上下文無關文法（Context-Free Grammar, CFG）是一個4元組G=(V, T, S, P)，其中，V和T是不相交的有限集，S∈V，P是一組有限的產生式規則集，形如A→α，其中A∈V，且α∈(V∪T)*。V的元素稱為非終結符，T的元素稱為終結符，S是一個特殊的非終結符，稱為文法開始符。 設G=(V, T, S, P)是一個CFG，則G產生的語言是所有可由G產生的字符串組成的集合，即L(G)={x∈T* | Sx}。一個語言L是上下文無關語言（Context-Free Language, CFL），當且僅當存在一個CFG G，使得L=L(G)。 *⇒ 例如，設文法G：S→AB A→aA|a B→bB|b 則L(G)={a^nb^m | n,m>=1} 其中非終結符都是大寫字母，開始符都是S，終結符都是小寫字母。
標簽： Context-Free Grammar CFG
上傳時間： 2013-12-10
上傳用戶：gaojiao1999
This design package includes reference materials for creating a USB - PS/2 combination mouse that auto-detects the interface and configures itself to operate on the appropriate bus. Documentation docs - Designing a low cost CY7C63723 combination mouse.pdf - application note for this design - schematic.pdf - mouse schematic Firmware Source Files src - chip.c - include file that defines CY7C63723 constants - combi.c - main source file - combi.hex - Intel hex file for programming a CY7C63723 microcontroller - combi.lst - output listing from c-compiler for use with the CYDB debugger - macros.h - defines macros used in combi.c - ps2defs.h - defines PS/2 interface constants - usb_desc.h - defines the USB descriptors - usbdefs.h - defines USB interface constants
標簽： combination materials reference creating
上傳時間： 2015-10-19
上傳用戶：784533221
VB6 has two very useful string functions: Join and Split. This code implements Join and Split functions using STL so that you can use them in your C++ programs
標簽： Split Join implements functions
上傳時間： 2015-10-31
上傳用戶：我們的船長
一:需求分析 1. 問題描述 魔王總是使用自己的一種非常精練而抽象的語言講話,沒人能聽懂,但他的語言是可逐步解釋成人能聽懂的語言,因為他的語言是由以下兩種形式的規則由人的語言逐步抽象上去的: ----------------------------------------------------------- (1) a---> (B1)(B2)....(Bm) (2)[(op1)(p2)...(pn)]---->[o(pn)][o(p(n-1))].....[o(p1)o] ----------------------------------------------------------- 在這兩種形式中,從左到右均表示解釋.試寫一個魔王語言的解釋系統,把 他的話解釋成人能聽得懂的話. 2. 基本要求: 用下述兩條具體規則和上述規則形式(2)實現.設大寫字母表示魔王語言的詞匯 小寫字母表示人的語言的詞匯 希臘字母表示可以用大寫字母或小寫字母代換的變量.魔王語言可含人的詞匯. (1) B --> tAdA (2) A --> sae 3. 測試數據: B(ehnxgz)B 解釋成 tsaedsaeezegexenehetsaedsae若將小寫字母與漢字建立下表所示的對應關系,則魔王說的話是:"天上一只鵝地上一只鵝鵝追鵝趕鵝下鵝蛋鵝恨鵝天上一只鵝地上一只鵝". | t | d | s | a | e | z | g | x | n | h | | 天 | 地 | 上 | 一只| 鵝 | 追 | 趕 | 下 | 蛋 | 恨 |
上傳時間： 2014-12-02
上傳用戶：jkhjkh1982
Winprint HylaFAX Makes a HylaFAX Server look like a standard Windows printer, as seamless as commercial FAX servers. This project is written in Borland C++ Builder
標簽： HylaFAX Winprint standard seamless
上傳時間： 2015-11-29
上傳用戶：hewenzhi
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.
標簽： represented integers group items
上傳時間： 2016-01-17
上傳用戶：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).
標簽： converts Toolbox complex logical
上傳時間： 2016-02-12
上傳用戶：a673761058
計算電磁學的３維矢量有限元程序 EMAP-3 is a vector (edge element) code. Vector codes are generally not affected by spurious modes and have other inherent advantages. The code is written in the C programming language and can be compiled and run on PCs, workstations, or mainframes.
標簽： generally affected element Vector
上傳時間： 2016-04-03
上傳用戶：1583060504
Auditory Simulation Development Computing System version 1.5.2, is based upon a unified re-interpretation in ANSI C of code
標簽： Development Simulation Computing re-interp
上傳時間： 2016-08-29
上傳用戶：壞天使kk
Auditory Simulation Development Computing System(unix) version 1.5.2, is based upon a unified re-interpretation in ANSI C of code
標簽： Development Simulation Computing Auditory
上傳時間： 2014-01-09
上傳用戶：zaizaibang
