計算機科學概論課后答案

newis_uutupieLe_ans5/zb/U44:34FinFaye3t)/

AnswerstoExercises

Chapter1Exercises

ForExercises1-10,matchthefollowingpeoplewiththeiraccomplish-

ments.

A.Leibniz

B.Pascal

C.Babbage

D.Lovelace

E.Hollerith

F.Byron

G.Turing

H.Jacquard

1.WhatFrenchmathematicianbuiltandsoldthefirstgear-driven

mechanicalmachinethatdidadditionandsubtraction?

B

2.Whobuiltthefirstmechanicalmachinethatdidaddition,subtraction,

multiplication,anddivision?

A

3.Whodesignedthefirstmechanicalmachinethatincludedmemory?

C

4.Whowasconsideredthefirstprogrammer?

D

5.Whoproposedthatapunchedcardbeusedforcountingthecensus?

E

6.WhoeditedBabbage'swork?

D

7.WhowasAdaLovelace'sfather?

F

8.WhowouldhavebeenmentionedinthebooktheCodeBreakers^

G

9.Whodevelopedtheconceptofpunchedholesusedinweavingcloth?

H

10.WhoisassociatedwithIBM?

E

L.ew±B_uutupieue_aiis5/zb/U4a:34VMpage3bti甲

568AnswerstoExercises

ForExercises11-23,matchthehardwarelistedtotheappropriategenera-

tion.

A.First

B.Second

C.Third

D.Fourth

E.Fifth

11.Circuitboards

C

12.Transistor

B

13.Magneticcorememory

B

14.Cardinput/output

A

15.Parallelcomputing

D

16.Magneticdrum

A

17.Magnetictapedrives

A

18.Integratedcircuits

C

19.Personalcomputer

D

20.Vacuumtube

A

21.Largescaleintegration

D

22.Magneticdisc

B

23.Networking

D

ForExercises24-38,matchthesoftwareorsoftwareconceptslistedtothe

appropriategeneration.

L.ew±B_uutupieue_aiis5/zb/U4a:34VMpage3t>”甲

(h叩ter1Exercises569

A.First

B.Second

C.Third

D.Fourth

E.Fifth

24.Assemblers

A

25.FORTRAN

B

26.Operatingsystems

C

27.Structuredprogramming

D

28.Timesharing

C

29.HTML(forWeb)

E

30.Loaders

B

31.Spreadsheets

D

32.Wordprocessors

D

33.Lisp

B

34.PC-DOS

D

35.Loaders/linkersbundledintoOperatingSystem

C

36.Java

E

37.SPSS

c

38.C++

D

L.ew±B_uuuipieLe_ans5/zb/U4FinFayes/u甲

570AnswerstoExercises

Exercises39-55areshortanswer.

39.Whatdowemeanbythestatementthatthe1980sand1990smustbe

characterizedbythechangingprofileoftheuser?

Theoriginaluserwastheprogrammerwhohadaproblemtosolve.By

the1970s,applicationprogramswerebeingwrittensuchthatnon-

programmerscouldusethemtosolveproblems.Withtheadventof

thepersonalcomputer,manypeoplebeganusingthecomputerfor

personalcorrespondence,personalaccounts,andgames.

40.Distinguishbetweencomputingasatoolandcomputingasadisci-

pline.

Computingasatoolreferstotheuseofcomputingbypeopletosolve

problemsintheirprofessionalorpersonallife.Computingasadisci-

plinereferstothestudyofthebodyofknowledgethatmakesup

computerscienceand/orcomputerengineering.

41.Iscomputingamathematicaldiscipline,ascientificdiscipline,oran

engineeringdiscipline?Explain.

Computingisneitheramathematicaldisciplinenorascientificdisci-

plinenoranengineeringdiscipline;ithasrootsinallthreedisciplines.

Booleanalgebra,logic,andnumericalanalysiscontributegreatlyto

thefoundationsofcomputing.Simulationandmodelbuildingfrom

thescientificdisciplinecontributetothefoundationsofcomputing.

