Adityaxv's blog

Need an explanation of the 3rd testcase of this problem.
By Adityaxv, 5 months ago, In English

Problem

According to me P = 85 and Q = 10. So, the answer should be 8. But why the expected answer is 500000012?

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5 months ago, # |
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perform modular division(Fermat's Theorem) on it you will get that o/p My Solution

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5 months ago, # |
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Yeah you are right, 85/10 = 8.

I think the authors made a mistake probably.

And we should do a complete retesting for all those who got AC during the contest.

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5 months ago, # |
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you need to calculate $$$Q^{-1}$$$ mod $$$10^9 + 7$$$ using Fermat's theorem (modular inverse) which is $$$700000005$$$, then multiply it by $$$85$$$ mod $$$10^9 + 7$$$, which is equal to $$$500000012$$$

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