Occult

Problem DescriptionPog and Szh are playing games. Firstly Pog draw a tree on the paper. Here we define 1 as the root of the tree. Then Szh choose some nodes from the tree. He wants Pog helps to fi

DescriptionThere is an area map that is a rectangular matrix n × m, each cell of the matrix contains the average height of a corresponding area part. Peter works for a company that has to build

Problem Description我们定义“区间的价值”为一段区间的最大值*最小值。一个区间左端点在L，右端点在R，那么该区间的长度为(R−L+1)。现在聪明的杰西想要知道，对于长度为k的区间，最大价值的区间价值是多少。当然，由于这个问题过于简单。我们肯定得加强一下。我们想要知道的是，对于长度为1∼n的区间，最大价值的区间价值分别是多少。

DescriptionMr. Flower's business is growing much faster than originally planned. He has now become the CEO of a world-famous beef corporation. However, the boss never lives a casual life because

DescriptionBobo has a balanced parenthesis sequence P=p1 p2…pn of length n and q questions.The i-th question is whether P remains balanced after pai and pbi  swapped. Note that questions are