考虑统计每一轮(以抽到小丑为一轮)的贡献,不难发现答案即期望轮数*每轮期望次数 关于期望轮数,当前牌堆里已经在$S$中的卡实际上没有意义,不妨将这一类卡从牌堆中删除 此时,定义$f_{i}$表示$S$中含有$n-i$个元素,之后期望还需要几轮(包括当前这轮) 显然$f_{0}=1$,问题即求$f_{n}$,不难得到转移为$f_{i}=\frac{m}{m+i}(f_{i}+1)+\frac{i}{m+i}f_{i-1}$ 将其化简,即有$f_{i}=f_{i-1}+\frac{m}{i}$,因此…

Codeforces 题面传送门 & 洛谷题面传送门 真·两天前刚做过这场的 I 题,今天模拟赛就考了这场的 H 题,我怕不是预言带师 提供一种奇怪的做法,来自于同机房神仙们,该做法不需要 Min-Max 容斥,也不用爆推组合数,只需要比较强的眼力的初中数学求解二元一次方程组知识. 期望题没往 Min-Max 容斥的方向去想,不愧是我(大雾 首先我们先考虑一些复杂度比较高的多项式复杂度做法.注意到对于任何一个局面而言,我们并不用关心 \(S\) 里究竟具体有哪些数,也不用关心牌堆中具体有哪些数字…

\(\mathcal{Description}\)   Link.   打乱的 \(n\) 张编号 \(1\sim n\) 的数字排和 \(m\) 张鬼牌.随机抽牌,若抽到数字,将数字加入集合 \(S\):否则,还原牌堆(但不清空 \(S\)).若 \(S=[1,n]\) 且抽到鬼牌时结束抽牌.求期望抽牌次数.   \(n,m\le2\times10^6\). \(\mathcal{Solution}\)   称从初始牌堆开始抽牌一直到抽到鬼牌为一轮操作,发现结束时必然抽了若干个完整的轮且不能中…

CARDS Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 1448   Accepted: 773 Description Alice and Bob have a set of N cards labelled with numbers 1 ... N (so that no two cards have the same label) and a shuffle machine. We assume that N i…

Alice and Bob have a set of N cards labelled with numbers 1 ... N (so that no two cards have the same label) and a shuffle machine. We assume that N is an odd integer. The shuffle machine accepts the set of cards arranged in an arbitrary order and pe…

题目链接:Cards 听说这道题是染色问题的入门题,于是就去学了一下\(Bunside\)引理和\(P\acute{o}lya\)定理(其实还是没有懂),回来写这道题. 由于题目中保证"任意多次洗牌都可用这\(m\)种洗牌法中的一种代替",于是有了封闭性. 结合律显然成立. 题目中还保证了"对每种洗牌法,都存在一种洗牌法使得能回到原状态",逆元也有了. 只剩下一个单位元,我们手动补上.单位元就是不洗牌. 所以所有的洗牌方案构成了一个置换群.于是就可以用$Bunsid…

E. Vladik and cards time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Vladik was bored on his way home and decided to play the following game. He took n cards and put them in a row in front…

1004: [HNOI2008]Cards Description 小春现在很清闲,面对书桌上的N张牌,他决定给每张染色,目前小春只有3种颜色:红色,蓝色,绿色.他询问Sun有 多少种染色方案,Sun很快就给出了答案.进一步,小春要求染出Sr张红色,Sb张蓝色,Sg张绝色.他又询问有多少种方 案,Sun想了一下,又给出了正确答案. 最后小春发明了M种不同的洗牌法,这里他又问Sun有多少种不同的染色方案. 两种染色方法相同当且仅当其中一种可以通过任意的洗牌法(即可以使用多种洗牌法,而每种方法可以使…

C. Hongcow Buys a Deck of Cards time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output One day, Hongcow goes to the store and sees a brand new deck of n special cards. Each individual card is eit…

传送门 time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output ZS the Coder has recently found an interesting concept called the Birthday Paradox. It states that given a random set of \(23\) people,…

题目链接: 传送门 Little Elephant and Cards time limit per test:2 second     memory limit per test:256 megabytes Description The Little Elephant loves to play with color cards. He has n cards, each has exactly two colors (the color of the front side and the…

题目链接: 传送门 Invitation Cards Time Limit: 5000MS     Memory Limit: 32768 K Description In the age of television, not many people attend theater performances. Antique Comedians of Malidinesia are aware of this fact. They want to propagate theater and, mo…

E. George and Cards   George is a cat, so he loves playing very much. Vitaly put n cards in a row in front of George. Each card has one integer written on it. All cards had distinct numbers written on them. Let's number the cards from the left to the…

Soldier and Cards 题目: Description Two bored soldiers are playing card war. Their card deck consists of exactly n cards, numbered from 1 to n, all values are different. They divide cards between them in some manner, it's possible that they have differ…

18.2 Write a method to shuffle a deck of cards. It must be a perfect shuffle—in other words, each of the 52! permutations of the deck has to be equally likely. Assume that you are given a random number generator which is perfect. 这道题让我们实现一个洗牌的算法,实际上洗…

