The O(n) Club: Interleaving String — Your DP Soap Opera Starter Pack
The O(n) Club: Interleaving String — Your DP Soap Opera Starter Pack ⚡ TL;DR Check if s3 is a flawless mashup of s1 and s2, but don’t mess…
The O(n) Club: Non-decreasing Array — Change Once Or Never
The O(n) Club: Non-decreasing Array — Change Once Or Never ⚡ TL;DR This LeetCode classic asks: Can you rescue your out-of-order array by…
The Mutex Club: Mastering wait()/notify() for Effortless Thread Messaging
Key Insights # wait()/notify(): The Signalling Superpower Threads don’t just fight over mutexes—they need a way to communicate.…
The Mutex Club: Immutable DTOs — Distributed Data’s Unbreakable Bodyguard
Immutable DTOs: Your Data’s Bodyguard Let’s cut to the chase: when objects wander through microservices like unsupervised toddlers, someone’s…
The O(n) Club: Best Time to Buy and Sell Stock with a Transaction Fee (Or, How to Not Get Fleeced by the Middleman)
The O(n) Club: Best Time to Buy and Sell Stock with a Transaction Fee (Or, How to Not Get Fleeced by the Middleman) ⚡ TL;DR Maximize stock…
The O(n) Club: Minimum Depth of Binary Tree – Stop Calling Null a Leaf
The O(n) Club: Minimum Depth of Binary Tree – Stop Calling Null a Leaf ⚡ TL;DR Shortest path from root to an actual leaf (not a lonely child…
The Mutex Club: Mastering MDC for Debuggable Logs
The Mutex Club: Mastering MDC for Debuggable Logs ## Key Insights ### Logging with Thread-Local Context MDC (Mapped Diagnostic Context) is…
The Mutex Club: BlockingQueue Solves the Bounded Buffer Problem
TL;DR BlockingQueue in Java is the bounded buffer you didn’t know you needed: fixed-size, FIFO-ordered, thread-safe by default. put()…
The O(n) Club: Longest Substring with At Least K Repeating Characters — Chop Shop Edition
The O(n) Club: Longest Substring with At Least K Repeating Characters — Chop Shop Edition ⚡ TL;DR Your PM says, “Give me the longest…
The O(n) Club: All the Binary Tree Paths Your Leaves Will Ever Need
The O(n) Club: All the Binary Tree Paths Your Leaves Will Ever Need ⚡ TL;DR You want every root-to-leaf path in a binary tree? Great! DFS is…