What is topological sort for?
PICTURE THIS: 1, 2, 2, 8
Mean3.25average
Median2middle
Mode2most often
Simple meaning
Ordering tasks with prerequisites in a DAG.
WHY — Graphs instead of guessing?
Why interviewers care about Graphs:
Graphs questions separate people
who only read docs from people who shipped.
Keep it short, concrete,
and tied to DSA work.
Stay structured
Name the idea, why it exists, then one short example.
Close cleanly
End with when you use it and one common pitfall.
STEPS — What happens step by step?
Before you speak the answer, walk the interviewer through these steps:
- 1Ordering tasks with prerequisites
in a DAG.
- 2Kahn’s algorithm or DFS
finishing times.
- 3How it works
Cycles mean impossible schedules.
- 4Give an example
One tiny concrete case you can say aloud.
- 5Common mistake
What juniors usually get wrong.
- 6Close
When you pick this over the alternative.
EXAMPLE — See it in action
Here's a short line you can speak, broken into clear beats:
Say this line
“Kahn’s algorithm or DFS finishing times.”
Break into beats
KahnsalgorithmorDFSfinishing
Speaking order
2987408337471632900
Note: Adapt this scaffold to your own project — keep it under 60–90 seconds.
Key takeaway
Ordering tasks with prerequisites in a DAG. Kahn’s algorithm or DFS finishing times.