trajectory
py-failing-suite-01core-12pythonDifficulty tier 1/5

Fix the off by one in an inclusive date range

off-by-onedatesentry-level

Task parameters

Reference steps
6
Step ceiling
25
Runs
15
Solved
12 of 15
Models
5

What is broken, and what fixed means

A small date utility library has one off by one error in the function that expands a start and end date into a list of dates. The library documents the range as inclusive of both ends, and three of its tests fail because the implementation excludes the end date. Everything needed to diagnose this is visible in the workspace, including a test suite that reproduces the failure.

Results by model

One group per model. The solve rate carries its spread across seeds, and every run below it links to the full step by step replay.

stub:hasty

0.0%+/- 0.0% over 3 seeds

3 runs, seeds 0, 1, 2

stub:methodical

100.0%+/- 0.0% over 3 seeds

3 runs, seeds 0, 1, 2

stub:reckless

100.0%+/- 0.0% over 3 seeds

3 runs, seeds 0, 1, 2

stub:sloppy

100.0%+/- 0.0% over 3 seeds

3 runs, seeds 0, 1, 2

stub:thrasher

100.0%+/- 0.0% over 3 seeds

3 runs, seeds 0, 1, 2