The O(n) Club: Number of Islands — Why Diagonal Swimming Doesn’t Count
The O(n) Club: Number of Islands — Why Diagonal Swimming Doesn’t Count ⚡ TL;DR Given a grid of ‘1’s (land) and…
The O(n) Club: Alien Dictionary: Sorting Out Topo-Sorted Antics
The O(n) Club: Alien Dictionary – Sorting Out Topo-Sorted Antics ⚡ TL;DR The aliens dumped a list of words in your inbox and expect you to…
The O(n) Club: Combination Sum III, or: Picking K Numbers that Add Up, But Skip the Guilt
The O(n) Club: Combination Sum III, or: Picking K Numbers that Add Up, But Skip the Guilt ⚡ TL;DR Find every possible set of k unique numbers…
The O(n) Club: Palindrome Pairs — Hashmaps, Not Hunches
The O(n) Club: Palindrome Pairs — Hashmaps, Not Hunches ⚡ TL;DR Find every unique pair of indices (i, j) in an array of words where words[i] +…
The O(n) Club: Open the Lock (LeetCode 752) — When BFS Is Literally All You Need
The O(n) Club: Open the Lock (LeetCode 752) — When BFS Is Literally All You Need ⚡ TL;DR You’ve got a 4-wheel lock (think: digital nightmare),…
The O(n) Club: Koko Eating Bananas — Why Monkeys Ace Coding Interviews
The O(n) Club: Koko Eating Bananas — Why Monkeys Ace Coding Interviews ⚡ TL;DR Banana-eating is serious work, apparently. Koko wants to finish…
The O(n) Club: Candy: Because Satisfying Kids—and Your Interviewer—Takes Two Passes
The O(n) Club: Candy: Because Satisfying Kids—and Your Interviewer—Takes Two Passes ⚡ TL;DR LeetCode 135, aka the “Why kids riot over…
The O(n) Club: Remove Duplicates from Sorted Array II—Twice Is Nice, Thrice Is Jail
The O(n) Club: Remove Duplicates from Sorted Array II—Twice Is Nice, Thrice Is Jail ⚡ TL;DR Your sorted array needs some tough love: keep each…
The O(n) Club: Range Sum Query – Mutable (Or Why Prefix Sums Need Therapy)
The O(n) Club: Range Sum Query – Mutable (Or Why Prefix Sums Need Therapy) ⚡ TL;DR If you want fast range sums and in-place updates,…
The O(n) Club: Unique Paths III and the Roomba That Never Misses a Spot
The O(n) Club: Unique Paths III and the Roomba That Never Misses a Spot ⚡ TL;DR Pathfinding? Easy. Pathfinding without leaving a single square…