感觉这个贪心证明挺不错的。   Problem Statement You are given \(N\) integers; the \(i\)-th of them is \(A_i\). Find the maximum possible sum of the absolute differences between...

      带关于\(n\)的高次项也可以矩阵加速。   题目描述 这是一道很简单的题。 给你两个数\(a_1,a_2\)，求\(a_n\)在模\(2147439647\)下的值。 满足递推关系：\(a_n=a_{n-1}+2a_{n-2}+n^4\) 保...

      排列的转化以及拓扑排序的建模加线段树优化连边。   Problem Statement You are given a permutation \(P_1\dots P_N\) of the set \(\{1, 2,\dots , N\}\). You can apply the following...

      这个题真是太有意思了ovo   Description Ehab is interested in the bitwise-xor operation and the special graphs. Mahmoud gave him a problem that combines both. He has a complet...

      应用DFS树来构造答案的一道题。   Description All Berland residents are waiting for an unprecedented tour of wizard in his Blue Helicopter over the cities of Berland! It is wel...

      应该是比较好想的状压，回文算法虽然没怎么学过，但是要知道回文的性质呀。   Description After learning a lot about space exploration, a little girl named Ana wants to change the ...

      是一道比较有水平的期望题，和AGC028B很像。   题目描述 在不存在的\(\text{noip day3}\) ⾥，小\(\text w\)见到了⼀堆堆的谜题。 比如这题为什么会叫共轭？ 他并不知道答案。 有\(n\)...

      这个题依然是Mayfly（tql）的idea，感觉思路也比较奇特。   Description Buber is a Berland technology company that specializes in waste of investor's money. Recently Buber decided...

      当时打这场ACM的时候是julao队友Mayfly做出来的，要把数位转化到图上去跑。 Description You are given two positive integers \(d\) and \(s\). Find minimal positive integer \(n\) which is ...

      把一个数学题建成一个图论题    Problem Statement Find the smallest possible sum of the digits in the decimal notation of a positive multiple of \(K\).   Constrai...