addressbeginning

beginning  时间:2021-05-17  阅读:()
BeginningCforEngineersFall2005Instructor:BettinaSchimanskiTAs:GabeMulley&JoelDeverWebsite:www.
cs.
rpi.
edu/~schimb/beginC2005Lecture1–Section2(8/31/05)Section4(9/1/05)OverviewCourseGoalsIntroductionUnixandtheHistoryofCFirstCProgramDataTypesandexpressionsI/OCourseGoalsIntroducegeneralconceptsofprogrammingBegintothinklikeaprogrammerStartprogramminginCWhyisthisimportantTounderstandbasiccomputerconceptsToappreciatestructuredprogrammingWillserveasabasisforanyfutureprogrammingyoudoNeededfortheLaboratoryIntroductiontoEmbeddedControl(LITEC)course–ENGR2350WhatisprogrammingGivenawell-definedproblem:FindanalgorithmtosolveaproblemExpressthatalgorithminawaythatthecomputercanexecuteitAnalgorithmisasequenceofinstructionstosolveaproblemsuchthat:EachinstructionisunambiguousandissomethingthecomputercandoAfteraninstructionisfinishedthereisnoambiguityaboutwhichinstructionistobeexecutednextExecutionfinishesinafinitenumberofstepsThedescriptionofthealgorithmisfiniteCProgrammingLanguageEvolvedfromBCPL(1967)andB(1969)ByDennisRitchieatBellLabsBythelate1970sitwaswidelyusedStandardizedin1989intheUSthroughtheAmericanNationalStandardsInstitute(ANSI)andworldwidethroughInternationalStandardsOrganization(ISO)C++isasupersetofCCStandardLibraryCprogramsconsistofmanyfunctionsCStandardLibrary-collectionofexistingfunctionsProgramminginCisacombinationof:CreatingyourownfunctionsUsingCStandardLibraryfunctionsCPortabilityCishardware-independentApplicationsinCcanrunwithlittleornomodificationsonawiderangeofcomputersystemsUseANSIstandardlibraryfunctionsinsteadofyourownequivalentRAM(memory)I/ODevicesCentralProcessingUnit(CPU)SecondaryStorageRegistersComputerArchitectureofaComputerI/OdevicesInputOutputCPUALUMainMemorySecondaryStorageI/ODevicesCommunicationswiththeoutsideworldInputdevices:keyboardmousejoystickscannermicrophoneOutputdevices:screenprintercomputerspeakersnetworksRAM(memory)I/ODevicesCentralProcessingUnit(CPU)SecondaryStorageRegistersComputer"Administrative"sectionofthecomputer–supervisesoperations:controlsI/OandALUHas2componentstoexecuteprograminstructionsArithmetic/LogicUnitperformsarithmeticoperations,andmakeslogicalcomparisonsControlUnitcontrolstheorderinwhichyourprograminstructionsareexecutedUsesoneormoreregistersasscratchspaceforstoringnumbersbetweeninstructionsAtypicalCPUtodaycanexecutemillionsofarithmeticoperationsinasecondRAM(memory)I/ODevicesCentralProcessingUnit(CPU)SecondaryStorageRegistersComputerCentralProcessingUnit(CPU)RAM(memory)I/ODevicesCentralProcessingUnit(CPU)SecondaryStorageRegistersComputerCentralProcessingUnit(CPU)RAM(memory)I/ODevicesCentralProcessingUnit(CPU)SecondaryStorageRegistersComputerCentralProcessingUnit(CPU)ManycomputersnowhavemultipleCPUs(multiprocessors)andcanthereforeperformmanyoperationsatatimeMainMemorySometimescalledrandomaccessmemory(RAM).
Storesthenumbers(data)thataprogramuseswhenitrunsonthecomputer.
Containsmillionsofcircuitswhichareeitherofforon(0or1)BinaryAlsostorestheinstructionsoftheprogramthatisrunningonthecomputer.
Dividedintofixedsizeunitsofmemorycalledwords.
eachwordstoresonenumbereachwordhasitsownaddressRAM(memory)I/ODevicesCentralProcessingUnit(CPU)SecondaryStorageRegistersComputerDataProgramInstructionsMainMemoryRAM(memory)I/ODevicesCentralProcessingUnit(CPU)SecondaryStorageRegistersComputerDataProgramInstructionsSecondaryStoragePermanentstorageusedtosavedataandprogramswhentheyarenotrunningonthecomputer.
Dataandprogramsareorganizedintovaryingsizeunitscalledfiles.
Filesareorganizedintodirectoriesthatcancontainsubdirectories.
SecondarystorageischeaperperMegabytethanmainmemory,butaccesstodataismuchslowerRAM(memory)I/ODevicesCentralProcessingUnit(CPU)SecondaryStorageRegistersComputerSecondaryStorageRAM(memory)I/ODevicesCentralProcessingUnit(CPU)SecondaryStorageRegistersComputerTheProgrammingProcessUseaneditor(suchasEmacs,Notepad,Vi,etc.
