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
Over the years, this bestselling guide has helped countless programmers learn how to support computer peripherals under the Linux operating system, and how to develop new hardware under Linux. Now, with this third edition, it s even more helpful, covering all the significant changes to Version 2.6 of the Linux kernel. Includes full-featured examples that programmers can compile and run without special hardware.
標簽: bestselling programmers countless compute
上傳時間: 2014-01-13
上傳用戶:小草123
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
Abstract: By using gateway systems on large 32-bit platforms, networks of small, 8- and 16-bit microcontrollers can be monitored and controlled over the Internet. With embedded Linux, these gateways are easily moved from full-blown host PCs to embedded platforms like the PC104. In this class you will learn about hardware platforms that support embedded Linux, Linux kernel configuration, feature selection, installation, booting and tuning.
標簽: bit platforms Abstract networks
上傳時間: 2014-01-05
上傳用戶:kytqcool
基于ecos的redboot,該包支持多種處理器。用戶可以根據自己硬件平臺,通過ecosconfig來配置,配置界面和編譯linux kernel差不多。本包已經正對Intel IXP2400平臺做了相應配置,硬件平臺為雙CUP架構。壓縮文件中有更為詳細的說明。
上傳時間: 2014-01-09
上傳用戶:siguazgb
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
簡要的講解了一下,linux kernel的啟動過程。
標簽:
上傳時間: 2016-02-15
上傳用戶:410805624
1.under bootloader 1)cd your_dir/mrua_EM8620L_2.5.115.RC8_dev.arm.bootirq/MRUA_src/loader 2)將flash_v3.c改名為flash.c替換原來的flash.c 3)編譯 2.under linux kernel 1)cd armutils_2.5.108.0/build_arm/linux-2.4.22-em86xx/drivers/mtd 2)將mtdblock_v4.c改名為mtdblock.c替換原來的mtdblock.c 3)cd armutils_2.5.108.0/build_arm/linux-2.4.22-em86xx/drivers/mtd/chips 4)將cfi_cmdset_0002_v4.c改名為cfi_cmdset_0002.c替換原來的cfi_cmdset_0002.c 5)編譯。 note:如果在使用cat等指令寫flash的過程中出現下面的信息: Flash write to Buffer aborted @ 0x****** = 0x****** 是正常信息。
標簽: bootloader MRUA_src your_dir bootirq
上傳時間: 2013-12-17
上傳用戶:陽光少年2016
這本書非常之不錯,詳細介紹linux kernel source,對深入學習linux的人有很大幫助
標簽:
上傳時間: 2016-11-22
上傳用戶:jackgao
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