Turn a minute-by-minute common-free-time scan into a sweep that handles 3,000 calendars in <3 s with identical output
Exact prompt
# Task: make common_free fast `slots.py:common_free` is correct but far too slow for real calendars (it scans every minute). Rewrite it so that it returns exactly the same result (same list of tuples, same order) for every input, but runs fast: the grader times a call with 3,000 people x 60 busy intervals each over a horizon of 50,000,000 minutes and requires < 3 s wall-clock, and compares your output with the original on many random and edge-case inputs (touching/overlapping/empty intervals, intervals outside the window, min_len boundaries, start == end). Keep the function name and signature. Standard library only. No network.
The rewrite is short, but exact equality on edge cases (empty/inverted intervals, clipping, min_len=0, start==end, touching intervals) is where sloppy sweeps fail. Original benchmark task written for usecaserank.com (not based on a specific public post). Headless, offline run on a reproducible fixture. Each run's notes say how its cost was measured (estimates are marked).
Success criteria: 1. output_identical: output equals the original implementation on 11 edge cases and 400 seeded random inputs. 2. fast_enough: one call with 3,000 people x 60 intervals over a 50,000,000-minute horizon takes < 3.0 s (subprocess capped at 30 s; timeout = fail).
Best model for this task so far: Claude Haiku 5.5 (effort default (no --effort flag) · thinking on) (success, $0.0049, 20s).
All runs (4)
100% pass rate across 4 eligible runs: 4 pass, 0 partial, 0 fail. Partial and failed runs are listed below with everything else.ⓘ
| Model | Cost | Time | Step-insⓘ | Autonomy | Outcome | Trustⓘ | Date | Compare |
|---|---|---|---|---|---|---|---|---|
| OGPT-6.1 Soldefault · thinking on | $0.06 | 55s | 0 | Fully autonomous | pass | Trust 80% | 2026-10-22 | |
| AClaude Haiku 5.5default · thinking on | $0.0049 | 20s | 0 | Fully autonomous | pass | Trust 80% | 2026-10-17 | |
| AClaude Opus 5.5default · thinking on | $0.11 | 23s | 0 | Fully autonomous | pass | Trust 80% | 2026-10-17 | |
| AClaude Sonnet 5.5default · thinking on | $0.04 | 12s | 0 | Fully autonomous | pass | Trust 80% | 2026-10-17 |
Embed this result
A live badge for this use case. It links back here and updates as new runs are published.
Get new runs and ranking changes weekly
Which models got better or cheaper on real tasks like this one.