#include <iostream> using namespace std; //请在begin和end间完成Matrix类的编写，重载>>及<<运算符，建议重载为友元函数 /*********begin**********/ class Matrix { private: int mat[2][3]; public: friend istream& operator>>(istream& in, Matrix& m); friend ostream& operator<<(ostream& out, const Matrix& m); }; istream& operator>>(istream& in, Matrix& m) { for (int i = 0; i < 2; i++) { for (int j = 0; j < 3; j++) { in >> m.mat[i][j]; } } return in; } ostream& operator<<(ostream& out, const Matrix& m) { for (int i = 0; i < 2; i++) { for (int j = 0; j < 3; j++) { out << m.mat[i][j] << ' '; } out << endl; } return out; } /*********end*********/ int main() { Matrix m1; cin>>m1; cout<<"output matrix"<<endl; cout<<m1; }补全代码

完整的代码如下：

#include <iostream> 
using namespace std; 

//请在begin和end间完成Matrix类的编写，重载>>及<<运算符，建议重载为友元函数 
/*********begin**********/ 
class Matrix { 
private: 
    int mat[2][3]; 
public: 
    friend istream& operator>>(istream& in, Matrix& m); 
    friend ostream& operator<<(ostream& out, const Matrix& m); 
}; 

istream& operator>>(istream& in, Matrix& m) { 
    for (int i = 0; i < 2; i++) { 
        for (int j = 0; j < 3; j++) { 
            in >> m.mat[i][j]; 
        } 
    } 
    return in; 
} 

ostream& operator<<(ostream& out, const Matrix& m) { 
    for (int i = 0; i < 2; i++) { 
        for (int j = 0; j < 3; j++) { 
            out << m.mat[i][j] << ' '; 
        } 
        out << endl; 
    } 
    return out; 
} 
/*********end*********/ 

int main() { 
    Matrix m1; 
    cin >> m1; 
    cout << "output matrix" << endl; 
    cout << m1; 
}