The O(n) Club: Remove Duplicates from Sorted List – But Please, Don’t Use a HashSet
The O(n) Club: Remove Duplicates from Sorted List – But Please, Don’t Use a HashSet ⚡ TL;DR Your ordered singly linked list is full of…
The Mutex Club: Unlocking JVM Secrets with JConsole, VisualVM & JFR
Key Insights Think of JConsole as the scrappy knight on patrol, VisualVM as the armored siege engine, and JFR as the spy network you leave on…
The Mutex Club: Master Java Thread Dumps Like a Pro
Key Insights # What Is a Thread Dump? A thread dump is the JVM’s panic selfie—a real-time snapshot of every thread, complete with names, IDs,…
The O(n) Club: Island Perimeter — Don’t Forget to Subtract the Neighbors
The O(n) Club: Island Perimeter — Don’t Forget to Subtract the Neighbors ⚡ TL;DR Calculate the perimeter of a single “island”…
The O(n) Club: Top K Frequent Words—How To Count, Sort, and Not Cry
The O(n) Club: Top K Frequent Words—How To Count, Sort, and Not Cry ⚡ TL;DR Count each word. Sort the results by how often each word shows up…
The Mutex Club: Avoiding Concurrency Traffic Jams
Intro: When One Lock Becomes a Traffic Jam Imagine a nightclub bouncer armed with a single click-lock guarding the only bathroom. That’s your…
The Mutex Club: Herding Threads with Barriers (No More Deadlocks)
Key Insights # What Is a Thread Barrier? Thread barriers pause every thread at a rendezvous point until the entire group arrives. Picture…
The O(n) Club: Minimum Cost for Tickets (aka, The ‘Why Can’t I Just Be Greedy’ Problem)
The O(n) Club: Minimum Cost for Tickets (aka, The ‘Why Can’t I Just Be Greedy’ Problem) ⚡ TL;DR Given a random set of travel…
The O(n) Club: How to Actually Rebuild a Binary Tree from Inorder and Postorder (Without Crying)
The O(n) Club: How to Actually Rebuild a Binary Tree from Inorder and Postorder (Without Crying) ⚡ TL;DR Given two arrays (inorder,…
The Mutex Club: Building Bulletproof Job Schedulers with Smart Retries
Key Insights – Building a Job Scheduler with Retry # Balancing Reliability and Resources A modern job scheduler—whether you’re wiring up n8n,…