Memory game as an online experiment - Conflicts between my concept and UX
As a data analyst, I wanted to start a project where I could work with my own dataset. My goal is to build a database that is suitable for predictiv…
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Why doubling makes a dynamic array O(1) (and the realloc bug almost everyone writes)
If you have used std::vector or Python lists, you have used a dynamic array. In C you have to build it yourself, and two details decide whether it i…
Rod Cutting: Unbounded Knapsack With a Different Label on the Inputs
Chapter 7 introduced Unbounded Knapsack and ended with a promise: every problem in the unbounded family inherits the same structure, just with a dif…
Understanding Stacks and Queues in Go
Stacks and queues are two of the simplest data structures, and two of the most useful. They show up everywhere: undo history, parsing, graph travers…
Autocomplete Like a Jedi: Building a Trie from Scratch
The Quest Begins (The "Why") Ever stared at a search box, typed “jav” and watched the suggestions pop up instantly—“JavaScript”, “Java”, “JAVA_HOME”…
Inorder Traversal: The Matrix
The Quest Begins (The "Why") I still remember the first time I was asked to print the nodes of a binary tree in sorted order during a technical inte…
LeetCode 4000 - 4010 problems: patterns and approaches explained
LeetCode has started publishing problems numbered 4000 and above. At the time of writing this post, there are already 4055 problems. In this post, I…
The hashCode()-to-Array-Index Bug Almost Everyone Writes Once
"hash % capacity" looks trivial until you trace it by hand. Two separate bugs hide in that one line — and the fix for one of them has its own hole.…
Columnar Data Structure in Java
What if we need traditional object-oriented API and extra high performance for field-wise operations in one place? I designed my CPS exactly having…
I Built My Own Fail-Fast HashMap — Here's Why a Boolean Flag Wasn't Enough
If you've done LeetCode's Design HashMap , you've implemented put , get , and remove . What that exercise usually skips is the part that actually br…
Monotonic Stack: The Matrix of Array Problems
The Quest Begins (The “Why”) Ever spent an hour wrestling with a brute‑force solution that felt like you were trying to break through a concrete wal…
Binary Search: The Matrix of Algorithms – Patterns, Edge Cases, and Real Interview Questions
The Quest Begins (The "Why") I still remember the first time I bombed an interview because I tried to solve a “find the target in a sorted array” qu…
Dynamic Programming: The Matrix of Patterns
The Quest Begins (The "Why") I still remember the first time I saw a dynamic programming question pop up on a whiteboard during an interview. The pr…
I built a content recommender as a graph, and it found similarities I wasn't looking for
Most beginner recommendation projects are a dictionary lookup. You type "comedy", it returns the comedy list. That works, and it is also the reason…
The Matrix of Tree Traversals: Recursive vs Iterative Explained
The Quest Begins (The "Why") I still remember the first time I was asked to validate a binary search tree in an interview. My brain went into panic…
An O(1) Space Alternative to "Rearrange Array Alternately" Using Sequential Suffix Reversal
If you've spent time on LeetCode or GeeksforGeeks, you've probably run into the classic "Rearrange Array Alternately" problem. The premise: given a…
What Building a C++ Benchmarking Suite Taught Me About "Simple" Data Structures
We all know the Big-O complexity of basic data structures. Arrays are O(n) for search. Hash maps are O(1). Linked lists are... well, complicated. Bu…
Greedy Algorithms: Choosing Your Path Like Neo in The Matrix
The Quest Begins (The "Why") I still remember the first time I stared at a whiteboard covered in overlapping intervals during a mock interview. The…
Arrays vs Linked Lists: Why the Textbook Winner Loses on Real Hardware
📺 Prefer to watch? 90-second YouTube Short · 💬 Telegram Originally published on software-engineer-blog.com . Every data-structures course teaches th…
The Data Structure That Finally Made Recursion Click For Me
Data structures and algorithms in C++ was probably the course that pushed me the hardest this year. A lot of it clicked eventually, but one topic in…
Recursion in C++ Explained Simply: Base Case, Call Stack, LIFO and Stack Overflow
When I first heard about recursion, I found it a little confusing. A function calling itself? How does that even work? The easiest way to understand…
The circular_buffer trap: how a 'faster' data structure spiked my CPU from 2% to 25%
There's a special kind of bug that only shows up after you've made your code "better." You swap in the data structure everyone agrees is more effici…
The Union‑Find Fellowship: Finding Your Tribe in Code
The Quest Begins (The "Why") I still remember the first time I stared at a LeetCode problem that asked me to count the number of islands in a grid.…
JavaScript has no sorted containers. I built one for TypeScript.
JavaScript ships with Array , Set , and Map — but nothing that keeps its elements sorted as you insert. If you've ever built a leaderboard, an order…
The Binary Search Strikes Back: A Jedi's Guide to Finding Things Fast
The Quest Begins (The "Why") Honestly, I used to dread interview questions that started with “Given a sorted array…”. My first attempt was a clumsy…
Segment Trees: The Matrix of Range Queries
The Quest Begins (The "Why") I still remember the first time I faced a problem that asked for the sum of numbers in a sub‑array, over and over again…
What I Learned in Week 8 of Python — Stacks, Queues & Linked Lists
Week 7 was hash maps and two pointers — patterns that lean on Python's built-in dict , set , and list . Week 8 was different. This week I built the…
You Don't Use Linked Lists. But They're Running Half Your Software.
The data structure everyone learns for interviews and forgets by Monday — and why that's exactly backwards. Here's the honest version of what most l…
The Bitwise Jedi: Mastering the XOR Trick Like a Lightsaber
The Quest Begins (The "Why") I still remember the first time I faced a coding interview where the interviewer slid a simple array across the whitebo…
The Monotonic Stack: Like Gandalf's Staff for Array Problems
The Quest Begins (The "Why") Honestly, I still remember the first time I stared at the Daily Temperatures problem on LeetCode and felt like I was tr…