Problem context and objectives
Mission briefing
Archive pathfinder · Clues branch through a living archive
Explore only the branches that can still contain the answer: Levels of the Grove.
Ignoring the parent-child rule turns a focused search into a full maze traversal.
How you win
- 1Recognize when Tree breadth-first search matches the clues
- 2Keep this true after every move: the queue contains exactly the next unprocessed frontier
- 3Reach the result within O(n)
Rules and pressure
- Target cost: O(n)
- State rule: the queue contains exactly the next unprocessed frontier
New words in this mission
Open a term for a plain-language explanation.durable queue+
A waiting line that keeps work until a consumer finishes it. It absorbs bursts and lets failed work be retried.
Lesson 1 of 3
Predict the depth first. Every example is a complete tree: the last level fills from the left. Lesson questions refer to the original tree.
Freeze the level boundary before adding children.
Your call · A level starts with 2 nodes. Removing the first adds 2 children. How many nodes should this level process in total?