C++第八章习题答案(大题非选做).doc

8-3 (1)c1=(5,4)c2=(2,10)c3=c1-c2=(3,-6)c4=c1+c2=(7,14)(2)class A!class B!class C!class B!class C!(3)B1:display()D1:display()8-4 (1) x=p.x;y=p.y;x = p.get_x() & y = p.get_y()*this(2) virtual*ptrptr = &d8-5 (1)#include using namespace std;class Pointprivate: float x, y;public: Point(float xx=0, float yy=0) x = xx; y = yy; Point operator + (Point p) return Point(x+p.x, y+p.y); Point operator - (Point p) return Point(x-p.x, y-p.y); float getx() return x; float gety() return y; ;int main(void) Point one(1, 2), two(3, 4), a, b; a = (one + two); couta.getx(),a.gety()endl; b = (one - two); coutb.getx(),b.gety()endl; system(pause); return 0;(2)#include using namespace std;class Allpublic: int Double(int x) coutINTendl; return x*2; long Double(long x) coutLONGendl; return x*2; float Double(float x) coutFLOATendl; return x*2; double Double(double x) coutDOUBLEendl; return x*2; ;int main(void) All one; int a=5; long b=25; float c=3.14; double d=3.1415926; coutone.Double(a)endl; coutone.Double(b)endl; coutone.Double(c)endl; coutone.Double(d)endl; system(pause); return 0;(3)#include using namespace std;class Pointprivate: float x, y, z;public: Point(float xx=0, float yy=0, float zz=0) x = xx; y = yy; z = zz; Point operator + (Point p) return Point(x+p.x, y+p.y, z+p.z); Point operator - (Point p) return Point(x-p.x, y-p.y, z-p.z); Point operator = (Point p) return Point(x=p.x, y=p.y, z=p.z); void tell() cout(x,y,z)endl; ;int main(void) Point one(1, 2, 3), two(4, 5, 6); Point a, b; a = (one + two); b = (one - two); a.tell(); b.tell(); system(pause); return 0;(4)#include using namespace std;class vehiclepublic: virtual void tell(void)=0;class car:public vehiclepublic: void tell() coutCARendl; ;class truck:public vehiclepublic: void tell() coutTRUCKendl; ;class boat:public vehiclepublic: void tell() coutBOATendl; ;int main(void) car one; truck two; boat three; one.tell(); two.tell(); three.tell(); system(pause); return 0;(5)#include using namespace std;#include #define PI 3.14159265class Shapepublic: virtual float GetArea()=0; virtual float GetPerim()=0;class Rectangle:public Shapeprivate: float a, b, c; /三边长 public: Rectangle(float aa, float bb, float cc) a = aa; b = bb; c = cc; float GetArea() /海伦公式 float p=(a+b+c)/2; return sqrt(p*(p-a)*(p-b)*(p-c); float GetPerim() return a+b+c; ;class Circle:public Shapeprivate: float r; /半径public : Circle(float rr) r = rr; float GetArea() return PI*r*r; float GetPerim() return 2*PI*r; ;int main(void) Rectangle one(3, 3, 4); Circle two(6