Java DSA Notes: 32 Pages of Data Structures & Algorithms

🚀 Day 68/100 – DSA Challenge Consistency builds confidence 💯 Today’s problem focused on mirror distance of a number. 🔍 Problem: Given an integer, reverse its digits and find the absolute difference between the original number and its reversed form. 🧠 Approach: The idea is simple but powerful — extract digits one by one, build the reversed number, and compute the difference. 💡 Key Learning: Problems like this strengthen core concepts of number manipulation and logical thinking, which are essential for cracking interviews. Every small step is adding up. On to Day 69 🚀 #100DaysOfCode #DSA #Java #CodingJourney #Consistency #ProblemSolving #KeepLearning

If you are preparing for coding interviews, mastering array problems is essential. In this short video, I covered 3 important patterns: - Reverse an array - Rotate array by k positions - Merge two sorted arrays These problems form the foundation for many advanced algorithmic questions. Understanding these patterns helps improve both problem-solving skills and coding efficiency. Explore structured DSA in Java roadmap + practice: www.quipoin.com #DSA #Java #Programming #Coding #SoftwareEngineering #InterviewPreparation #Algorithms

Why does your code slow down as data grows? The answer lies in Time Complexity a fundamental concept that every developer must understand. In this short video, I covered: - What is Time Complexity - Big O Notation explained simply - Difference between O(1), O(log n), O(n), O(n²) - Why efficient code matters Understanding this can completely change how you write code and prepare for interviews. Explore structured DSA in Java roadmap + practice: www.quipoin.com #DSA #Java #Programming #Coding #SoftwareEngineering #BigO #InterviewPreparation

🚀 Week 9 Completed – #100DaysOfCode | DSA in Java Continuing the journey with consistent progress and deeper problem-solving. This week I focused on advanced tree concepts and sliding window technique, which are crucial for coding interviews. 📌 Topics Covered This Week: 🔹 Binary Search Trees (BST) Learned BST properties and operations Solved problems like finding the largest BST in a Binary Tree 🔹 Binary Trees (Advanced) Practiced problems like sum of left leaves Strengthened recursive thinking and tree traversal logic 🔹 Sliding Window Technique Applied sliding window approach to optimize subarray problems Implemented maximum subarray sum using sliding window 📌 Previously Covered Foundation: ✔ Arrays, Strings, Bit Manipulation ✔ Recursion & Backtracking ✔ Linked List, Stack, Queue ✔ Greedy Algorithms & Binary Trees 🧠 Key Learnings • Tree-based problems require a strong understanding of recursion and structure • Sliding window significantly reduces time complexity from O(n²) to O(n) • Choosing the right approach is becoming more intuitive with practice • Focus is now shifting towards optimization and pattern recognition 💻 Maintaining a structured GitHub repository with all topics organized step-by-step and consistent commits. Step by step, moving closer to interview-ready DSA skills. #100DaysOfCode #DSA #Java #ProblemSolving #SlidingWindow #BinaryTree #LearningInPublic

What you'll learn in this thread: ✅ What is a Thread (and the #1 beginner mistake) ✅ Thread Lifecycle — all 5 states explained ✅ Synchronization — volatile vs synchronized vs Lock ✅ Deadlock — how it happens + how to prevent it ✅ Thread Pools — which one to use & when 🎯 A tricky interview question 90% of devs get wrong 💡 Quick tip before you swipe: Never call run() directly. Always use start(). One line. Career-saving advice. 😅 🔁 Repost if this helped someone on your team. 💾 Save this — you'll need it before your next interview. 🔔 Follow for more Java deep-dives every week. #Java #Multithreading #Programming #SoftwareEngineering #JavaDeveloper #BackendDevelopment #CodingTips #TechTwitter #100DaysOfCode #InterviewPrep

Have you noticed that the same code can behave differently depending on the input? This is where Best Case, Average Case, and Worst Case Analysis becomes important. In this short video, I explained: - Best case (fastest execution) - Worst case (maximum time) - Average case (typical scenario) - Why worst-case analysis is commonly used Understanding this concept helps you build efficient and reliable algorithms, especially for real-world systems and coding interviews. 👉 Explore structured DSA in Java roadmap + practice: www.quipoin.com #DSA #Java #Programming #Coding #SoftwareEngineering #InterviewPreparation #Algorithms

📌 Java Methods Cheat Sheet for DSA 🚀 Practicing DSA in Java? Save time with this quick cheat sheet of the most useful methods: 🔹 Strings: length(), charAt(), substring(), indexOf(), toCharArray() 🔹 Arrays: sort(), fill(), equals(), binarySearch() 🔹 Collections & List: add(), remove(), get(), set(), contains(), size() 🔹 HashMap: put(), get(), containsKey(), keySet(), entrySet() 🔹 Stack/Queue: push(), pop(), peek(), offer(), poll() 💡 Perfect for LeetCode, coding rounds & DSA interviews. Share if this helps you solve problems faster! ⚡ #Java #DSA #CodingInterview #Programming #JavaDeveloper #DataStructures #LeetCode #InterviewPrep

📌 Java Methods Cheat Sheet for DSA 🚀 Practicing DSA in Java? Save time with this quick cheat sheet of the most useful methods: 🔹 Strings: length(), charAt(), substring(), indexOf(), toCharArray() 🔹 Arrays: sort(), fill(), equals(), binarySearch() 🔹 Collections & List: add(), remove(), get(), set(), contains(), size() 🔹 HashMap: put(), get(), containsKey(), keySet(), entrySet() 🔹 Stack/Queue: push(), pop(), peek(), offer(), poll() 💡 Perfect for LeetCode, coding rounds & DSA interviews. Share if this helps you solve problems faster! ⚡ #Java #DSA #CodingInterview #Programming #JavaDeveloper #DataStructures #LeetCode #InterviewPrep

🚀 Improving DSA one step at a time! Today I solved LeetCode 1446 – Consecutive Characters 🧠 🔍 Problem Insight: Find the longest substring where all characters are the same. 💡 Approach: Traverse the string and keep counting consecutive characters while tracking the maximum. ⚡ Time Complexity: O(n) ⚡ Space Complexity: O(1) 🎥 Full explanation: 👉https://lnkd.in/gbqbVV5Q 🔥 I’m posting daily LeetCode solutions with simple explanations. 👉 Follow me for DSA 👉 Subscribe for full tutorials 💬 Comment “DSA” if you're preparing for interviews! #LeetCode #DSA #Java #Coding #Programming #InterviewPrep #Developers

Mastering this hierarchy is the difference between writing code that "just works" and writing code that scales. 🚀 Save this cheat sheet for your next technical interview! 💾 #DataStructures #DSA #PlacementPrep #IndiaTech #SoftwareEngineering #UniqueSystemSkills #CodingFundamentals #TechInterviews #Java #Python