#include <iostream>
using namespace std;
class vehicle{
public:
    void run (){};
    void stop (){};
    vehicle(double ms,double w){
        maxspeed=ms;
        weight=w;
        cout<<"constring vehicle in called"<<endl;}
private:
    double maxspeed;
    double weight;
};
class bicycle:public vehicle{
public:
    bicycle(double h,double ms,double w):vehicle(ms,w){
        hight=h;
        cout<<"constring bicycle is called"<<endl;}
private:
    double hight;
};
class motorcar:public vehicle{
public:
    motorcar(double n,double ms, double w):vehicle(ms,w){
        seatnum=n;
        cout<<"constring motorcar is called"<<endl;}
private:
    double seatnum;
};
class motorcycle:public bicycle,public motorcar{
public:
    motorbicycle(double n,double h,double ms,double w):bicycle(double h,double ms,double w),
        motorcar(double n,double ms,double w)
    {cout<<"constring of motorbicycle is called"<<endl;}
};
int main(){
    motorbicycle m1(1.0,2.0,3.0,4.0);
    return 0;
}

受教了，谢谢各位！问题解决了，二楼辛苦了。有劳各位了，以后多指教。

麻烦再问一下，使用虚基类有什么好处呢？求指教。谢谢！

问题解决，谢谢解惑!