Thetechniquesfromengineeringofbuildinglargesystemscontribute

tothefoundationsofcomputing.

42.Distinguishbetweensystemsareasandapplicationsareasin

computingasadiscipline.

Thesystemsareasofcomputingasadisciplinerelatetotheunder-

standingandbuildingofcomputertools:algorithmsanddatastruc-

tures,programminglanguages,(computer)architecture,operating

systems,softwaremethodologyandengineering,andhuman-computer

communication.Theapplicationsareasincomputingrelatetothe

computer'suseasatool:numericalcomputation,databasesandinfor-

mationalretrieval,artificialintelligenceandrobotics,graphics,organi-

zationalinformatics,andbioinformatics.

43.DefinethewordabstractionandrelateittothedrawinginFigure1.2.

Anabstractionisamentalmodelthatremovescomplexdetails.An

abstractionletstheviewerseeonlythosedetailsthatarerelevantto

theuser'sview.Anengineisamentalmodelofacarfromthebuilder

ormechanic'sview.Thecockpitisthementalmodelforanordinary

driver,whodoesnothavetoknowthedetailsoftheengineinorderto

drivethecar.

L.ew±B_uuuipieLe_ans5/zb/U4FinFaye3/JL甲

(h叩ter1Exercises571

44.Namethesixsubjectsubareasofcomputerscience,calledsystems

areas,thatrelatetounderstandingandbuildingcomputingtoolsin

general.

algorithmsanddatastructures,programminglanguages,architecture,

operatingsystems,softwaremethodologyandengineering,and

human-computercommunication.

45.Namethesixsubjectsubareasofcomputerscience,calledapplications

areas,thatrelatetothecomputer'suseasatool.

numericalandsymboliccomputation,databasesandinformational

retrieval,artificialintelligenceandrobotics,graphics,organizational

informatics,andbioinformatics.

46.Definethewordprotocolandexplainhowitisusedincomputing.

Aprotocolisacodeprescribingstrictadherencetocorrectetiquette

andprocedure(asinadiplomaticexchange).Computingterminology

hasborrowedthewordtodescribethecorrectetiquetteforcomputers

tousewhencommunicatingwithoneanother.

47.Distinguishbetweenmachinelanguageandassemblylanguage.

Machinelanguageisthelanguagethatisbuiltintotheelectrical

circuitryofacomputer.

Assemblylanguageisalanguagemadeupofmnemoniccodesthat

representmachine-languageinstructions.

Programswritteninassemblylanguagearetranslatedintomachine

languageprogramsbyacomputerprogramcalledanassembler.

48.Distinguishbetweenassemblylanguageandhigh-levellanguages.

Whereasassemblylanguageisalanguagemadeupofmnemoniccodes

thatrepresentmachine-languageinstructions,high-levellanguagesuse

English-likestatementstorepresentagroupsofassembly-language

statementsormachine-languagestatements.Thereisaone-to-one

correspondencebetweenstatementsinanassemblylanguageandthe

statementstheyrepresentinmachinelanguage.Thereisaone-to-many

correspondencebetweenhigh-levelstatementsandthecorresponding

machine-languagestatements.

49.FORTRANandCOBOLweretwohigh-levellanguagesdefined

duringthesecondgenerationofcomputersoftware.Compareand

contrasttheselanguagesintermsoftheirhistoryandtheirpurpose.

FORTRANwaswrittenatIBMforuseinsolvingscienceandengi-

neeringproblems.Itwasnotformallydesignedandhasgrowngreatly

overtheyears.COBOLwasdesignbyateamforbusinessapplications

andhasbeenrelativelystable.

Liewis_uutupieLe_ans3/Nb/uea:34FinFaye,一、

572AnswerstoExercises

50.Distinguishbetweenanassemblerandacompiler.

Anassemblertranslatesassembly-languageprogramsintomachine

code.Acompilertranslatesprogramsinahigh-levellanguageinto

eitherassembly-languageprogramsormachine-languageprograms.

51.Distinguishbetweenasystemsprogrammerandanapplications

programmer.

