怎么办到bv和dv不一样

Question

#include <iostream>

using namespace std;

 

class Sample

{

        public:

                int v;

     

/******补充你的代码******/

      

/************************/

 

  };

 

void PrintAndDouble(Sample o)

{

        cout << o.v;

        cout << endl;

}

 

int main()

{

 

        Sample a(5);            

        Sample b = a;         

        PrintAndDouble(b);      

        Sample c = 20;

        PrintAndDouble(c);     

        Sample d;

        d = a;               

        cout << d.v;

        return 0;

}
要求最后运行结果为
9
22
5

Answer 1

 /******补充你的代码******/
    Sample(int a = 0) : v(a) {}
    Sample(const Sample &a) : v(a.v + 2) {}

    /************************/