LeetCode Card 304 — Topological Sort / Implement
Pattern signal
This pattern usually appears when the prompt involves ordering with prerequisites in a DAG. Course Schedule, build order, dependency resolution, and task execution pipelines point here.
What Implement means here
In BASIC, the Implement step is where you write the code in the same order as the chosen skeleton so the logic stays stable. For Topological Sort, that matters because the pattern only becomes useful once the candidate is explicit about what is being tracked, reduced, or preserved.
Interview move
A strong move is to transcribe the plan instead of improvising. In this pattern family, say out loud what representation makes the problem easier: the map entry, the pointer invariant, the recursion contract, the queue contents, or the DP state. That keeps the implementation attached to a reason.
Common miss
Candidates detect dependencies but fail to distinguish cycle detection from valid ordering construction. BASIC reduces that risk because the stage sequence forces you to earn the implementation instead of jumping straight into it.
BASIC prompt
“Given that this looks like Topological Sort, what is the simplest way to write the code in the same order as the chosen skeleton so the logic stays stable?”