### physics0523's blog

By physics0523, history, 3 months ago,

104855A - GCD,LCM and AVG

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104855B - Yugandhar's Letter for Diya

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104855C - Hungry Shark

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104855D - Colorful Paths

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104855E - Perfect Permutation

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104855F - Regular Covering

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Appendix: Code for all problems
• +16

 » 3 months ago, # |   0 Thank you for the problems!
 » 3 months ago, # | ← Rev. 3 →   +13 I did a random solution in problem A, now I know it's much easier.I did a sieve up to $10^6$, then I choose 3 primes randomly between the 101st and the 78401st prime, and asked 3 queries. So I took the maximum of 3 answers divided by the prime. solutionIt works because the probability of some number less than $10^9$ have some prime number less than $10^6$ and greater than $541$ (the 101st prime) as factor is something like $3/78300$, so the probability of get the right answer in each $10000$ tests is something like $(1 - (\frac{3}{78300})^3)^{10000} \approx 1-5.6\cdot 10^{-10}$