COMPUTER SCIENCE A Structured Programming Approach Using C Behrouz A. Forouzan & Richard F. Gilberg — THIRD EDITION Operator Description Example * Assoc Pr Identifiers amount 'Constants 3.14159 N N/A 16 ParentheticalExpressions (a + b) [ ]. ArrayIndex ary[i] N ninctionCall doIt(x, y) Y DirectMemberSelection str.mem N Left-Right 16 -> IndirectMemberSelection ptr->mem N ++ PostfixIncrement(cid:127)Decrement a++ Y ++ PrefixIncrement(cid:127)Decrement ++a Y sizeof SizeinBytes sizeof(int) N - OnesComplement a N ! Not la N Right-Left 15 + Plus(cid:127)Minus +a N & Address &a N * Dereference/Indirection *ptr N ( ) TypeCast (int)ptr N Right-Left 14 * / % Multiply(cid:127)Divide(cid:127)Modulus a * b N Left-Right 13 + - Addition(cid:127)Subtraction a + b N Left-Right 12 « » BitShiftLeft(cid:127)BitShift Right a << 3 N Left-Right 11 < <= > >= Comparison a < 5 N Left-Right 10 ss != Equal(cid:127)NotEqual a == b N Left-Right 9 & BitwiseAnd a & b N Left-Right 8 A BitwiseExclusiveOr a A b N Left-Right 7 BitwiseOr a b N Left-Right 6 && LogicalAnd a ScSc b N Left-Right 5 LogicalOr a b N Left-Right 4 ? : Conditional a ? x (cid:127)* Y N Right-Left 3 = += -= a = 5 *= /= %= >>= <<= Assignment a %= b Y Right-Left 2 &= A= a &= c a |= d > Comma a, b, c N Left-Right 1 *SideEffects(Yes/No) i PrecedenceTable . >H' ' i -t X \/o.U6 *+'- - Mi | J, - dUe X AH .v A f\£w \/ Computer Science: A Structured Programming Approach Using C, Third Edition DATE DUE Nov o5 rm LI 2o/H 1ft March a ao /tprtI \(p 3 2-6^6 AA Z7 ^i y Wt~7IS7 % JW 30 2(17 <15 im 1o :Qi8 Clb DEC 17 BtS fa » IAUG 0 ! 2012 7 Australia(cid:127)Brazil(cid:127)Japan(cid:127)Korea(cid:127)Mexico(cid:127)Singapore(cid:127)Spam(cid:127)UnitedKingdom(cid:127)UnitedStates SAN JACIN1U COLLEGE LIBHAHY-SOUTH Preface to Third Edition Thistext hastwoprimaryobjectives:toteach thebasicprinciplesol program- mbaisnigccaosno_sutrtulicntesdofinthteheCALCanMgucaugrer.icOuulurmtexftopruatsCtShe1secloabssjeacntidvetsointetahcehcothne- text of good software engineeringconcepts that we have developed through morethan 30yearsof experiencein industryand academia. Major ChangesinThird Edition This is a major change from the second edition. In addition to significant- changes in the presentation and material covered, it also updates the lan guagetothe ISO/IEC9899(1999),oras it is morecommonlyknown,C99. While we have made major changes, we have held true to our primary objectivesasoutlined above. Ihe text remainsa comprehensive introduction tocomputer programmingin asoftwareengineeringcontext. Themajorchangesareoutlined in thefollowingsections. Standard C(1999) Ihefollowingtopics,inalphabeticalorder,areexplicitlydiscussed in thetext. (cid:127) the Boolean type (cid:127) charactersetextensions(including Unicodeand wide-characters) (cid:127) complexarithmetic (cid:127) extendedmath library (cid:127) forstatementdeclarations (cid:127) integertypeextensions (cid:127) linecomments Extended Chapter Material In addition to the changes required by the inclusion of the new C99 exten- sions,severalchaptershavebeen revised or reorganized. AnewsectioninChapter4, Inter-FunctionCommunication,” providesa better understandingof howfunctionscommunicate. IV PrefacetoThird Edition v (cid:127) Theconceptof “incremental programdevelopment’ is presented through an example that starts in Chapter 4 and isextended in C hapter 5.A sec- ond example in Chapter8completesthediscussion. (cid:127) The discussion of text and binary files has been reworked to present the materialsin a morelogical,and less redundant,fashion. (cid:127) The presentation of structured types is changed to conform to C99 and . common usage (cid:127) Chapter 14. “Bitwise Operators," has been extended and includes more examples. In particular, we added several applications related to the Internetand network programming. (cid:127) Chapter 15,"Lists," hasalso been extended. It now includesan overview of the basic elements of data structures, including introductory discus- sionsof stack,queues,lists, trees,and