)tocreateaprogramfile(sourcefile)containsthetextoftheprogramwritteninsomeprogramminglanguage(likeC)UseapreprocessortoincludethecontentsofotherfilesUseacompilertoconvertthesourcefileintoamachinecodefile(objectfile)convertfrom"English"tobinarywithmachineoperationsUsealinkertoconverttheobjectfileintoanexecutablefile.
includeothermachinecodethattheprogramrequiresRuntheexecutablefileCreatingaCProgramACprogramisasetoffunctionsthatcollectivelysolveagivenproblem.
eachfunctionisasequenceofCstatements(instructions)executionalwaysbeginswithafunctionnamed"main"onefunctioncallsanotherfunctiontogetittoexecuteitsstatementsTheCstatementsinafunctionareexecutedoneaftertheotherinsequentialorderaswritten.
EachCstatementisendedbyasemi-colon.
FirstCProgramAnythingbetween/*and*/isacommentintendedtoimprovethereadabilityoftheprogram.
#includeisusedtotellthecompilerandlinkerwhatlibraryresourcestheprogramuses.
thelibrarydefineseverythingyouneedtodisplaymessagesonthescreenThisprogramcontainsonefunctionnamed"main".
Noticewheresemi-colonsareplaced.
Theprogramoutputs(printstothescreen)thewordsHello,World!
/*BettinaSchimanskiHelloWorldProgramprog01a.
cAugust31,2005*/#includeintmain(){printf("Hello,World!
\n");return0;}DisplayingMessagesOnTheScreen:UsingprintfTodisplayamessageonthecomputerscreenusetheprintfstatement.
Thebackslash"\"indicatesanescapesequence.
Thismeanstakethealternatemeaningofwhateverimmediatelyfollowsit.
\nmeanstostartanewline\tisatab\"isaquote\aisanaudiblealert(bell)Textstringsmustalwaysbesurroundedbydoublequotes.
printf("Hello,World\n");MoreExamplesprintf("Hello\nWorld!
\n");printf("\tFirstpartoflongmessage.
");printf("Secondpartoflongmessage.
\n");printf("\"Hello\"World!
"\n");HelloWorld!
Firstpartoflongmessage.
Secondpartoflongmessage.
"Hello"World!
"DefiningaCFunctionACfunctionhasthefollowingform:Thenameofthisfunctionis"main".
Theword"int"meansthatthisfunctionreturnsanintegernumber.
using0toindicatethattheprogramrancorrectly.
thisiswhatthereturnstatementdoesattheendofthefunctionThebracesdefinethebeginningandtheendofthefunction.
Thefirstlineofthefunctioniscalledthefunctionheader.
intmainsequenceofstatementsseparatedbysemicolonsreturn0;}FirstLab!
Gotohttp://www.
cs.
rpi.
edu/~schimb/beginC2005ClickonLectures&LabsandgotoLab1DojustPart1StandardDataTypesinCAdatatypetellswhattypeofdataisstoredinagivenmemorylocation.
StandardCdatatypesarebrokenintothefollowingtypes:IntegralTypesrepresentwholenumbersandtheirnegativesdeclaredasint,short,orlongFloatingTypesrepresentrealnumberswithadecimalpointdeclaredasfloat,ordoubleCharacterTypesrepresentsinglecharactersdeclaredascharCVariablesVariablesinCstoredatainmemorysothatthedatacanbeaccessedthroughouttheexecutionofaprogramAvariablestoresdatacorrespondingtoaspecifictype.
EachvariablethataCprogramusesmustbedeclaredatthebeginningofthefunctionbeforeitcanbeused.
specifythetypeofthevariablenumerictypes:intshortlongfloatdoublecharactertype:charspecifyanameforthevariableanypreviouslyunusedCidentifiercanbeused(withsomemoreexceptionsdiscussedlater)intx;floatsum,product;WhatDoesaVariableDeclarationDoAdeclarationtellsthecompilertoallocateenoughmemorytoholdavalueofthisdatatype,andtoassociatetheidentifierwiththislocation.
intapartmentNumber;floattax_rate_Y2K;charmiddleInitial;4bytesfortaxRateY2K1byteformiddleInitialVariableandfunctionNamesInCSomereservedwordsinC:breakcasecharconstcontinuedefaultdodoubleelseenumfloatforgotoifintlongreturnshortsignedstaticstructswitchtypedefunionunsignedvoidwhileVariablesandfunctionnamesinCarecalledidentifiers.
