Hardware interview practice
Verify a minimum energy-window engine
Implement an exhaustive oracle and four-entry tagged scoreboard core for the shortest contiguous nonnegative energy window whose sum reaches a threshold.
Reviewed example
Work through one case
Input
energy=[2,1,4,2]; threshold=6Expected output
found=1; start=2; length=2Window [4,2] reaches six in two elements, shorter than [2,1,4], and no one-element window qualifies.
What to cover
Requirements
- Build an exhaustive widened-arithmetic oracle and treat zero threshold or count above the configured maximum as a bad request.
- Return found=0 with zero start and length when no window qualifies; otherwise compare shortest length before lowest start.
- Store at most four predictions by transaction ID, compare and retire each response exactly once, and reject duplicate or unknown IDs.
- Flush every pending prediction on reset and provide an end-of-test empty check for missing responses.
- Identify exact-threshold hits, equal-length ties, zero density, response order, stalls, errors, and reset as follow-up coverage targets.