Time: 0:00
Test a custom input to verify an edge case (e.g. empty lists, negative numbers, duplicates).
This bug belongs to the logic errors pattern
The wrong operator, an inverted condition, a formula the right way round but backwards.
What went wrong: the code rules out every year divisible by 100. It forgets that years divisible by 400, like 2000, are leap years again.
The fix: return year % 400 == 0 or (year % 4 == 0 and year % 100 != 0)
Remember: when a rule says "except … unless …", check that every part is in the code.
The pattern behind it: logic errors.
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<iframe src="https://trybughunt.com/embed/957b0da0-b9db-467a-a3bf-209e0cbee822" title="Debugging challenge: Leap year check says 2000 was not a leap year" width="100%" height="580" loading="lazy" style="border:1px solid #d4d4d8;border-radius:12px;max-width:760px"></iframe>
<p style="font-size:14px">Debugging challenge from <a href="https://trybughunt.com/challenges/957b0da0-b9db-467a-a3bf-209e0cbee822">TryBugHunt</a></p>