相关疑难解决方法(0)

继承我的代码:

#include <iostream>
#include <cmath>
#include <sstream>
using namespace std;

class root
{
    protected :

            int size;
            double *array;

    public :

        virtual ~root() {}
        virtual root* add(const root&) = 0;
        virtual root* sub(const root&) = 0;
        virtual istream& in(istream&, root&) = 0;
        virtual int getSize() const = 0;
        virtual void setSize(int);
};

class aa: public root
{

    public :

        aa();
        aa(int);
        aa(const aa&);
        root* add(const root& a);
        root* sub(const root& a);
        istream& in(istream&, root&){}
        int getSize() const;
        void setSize(int);
}; …