1 class Matrix{
 2 public:
 3         Matrix(int dimM, int dimN){          //构造函数
 4                 a = new double *[dimM];               
 5                 int i = 0;
 6                 for(i = 0; i < dimM; i++){
 7                         a[i] = new double[dimN];
 8                 }
 9         }
10         
11         ~Matrix(){
12             for （int i = 0; i<M; i++) 
13                delete []a[i];
14             delete []a;
15         }                    
16         
17         void input(int m, int n);
18         void output(int m, int n);
19         Matrix (const Matrix & copy);    
20 
21 private:
22         int M;
23         int N;
24         double **a;                       
25         
26 };
27