graphs. (cid:127) Additional flowcharts and structure charts are included throughout the texttoprovide betterdesignconsiderationsforsomeof the morecomplex examples. (cid:127) AppendixD,"NumberingSystems,"providesanexpanded presentation of the material. (cid:127) Appendix 1, "Pointers to void and to Functions," has been expanded to includea discussion of usingpointer tovoid types. (cid:127) Appendix k. "Program Development,” is a new discussion of program developmentconcepts. (cid:127) Appendix L,“UnderstandingComplexDeclarations,"containsthediscus- sion on reading complex declarations, which has been removed from Chapter 10. A C Language Perspective While C is a complex and professional language, our classroom experience usingthepreviouseditionsof thisbookhasshown that beginningstudentscan easily understand it. We believe that if the language is put intoa perspective thatallowsthestudent tounderstand itsdesign,C is notadifficult language. There are two aspects of C that separate it from most other languages: expressionsand pointers.Theconceptof expressions,as used inC, is unique. Thefirst halfof thistextbuildsafirm understandingofexpressions.Weintro- duce pointersonlytotheextent necessary7tocover passingthem tofunctions in Chapter 4and arrays in Chapter8.Our experiences haveshown that with . a firm graspof theexpressionconcept, muchof the mysteryof Cdisappears In Chapters 9, we begin to develop the concept of pointers, which are further developed in Chapter 10. Chapter 11 provides a discussion of C’s approach to strings. Finally, Chapter 14 provides an extensive discussion of bitwiseoperators,asubject that isneeded tomakethebookcomplete. The last chapter is a simple introduction to data structures. While not all courses will have time to cover this chapter, those that do will give the cetoThirdEdition . Motivated students will find that sthtuedyecnatns"agehteaadlesgtaurpt”inotnoddaatatasstrturucctutureressover the term break. Theappendicesat theendofthetextcomprisea rich set of referencesto subjects required in the complete C language. These w.ill be of use to stu- dentswhogoontotakeothercoursesin theClanguage Featuresof the Book Severalfeaturesof this book make it uniqueand easyfor beginningstudents tounderstand. StructureandStyle Oneof our basic tenets is that good habitsareformed early.Thecorollaryis that bad habitsare hard to break.Therefore,weconsistentlyemphasize the principlesof structured programmingand softwareengineering.Throughout each chapter, short code snippets and programs are used to demonstrate techniques. Complete programs, generally found in the last section of the chapter, are written in a well-document consistent style. As programs are analyzed, style and standards are further explained. While we acknowledge that there are manygood styles, our experience hasshown that if students areexposed to one good style and adopt it, they will be better able to adapt to other goodstyles. Principle Before Practice Wheneverpossible,wedeveloptheprincipleot asubject beforewe introduce the language implementation. For example, in Chapter 5 we first introduce theconceptof logicaldataandselectionand thenweintroducetheif...else and suitch statements.Thisapproach gives the student an understandingof selection beforeintroducingthe nuancesof thelanguage. Visual Approach A brief scan of the hook will demonstrate that ourapproach is visual.1here are more than 400figures, plus more than 70 tablesand 180 program exam- pies.While this amount of material tends to create a large hook, the visual approach makesiteasyforstudentstofollowthe material. Examples While the programmingexamplesvary in complexity, each uses a consistent style.Ourexperience workingwith productional programs that live for 10 to 2to0wyoerakrswciothnvthinacnedpruosgrtahmatsrweraidttaebnleinanadteursned,ecrrsytpatnicdamblaennperor.gFraomrtshaartereeaassoienr, PrefacetoThirdEdition vii and to emphasize the structure of the language, we label the sections in a function with comments.We consistently