Hello everyone! I am your old friend Rikka. Welcome to Xuzhou. This is the first problem, which is a problem about the minimum spanning tree (MST). I promise you all that this should be the easiest problemeasiest problem for most people. A minimum sp…

题意: 有一排n个石子(注意n可以为0),每次可以取1~K个连续的石子,Adrien先手,Austin后手,若谁不能取则谁输. 思路: (1) n为0时的情况进行特判,后手必胜. (2) 当k=1时,很容易可以发现:若n为偶数则后手赢,n为奇数则先手赢. (3) 当k>1时,只要先手保证这一排石子两边对称,则后手必败,所以可知k>1时先手必胜. #include<bits/stdc++.h> using namespace std; int main() { ios::sync_w…

Problem Description Consider a un-rooted tree T which is not the biological significance of tree or plant, but a tree as an undirected graph in graph theory with n nodes, labelled from 1 to n. If you cannot understand the concept of a tree here, plea…

2019~2020icpc亚洲区域赛徐州站H. Yuuki and a problem 题意: 给定一个长度为\(n\)的序列,有两种操作: 1:单点修改. 2:查询区间\([L,R]\)范围内所有子集和中没出现的最小正整数. 思路: 对于维护序列的问题大概率是数据结构的题目了,先确定一下题目的性质. 操作2需要我们提取\([l,r]\)范围内的值,这可以用主席树解决,同时需要带修,所以可以用树状数组套主席树完成. 确定是树套树后,考虑怎么维护操作2. 我们考虑一个节点,先看看能不能表示成1,如…

球队内线我也总水平,这所学校得到了前所未有的8地方,因为只有两个少年队.因此,我们13并且可以被分配到的地方,因为13和非常大的数目.据领队谁oj在之上a谁去让更多的冠军.我和tyh,sxk,doubleq运的在大二就有机会參加亚洲现场赛,非常激动.牡丹江赛区是我和sxk和doubleq组成rainbow战队,我们对这次区域赛事实上就是去张张见识,添加大赛经验(外加公费旅游2333),但是当我们真正来到赛场的时候不知道为上面我非常渴望拿一块牌子. 第一天热身赛,double迅速切下水题.我一直再…

Average Score Time Limit: 2 Seconds      Memory Limit: 65536 KB Bob is a freshman in Marjar University. He is clever and diligent. However, he is not good at math, especially in Mathematical Analysis. After a mid-term exam, Bob was anxious about his…

Known Notation Time Limit: 2 Seconds      Memory Limit: 65536 KB Do you know reverse Polish notation (RPN)? It is a known notation in the area of mathematics and computer science. It is also known as postfix notation since every operator in an expres…

Problem Description Coach Pang is interested in Fibonacci numbers while Uncle Yang wants him to do some research on Spanning Tree. So Coach Pang decides to solve the following problem:Consider a bidirectional graph G with N vertices and M edges. All…

Problem Description Here N (N ≥ 3) rabbits are playing by the river. They are playing on a number line, each occupying a different integer. In a single move, one of the outer rabbits jumps into a space between any other two. At no point may two rabbi…

Information Entropy Time Limit: 2 Seconds      Memory Limit: 65536 KB      Special Judge Information Theory is one of the most popular courses in Marjar University. In this course, there is an important chapter about information entropy. Entropy is t…