電大《C++語言程序設計》期末考試試題及答案小抄參考

PAGE小抄版C++語言程序設計期末考試試題及答案姓名____________學號____________班號___________題號一二（1）二（2）三總分成績一、填空1．在類中必須聲明成員函數(shù)的原型，成員函數(shù)的實現(xiàn)部分可以寫在類外。2．如果需要在被調(diào)函數(shù)運行期間，改變主調(diào)函數(shù)中實參變量的值，則函數(shù)的形參應該是引用類型或指針類型。3．抽象類只能作為基類使用，而不能聲明它的對象。4．進行函數(shù)重載時，被重載的同名函數(shù)如果都沒有用const修飾，則它們的形參個數(shù)或類型必須不同。5．通過一個常對象只能調(diào)用它的常成員函數(shù)，不能調(diào)用其他成員函數(shù)。6．函數(shù)的遞歸調(diào)用是指函數(shù)直接或間接地調(diào)用自身。7．拷貝構(gòu)造函數(shù)的形參必須是本類對象的引用。二、閱讀下列程序，寫出其運行時的輸出結(jié)果

如果程序運行時會出現(xiàn)錯誤，請簡要描述錯誤原因。1．請在以下兩題中任選一題，該題得分即為本小題得分。如兩題都答，則取兩題得分之平均值為本小題得分。（1）程序：#include<iostream.h>#include<string.h>classBase{private:charmsg[30];protected:intn;public:Base(chars[],intm=0):n(m){strcpy(msg,s);}voidoutput(void){cout<<n<<endl<<msg<<endl;}};classDerived1:publicBase{private: intn;public: Derived1(intm=1):Base("Base",m-1) {n=m;} voidoutput(void) {cout<<n<<endl; Base::output(); }};classDerived2:publicDerived1{private: intn;public: Derived2(intm=2):Derived1(m-1) {n=m;} voidoutput(void) {cout<<n<<endl; Derived1::output(); }};intmain(){ BaseB("BaseClass",1); Derived2D; B.output(); D.output();}運行結(jié)果：1BaseClass210Base（2）程序：#include<iostream.h>classSamp{public: voidSetij(inta,intb){i=a,j=b;} ~Samp() { cout<<"Destroying.."<<i<<endl; } intGetMuti(){returni*j;}protected: inti; intj;};intmain(){ Samp*p; p=newSamp[5]; if(!p) { cout<<"Allocationerror\n"; return1; } for(intj=0;j<5;j++) p[j].Setij(j,j); for(intk=0;k<5;k++) cout<<"Muti["<<k<<"]is:"<<p[k].GetMuti()<<endl; delete[]p; return0;}運行結(jié)果：Muti[0]is:0Muti[1]is:1Muti[2]is:4Muti[3]is:9Muti[4]is:16Destroying..4Destroying..3Destroying..2Destroying..1Destroying..02．請在以下兩題中任選一題，該題得分即為本小題得分。如兩題都答，則取兩題得分之平均值為本小題得分。（1）程序：#include<iostream.h>#include<stdlib.h>classVector{public: Vector(ints=100); int&Elem(intndx); voidDisplay(void); voidSet(void); ~Vector(void);protected: intsize; int*buffer;};Vector::Vector(ints){ buffer=newint[size=s];}int&Vector::Elem(intndx){ if(ndx<0||ndx>=size) { cout<<"errorinindex"<<endl; exit(1); } returnbuffer[ndx];}voidVector::Display(void){ for(intj=0;j<size;j++) cout<<Elem(j)<<endl;}voidVector::Set(void){ for(intj=0;j<size;j++) Elem(j)=j+1;}Vector::~Vector(void){ delete[]buffer;}intmain(){ Vectora(10); Vectorb(a); a.Set(); b.Display();}運行結(jié)果：12345678910最后出現(xiàn)錯誤信息，原因是：聲明對象b是進行的是淺拷貝，b與a共用同一個buffer，程序結(jié)束前調(diào)用析構(gòu)函數(shù)時對同一內(nèi)存區(qū)進行了兩次釋放。（2）程序：#include<iostream.h>classCAT{public: CAT(); CAT(const&CAT); ~CAT(); intGetAge(){return*itsAge;} voidSetAge(intage){*itsAge=age;}protected: int*itsAge;};CAT::CAT(){ itsAge=newint; *itsAge=5;}CAT::~CAT(){ deleteitsAge; itsAge=NULL;}intmain(){CATa;cout<<"a'sage:"<<a.GetAge()<<endl;a.SetAge(6);CATb(a);cout<<"a'sage:"<<a.GetAge()<<endl;cout<<"b'sage:"<<b.GetAge()<<endl;a.SetAge(7);cout<<"a'sage:"<<a.GetAge()<<endl;cout<<"b'sage:"<<b.GetAge()<<endl;}運行結(jié)果：a'sage:5a'sage:6b'sage:6a'sage:7b'sage:7最后出現(xiàn)錯誤信息，原因是：聲明對象b是進行的是淺拷貝，b與a共用同一個buffer，程序結(jié)束前調(diào)用析構(gòu)函數(shù)時對同一內(nèi)存區(qū)進行了兩次釋放。三、閱讀下列程序及說明和注釋信息，在方框中填寫適當?shù)某绦蚨?，使程序完成指定的功能程序功能說明：從鍵盤讀入兩個分別按由小到大次序排列的整數(shù)序列，每個序列10個整數(shù)，整數(shù)間以空白符分隔。用這兩個序列分別構(gòu)造兩個單鏈表，每個鏈表有10個結(jié)點，結(jié)點的數(shù)據(jù)分別按由小到大次序排列。