Asystemsprogrammerwritesprogramsthataretoolstohelpothers

writeprograms.Anapplicationsprogrammerwritesprogramstosolve

specificproblems.

52.Whatwastherationalebehindthedevelopmentofoperatingsystems?

Thehumanoperatorwastooslow.Computerswereidlewhilethe

humanpreparedthenextprogramtoberun.Thecomputerhasthe

speedtoorganizeitself.

53.Whatconstitutessystemssoftware?

Utilityprogramssuchasloadersandlinkers,operatingsystems,and

languagetranslatorsaresystemssoftware.

54.Whatdothefollowingpiecesofsoftwaredo?

a.Loader

Aloaderputsaprogram'sinstructionsintomemorywheretheycan

beexecuted.

b.Linker

Alinkerisaprogramthatputspiecesofalargeprogramtogether

sothatitcanbeputintomemorywhereitcanbeexecuted.

c.Editor

Aeditorisawordprocessingprogramthatallowstheusertoenter

andedittext.

55.HowwastheprogramSPSSdifferentfromtheprogramsthatcame

beforeit?

SPSSwasthefirstapplicationprogramwrittensothatthenon-

programmcrusercouldenterdataandspecifytheprocessingofthe

data.

Chapter2Exercises

ForExercises1-5,matchthefollowingnumberswiththeirdefinition.

A.Number

B.Naturalnumber

C.Integernumber

D.Negativenumber

E.Rationalnumber

L.ew±B_uuuipieLe_ans5/zb/U4FinFaye3/3甲

(h叩ter2Exercises

1.Aunitofanabstractmathematicalsystemsubjecttothelawsofarith-

metic.

A

2.Anaturalnumber,anegativeofanaturalnumber,orzero.

C

3.Thenumberzeroandanynumberobtainedbyrepeatedlyaddingone

toit.

B

4.Anintegerorthequotientoftwointegers(divisionbyzeroexcluded).

E

5.Avaluelessthanzero,withasignoppositetoitspositivecounterpart.

D

ForExercises6-11,matchthesolutionwiththeproblem.

A.10001100

B.10011110

c.1101010

D.1100000

E.1010001

F.1111000

6.1110011+11001(binaryaddition)

A

7.1010101+10101(binaryaddition)

C

8.1111111+11111(binaryaddition)

B

9.1111111111(binarysubtraction)

F

10.1100111ill(binarysubtraction)

D

11.1010110101(binarysubtraction)

ForExercises12-17,marktheanswerstrueandfalseasfollows:

A.True

B.False

Liewis_uutupieLe_ans3/Nb/uea:34FinFaye3/B,一、

574AnswerstoExercises

12.Binarynumbersareimportantincomputingbecauseabinarynumber

canbeconvertedintoeveryotherbase.

B

13.Binarynumberscanbereadoffinhexadecimalbutnotinoctal.

B

14.Startingfromlefttoright,everygroupingoffourbinarydigitscanbe

readasonehexadecimaldigit.

B

15.Abyteismadeupofsixbinarydigits.

B

16.Twohexadecimaldigitscanbestoredinonebyte.

A

17.Readingoctaldigitsoffasbinaryproducesthesameresultwhether

readfromrighttoleftorlefttoright.

A

Exercises18-45areproblemsorshortanswerquestions.

18.Distinguishbetweenanaturalnumberandanegativenumber.

Anaturalnumberis0andanynumberthatcanbeobtainedbyrepeat-

edlyadding1toit.Anegativenumberislessthan0,andoppositein

signtoanaturalnumber,althoughweusuallydonotconsidernega-

tive0.

19.Distinguishbetweenanaturalnumberandarationalnumber.

Arationalnumberisanintegerorthequotientofintegernumbers.

(Divisionby0isexcluded.)Anaturalnumberis0andthepositive

integers.(SeealsodefinitioninanswertoExercise18.)

