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The Queue · D3

Order the jobs on one server to minimize total waiting time.

One server, one job at a time. Each job's wait is its start time — the sum of every service time queued ahead of it. Total waiting time is the sum across all jobs.
Practice — no rating pressure. Get as close to the optimum as you can; each play teaches the pattern.
Total wait
0
Jobs · tap to queue
Run order
Tap jobs above to build the run order.
About this puzzle

The Queue — practice the decision, scored against the optimum

What does the The Queue puzzle teach?

On one server, run the shortest job first — a job's wait is the sum of every service time ahead of it, so a long job up front taxes the whole queue.

Why do interviews ask about this?

Shortest-Job-First minimizes mean wait on a single server — the exchange-argument result behind OS short-job scheduling and latency-sensitive request queues.

How is it scored?

The engine computes the provably-optimal answer for the exact instance you played (dynamic programming, shortest-path, or exhaustive search — never a heuristic) and scores your attempt as a percentage of it. No login needed to see your score.