已知矩阵为2行3列，重载流插入运算符“<<”和流提取运算符">>"，使之能完成矩阵的输入和输出，完善下列代码 #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，矩阵元素可以为double型 /begin*/ /end/ int main() { Matrix m1; cin>>m1; cout<<"output matrix"<<endl; cout<<m1; }

以下是完整的代码：

#include <iostream>
using namespace std;

class Matrix {
private:
double data[2][3]; // 矩阵元素
public:
friend istream& operator>>(istream& ins, Matrix& matrix); // 流提取运算符
friend ostream& operator<<(ostream& outs, const Matrix& matrix); // 流插入运算符
};

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

ostream& operator<<(ostream& outs, const Matrix& matrix) {
for (int i = 0; i < 2; i++) {
for (int j = 0; j < 3; j++) {
outs << matrix.data[i][j] << " ";
}
outs << endl;
}
return outs;
}

int main() {
Matrix m1;
cin >> m1;
cout << "output matrix" << endl;
cout << m1;
return 0;
}