@(HDU)[Stirling數] Problem Description A murder happened in the hotel. As the best detective in the town, you should examine all the N rooms of the hotel immediately. However, all the doors of the rooms are locked, and the keys are just locked in the…

Examining the Rooms Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 1138    Accepted Submission(s): 686 Problem Description A murder happened in the hotel. As the best detective in the town, yo…

Examining the Rooms Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 1305    Accepted Submission(s): 796 Problem Description A murder happened in the hotel. As the best detective in the town, yo…

[HDU 3625]Examining the Rooms (第一类斯特林数) 题面 有n个房间,每个房间有一个钥匙,钥匙等概率的出现在n个房间内,每个房间中只会出现且仅出现一个钥匙.你能炸开门k次,问你能进入所有房间的概率.特殊要求:不能炸1号房间的门. T组询问 T<=2000,k<=n<=2000 分析 前置知识(如果你了解斯特林数,可以跳过) 圆排列:把n个元素排在一个圆周上,如果旋转之后两个圆周上的排列一样,那么这两个排列相同 第一类斯特林数S(n,m)表示把n个不同元素构成m…

这道题的知识点第一次听说 ,就是应用斯特林数.题目的意思是给你房间数N,和最多能破门的个数,让你求能全部把房间打开的概率! a[i][j]=a[i-1][j-1]+(i-1)*a[i-1][j]; #include <cstdio> #include <cstring> #include <cmath> #include <algorithm> using namespace std; ],a[][]; void inti() { f[]=; f[]=; ;…

题目大意:有n个房间,n!个钥匙,在房间中,最多可以破k扇门,然后得到其中的钥匙,去开其它的门,但是第一扇门不可以破开,求可以打开所有门的概率. 题解:首先,建立这样的一个模型,题目相当于给出一个图,求形成1--K个环的可能性有多大.但是节点1不可以形成子环.那么首先,n个点形成1--k个环就是第一类斯特灵数的定义,但是该如何处理1的问题呢,既然算起来比较麻烦,那么正难则反,减去节点1成为自环的情况就可以了.第一类斯特林公式:S(m,n)=(m-1)*S(m-1,n)+S(m-1,n-1). #…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=3625 题意: 有n个房间,每个房间里放着一把钥匙,对应能开1到n号房间的门. 除了1号门,你可以踹开任意一扇门(不用钥匙),但你最多只能踹k次. 问你能将所有门打开的概率. 题解: · P(打开所有门) = 能打开所有门的钥匙放置情况数 / 钥匙放置的总情况数 · 钥匙放置的总情况数 = n! 那么考虑下能打开所有门的钥匙放置情况数... 由于每个房间里有且只有一把钥匙,所以如果将每个房间连向房间内…

<题目链接> <转载于 >>> > 题目大意:有n个锁着的房间和对应n扇门的n把钥匙,每个房间内有一把钥匙.你可以破坏一扇门,取出其中的钥匙,然后用取出钥匙打开另一扇门(如果取出的钥匙能打开房门则接着打开,取出其中钥匙,如此往复,若打不开则继续破坏一扇门).最多可以破坏k(k<=n)扇门,但是编号为1的门只能用钥匙打开.求能打开所有门(被破坏或是被钥匙打开)的概率. 解题分析: 钥匙和门的关系是成环状的,打开一个门之后,该环内的所有房间都可以进入,怎么说呢,…

---恢复内容开始--- 2017-08-10 20:32:37 writer:pprp 题意如下: Recently in Teddy's hometown there is a competition named "Cow Year Blow Cow".N competitors had took part in this competition.The competition was so intense that the rank was changing and changi…

题目:http://acm.hdu.edu.cn/showproblem.php?pid=3625 n^2 求斯特林数就行.要减去的就是1号钥匙在1号房间的方案,即 s[ n-1 ][ m-1] . 注意是 <=m . #include<iostream> #include<cstdio> #include<cstring> #include<algorithm> #define ll long long using namespace std; ;…

题目:http://acm.hdu.edu.cn/showproblem.php?pid=3625 学习斯特林数:https://blog.csdn.net/qq_33229466/article/details/75042895 https://www.cnblogs.com/gzy-cjoier/p/8426987.html http://www.cnblogs.com/zhouzhendong/p/Stirling-Number.html 关于这道题: 得到一把钥匙后,可以连续开的门与钥匙…

题目大意 n个房间对应n把钥匙 每个房间的钥匙随机放在某个房间内,概率相同. 有K次炸门的机会,求能进入所有房间的概率 一号门不给你炸 分析 我们设\(key_i\)为第i间房里的钥匙是哪把 视作房间i向房间\(key_i\)连了一条有向边 这相当于n个点n条边,且每个点出度入度都为1 就是m个环,就是置换嘛 相当于第一类斯特林数\(\left [\begin{matrix} n\\ m \end{matrix}\right]\) 做法 一个环中炸掉一个门就可以开环中所有的门 问题转化为求环的数…

题目链接: http://acm.hdu.edu.cn/showproblem.php? pid=3625 题目大意: 有N个房间,每一个房间的要是随机放在某个房间内,概率同样.有K次炸门的机会. 求能打开全部房间门,进入全部房间的概率有多大. 解题思路: 门和钥匙的相应关系出现环.打开一个门后,环内的门都能够打开. 也就意味着: N个房间的钥匙与门形成1~K个环的概率有多大. 也就是求N个元素.构成K个以内的环,且1不成自环的概率. N个元素形成K个环的方法数是第一类stirling数 S(N…

