填空题
[程序](2分)
#include
class A{
int x;
public:
A(int a){x=a;}
virtual void print1{cout<<"x="<
void fun2{print3;}
};
class B:public A{
int y:
public:
B(int a,int b):A(a){y=b;}
void print4{cout<<"y="< }
void fun5{print6;}
};
class C:public B{
int z;
public:
C(int a,int b,int C):B(a,b){z=c;}
void print7{cout<<"z="< }
void fun8{print9;}
};
void main(void)
{ A a1(5),*p1;
B bl(10,15);
C c1(20,30,40);
a1.fun10;b1.fun11;c1.fun12;
pl=&b1; pl->fun13;p1=&c1;pl->fun14;
}
程序输出的第四行是 15(17) 16 ,第五行是 17(18) 18