D. Choosing Capital for Treeland time limit per test 3 seconds memory limit per test 256 megabytes input standard input output standard output The country Treeland consists of n cities, some pairs of them are connected with unidirectional roads. Over…

本书转译自日文,日文版则是在美国的“Choosing Wisely”项目中选择了100个相对常见的过度医疗项目做解说.Choosing Wisely项目,是由美国多个专业医学组织发起的列出过度医疗项目的活动. 日文作者是兽医专业的新闻记者,中文译者不是医学专业人员,个别专业词语翻译有误,“随机对照试验”翻译成“随机比较试验”了,有些句子翻译的也比较别扭.基于以上两点,这本书的权威性可信度我认为都不算太高,只能给三星.感兴趣的话还是应该直接上网看英文原版. 以下是书中部分信息的摘抄: 1:以美国内…

http://sqlite.org/whentouse.html Appropriate Uses For SQLite SQLite is not directly comparable to client/server SQL database engines such as MySQL, Oracle, PostgreSQL, or SQL Server since SQLite is trying to solve a different problem. Client/server S…

A key is a column or expression on which you can build an index. Follow these guidelines for choosing keys to index: Consider indexing keys that are used frequently in WHERE clauses. Consider indexing keys that are used frequently to join tables in S…

Choosing Capital for Treeland Description The country Treeland consists of n cities, some pairs of them are connected with unidirectional roads. Overall there are n - 1 roads in the country. We know that if we don't take the direction of the roads in…

home Choosing a Linux Tracer (2015) 08 Jul 2015 Linux Tracing is Magic! A tracer is an advanced performance analysis and troubleshooting tool, but don't let that intimidate you... If you've used strace(1) or tcpdump(8) – you've used a tracer. System…

Choosing Capital for Treeland time limit per test 3 seconds memory limit per test 256 megabytes input standard input output standard output The country Treeland consists of n cities, some pairs of them are connected with unidirectional roads. Overall…

来源:http://podlipensky.com/2012/06/choosing-web-framework-asp-net-mvc-vs-django-python-vs-ruby-on-rails/ How often do you emerge from you cubicle to look around, note new faces or new facial expression on old ones? How often do you emerge from you tec…

[HackerRank]Choosing White Balls 题目大意: 有\(n(n\le30)\)个球排成一行,每个球的颜色为黑或白. 执行\(k\)次操作,第\(i\)次操作形式如下: 从\([1,n−i+1]\)中,等概率随机选择一个整数\(x\). 移除从左往右数的第\(x\)个球,或从右往左数的第\(x\)个球.之后,所有右侧的球的编号减\(1\). 给定每个球的颜色信息,求在最优策略下,期望的移除白球数量最大值. 思路: 状压DP+哈希表. 源代码: #include<cstd…

Choosing number [题目链接]Choosing number [题目类型]矩阵 &题解: 这题就和已经dp极像了,所以找方程就很困难了.可以这样找: 设f(n)是前n-1个人已经完成,第n个人选>k,g(n)是前n-1个人已经完成,第n个人选<=k. 那么f(n)=f(n-1)*(m-k)+g(n-1)*(m-k) g(n)=f(n-1)*k+g(n-1)*(k-1) 最后答案是f(n)+g(n) 所以这题难就难在想公式上 [时间复杂度]\(O(logn)\) &…