Level 3 · Advanced · Structure and efficiency
Repair an expiring cache
Fix expiration boundaries, updates, and recency in an existing cache.
90-minute timed challenge
- Accuracy
- 50
- Performance
- 30
- Submission time
- 20
Accuracy 50 · performance 30 · submission time 20. Pass all 4 required checks, earn at least 35 accuracy points, and return correct results for both large-input patterns to pass. Performance and time points are added only for passing solutions. One attempt per problem, up to 5 submissions within 90 minutes. Passing results take priority; within the same pass status, the highest score is retained.
Starting a timed challenge or submitting an introductory task costs 5P. Resuming an attempt and system regrading are free.
Time is measured from start to submission. Each submission records its time score, excluding grading wait time. The deadline for additional submissions continues to run.
View scoring details
Performance uses two large-input patterns with up to 30000 items. Each runs 3 times excluding setup and result validation; the slower of their median times is used. At most 60ms earns 30 points, 2.5× earns 24, 5× earns 18, 10× earns 9, and slower earns 0.
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