李爱华、程磊_面向对象程序设计课后答案.doc

第二章2-4#include using namespace std;Add(int a,int b);int main()int x,y,sum;coutxy;sum = add(x,y);cout x+y=sumendl;Add(int a,int b)return a+b;2-5(1)this is a C+ program.(2)x=50.6 y=10 z=Ax=216.34 y=10 z=Ax=216.34 y=2 z=Ax=216.34 y=2 z=E(3)xyz500100005001500150050020015002-6#include using namespace std; int main() int *p,*init; int countp=0; int countn=0; p = new int20; init = p; for(int i=0;i*p; p+; p = p-20; for( i=0;i0) countp+; if(*p0) countn+; cout*p ; p+; cout正数有:countpendl; cout负数有:countnendl; p = init;delete p;return 0;2-7不做要求#include /#include using namespace std;void checkagescore(string name,int age)if (name = exit) throw name;if(age50)throw age;int main()string name;int age;for(int i=0 ;iage ; trycheckagescore(name,age);catch( string)coutexception :name is exitendl;continue;catch(int)coutexception :age is not properendl;continue; coutname:name age :ageendl;return 0;第三章3-1（1）A（2）C（3）B（4）C（5）C（6）B （7）B（8）C（9）C3-7（1）main()函数中 p1.age = 30;语句是错误的。age 是类的私有成员（2）构造函数应当给常数据成员和引用成员初始化，将构造函数改为：A(int a1,int b1):a(a1),b(b1)或A(int a1 ):a(a1),b(a)再将main中的A a(1,2); 改为A a(1);(3)(1)在Test 类中添加语句：void print();void Print() coutx-y=x-yendl;改为void Test:Print() coutx-y=x-yendl;main函数中Init(38,15);改为：A.Init(38,15);Print();改为：A.Print(); 3-8(1)Constructing AConstructing BDestructing BDestructing A(2)double a,double bpoint & pp.x3-9class box int len1,len2,len3;public: box(int l1,int l2,int l3)len1 = l1;len2 = l2; len3 = l3; long volumn()return len1*len2*len3;3-10class Testint m1,m2; public:void Init(int a,int b)m1 = a;m2 = b;void Pring()coutm1 m2endl;3-11略3-12第四章4-6（1）D（2）D（3）D（4）D（5）B（6）D4-7（1）static int count = 0;这样初始化静态成员值是不对的将其改为static int count;在类外，main函数前加int Sample:count = 0;（2）#include /#include using namespace std;class Ctestprivate:int x; const int y1;public:const int y2;Ctest(int i1,int i2):y1(i1),y2(i2)y1 =10;/y1 为常量不能赋值x = y1;int readme() const;int Ctest:readme ()constint i;i = x;x+; /常函数内不能改变成员值return x; int main()Ctest c(2,8);int i = c.y2;c.y2 = i;/y2为常量,不能改值i = c.y1;/y1私有,类外不能访问return 0;将出错语句全部注释4-8(1)题中印刷错误，将class C构造函数改为：C()coutconstructor C:;运行结果为：constructor Aconstructor Bconstructor C(2)40(3)3434-9略4-10 #include #include class Studentint number;char name20;public:Student(int i=0,char *s=0)/构造学生对象 number=i; strcpy(name,s); void Print()/输出结果 coutNumber:numberendl;coutName:namest2.number;/返回成员number的比较结果int main()Student st5=Student(65,Li),Student(78,Zhang),Student(80,wang),Student(92,zhao),Student(50,zhen);int max = 0;int min = 0;for(int i=1;i5;i+)if(!greaterthan(stmax,sti)max = i;if(!greaterthan(sti,stmin)min = i;cout最大成绩:endl; stmax.Print ();cout最小成绩:endl;stmin.Print ();return 0;4-11#include #include using namespace std;class Bookchar *name;char*author;int sale;public:Book() name = 0; author = 0; sale = -1;Book(char* a ,char* b,int c) name = new charstrlen(a)+1;strcpy(name,a);author = new charstrlen(b)+1;strcpy(author,b);sale = c;void print()coutautor authorendl;coutname nameendl;coutprice