The O(n) Club: Binary Tree Level Order Traversal II – Boss Mode Unlocked
The O(n) Club: Binary Tree Level Order Traversal II – Boss Mode Unlocked ⚡ TL;DR Need to traverse a tree from leaf to root, level by level?…
The O(n) Club: Letter Case Permutation — Brute Force Meets Java’s Fashion Police
The O(n) Club: Letter Case Permutation — Brute Force Meets Java’s Fashion Police ⚡ TL;DR You get a string. For every letter, you swap its case…
The O(n) Club: Longest Univalue Path: When Trees, Edges, and Your Patience All Snap
The O(n) Club: Longest Univalue Path — When Trees, Edges, and Your Patience All Snap ⚡ TL;DR Find the longest path—counted in edges, not…
The O(n) Club: Valid Palindrome: Why Your String Doesn’t Care About Punctuation
The O(n) Club: Valid Palindrome – Why Your String Doesn’t Care About Punctuation ⚡ TL;DR Check if a string’s a palindrome, but ignore…
The O(n) Club: Longest String Chain — The O(n) Club Edition
The O(n) Club: Longest String Chain — The Interview Jenga That Breaks Spirits ⚡ TL;DR Find the biggest possible chain where each word is built…
The O(n) Club: Score of Parentheses—Where Mildly Annoying Brackets Become Mathematical Fireworks
The O(n) Club: Score of Parentheses—Where Mildly Annoying Brackets Become Mathematical Fireworks ⚡ TL;DR Don’t (re)curse yourself! You…
The O(n) Club: Taming LeetCode’s Flatten Nested List Iterator Without Losing Your Mind
The O(n) Club: Taming LeetCode’s Flatten Nested List Iterator Without Losing Your Mind ⚡ TL;DR If you thought recursion was wild, try feeding…
The O(n) Club: Hamming Distance: When Your Bits Can’t Agree (And Why XOR is King)
The O(n) Club: Hamming Distance — When Your Bits Can’t Agree (And Why XOR is King) ⚡ TL;DR How many bits do x and y disagree on? XOR them,…
The O(n) Club: Sum of Left Leaves — Because Trees Are Funnier Than You Think
The O(n) Club: Sum of Left Leaves — Because Trees Are Funnier Than You Think ⚡ TL;DR If you can’t tell your left from your right, this is the…
The O(n) Club: Palindrome Partitioning II—Fewer Cuts, Less Regret
The O(n) Club: Palindrome Partitioning II—Fewer Cuts, Less Regret ⚡ TL;DR Chop a string into palindromic slices using as few cuts as possible…