摘要： You are given a tree (an acyclic undirected connected graph) withNnodes, and edges numbered 1, 2, 3...N-1.We will ask you to perfrom some instructions... 阅读全文

摘要： Petya loves lucky numbers. We all know that lucky numbers are the positive integers whose decimal representations contain only the lucky digits4and7. ... 阅读全文

摘要： They say that Berland has exactly two problems, fools and roads. Besides, Berland hasncities, populated by the fools and connected by the roads. All B... 阅读全文

摘要： As you know, an undirected connected graph withnnodes andn - 1edges is called atree. You are given an integerdand a tree consisting ofnnodes. Each nod... 阅读全文

摘要： 题意：给出一棵树，root=1,树有点权，有一个人叫做M有3种操作：1 u v 把u到v路径上的所有点的点权都给M2 u 若u的点权在M手上，拿走3 u 把u为根的子树的所有点权都给M每一个操作过后，输出M拥有的点权想法：要维护路径，用树链剖分要维护子树，用dfs序但是这样貌似要写很多然而后来知道树... 阅读全文

摘要： 一棵树，初始边权和点权都为0现在有m个操作，每一个操作：ADD1 u v k: for nodes on the path from u to v, the value of these nodes increase by k.ADD2 u v k: for edges on the path fr... 阅读全文

摘要： Problem DescriptionOO has got a array A of size n ,defined a function f(l,r) represent the number of i (li) satisfy aimod aj=0,now OO want to know∑i=1... 阅读全文

摘要： Ilya got tired of sports programming, left university and got a job in the subway. He was given the task to determine the escalator load factor.Let's ... 阅读全文

摘要： nparticipants of the competition were split intomteams in some manner so that each team has at least one participant. After the competition each pair ... 阅读全文

摘要： 离散化的大概思路:比如说给你一组数据141000100000，如果直接开线段,显然是浪费,那么我们只要进行映射:1142100031000004接下来我们只要对1234建立线段树就行了只需要[1,4]的区间离散化就相当于是先做映射，然后再建树。本题大意：给定一些海报，可能相互重叠，告诉你每个海报的宽... 阅读全文