The O(n) Club: Delete Nodes and Return Forest – Chainsaw Edition
The O(n) Club: Delete Nodes and Return Forest – Chainsaw Edition ⚡ TL;DR Delete designated nodes from your binary tree, then collect the roots…
The O(n) Club: Average of Levels in a Binary Tree (Or Why Java Hates Decimals)
The O(n) Club: Average of Levels in a Binary Tree (Or Why Java Hates Decimals) ⚡ TL;DR For each level of your binary tree, don’t…
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: 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: 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: Convert BST to Greater Tree—Because Your Nodes Have FOMO
The O(n) Club: Convert BST to Greater Tree—Because Your Nodes Have FOMO ⚡ TL;DR Want every node in your BST to brag about all the higher…
The O(n) Club: Maximum Width of Binary Tree: Counting Gaps Like a Pro
The O(n) Club: Maximum Width of Binary Tree—Counting Gaps Like a Pro ⚡ TL;DR Width isn’t about how many nodes you see—it’s about the full…
The O(n) Club: Distribute Coins in Binary Tree — The DFS Therapy Session
The O(n) Club: Distribute Coins in Binary Tree — The DFS Therapy Session ⚡ TL;DR Binary tree out of coin balance? Every node needs exactly one…
The O(n) Club: Populating Next Right Pointers in Each Node II: Now With 100% More Pointer-Juggling
The O(n) Club: Populating Next Right Pointers in Each Node II — Now With 100% More Pointer-Juggling ⚡ TL;DR Given a binary tree where some…
The O(n) Club: Trim a Binary Search Tree—Because Even BSTs Need Spring Cleaning
The O(n) Club: Trim a Binary Search Tree—Because Even BSTs Need Spring Cleaning ⚡ TL;DR You’ve got a BST and strict instructions: keep only…