identifiersareusedformanyotherthingsaswellRulesforconstructingvalididentifiersinC:cancontainletters(upperandlowercase),digits,andtheunderscore(_)charactercannotstartwithadigitcannotbeareservedwordcanbeatmost256characterslong,thoughsomecompilersonlylookatfirst32charactersarecasesensitiveIdentifiersVALIDapartment_numbertax_rate_Y2KPrintHeadingageOfHorse_NOTVALID(Why)apartment#2000TaxRateAge-Of-Catdayofweek**UsingmeaningfulvariablenamesisagoodprogrammingpracticeGivingaValuetoaVariableYoucanassign(give)avaluetoavariablebyusingtheassignmentoperator=VARIABLEDECLARATIONScharmiddleInitial;charletter;intapartmentNumber;VALIDASSIGNMENTSTATEMENTSmiddleInitial='K';letter=middleInitial;apartmentNumber=8;AssignmentStatementAnassignmentstatementisusedtoputavalueintoavariable.
ThepreviousvalueisreplacedSyntax:=;isanydeclaredvariableintheprogramisanythingthatproducesavalueoftheappropriatetype(moreonthislater)first,theexpressiononrightisevaluated.
thentheresultingvalueisstoredinthememorylocationofvariableonleft.
Examples:count=10;count=count+1;area=3.
14*radius*radius;NOTE:AnautomatictypecoercionoccursafterevaluationbutbeforethevalueisstoredifthetypesdifferforexpressionandvariableExamplesArithmeticExpressionsWithIntegers(int,long)Operators:resultisalwaysanintegerSymbolNameExampleValue(x=10,y=3)+additionx+y13–subtractionx–y7*multiplicationx*y30/quotientx/y3%remainderx%y1–unaryminus–x-10+unaryplus+x10ArithmeticExpressionsContinued…Youcanstringtheoperatorstogethertobuildlongerexpressions.
useparenthesestospecifyorderofoperationsprecedence(aftersub-expressionsinparentheses):first:unaryplusandminusfromrighttoleftsecond:*and/and%fromlefttorightthird:+and–fromlefttorightArithmeticExpressionExampleinty=2;intz;z=-y*3*(4+5)%10+--3;-2*3*9%10+--3-2*3*9%10+3-6*9%10+3-54%10+3-4+3-1ArithmeticExpressionsWithReals(float,double)Arithmeticexpressionswithrealnumbers(numberswithdecimalpoints)workthesamewayaswithintegers,withafewexceptions:thereisnoremainderoperator("%")the"/"operatormeans"divide"(vsquotient),computingtheanswertomanydecimalplacestheresultisarealvalueratherthananintegervalueImportant:Realvaluesareapproximateandmaycontainerrorsinthelastfewdigits.
about7digitsofaccuracyfortypefloatabout14digitsofaccuracyfortypedoubleMixedModeArithmeticExpressionsArithmeticexpressions:bothintegersandfloatscangettricky.
ifbothoperandsareintegers,integerarithmeticisusedifeitheroperandisafloat,floatarithmeticisusedanintegeroperandisconvertedtofloatfortheoperationExamples:inta,x;x=3.
59;/*xgetsthevalue3(norounding)*/floaty=3;/*ygetsthevalue3.
0*/a=12;/*agetsthevalue12*/floatavg=(a+x)/2;/*avggetsthevalue7.
0…UHOH!
!
!
*/PrintingvariablesandconstantstothescreenwithprintfUsethefollowingconversionspecifications:%dforaninteger%ldforalonginteger%cforacharacter%fforafloat%fforadoubleExample:Output:intsum=5;floatavg=12.
2;charch='A';printf("Thesumis%d\n",sum);Thesumis5printf("avg=%f"\n",avg);avg=12.
2prinf("ch=%c\n",ch);ch=Aprintf("%d,%f,%c\n",sum,avg,ch);5,12.
2,Aprintf("%d\n",5);5Note:seep.
153inyourtextbookforacompletelistofalldatatypesReadingdatafromthekeyboardwithscanfUsedtoassignavaluetypedonthekeyboardtoavariable.
Usedsimilarlytoprintf.
Youmustusethefollowingconversionspecifications:DataTypeprintfconverstionspec.
scanfconversionspec.
int%d%dlong%ld%ldfloat%f%fdouble%f%lfchar%c%ccharacterstring%s%sTheusermusttypeavaluefollowedbytheEnterKey.
Ex:scanf("%d",&num);Example:ProgramtofindtheaverageoftwonumbersNotethatyoucandeclaremorethanonevariableperline.
Wedivideby2.
0insteadof2sothattherighthandsideisafloat(i.
e.
notruncationtakesplace)scanfisusedsimilarlytoprintf,exceptthatyouneedtoputanampersand(&)beforethevariablenameThefirstargumentofthescanffunctionistheconversionspecifier(s)inquotes,thenthevariablename(s)#includeintmain(){intnum1,num2;floatavg;/*gettwoinputs*/printf("Enterthefirstinteger:");scanf("%d",&num1);printf("Enterthesecondinteger:");scanf("%d",&num2);/*computeandprinttheavg*/avg=(num1+num2)/2.
0;printf("Theaverageis%f\n",avg);return0;}FinishLab1Gotohttp://www.
cs.
rpi.
edu/~schimb/beginC2005ClickonLectures&LabsandgotoLab1DoPart2HomeworkReadChapters1,2and9Dueatthebeginningofnextclass:HW1AcademicIntegrityStatementFYI:InfoonCygwin,Putty,SecureCRT,andEmacsareonthewebsite

