The government of a small but important country has decided that the alphabet needs to be streamlined and reordered. Uppercase letters will be eliminated. They will issue a royal decree in the form of a String of B and A characters. The first character in the decree specifies whether a must come ( B )Before b in the new alphabet or ( A )After b . The second character determines the relative placement of b and c , etc. So, for example, "BAA" means that a must come Before b , b must come After c , and c must come After d . Any letters beyond these requirements are to be excluded, so if the decree specifies k comparisons then the new alphabet will contain the first k+1 lowercase letters of the current alphabet. Create a class Alphabet that contains the method choices that takes the decree as input and returns the number of possible new alphabets that conform to the decree. If more than 1,000,000,000 are possible, return -1. Definition
标签: government streamline important alphabet
上传时间: 2015-06-09
上传用户:weixiao99
电力系统在台稳定计算式电力系统不正常运行方式的一种计算。它的任务是已知电力系统某一正常运行状态和受到某种扰动,计算电力系统所有发电机能否同步运行 1运行说明: 请输入初始功率S0,形如a+bi 请输入无限大系统母线电压V0 请输入系统等值电抗矩阵B 矩阵B有以下元素组成的行矩阵 1正常运行时的系统直轴等值电抗Xd 2故障运行时的系统直轴等值电抗X d 3故障切除后的系统直轴等值电抗 请输入惯性时间常数Tj 请输入时段数N 请输入哪个时段发生故障Ni 请输入每时段间隔的时间dt
上传时间: 2015-06-13
上传用户:it男一枚
并联有源共模电流抑制方法的matlab仿真,建立仿真模型,分析补偿特性
上传时间: 2015-09-14
上传用户:清风冷雨
上下文无关文法(Context-Free Grammar, CFG)是一个4元组G=(V, T, S, P),其中,V和T是不相交的有限集,S∈V,P是一组有限的产生式规则集,形如A→α,其中A∈V,且α∈(V∪T)*。V的元素称为非终结符,T的元素称为终结符,S是一个特殊的非终结符,称为文法开始符。 设G=(V, T, S, P)是一个CFG,则G产生的语言是所有可由G产生的字符串组成的集合,即L(G)={x∈T* | Sx}。一个语言L是上下文无关语言(Context-Free Language, CFL),当且仅当存在一个CFG G,使得L=L(G)。 *⇒ 例如,设文法G:S→AB A→aA|a B→bB|b 则L(G)={a^nb^m | n,m>=1} 其中非终结符都是大写字母,开始符都是S,终结符都是小写字母。
标签: Context-Free Grammar CFG
上传时间: 2013-12-10
上传用户:gaojiao1999
使用UML对系统进行建模 面向对象的软件工程,同传统的面向过程的软件工程相比,在需求的获取、系统分析、设计和实现方面都有着很大的区别。UML是OOA和OOD的常用工具。使用UML来构建软件的面向对象的软件工程的过程,就是一个对系统进行不断精化的建模的过程。这些模型包括用例模型、分析模型、设计模型,然后,我们需要使用具体的计算机语言来建立系统的实现模型。
上传时间: 2014-11-04
上传用户:lindor
We have a group of N items (represented by integers from 1 to N), and we know that there is some total order defined for these items. You may assume that no two elements will be equal (for all a, b: a<b or b<a). However, it is expensive to compare two items. Your task is to make a number of comparisons, and then output the sorted order. The cost of determining if a < b is given by the bth integer of element a of costs (space delimited), which is the same as the ath integer of element b. Naturally, you will be judged on the total cost of the comparisons you make before outputting the sorted order. If your order is incorrect, you will receive a 0. Otherwise, your score will be opt/cost, where opt is the best cost anyone has achieved and cost is the total cost of the comparisons you make (so your score for a test case will be between 0 and 1). Your score for the problem will simply be the sum of your scores for the individual test cases.
标签: represented integers group items
上传时间: 2016-01-17
上传用户:jeffery
The XML Toolbox converts MATLAB data types (such as double, char, struct, complex, sparse, logical) of any level of nesting to XML format and vice versa. For example, >> project.name = MyProject >> project.id = 1234 >> project.param.a = 3.1415 >> project.param.b = 42 becomes with str=xml_format(project, off ) "<project> <name>MyProject</name> <id>1234</id> <param> <a>3.1415</a> <b>42</b> </param> </project>" On the other hand, if an XML string XStr is given, this can be converted easily to a MATLAB data type or structure V with the command V=xml_parse(XStr).
标签: converts Toolbox complex logical
上传时间: 2016-02-12
上传用户:a673761058
传统的入侵检测系统在网络上存在自适应差、缺乏扩展性、数据过载等问题,而基于数据挖掘的入侵检测技术通过数据挖掘的方法,自动地从训练数据中提取出入侵检测的知识和模式,很好地解决了传统入侵检测系统中存在的问题。本文提出了一种基于数据挖掘的入侵检测系统模型,分析了几种入侵检测技术的数据挖掘方法。
上传时间: 2013-11-28
上传用户:caixiaoxu26
:针对三容水箱是较为典型的非线性、时延对象,具有很强的代表性这一特点, 通过机理建模方法建立了三容水箱的一般数学模型。分析了线性和非线性阻力板的流量特性, 并通过实验测定了阻力板流量系数。最后给出了三容水箱的线性化模型。由仿真实验可知,非线性模型的阶跃响应和实验测得的响应曲线相吻合,
上传时间: 2013-12-24
上传用户:semi1981
汉诺塔!!! Simulate the movement of the Towers of Hanoi puzzle Bonus is possible for using animation eg. if n = 2 A→B A→C B→C if n = 3 A→C A→B C→B A→C B→A B→C A→C
标签: the animation Simulate movement
上传时间: 2017-02-11
上传用户:waizhang