bnu-faraway/XVIII Open Cup named after E.V. Pankratiev. Grand Prix of Peterhof

Info

Date:2018.10.02

Link

Solutions

A City Wall

solved by gjy


gjy’s solution

考虑将正六边形拉长,如果花2格,能够包住的点数增加个数为 1,2,3,3,4,5……

如果花1格,在当前图形的基础上拉长收益最大的边,收益为0,1,1,1,2,2,2,3……

暴力向上模拟即可,时间复杂度\(O(\sqrt{n})\)

B Domino Colorings

solved by


’s solution

C Counterquestion

solved by


’s solution

D Galaxy Center

solved by


’s solution

E IBM 1403

F Line Tracing

upsolved by


’s solution

G The Queen and the Knight

H Product of Roots

upsolved by gjy


gjy’s solution

\[f(x)=\prod_{i=1}^{n}(1+a_ix)=exp(\sum_{i=1}^{n}ln(1+a_ix))\]

\[g(x)=\prod_{i=1}^{n}(1+b_ix)=exp(\sum_{i=1}^{n}ln(1+b_ix))\]

\[h(x)=\prod_{i=1}^{n}(1+a_ib_ix)=exp(\sum_{i=1}^{n}ln(1+a_ib_ix))\]

对f,g多项式取ln,算出lnh,对该多项式求exp,得到h。

I Safe Landing

solved by ghc,gjy


ghc,gjy’s solution

签到题

J Perfect Square

upsolved by


’s solution

Replay

ghc

gjy

sk