Invitation Cards Time Limit : 16000/8000ms (Java/Other)   Memory Limit : 524288/262144K (Java/Other) Total Submission(s) : 7   Accepted Submission(s) : 1 Problem Description In the age of television, not many people attend theater performances. Antiq…

E. Vladik and cards 题目链接 http://codeforces.com/contest/743/problem/E 题面 Vladik was bored on his way home and decided to play the following game. He took n cards and put them in a row in front of himself. Every card has a positive integer number not e…

转载请注明 http://blog.csdn.net/eclipsexys 翻译自Developer Android.时间仓促,有翻译问题请留言指出,谢谢 创建Lisst和Cards 在你的应用程序创建复杂的清单,并与材料设计风格卡.您能够使用RecyclerView和CardView部件. 创建RecyclerView 该RecyclerView widget是ListView中的更先进,更灵活的版本号.这个小工具是一个容器.用于显示.能很有效地维护了意见数量有限,滚动大的数据集. 当你有收集…

题目链接: E. ZS and The Birthday Paradox. time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output ZS the Coder has recently found an interesting concept called the Birthday Paradox. It states that giv…

[题目] 从扑克牌中随机抽5张牌,判断是不是一个顺子,即这5张牌是不是连续的.2-10为数字本身,A为1,J为11,Q为12,K为13,而大小王可以看成任意数字. [分析] 这题目很有意思,是一个典型的寓教于乐的题目.我们需要把扑克牌的背景抽象成计算机语言.不难想象,我们可以把5张牌看成由5个数字组成的数组.大小王是特殊的数字,我们不妨把它们都当成0,这样和其他扑克牌代表的数字就不重复了. 接下来我们来分析怎样判断5个数字是不是连续的.最直观的是,我们把数组排序.但值得注意的是,由于0可以当成任…

http://www.behardware.com/art/lire/845/ --> Understanding 3D rendering step by step with 3DMark11 - BeHardware>> Graphics cards Written by Damien Triolet Published on November 28, 2011 URL: http://www.behardware.com/art/lire/845/ Page 1 Introduct…

Define “Straight” as 5 cards with consecutive numbers. Determine if the deck can be fully divided into sets of “Straight”. Example: 1, 2, 3, 4, 4, 5, 5, 6, 7, 8 -> TrueYou may assume the cards are sorted 这个是用一个hashtable,key是数字,value是出现次数 然后遍历原数组,每一个数…

MUH and House of Cards Time Limit:1000MS     Memory Limit:262144KB     64bit IO Format:%I64d & %I64u Submit Status Practice CodeForces 471C Description Polar bears Menshykov and Uslada from the zoo of St. Petersburg and elephant Horace from the zoo o…

F. Video Cards time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Little Vlad is fond of popular computer game Bota-2. Recently, the developers announced the new add-on named Bota-3. Of course…

Cards 题意: 给你n个牌,n是偶数,要你把这些牌分给n/2个人,并且让每个人的牌加起来相等. 题解: 这题我做的时候,最先想到的是模拟,之后码了一会,发现有些麻烦,就想别的方法.之后发现只要把它给的数排序就好了,排完序后输出原来的位置就好,因为每2个都能配对所以最小肯定配最大,第二小配第二大-- 之后就可以a了 代码: #include <bits/stdc++.h> using namespace std; const int INF=0x3f3f3f3f; typedef long…

A. Bear and Five Cards time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output A little bear Limak plays a game. He has five cards. There is one number written on each card. Each number is a posit…

For built-in types, there are conditional operators (<, >, ==, etc.) that compare values and determine when one is greater than, less than, or equal to another. For user-defined types, we can override the behavior of the built-in operators by provid…

Burnside/Polya+背包DP 这道题目是等价类计数裸题吧……>_> 题解:http://m.blog.csdn.net/blog/njlcazl_11109/8316340 啊其实重点还是:找出每个置换下的不动点数目 这道题比较特殊,牌的数量是限定的,所以只能DP来搞……(dp[R][G][B]表示的是R张红牌,G张绿牌,B张蓝牌在当前这个置换下,有多少种方案是会置换回自身的) 恒等置换单独处理一下即可(其实就是总染色数,多重集排列数吧……$\frac{N!}{R!G!B!}$) 最…

1004: [HNOI2008]Cards Time Limit: 10 Sec  Memory Limit: 162 MBSubmit: 2928  Solved: 1754[Submit][Status][Discuss] Description 小春现在很清闲,面对书桌上的N张牌,他决定给每张染色,目前小春只有3种颜色:红色,蓝色,绿色.他询问Sun有多少种染色方案,Sun很快就给出了答案.进一步,小春要求染出Sr张红色,Sb张蓝色,Sg张绝色.他又询问有多少种方案,Sun想了一下,又给出…

A. Cards time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output There are n cards (n is even) in the deck. Each card has a positive integer written on it. n / 2 people will play new card game. At…