大学C++面向对象程序设计 2018试题及参考答案

…………试卷装订线………………装订线内不要答题，不要填写考生信息………………试卷装订线……………………试卷装订线………………装订线内不要答题，不要填写考生信息………………试卷装订线……………………试卷装订线………………装订线内不要答题，不要填写考生信息………………试卷装订线……………………试卷装订线………………装订线内不要答题，不要填写考生信息………………试卷装订线…………重点大学考试试题答案（A卷）2018 ~2019 学年1 学期面向对象程序设计课程一、单选题（每小题2分，共20分）CCDCB AAABA二、改错题(共3小题，每小题6分，共18分)1. main()函数第3句出错，因为类Complex无类类型转换函数，将Complex对象转换成float。

改正：在Complex中类增加：operator float(){ return real; }2. main()函数第2句出错，因为常对象obj不能调用非常成员函数，改正：在CTest类中：将CTest(int x)换成fCTest(int x) const。

或者将main()中const CTest obj(5);换成CTest obj(5);3. 当程序执行对象p2的析构函数时，对象p1的数据成员ptr出现了所谓的“指针悬挂问题”,这说明C++中提供给对象的默认的赋值运算符并不是万能的，解决的办法就是重载赋值运算符“=”，使对象不但能浅拷贝，还能实现深层拷贝。

STRING& STRING::operator=(const STRING&s){if(this==&s)return *this;delete ptr;ptr=new char[strlen(s.ptr)+1];strcpy(ptr,s.ptr);return *this;}三、读程序，给出程序的输出结果。

（每小题6分，共24分）【1】Constructor of PersonConstructor of StudentConstructor of PersonConstructor of TeacherDestructor of TeacherDestructor of PersonDestructor of StudentDestructor of Person【2】12,2【3】56789【4】1123444四、编程题（共38分=12分+12分+14分）1. 解答：#include<iostream.h>class Test ……………………………4分{ int x,y;public:void init(int,int);void print();};void Test::init(int i,int j) ……………………………4分{ x=i;y=j;}void Test::print() ……………………………4分{ cout<<"测试结果："<<x<<"-"<<y<<"="<<x-y<<endl;}2.解答：①fraction operator +(fraction & f1,fraction & f2) { ……………………………4分int nfz = f1.fz*f2.fm+f1.fm*f2.fz;int nfm = f1.fm*f2.fm;return fraction(nfz,nfm);}②fraction & fraction::operator =(fraction & f) { ……………………………4分fz=f.fz;fm=f.fm;return *this;}③istream & operator >>(istream & is,fraction & f) { ……………………………4分is>>f.fz>>f.fm;return is;}3.解答：#include<iostream>using namespace std;class employee{ ……………………………4分protected:char name[20];int empNo;float salary;public:employee(char *cp="李强",int no=1001);employee(employee&);void setname(char *cp);void setempNo(int no);void setsalary(float sa);char*getname();int getempNo();float getsalary();void display();employee compsalary(employee *emp);};employee::employee(char *cp,int no){ int i=0;while(*cp){ name[i]=*cp;i++;cp++;}name[i]='\0';empNo=no;}employee::employee(employee &em){ int i=0;while([i]){ name[i]=[i];i++;}name[i]='\0';empNo=em.empNo;salary=em.salary;}void employee::setname(char *cp){ int i=0;while(*cp){ name[i]=*cp;i++;cp++;}name[i]='\0';}void employee::setempNo(int no){ empNo=no;}void employee::setsalary(float sa){ salary=sa;}char*employee::getname(){ return name;}int employee::getempNo(){ return empNo;}float employee::getsalary(){ return salary;}void employee::display(){ cout<<"工号为"<<empNo<<"的雇员"<<name<<"的月薪为"<<salary<<endl; }employee employee::compsalary(employee *emp){if(this->salary>=emp->salary)return *this;elsereturn *emp;}class worker : public employee ……………………………4分{public:worker(char*,int,int);void setproductNum(int n){ productNum=n;}int getproductNum(){ return productNum;}void pay();private:int productNum;static float proper; //每件产品的利润};float worker::proper=20; //假设每件产品的利润为20元worker::worker(char *name,int no,int pronum):employee(name,no){productNum=pronum;}void worker::pay(){salary=productNum*proper*0.2;}class technician : public employee ……………………………4分{public:technician(char*,int,float);void sethours(float h){ workHours=h;}float gethours(){ return workHours;}void pay();private:float workHours;static float payperhour; //科研人员每小时工作的酬金};float technician::payperhour=40; //假设科研人员每小时工作的酬金为40元technician::technician(char *name,int no,float hours):employee(name,no){ workHours=hours;}void technician::pay(){ salary=workHours*payperhour;}class salesman : public employee{public:salesman(char*,int,float);void setmonthlysales(int num){ monthlysales=num;}int getmonthlysales(){ return monthlysales;}void pay();private:float monthlysales;static float percent; //销售人员的销售提成};float salesman::percent=0.5; //假设销售人员的销售提成为50% salesman::salesman(char *name,int n,float sn):employee(name,n){monthlysales=sn;}void salesman::pay(){salary=monthlysales*percent;}void main() ……………………………2分{worker w1("张三",1001,1000);technician t1("李四",1002,200);salesman s1("王五",1003,10000);w1.pay();t1.pay();s1.pay();cout<<"工人"<<w1.getname()<<"的月薪为"<<w1.getsalary()<<"元\n";cout<<"科研人员"<<t1.getname()<<"的月薪为"<<t1.getsalary()<<"元\n";cout<<"销售人员"<<s1.getname()<<"的月薪为"<<s1.getsalary()<<"元\n"; }。