someng的博客

https://abc095.contest.atcoder.jp/tasks/abc095_b问题描述：Akaki, a patissier, can make N kinds of doughnut using only a certain powder called "Okashi no Moto" (literally "material of pastry", simply called...

https://arc078.contest.atcoder.jp/tasks/arc078_b 问题描述 Fennec and Snuke are playing a board game. On the board, there are N cells numbered 1 through N, and N−1 roads, each connecting two cells. Ce...

https://arc099.contest.atcoder.jp/tasks/arc099_b 问题描述 Let S(n) denote the sum of the digits in the decimal notation of n. For example, S(123)=1+2+3=6. We will call an integer n a Snuke number when,...