CF53E Dead Ends 洛谷评测传送门 题目描述 Life in Bertown has become hard. The city has too many roads and the government spends too much to maintain them. There are nn junctions and mm two way roads, at which one can get from each junction to any other one. The…

题意: 给一个n(n<=10)个节点的无向图,图里面有m条边,以这m条边构建生成树,求所有生成树中只含有k个度数为1的点的方案数. 题解: 看见这个数量级就一定会想到状态压缩dp... 那让我们设计一下状态: dp[i][j] 表示生成树的状态为i时,所含的度数为1的点的状态j的方案数. 那么就可以进行状态转移了,每次有两种更新方式: 1:加入一条边(也就是一个新点)到原来度数为1的点,相当于替换了. 2:把边加到一个度数不为1的节点上. 时间复杂度: O(能过) 废话少说上代码: #inclu…

Example 1: A never stop while loop return a never type. function run(): never { while(true){ let foo = "bar"; } } Example 2: Never run If block ; ) { let bar: never = foo; } You can use this to do exhaustive checks in union types. For example, l…

本文引自http://blog.jobbole.com/23286/ 很早就对Google的PageRank算法很感兴趣,但一直没有深究,只有个轮廓性的概念.前几天趁团队outing的机会,在动车上看了一些相关的资料(PS:在动车上看看书真是一种享受),趁热打铁,将所看的东西整理成此文. 本文首先会讨论搜索引擎的核心难题,同时讨论早期搜索引擎关于结果页面重要性评价算法的困境,借此引出PageRank产生的背景.第二部分会详细讨论PageRank的思想来源.基础框架,并结合互联网页面拓扑结构讨论P…

转载自:Context and Interception : The .NET Context Every new app domain starts with a single context, called the default context. The default context provides no component services at all. The main reason why it exists is to help maintain a consistent p…

http://www.onjava.com/pub/a/onjava/2001/05/30/optimization.htmlComparing the performance of LinkedLists and ArrayLists (and Vectors) (Page last updated May 2001, Added 2001-06-18, Author Jack Shirazi, Publisher OnJava). Tips: ArrayList is faster than…

阶段性总结 Boolean retrieval 单词搜索 [Qword1 and Qword2]               O(x+y) [Qword1 and Qword2]- 改进: Galloping Search   O(2a*log2(b/a)) [Qword1 and not Qword2]        O(m*log2n)  [Qword1 or not Qword2]           O(m+n) [Qword1 and Qword2 and Qword3 and ...…

网络信息的特点在于: Query: "IBM" --> "Computer" --> documentIDs. In degree i 正比于 1/iα ,  例如: α = 2.1 即:i越大,量越少. Query processing §  First retrieve all pages meeting the text query (say venture capital). §  Order these by their link popula…

GeoDefense Time Limit: 12000/5000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 745    Accepted Submission(s): 307 Problem Description Tower defense is a kind of real-time strategy computer games. The goal of towe…

Problem I. Instruction 题目连接: http://codeforces.com/gym/100531/attachments Description Ingrid is a head of a big railway station and, among other duties, is responsible for routing trains to the right platforms. The station has one entrance, and there…