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
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
FuncPlotter is a combined Java application and applet for displaying two-dimensional plots of explicit functions in one variable (ie, FuncPlotter plots functions of the form y = f(x), where f(x) is composed from common mathematical operators).
標簽： two-dimensional FuncPlotter application displaying
上傳時間： 2015-12-16
上傳用戶：妄想演繹師
The Bad Beginning: A Terrible Tale Do you enjoy happy endings? If so, The Bad Beginning by Lemony Snicket is a book you’ll want to avoid. This is a story with a bad beginning, a bad middle and a bad ending. Why would anyone want to read such a thoroughly bad book? It’s all in good fun!
標簽： Beginning The Bad Terrible
上傳時間： 2013-12-28
上傳用戶：笨小孩
神經網絡工具箱，包含SVM和NPA、"one-against-all" 、"one-against-one" 算法，有大量的例子。
上傳時間： 2016-04-23
上傳用戶：xhz1993
GNU ccScript is a C++ class framework for creating a virtual machine execution system for use with and as a scripting/assembler language for state-transition driven realtime systems. The most common example of this is as the core of the scripting engine found in GNU Bayonne.
標簽： framework for execution ccScript
上傳時間： 2013-12-18
上傳用戶：sssl
Name Function --- --- --- --- --- --- Check_SST_39VF160 Check manufacturer and device ID CFI_Query CFI Query Entry/Exit command sequence Erase_Entire_Chip Erase the contents of the entire chip Erase_One_Sector Erase a sector of 2048 word Erase_One_Block Erase a block of 32K word Program_One_Word Alter data in one word Program_One_Sector Alter data in 2048 word sector Program_One_Block Alter data in 32K word block Check_Toggle_Ready End of internal program or erase detection using Toggle bit Check_Data_Polling End of internal program or erase detection using Data# polling
標簽： manufacturer Check_SST Function CFI_Que
上傳時間： 2013-12-21
上傳用戶：徐孺
漢諾塔！！！ 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
標簽： the animation Simulate movement
上傳時間： 2017-02-11
上傳用戶：waizhang
Genetic Algorithm example using Java You have 10 cards numbered 1 to 10. You have to divide them into 2 piles so that: The sum of the first pile is as close as possible to 36 and the product of all in second pile is as close as poss to 360.
標簽： have Algorithm You numbered
上傳時間： 2017-03-08
上傳用戶：lacsx
This book brings together indispensable knowledge for building efficient, high-value, Linux-based embedded products: information that has never been assembled in one place before. Drawing on years of experience as an embedded Linux consultant and field application engineer, Christopher Hallinan offers solutions for the specific technical issues you re most likely to face, demonstrates how to build an effective embedded Linux environment, and shows how to use it as productively as possible.
標簽： indispensable Linux-based high-value efficient
上傳時間： 2014-01-24
上傳用戶：ANRAN
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