follow a style that places onlyone declaration,definition,orstatement onaline. Ihesourcecodefor theseprogramsisavailableon theCourse Technology . Website(see ’WebSiteSupportMaterials”laterinthisPreface) Studentsare able torun theseprograms and toexplorerelated topics throughmodification andexperimentation. Coding Techniques Throughout the text weincludecodingtechniques that makeprogramsmore readableandoftenmoreefficient.Forexample,in theanalyTsisof Program 5-4 youwill find the followingdiscussion: Where do we check for greater than} The answer is that we default thegreaterthanconditiontotheouterelse....Whencod- inga two-way selection statement, try to code the most probable condition first; with nested selection statements, code the most . probablefirstandtheleastprobablelast These techniques are drawn from our extensive industry and classroom . experience Software Engineering A discussionofsoftwareengineeringprinciplesconcludeseachchapter.Our . intent isnot toreplacea separatecourseinsoftwareengineering Rather,we firmly believe that by incorporating basic software engineering principles earlyintheir studies,students will bebetterprepared for a formal treatment of the subject. Even more important, by writing well-engineered programs from thebeginning,students will not be forced tounlearnandrelearn.Ihey willbetter understandsoftwarediscussionsintheir subsequent classes. While the software engineering sections are found at the end of each chapter,theyaremostsuccessfullytaughtbyintroducingthemasthechapter unfolds.Then,a short reviewat theendof thechapter summarizes theprin- ciples that havebeendemonstratedduringthelectures. These sections are visually distinguishable from the rest of the chapter. Theyhavebeen set apart for severalreasons.First,theyareinreality a small bookwithinabook.Whilethesesectionscontainimportantmaterial,thebook standsonitsownwithout them.Youmay,therefore,decide tocover thesoft- ware engineering sections as formal lecture topics or informally while the chapter material is beingcovered.You maydecide toassign them to thestu- dent as additional reading,or,you may decide toexclude thementirely from thecourse. Ingeneral,softwareengineeringsections directlyor indirectlypertain to the chapter material. Where they don’t, they discuss general software engi- neeringsubjects,suchascohesion,coupling,andquality. vjjj PrefacetoThirdEdition Pedagogical Material Endchapter material meetstwopedagogicalobjectives:first, it helpsthestu- dentstorevieworsummarizewhat they havelearned,andsecond, it teststhe students’masteryof thechapter material. Review Material (cid:127) Tips and Common Programming Errors points out helpful hints and possibleproblemareas. (cid:127) KeyTermsprovidesa listoftheimportanttermsintroduced in thechapter. (cid:127) Summarycontains a concise overview of the key points for students to understand in thechapter. PracticeSets (cid:127) Review Questions contain several multiple choice questions that are similar to thequestionsfound in theexamination database.Theanswers to the odd-numbered questions are included in the solutions on the CourseTechnologywebsite. (cid:127) Exercisesare short questions covering the material in the chapter.The answerstotheodd-numbered exercisesarealsoincluded in thesolutions on theCourseTechnologywebsite. (cid:127) Problemsare short coding problems, generally intended to be run on a computer. They can usually be developed in two to three hours. Once again,odd-numberedsolutionsarefound on thewebsite. (cid:127) Projectsarelonger, majorassignmentsthat maytake theaveragestudent sixtoninehourstodevelop. Appendicesand Cover Material Ilu appendicesareintended toprovidequickreference material,suchasthe UnicodeCharacter Set,or toprovidea reviewof material,such asnumbering systems, usuallycovered in ageneralcomputerclass. Ihe inside coverscontain t—wo important references that are used con- tinually throughout the course the Precedence Table and the Formatted I/OCodes. WebSiteSupport Materials '1 <~Hl"St lechn°logy Web site (http://www.course.com) are twnsetsoff materia|ls,onefor the professorand onefor thestudent. 