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Can someone explain what's going on with the tests in Task A Codeforces Round 1004 (Div. 2)?
By Qw04_Dragoknight, history, 3 hours ago, In English

This is my first post on codeforces, so I apologize for the quality. In the last 1004th round, I tilted hard because of Task A. I think there's a mistake in the tests here. Can someone explain me why I got WA in test case 2. There was x = 1 and y = 9. So if we take n=9 S(9)=9 and S(n+1)=S(10)=1, and the answer is YES.

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3 hours ago, # |
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    3 hours ago, # ^ |
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    if x=9 and y=1 then n=9, s(9)=9=x and s(9+1)=s(10)=1=y but there is x=1 and y=9 so, NO is correct answer and YES is wrong answer

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      3 hours ago, # ^ |
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      Oh, thank you I thought the order of x and y was not important...

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You found a value of n satisfying $$$S(n) = 9$$$ and $$$S(n + 1) = 1$$$, but they asked if there exists $$$n$$$ such that $$$S(n) = 1$$$ and $$$S(n + 1) = 9$$$. You interchanged $$$x$$$ and $$$y$$$.

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