spinservers($179/月),1Gbps不限流量服务器,双E5-2630Lv3/64GB/1.6T SSD/圣何塞机房

中秋节快到了,spinservers针对中国用户准备了几款圣何塞机房特别独立服务器,大家知道这家服务器都是高配,这次推出的机器除了配置高以外,默认1Gbps不限制流量,解除了常规机器10TB/月的流量限制,价格每月179美元起,机器自动化上架,一般30分钟内,有基本自助管理功能,带IPMI,支持安装Windows或者Linux操作系统。配置一 $179/月CPU:Dual Intel Xeon E...

BGP.TO日本和新加坡服务器进行促销,日本服务器6.5折

BGP.TO目前针对日本和新加坡服务器进行促销,其中日本东京服务器6.5折,而新加坡服务器7.5折起。这是一家专门的独立服务器租售网站,提供包括中国香港、日本、新加坡和洛杉矶的服务器租用业务,基本上都是自有硬件、IP资源等,国内优化直连线路,机器自动化部署上架,并提供产品的基本管理功能(自助开关机重启重装等)。新加坡服务器 $93.75/月CPU:E3-1230v3内存:16GB硬盘:480GB ...

hostkey俄罗斯、荷兰GPU显卡服务器/免费Windows Server

Hostkey.com成立于2007年的荷兰公司,主要运营服务器出租与托管,其次是VPS、域名、域名证书,各种软件授权等。hostkey当前运作荷兰阿姆斯特丹、俄罗斯莫斯科、美国纽约等数据中心。支持Paypal,信用卡,Webmoney,以及支付宝等付款方式。禁止VPN,代理,Tor,网络诈骗,儿童色情,Spam,网络扫描,俄罗斯色情,俄罗斯电影,俄罗斯MP3,俄罗斯Trackers,以及俄罗斯法...

beginning为你推荐
systemsnod32债券127adbandroid支持ipad水土保持ios8支持ipad支持ipad支持ipad支持ipad支持ipad
欧洲欧洲vps 免费顶级域名 国外主机 php主机 idc评测网 godaddy续费优惠码 双拼域名 台湾谷歌 卡巴斯基是免费的吗 空间首页登陆 免费外链相册 带宽租赁 789 上海电信测速 cxz 主机管理系统 防cc攻击 lamp什么意思 广州主机托管 godaddy中文 更多