = arr.length - 1 ∙ Swap elements at both ends ∙ Move pointers inward until they meet ✅ Input: {1, 2, 3, 4, 5} ✅ Output: 5 4 3 2 1 💡 Why Two-Pointer? Instead of using extra space, we swap in-place — making it O(n) time and O(1) space! No extra array needed. Just two pointers doing the work. 💪 Every small concept I practice brings me one step closer to DSA mastery. Keep building. Keep learning. 🙌 #100daysofcode #dsa #java #program #array #problem #leetcode #javadeveloper #learning

🚀 Day 15/45 – Understanding Polymorphism in Java On Day 15 of my Java learning journey, I explored Polymorphism, one of the key pillars of Object-Oriented Programming. Polymorphism allows the same method to behave differently based on the context, making code more flexible and reusable. 📚 What I Learned Today Today I learned: ✔ What polymorphism is and why it is important ✔ Method overloading (compile-time polymorphism) ✔ Method overriding (runtime polymorphism) ✔ Difference between overloading and overriding 💻 Practice Work To apply my learning, I implemented: • A method overloading example using different parameters • A method overriding example using inheritance 🎯 Key Takeaway Polymorphism improves code flexibility and helps in designing scalable applications. It allows developers to use a single interface with multiple implementations. Understanding these OOP concepts step by step is strengthening my programming foundation. #Java #Programming #LearningInPublic #CodingJourney #SoftwareDevelopment #OOP

Day 65 of #100DaysOfLeetCode 💻✅ Solved “Majority Frequency Group” problem in Java. Approach: • Created a frequency array of size 26 for all characters • Counted occurrences of each character in the string • For each unique frequency, counted how many characters share that frequency • Selected the frequency with the highest group size • In case of tie, chose the higher frequency • Built the result string with characters having the selected frequency Performance: ✓ Runtime: 5 ms (Beats 57.84% submissions) ✓ Memory: 44.51 MB (Beats 72.88% submissions) Key Learning: ✓ Practiced frequency grouping techniques ✓ Learned how to handle tie-breaking conditions ✓ Strengthened logic building with nested loops and conditions Learning one problem every single day 🚀 #Java #LeetCode #DSA #Strings #Hashing #ProblemSolving #CodingJourney #100DaysOfCode

Day 3 | Java & DSA Progress Today’s learning was focused on strengthening my understanding of Strings in Java along with solving a key problem from the NeetCode 150 sheet. 🔹 Explored Strings in depth: String creation & immutability String methods (basic to advanced) StringBuilder vs StringBuffer Conversions, formatting & regex basics 🔹 Practiced some questions: Anagram check First non-repeating character Longest substring without repeating characters String compression & more 🔹 Solved Top K Frequent Elements from NeetCode 150 GitHub repository : https://lnkd.in/gqy2AykW https://lnkd.in/gj7Vqq6q #Java #DSA #LearningInPublic #NeetCode150 #CodingJourney

Reversed String in Java | Easy Logic + Coding 💡 Strong fundamentals are essential to become a confident developer. This example shows how String Reversal works using simple logic: • Start with a given string • Traverse the string from last character to first • Use loop or built-in methods • Form the reversed string Practicing these types of problems improves logical thinking and strengthens coding basics. 📊 Example Input : LIVE Output : EVIL 🎥 I’ve also created a short video explaining this concept with code: YouTube link : https://lnkd.in/eKH2JJwa #Java #Programming #ProblemSolving #Coding #SoftwareDevelopment #Learning #CSE #Developers #LogicBuilding #String