Problem context and objectives
Mission briefing
Archive pathfinder · Clues branch through a living archive
Explore only the branches that can still contain the answer: The Right Horizon.
Ignoring the parent-child rule turns a focused search into a full maze traversal.
How you win
- 1Recognize when Binary tree right side view matches the clues
- 2Keep this true after every move: the queue contains one complete next frontier before that level begins
- 3Reach the result within O(n) time and O(width) space
Rules and pressure
- Target cost: O(n) time and O(width) space
- State rule: the queue contains one complete next frontier before that level begins
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 visible value at each depth, then run the queue. Lesson questions refer to the original tree.
Freeze the level boundary before adding children. The visual's root is the tree decoded with its null gaps preserved.
Your call · Level two contains 2 and 3. After adding the children of 2, which node is last in this level?