Tim_Dee_fan's blog

System testing
By Tim_Dee_fan, history, 17 months ago, In English

Hello codeforces

Codeforces Round 891 (Div. 3) where hacks? why now is System testing? Can explain what it is?

Thank you

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17 months ago, # |
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They removed the test cases for problem F which had a query with x=0 in them (which was illegal input according to the problem set) and rejudged all submissions (and also invalidate hacks with x=0 (invalidating x=0 as a valid input)). The hacking phase continues.

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    17 months ago, # ^ |
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    Where did you get this information from?

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      17 months ago, # ^ |
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      I checked the solution of the author of the blog https://mirror.codeforces.com/blog/entry/119122. Most (probably all) of his solutions for problem F WA on Test 7 (prior to the incident). (Saw the test case too it had 4 queries with x=0). I rechecked them post fixation and they seem AC.
      Hence, I made a conclusion about the situation.
      One may argue it's time wasting but... Doesn't matter :)

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17 months ago, # |
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Thank you

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17 months ago, # |
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The announcement is gone now and so are the hacks. Is it unrated?

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    17 months ago, # ^ |
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    The announcement is back now. They mentioned that they fixed the tests and reverted illegal hacks. There is No mention of it being unrated.
    I checked some cases using the status tab which fail at test 7 (the first illegal test case with x=0 in it's query) Out of some 40 random tests, I only found approximately 6 of them failing only at the x=0 query. Rest of them also failed at different not-illegal queries of test 7. Hence the notion of "the error affecting only some people."

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