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Boss fightThe Nested Rune Decoder

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Problem context and objectives
Mission briefing

Game event engineer · Actions arrive faster than the world can resolve them

Process events in the exact order promised by the data structure: The Nested Rune Decoder.

The wrong removal order changes gameplay and creates impossible replays.

How you win

  1. 1Recognize when Nested context stack matches the clues
  2. 2Keep this true after every move: each stack frame stores the exact outer text and repeat count waiting for a closing bracket
  3. 3Reach the result within O(n + C), including intermediate copies

Rules and pressure

  • Target cost: O(n + C), including intermediate copies
  • State rule: each stack frame stores the exact outer text and repeat count waiting for a closing bracket
Lesson 1 of 3

Keep outer and inner contexts separate. The most recently saved frame finishes first.

Your call · After the inner ] in 3[a2[c]], what are current and the remaining saved frame?

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