#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;
}

#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)//这句首先这个构造函数名字和类名字不一样，再者父类初始化列表按你的做法应该这写:bicycle(h,ms,w),motorcar(n,ms,w)
    {cout<<"constring of motorbicycle is called"<<endl;}
};
int main(){
    motorbicycle m1(1.0,2.0,3.0,4.0);//类的名字打错了
    return 0;
}

注意虚基类的应用···

二楼正确，这种错误可不能常犯哦

看不懂了....

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！

使用虚基类在实例化的时候可以避免歧义，比如说有基类A，另有类B和C都继承了A，然后再有类D继承了B和C，这时候如果没有使用虚基类，D在访问从A类继承的方法和属性的时候就有可能出现歧义，因为B和C在实例化的时候内存中都有一份A的实例，编译器不知道是访问的方式，因为D->B->A和D->C->A都可以；如果使用虚基类B和C中存在的就不是A的实例了，而是存在一个指向A实例的指针，D访问从A类继承的方法和属性时就没有歧义，但是这也并不能完全消除歧义，需要设计类时合理安排。

问题解决，谢谢解惑!