20.Labelthefollowingnumbersnatural,negative,orrational.

a.1.333333

rational

b.-1/3

negative,rational

c.1066

natural

d.2/5

rational

e.6.2

rational

L.ew±B_uuuipieLe_ans5/zb/U4FinFaye3/3甲

(h叩ter2Exercises575

f.兀(pi)

notanylisted

21.If891isanumberineachofthefollowingbases,howmanyIsare

there?

a.base10

891

b.base8

Can'tbeanumberinbase8

c.base12

1261

d.base13

1470

e.base16

2193

22.Express891asapolynomialineachofthebasesinExercise21.

8*102+9*10+1

Can'tbeshownasapolynomialinbase8.

8*122+9*12+1

8*132+9*13+1

8*162+9*16+1

23.Convertthefollowingnumbersfromthebaseshowntobase10.

a.Ill(base2)

7

b.777(base8)

511

c.FEC(base16)

4076

d.777(base16)

1911

e.111(base8)

73

24.Explainhowbase2andbase8arerelated.

Because8isapowerof2,base-8digitscanbereadoffinbinaryand3

base-2digitscanbereadoffinoctal.

25.Explainhowbase8andbase16arerelated.

8and16arebothpowersoftwo.

L.ew±B_uuuipieLe_ans5/zb/U4FinFayes/b甲

576AnswerstoExercises

26.Expandthetableonpage40toincludethenumbersfrom11through

16.

binaryoctaldecimal

00000

00111

01022

on33

10044

10155

no66

in77

1000108

1001119

10101210

10111311

11001412

11011513

11101614

11111715

100002016

27.ExpandthetableinExercise26toincludehexadecimalnumbers.

L.ew±B_uuuipieLe_ans5/zb/U4FinFayes/1甲

(h叩ter2Exercises577

28.Convertthefollowingbinarynumberstooctal.

a.111110110

766

b.1000001

101

c.10000010

202

d.1100010

142

29.Convertthefollowingbinarynumberstohexadecimal,

a.10101001

A9

b.11100111

E7

c.01101110

6E

d.01121111

Thisisnotabinarynumber

30.Convertthefollowinghexadecimalnumberstooctal.

a.A9

251

b.E7

347

C.6E

156

31.Convertthefollowingoctalnumberstohexadecimal.

a.777

IFF

b.605

185

c.443

123

d.521

151

e.1

Liewis_uutupieLe_ans3/Nb/uea:34FinFayes/a,一、

578AnswerstoExercises

32.Convertthefollowingdecimalnumberstooctal.

a.901

1605

b.321

501

c.1492

2724

d.1066

2052

e.2001

3721

33.Convertthefollowingdecimalnumberstobinary.

a.45

101101

b.69

1000101

C.1066

10000101010

d.99

1100011

e.1

1

34.Convertthefollowingdecimalnumberstohexadecimal.

a.1066

42A

b.1939

793

c.1

1

d.998

3E6

e.43

2B

35.Ifyouweregoingtorepresentnumbersinbase18,whatsymbols

mightyouusetorepresentthedecimalnumbers10through17other

thanletters?

Anyspecialcharacterswouldwork,aswellascharactersfromanother

alphabet.Let'suse#for16and@for17.

L.ew±B_uuuipieLe_ans5/zb/U4FinFayes/y甲

(h叩ter2Exercises579

36.Convertthefollowingdecimalnumberstobase18usingthesymbols

yousuggestedinExercise15.

a.1066

354

b.99099

#@F9

c.1

1

37.Performthefollowingoctaladditions.

a.770+665

1655

b.101+707

1010

c.202+667

1071

38.Performthefollowinghexadecimaladditions.

a.19AB6+43

19AF9

b.AE9+F

AF8

c.1066+ABCD

BC33

39.Performthefollowingoctalsubtractions.

a.1066-776

70

b.1234-765

247

c.7766-5544

2222

40.Performthefollowinghexadecimalsubtractions.

a.ABC-111

9AB

b.9988-AB

98DD

c.A9F8-1492

9566

L.ew±B_uutupieue_aiis5/zb/U4a:34VMpagesau甲

580AnswerstoExercises

41.Whyarebinarynumbersimportantincomputing?

Dataandinstructionsarerepres