saleendl;Book() if(!name ) delete name;if(!author)delete author;int main() Book b1(c+,li ai hua,12); Book b2;return 0; 第五章5-8 改错题答案不唯一(1) class DC int x;public:DC()x =100;(2)编译无错,但逻辑错误,可改为: class BCprotected:int x;public:BC(int i=0)x = i;class DC:private BCpublic:DC(int i):BC(i);(3)将DC构造函数改为:DC(int i):BC(i)y = 0;5-9(1) base class(2)(10,5)(3,9-18,33)(13,19)(13,19-18,33)(13,19)5-10#include using namespace std;class Shapeint x,y;public:Shape(int ix,int iy)x = ix; y = iy;virtual void show()coutpos: x yendl;class Circle :public Shapeint radius;public:Circle(int ix,int iy,int r):Shape(ix,iy),radius(r)void show() Shape:show ();coutcircle: radiusendl;class Rect :public Shapeint width,higth;public:Rect(int ix,int iy,int iw,int ih):Shape(ix,iy),width(iw),higth(ih)void show() Shape:show ();coutwidth and higth: width higthendl;int main()Shape s1(1,1);Rect r1(2,2,8,8);Circle c1(3,3,9);r1.show ();c1.show();return 0;第六章6-4 d=3D:fun();6-5C:print(),cinfo=2C:print(),cinfo=2D:print(),dinfo=4B类不能定义对象，否则编译通不过，因为B未定义基类A中的虚函数print(),它也是个虚基类。6-6#include using namespace std;class Mammalpublic:virtual void Speak()coutin Mammalendl;class Dog:public Mammalpublic:void Speak()coutdog barkSpeak ();return 0;运行结果: dog bark6-7#include using namespace std;class BaseClasspublic: virtual BaseClass()coutdestruct Baseendl;class Derived:public BaseClasspublic:Derived()coutdestruct derivedendl;int main()BaseClass *pbase;pbase = new Derived;delete pbase; 结果将不能正常执行子类析构6-8 以圆形和正方形为例#include using namespace std;class Shapepublic:virtual float area() = 0;class Circle :public Shapeint radius;public:Circle(int r):radius(r)float area() return 3.14*radius*radius;class Square :public Shapeint width;public:Square(int w):width(w)float area() return width*width;int main()float areaSum= 0;Shape * pS3;pS1 = new Circle(1);pS2 = new Square(2);areaSum += pS1-area ();areaSum += pS2-area ();coutareaSumendl;return 0;6-9#include using namespace std;class Studentpublic:virtual void show() = 0;class Junior :public Studentpublic:void show()coutthis would be info for junior studentsendl;class Senior :public Studentpublic:void show()coutthis would be info for Senior studentsshow ();pstu = new Senior;pstu-show ();return 0;第七章7-1#include #include using namespace std;class vectorint x,y;public:vector(int ix=0,int iy=0)x =ix;y = iy;vector operator+(vector& v1)return vector(x+v1.x,y+v1.y);vector& operator+=(vector& v1)x +=v1.x;y +=v1.y;return *this;voidshow()cout(x,y)endl;int main() vector v1(1,2),v2(3,4),v3;v3 = v1+v2;v1+=v2;v3.show();v1.show();return 0;7-2 #include class Complex private: double real,image;public: Complex(double x=0.0,double y=0.0) real =x; image =y; bool operator !=(const Complex &c);Complex operator -(const Complex &c); bool operator =(const Complex &c); Complex operator -(); Complex &operator +=(const Complex &c); void Print();void Complex:Print()coutreal + imageiendl; Complex Complex :operator -(const Complex &c)Complex temp(real-c.real,image-c.image);return temp;bool Complex :operator =(const Complex &c)return (real=c.real & image=c.image); bool Complex:operator !