1 PrefacetoThirdEdition ix Professor Materials The professors materials include thesolutions to all review questions, exer- cises, and problems. Because the projects are more complex assignments lor which there is nostandardanswer,wedo not providesolutionsfor them. In addition to the end-material solutions, there are three other sets ol support materials: (1) Copies of all programs in the text.The programs have been extensively tested on at least two different computers with different operatingsystems.Allof themconform totheC99Standard. (2) PowerPoint materials covering objectives, figures, programs, impor- tant points,andchaptersummaries.The PowerPoint materialscan beusedas is oredited tosuit individual class needs.Thisflexibilityallows professors to argument the text materials with their own. It also allows them to rearrange the materials tosuit their individual needsand style. . (3) New with the third edition is the availability of ExamView® This objective-based test generator lets the professor create paper, LAN, or Web- based tests from testhanks designed specifically for this text. Using the QuickTest Wizard, theycan easilyand quicklycreate true/falseand multiple- choice tests. It is also possible to add questions that cover supplemental material provided by the professor. StudentMaterials I he student materials include the solutions to the odd-numbered review questions,exercises,and problems.Theyalsohaveaccess to thecopiesof the programs used in the text Acknowledgments Nobookof thisscopecan hedeveloped without thesupport ol manypeople. Reviewers Toanyone who has not been through the process, the value ol peer reviews cannot heappreciated enough. Writinga text rapidly becomes a myopic pro- cess.Theimportantguidanceof reviewerswhocanstand hackand review the text asawholecannot bemeasured.Wewouldespeciallylike toacknowledge thecontributionsof the reviewersof all threeeditions. StephenAllen,Utah StateUniversity MaryAstone, /royStateUniversity Ali Behforooz,Towson StateUniversity George Berrv,Wentworth Instituteoj technology Ernest Carey,UtahValleyStateCollege PingChu Chu, Fayetteville StateUniversity r PrefacetojhirdEdition ConstanceConner,CityCollegeof San Francisco JohnS.DaPonte,SouthernConnecticut StateUniversity Maurice L.Eggen,TrinityUniversity/ PeterGabrovsky,CSU Northridge RobertGann, HartwickCollege HenryGordon, KutztownUniversity RickGraziani,CabrilloCollege BarbaraGuillott,Louisiana StateUniversity JerzyJaromczyk,University of Kentucky John Kinio, HumberCollege Roberta Klibaner,Collegeof Staten Island JosephA.Konstan,Universityof Minnesota Krishna Kulkarni, RustCollege JohnLowther, MichiganTechnological University Mike Michaelson, PalomarColle—ge Kara Nance,University ofAlaska Fairbanks Ali Nikzad, Huston-TillotsonCollege Jo.Ann Parikh,SouthernConnecticut StateUniversity Mark Parker,ShorelineCommunity College SavithaPinnepalli,Louisiana StateUniversity Oskar Reiksts, KutztownUniversity Jim Roberts,Carnegie MellonUniversity AliSalenia,South Dakota StateUniversity LarrySells,OklahomaCity University ShashiShekhar,University of Minnesota RobertSignorile, BostonCollege BrendaSonderegger,Montana StateUniversity DeborahSturm,Collegeof Staten Island VenkatSubramanian.University of Houston John B. Iappen,Universityof SouthernColorado MarcThomasm,California StateUniversity, Bakersfield John Irono,St. Michael'sCollege KC.Wong, Fayetteville StateUniversity CourseTechnologyStaff Our thanks to our editors,Alyssa Pratt, Senior Product Manager, and Mary hranz,SeniorAcquisitions Editor, for helping us produce the book. We are also indebted to the Quality Assurance staff who diligently double-checked eachc^aP^eranc^ program.Our thanksto Burt LaFountain, Serge Palladino, andChrisScr’iver. * W<?U^ a^S° to diank the staff at GEX PublishingServices, espe- ci(cid:127)allySandra Mitchell,whoablyguided the bookthrough production. BehrouzA. Forouzan Richard F.Gilberg