程序代码：

#ifndef HEADER_VECTOR
#define HEADER_VECTOR 
class Matrix;
class Vector{
    int *v;
    int sz;
public:
    void remove(){delete[] v;}
    void set(int);
    int& operator[](int);
    int size(){return sz;}
    void display();
    friend Vector multiply(const Matrix &m,const Vector &v);    
};
#endif

程序代码：

#ifndef HEADER_MATRIX
#define HEADER_MATRIX
class Vector;
class Matrix{
    int *m;
    int szl,szr;
public:
    void set(int,int);
    void remove(){delete[] m;}
    int sizel{return szl;}
    int sizer{return szr;}
    int&elem(int ,int );
    friend Vector multiply(const Matrix &m,const Vector & v);
};
#endif