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The Braided Chains

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Problem context and objectives
Mission briefing

Portal network mechanic · Travel portals are connected as a one-way chain

Repair the links without losing the unexplored route: The Braided Chains.

Overwrite one next pointer too early and the rest of the expedition becomes unreachable.

How you win

  1. 1Recognize when Sorted list merge matches the clues
  2. 2Keep this true after every move: the merged prefix is sorted and contains exactly the consumed nodes
  3. 3Reach the result within O(n + m)

Rules and pressure

  • Target cost: O(n + m)
  • State rule: the merged prefix is sorted and contains exactly the consumed nodes
Lesson 1 of 3

Both chains are sorted, so the next globally smallest node must be one of the two fronts.

Your call · The fronts are 3 and 2. Which enters the braid?

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