超星 - 多态(2021) - 查题吧

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写结果。#includeusingnamespacestd;classB0{public:virtualvoiddisplay()=0;};classB1:publicB0{public:voiddisplay(){cout<<"B1"；}};classD1:publicB1{public:voiddisplay(){cout<<"D1";}};voidfun(B0ptr){ptr->display();}intmain(){B0p;B1b1;D1d1;p=&b1;fun(p);p=&d1;fun(p);return 0；}

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写结果classA{intm;public:A(inta=0){m=a;}virtualvoidf(){cout<f();p->g();}

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写结果。classA{public:A(){}virtualvoidfunc(){cout<<"DA";}~A(){func();}};classB:publicA{public:B(){}voidfunc(){cout<<"DB";}~B(){func();}};intmain(){B b；A &a=b；return 0；}

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写结果。classB{public:B(inti){b=i+50;show()；}B(){}virtualvoidshow(){cout<<"B"<

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写结果。classBase{public:Base(){}virtualBaseafn(){cout<<"B";returnthis;}};classSubclass:publicBase{public:Subclass(){}virtualBaseafn(){cout<<"S";returnthis；}};voidtest(Base&x){Base*b;b=x.afn()；}int main(){Basebc；Subclasssc;test(bc);test(sc);}

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写结果。classpoint{public:point(inti=0,intj=0){x0=i;y0=j;}virtualvoidset()=0；virtualvoiddraw()=0;protected:intx0,y0;};classline:publicpoint{public:line(inti=0,intj=0,intm=0,intn=0):point(i,j){x1=m;y1=n;}voidset(){cout<<"LS";}voiddraw(){cout<<"LD";}protected:intx1,y1;};classellipse:publicpoint{public:ellipse(inti=0,intj=0,intp=0,intq=0):point(i,j){x2=p;y2=q;}voidset(){cout<<"ES"；}voiddraw(){cout<<“ED”;}protected:intx2,y2;};voiddrawobj(pointp){p->draw()；}voidsetobj(pointp){p->set()；}intmain(){linelineobj=newline;ellipseelliobj=newellipse;drawobj(lineobj);drawobj(elliobj);setobj(lineobj);setobj(elliobj);deletelineobj;deleteelliobj;}

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转移到ch7综合。写结果。classA{intx,y;public:A(inta,intb){x=a;y=b;}voidDisplay(){cout<

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写结果。classvehicle{intMaxSpeed;intWeight;public:vehicle(){MaxSpeed=0;Weight=0;}virtual~vehicle(){Stop();}virtualvoidStop(){cout<<"VS";}};classbicycle:virtualpublicvehicle{intHeight;public:~bicycle(){Stop();}voidStop(){cout<<"BS";}};classmotorcar:virtualpublicvehicle{intSeatNum;public:~motorcar(){Stop();}voidStop(){cout<<"MAS";}};classmotorcycle:publicbicycle,publicmotorcar{public:~motorcycle(){Stop();}voidStop(){cout<<"MYS";}};intmain(){vehicle*ptr;motorcycled;ptr=&d;ptr->Stop();}

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写结果。classA{public:virtualvoidPrint()=0；}；classA1:publicA{public:voidPrint(){cout<<"A1P";} };classB1:publicA{public:voidPrint(){cout<<"B1P";} };voidfun(Ap){p->Print()；}intmain(){Aptr;A1a1;B1b1;ptr=&a1；fun(ptr);ptr=&b1；fun(ptr);return 0；}

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写结果。class Base{ public: virtual void Set(int b){x=b；}virtual int Get() { return x；} private: int x;};class Derived: public Base{ public: void Set(int d){y = d;} int Get() {return y;} private: int y;};int main( ){ Base B_obj; Derived D_obj; Base *p=&B_obj; p->Set(10);cout<Get(); p=&D_obj;p->Set(20);cout<< p->Get();p->Base::Set(30);cout<< p->Base::Get();p->Set(p->Get()+20)；cout<< p->Get();return 0；}

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