cxkong1392661293的专栏

#include using namespace std; class Complex {public: Complex(){real=0;imag=0;} Complex(double r,double i){real=r;imag=i;} Complex operator+(Complex &c2); Complex operator-(Complex &c2); Comple

#include class Matrix {public: Matrix(); friend Matrix operator+(Matrix &,Matrix &); void input(); void display(); private:  int mat[2][3]; }; Matrix::Matrix() {for(int i=0;i for(int j=0;j

#include using namespace std; class Shape {public: virtual double area()const=0; }; class Circle:public Shape {public: Circle(double r):radius(r){} virtual double area() const{return 3.14159*