然后將兩個鏈表合成為一個新的鏈表，新鏈表的結(jié)點數(shù)據(jù)仍然按由小到大次序排列。最后按次序輸出合并后新鏈表各結(jié)點的數(shù)據(jù)。程序運行結(jié)果如下，帶下劃線部分表示輸入內(nèi)容，其余是輸出內(nèi)容：13579111315171924681012141618201234567891011121314151617181920#include<iostream.h>#include<stdlib.h>//類定義部分template<classT>classNode{private:Node<T>*next;//指向后繼節(jié)點的指針public:Tdata;//數(shù)據(jù)域Node(constT&item,Node<T>*ptrnext=NULL);//構(gòu)造函數(shù)voidInsertAfter(Node<T>*p);//在本節(jié)點之后插入一個同類節(jié)點pNode<T>*DeleteAfter(void);//刪除本節(jié)點的后繼節(jié)點,返回其地址Node<T>*NextNode(void)const;//獲取后繼節(jié)點的地址};template<classT>classLinkedList{private:Node<T>*front,*rear;//表頭和表尾指針Node<T>*prevPtr,*currPtr;//記錄表當前遍歷位置的指針,由插入和刪除操作更新intsize;//表中的元素個數(shù)intposition;//當前元素在表中的位置序號。由函數(shù)Reset使用Node<T>*GetNode(constT&item,Node<T>*ptrNext=NULL);//生成新節(jié)點，數(shù)據(jù)域為item，指針域為ptrNextvoidFreeNode(Node<T>*p);//釋放節(jié)點voidCopyList(constLinkedList<T>&L);//將鏈表L拷貝到當前表

//（假設當前表為空）。被拷貝構(gòu)造函數(shù)、operator=調(diào)用public:LinkedList(void);//構(gòu)造函數(shù)LinkedList(constLinkedList<T>&L);//拷貝構(gòu)造函數(shù)~LinkedList(void);//析構(gòu)函數(shù)LinkedList<T>&operator=(constLinkedList<T>&L);//重載賦值運算符intListSize(void)const;//返回鏈表中元素個數(shù)（size）intListEmpty(void)const;//size為0時返回TRUE,否則返回FALSEvoidReset(intpos=0);//將指針currPtr移動到序號為pos的節(jié)點，

//prevPtr相應移動,position記錄當前節(jié)點的序號voidNext(void);//使prevPtr和currPtr移動到下一個節(jié)點intEndOfList(void)const;//currPtr等于NULL時返回TRUE,否則返回FALSEintCurrentPosition(void)const;//返回數(shù)據(jù)成員positionvoidInsertFront(constT&item);//在表頭插入一個數(shù)據(jù)域為item的節(jié)點voidInsertRear(constT&item);//在表尾添加一個數(shù)據(jù)域為item的節(jié)點voidInsertAt(constT&item);//在當前節(jié)點之前插入一個數(shù)據(jù)域為item的節(jié)點voidInsertAfter(constT&item);//在當前節(jié)點之后插入一個數(shù)據(jù)域為item的節(jié)點TDeleteFront(void);//刪除頭節(jié)點,釋放節(jié)點空間，更新prevPtr、currPtr和sizevoidDeleteAt(void);//刪除當前節(jié)點,釋放節(jié)點空間，更新prevPtr、currPtr和sizeT&Data(void);//返回對當前節(jié)點成員data的引用voidClearList(void);//清空鏈表：釋放所有節(jié)點的內(nèi)存空間。};//類實現(xiàn)部分略template<classT>voidMergeList(LinkedList<T>*la,LinkedList<T>*lb,LinkedList<T>*lc){//合并鏈表la和lb,構(gòu)成新鏈表lc。//函數(shù)結(jié)束后，程序的數(shù)據(jù)所占內(nèi)存空間總數(shù)不因此函數(shù)的運行而增加。while(!la->ListEmpty()&&!lb->ListEmpty()){ if(la->Data()<=lb->Data()) {lc->InsertRear(la->Data()); la->DeleteAt(); }else {lc->InsertRear(lb->Data()); lb->DeleteAt(); }}while(!la->ListEmpty()){lc->InsertRear(la->Data()); la->DeleteAt();}while(!lb->ListEmpty()){lc->InsertRear(lb->Data()); lb->DeleteAt(); }}intmain(){LinkedList<int>la,lb,lc; intitem,i;//讀如數(shù)據(jù)建立鏈表la for(i=0;i<10;i++) { cin>>item;la.InsertRear(item); } la.Reset();//讀如數(shù)據(jù)建立鏈表lb for(i=0;i<10;i++) { cin>>item;lb.InsertRear(item); } lb.Reset(); MergeList(&la,&lb,&lc);//合并鏈表 lc.Reset();//輸出各節(jié)點數(shù)據(jù)，直到鏈表尾while(!lc.EndOfList()) {cout<<lc.Data()<<"";lc.Next();//使currPtr指向下一個節(jié)點 }cout<<endl;}Visa-freepolicybringsChengdubiz,tourismboost.Makingnationalheadlinesseveraltimes,Chengdu's72-hourvisa-freepolicyhasattractedwideattentionfrombothChineseandforeignexpertsandbusinessmensinceittookeffectonSept1lastyear.Theprogrampermitscitizensfrom51countriesandregionsincludingtheUnitedStates,Australia,CanadaandJapanwhohavevalidvisasandflightticketstoathirdcountrytospendthreedaysinthecity.ThecapitalofSichuanprovinceisthefirstcityinthewesternregionofChinatoofferforeigntouristsathree-dayvisaandthefourthnationwidetoadoptthepolicyfollowingShanghai,BeijingandGuangzhou.LiZhiyong,deputydeanofthetourisminstituteatSichuanUniversity,saidthemove"contributestoalargeincreaseinthenumberofoverseastouristsandraisesthecity'slevelofinternationalization"."Thepolicywillalsobringdirecteconomicrevenue,"Lisaid."Chengduhasmanyculturallegaciesandisalsoaparadiseforpandaloverswiththeworld'slargestbreedingandresearchcenter.Threedaysarelongenoughforforeignvisitorstovisitthoseiconictouristspots,"henoted.ThecityishometotheremainsoftheJinshacivilizationthatdatesbackmorethan3,000yearsaswellastheQingchengMountainsandtheDujiangyanirrigationsystem.QingchenghaslongbeenrecognizedasthebirthplaceofTaoism,China'sancientindigenousreligion,whileDujiangyanisconsideredtobetheoldestfunctioningwater-controlprojectintheworld.Chengdurankedthirdintouristfacilities,managementandservicesamong60Chinesecitiesinacustomersatisfactionsurveyreleasedlastyear.But,Liaddedthateffortsarestillneededtodevelopmoretourismproducts,improveEnglishservicesandprovideaccuratetranslationoftrafficsignsandscenicbillboards.ZhaoYun,chairwomanofBritishChamberofCommerceSouthwestChina,toldChinaDailythathiscolleaguesfoundthepolicyveryconvenient."ABritishclientonceflewhereandstayedforjustonedaytocheckherorderedgoods,"shesaid.ZhaowasborninShanxiprovince,butshehaslivedinChengduformorethan10years."Mylifewaslikearunningracemovingfromplacetoplace.IalsolivedinBeijingandShanghaibefore,"shesaid."ButChengduisaplacethatyouneverwanttoleaveoncesettlingdown.Itisnowmysecondhometown,"shesaid.Iftheenvironmentisfurtherimproved,thecitywillattractmorepeopletovisitandlive,withthe72-hourvisa-freepolicyandcompellingconditionsintransportation,culture,climateandcuisine,hesaid.Foreignersalsogavepositivefeedbackonthepolicy.AspokesmanfromDellIncsaidthecompanyhasaglobalhubofoperationinChengdu,sothethree-dayvisa"hasanimmediateandpositiveinfluenceonthecompany'sbusinessdevelopment".RudyButtignol,presidentofthepublicbroadcastingcompanyinBritishColumbia,Canada,saidhisworkrequiresfrequenttraveltoChengduandthepolicy"makesthetripseasier".Datafromthecity'spublicsecuritybureaushowssome100foreignvisitorsenjoyedthe72-hourpolicybytheendofMarch,mostofthemfromtheUnitedStates,theUnitedKingdomandGermany.Chengdualsoreportedrobustgrowthinitsoveralltouristindustrylastyear.Officialstatisticsshowthatitreceivedsome150milliontouristslastyear,anincreaseof28percentfrom2012.Around1.7millioncamefromabroad,anincreaseof12percent.Totalrevenuefromtourismsurpassed133billionyuan($21.7billion).DuringhisvisittoKazakhstaninSeptember,ChinesePresidentXiJinpingproposedthatChinaandCentralAsiajoinhandstobuildaSilkRoadeconomicbelttoboostcooperation.TheideahasbeenwidelyechoedinCentralAsiancountries,becominganencouragingblueprintforChineseareasalongtheSilkRoadthathaslinkedAsiaandEuropeformorethan2,000years.Inthenextthreeweeks,ChinaDailyreporterswilltravelthroughthebeltinChi