=(const Complex &c)return (real!=c.real | image!=c.image); Complex Complex :operator -()return Complex(-real,-image); Complex &Complex :operator +=(const Complex &c)real+=c.real; image+=c.image;return *this; int main()Complex c1(2,7),c2(4,2),c3;c3=c1-c2; c3.Print();if(c3=c1)coutc3 equals to c1endl; else coutc3 doesn?t equale to c1endl;c3=-c2; c3.Print();c3+=c2;c3.Print();if(c3 != c1)coutc3!=c1endl;return 0;7-3#include using namespace std;bool rn(int y)bool flag = 0;if(y%400=0 | y%4 =0&y%100!=0)flag = 1;return flag;class Date private:int month, day, year;public:Date(int m, int d, int y); Date& operator+(int days);void showDate(); ;Date:Date(int y, int m, int d) if (m0 & m0 & d0 & y0;)int diff ;switch(month)case 1:case 3:case 5:case 7:case 8:case 10:case 12: diff = 31 -day;break;case 4:case 6:case 9:case 11: diff = 30 -day;break;case 2:if (rn(year)diff = 29 - day;else diff = 28 -day; break; if(idiff)i-= diff+1;day = 1;month+;if(month12)year+;month = 1;elseday+= i;break;return *this;void Date:showDate()coutyear.month.dayendl;int main()Date obj(1996,1,1); obj.showDate ();obj = obj+59; obj.showDate(); return 0; 7-4 以+，=为例#include#includeusing namespace std;class String char *sbuf; int length;public:String()length=0;sbuf=new char;sbuf0=0;String(char *s) /用字符串初始化 length=strlen(s);sbuf=new charlength+1;strcpy(sbuf,s);String (String& str)length=str.length ;sbuf=new charlength+1;strcpy(sbuf,str.sbuf );String()delete sbuf; String & operator =(String& str)if(sbuf = str.sbuf )return *this;elsesbuf = new charstr.length +1;strcpy(sbuf,str.sbuf );return *this;String operator +(String& str)/此函数需配合拷贝构造函数String st; st.length = length + str.length ; st.sbuf = new charst.length+1 ; st.sbuf 0 = 0; strcpy(st.sbuf,sbuf); strcat(st.sbuf,str.sbuf ); return st;char & operator(int i)if(i=length) /对下标进行检查，超出范围则报错退出程序 cout下标越界错误！endl;exit(0);return sbufi;void Show()coutsbufendl;int main()String s1(hello);String s2(world),s3 ; s3 = s1+s2; /s3.Show ();return 0; 其他略第八章8-1（1）template T fun(T a). (2)templateT test(T a).(3)templateclass Array public: void fun();templatevoid Array:fun().(4)Array a1,a2,a3;8-4#includeusing namespace std;template T max(T a,T b,T c)T temp;temp=ab?a:b;temp=tempc?temp:c;return temp;int main()coutmax(11,29,22)endl;coutmax(3.14f,28.3f,6.7f)endl;coutmax(c,b,a)endl;return 0;8-5及8-6 #include#includeusing namespace std;template void sort_bubble(T arr,int n)for(int i=0; in-1;i+)for(int j=0;jn-1-i;j+)if( arrjarrj+1)T temp; temp=arrj; arrj=arrj+1; arrj+1=temp;class studentint num;string name;public:student(int n=0,string ns=)num = n;name = ns;bool operator(student s1)return (nums1.num );void print()coutnum name;coutendl;int main()int arri=2,4,1,43,56,78;float arrf=1.2f,4.5f,21.4f,98.9f;sort_bubble(arri,6);sort_bubble(arrf,4);for(int i=0;i6;i+)coutarrii ;coutendl;student stuarr = student(3,liqing),student(1,liou),student(4,