Examining the Rooms Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 1661    Accepted Submission(s): 1015 Problem Description A murder happened in the hotel. As the best detective in the town, yo…

HDU 1000 A + B Problem  I/O HDU 1001 Sum Problem  数学 HDU 1002 A + B Problem II  高精度加法 HDU 1003 Maxsum  贪心 HDU 1004 Let the Balloon Rise  字典树,map HDU 1005 Number Sequence  求数列循环节 HDU 1007 Quoit Design  最近点对 HDU 1008 Elevator  模拟 HDU 1010 Tempter of th…

Given an array of meeting time intervals consisting of start and end times [[s1,e1],[s2,e2],...] (si < ei), find the minimum number of conference rooms required. For example,Given [[0, 30],[5, 10],[15, 20]],return 2. 这道题是之前那道Meeting Rooms的拓展,那道题只让我们是…

Given an array of meeting time intervals consisting of start and end times [[s1,e1],[s2,e2],...] (si < ei), determine if a person could attend all meetings. For example,Given [[0, 30],[5, 10],[15, 20]],return false. 这道题给了我们一堆会议的时间,问我们能不能同时参见所有的会议,这实际…

Time Limit:2000MS     Memory Limit:262144KB     64bit IO Format:%I64d & %I64u Submit Status Practice CodeForces 519E Description A and B are preparing themselves for programming contests. The University where A and B study is a set of rooms connected…

Game Rooms Time Limit: 4000/4000 MS (Java/Others)    Memory Limit: 65535/65535 K (Java/Others)Total Submission(s): 305    Accepted Submission(s): 84 Problem Description Your company has just constructed a new skyscraper, but you just noticed a terrib…

Zones和Rooms结构: 相对于SFS 1.X而言,在Zones和Rooms的配置上,SFS2X有了显著的改善.尤其是我们建立了房组这样一个简单的概念,它允许在一个逻辑组中管理Rooms,从而独立于其他Rooms.Users可以订阅发生在该组中他们只感兴趣的事件,而忽略其他所有的. 这种方法的好处是通过服务器发送的初始room列表将会更小,并且对于发送到每个客户端的事件数量也会大幅度减少,特别是在一些高流量的应用程序中. 概念说明示例: User可以订阅最初的Room群消息和接收Room的升…

原题链接在这里:https://leetcode.com/problems/meeting-rooms-ii/ Given an array of meeting time intervals consisting of start and end times [[s1,e1],[s2,e2],...] (si < ei), find the minimum number of conference rooms required. For example,Given [[0, 30],[5, 1…

原题链接在这里:https://leetcode.com/problems/meeting-rooms/ Given an array of meeting time intervals consisting of start and end times [[s1,e1],[s2,e2],...] (si < ei), determine if a person could attend all meetings. For example,Given [[0, 30],[5, 10],[15,…

为什么我用nodejs用这个两个函数获取都会出错呢?是不是socket的api改了?请问现在获取房间数和当前房间的客户怎么获取?什么函数?谢谢!!急求!     网友采纳 版本问题.io.sockets.manager.rooms 用 io.sockets.adapter.rooms 代替io.sockets.clients('particular room') 换成了 io.sockets.adapter.rooms['private_room'];…

题目: Given an array of meeting time intervals consisting of start and end times [[s1,e1],[s2,e2],...] (si < ei), find the minimum number of conference rooms required. For example,Given [[0, 30],[5, 10],[15, 20]],return 2. 链接: http://leetcode.com/probl…

题目链接:E. A and B and Lecture Rooms 题目大意 给定一颗节点数10^5的树,有10^5个询问,每次询问树上到xi, yi这两个点距离相等的点有多少个. 题目分析 若 x==y 直接返回 n. 先求出 x, y 两个点的中点. 先求出 LCA(x, y) = z,假设 Depth[x] >= Depth[y] ,若Depth[x] == Depth[y] ,那么 z 就是它们的中点. 答案就是,n - Size[fx] - Size[fy],fx 是从x向上跳,一直跳…

Problem: Given an array of meeting time intervals consisting of start and end times [[s1,e1],[s2,e2],...] (si < ei), find the minimum number of conference rooms required. For example,Given [[0, 30],[5, 10],[15, 20]],return 2. Analysis: This problem l…

Game Rooms Time Limit: 4000/4000MS (Java/Others)     Memory Limit: 65535/65535KB (Java/Others) Submit Status Your company has just constructed a new skyscraper, but you just noticed a terrible problem: there is only space to put one game room on each…

转载请注明出处: http://www.cnblogs.com/fraud/          ——by fraud E. A and B and Lecture Rooms A and B are preparing themselves for programming contests. The University where A and B study is a set of rooms connected by corridors. Overall, the University ha…

对于刚学习Unix/Linux环境C编程的小朋友们或者写了很多所谓的C代码的老手们(其实很可能是机械程序员或者是伪程序员)来说,要记住gdb的eXaming memory的语法其实是相当不容易的,如果学习了gdb的这一语法后不再反复操练,很快就会忘记得干干净净. 先看看gnu/docs/gdb上怎么说, 8.5 Examining memoryYou can use the command x (for "examine") to examine memory in any of se…

There are N rooms and you start in room 0.  Each room has a distinct number in 0, 1, 2, ..., N-1, and each room may have some keys to access the next room. Formally, each room i has a list of keys rooms[i], and each key rooms[i][j] is an integer in […