Alice and BobTime Limit: 1 Sec  Memory Limit: 64 MBSubmit: 255  Solved: 43 Description Alice is a beautiful and clever girl. Bob would like to play with Alice. One day, Alice got a very big rectangle and wanted to divide it into small square pieces.…

https://www.bnuoj.com/v3/contest_show.php?cid=9147#problem/C [题意] 初始时有n个数,定义操作为从n个数中取出两个数x,y,如果|x-y|不在set中,操作就是合法的,并且把|x-y|加到set里.最后不能操作的人输.A和B轮流操作,A先手,问最后谁赢. [思路] 通过观察发现6,8,10和3,4,5的情况其实是一样的,不同的是前者的每个数都是后者的2倍.所以可以想到与GCD有关,而且GCD本身也是辗转相减.所以就想到了GCD.最后很…

题意 多组询问,每次给定 \(n\) ,求:\(\sum_{i=1}^nlcm(i,n)\) . \(\rm T \leq 3\times 10^4\ ,n \leq 10^6\). 分析 推式子: \[\sum_{i=1}^n{\frac{in}{gcd(i,n)}}\] 枚举 \(gcd\) : \[n\sum_{d|n}{\sum_{i=1}^n[gcd(i,n)=d]\frac{i}{d}}\] \[n\sum_{d|n}{\sum_{i=1}^{\frac{n}{d}}[i\perp…

源自:百度百科 辗转相除法 辗转相除法:辗转相除法是求两个自然数的最大公约数的一种方法,也叫欧几里德算法. 例如,求(,): ∵ ÷=(余319) ∴(,)=(,): ∵ ÷=(余58) ∴(,)=(,): ∵ ÷=(余29) ∴ (,)=(,): ∵ ÷=(余0) ∴ (,)= : ∴ (,)=. 用辗转相除法求几个数的最大公约数,可以先求出其中任意两个数的最大公约数,再求这个最大公约数与第三个数的最大公约数,依次求下去,直到最后一个数为止.最后所得的那个最大公约数,就是所有这些数的最大公约数…

Alice and Bob decided to eat some fruit. In the kitchen they found a large bag of oranges and apples. Alice immediately took an orange for herself, Bob took an apple. To make the process of sharing the remaining fruit more fun, the friends decided to…

联系: http://soj.me/1732 Constraints Time Limit: 1 secs, Memory Limit: 32 MB Description: Alice is a beautiful and clever girl. Bob would like to play with Alice. One day, Alice got a very big rectangle and wanted to divide it into small square pieces.…

Alice and Bob Time Limit: 10000/5000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)Total Submission(s): 147    Accepted Submission(s): 22 Problem Description As you know, Alice and Bob always play game together, and today they get a…

Description Alice和Bob在玩游戏.有n个节点,m条边(0<=m<=n-1),构成若干棵有根树,每棵树的根节点是该连通块内编号最 小的点.Alice和Bob轮流操作,每回合选择一个没有被删除的节点x,将x及其所有祖先全部删除,不能操作的人输 .注:树的形态是在一开始就确定好的,删除节点不会影响剩余节点父亲和儿子的关系.比如:1-3-2 这样一条链 ,1号点是根节点,删除1号点之后,3号点还是2号点的父节点.问有没有先手必胜策略.n约为10w. 显然只要算出每颗子树的sg值就可以…

Alice and Bob Time Limit: 1000ms   Memory limit: 65536K 题目描述 Alice and Bob like playing games very much.Today, they introduce a new game. There is a polynomial like this: (a0*x^(2^0)+1) * (a1 * x^(2^1)+1)*.......*(an-1 * x^(2^(n-1))+1). Then Alice as…

http://acm.sdut.edu.cn/sdutoj/problem.php?action=showproblem&problemid=2608 Alice and Bob Time Limit: 1000ms   Memory limit: 65536K  有疑问?点这里^_^ 题目描述 Alice and Bob like playing games very much.Today, they introduce a new game. There is a polynomial li…