c++ 的用 new 和delete 进行二维数组动态内存的创建和删除

 1.数组指针 A (*ga)[n] = new A[m][n];           ...     delete []ga;2.二级指针 A** ga = new A*[m];  for(int i = 0; i < m; i++)           ga[i] = new A[n];   ...    for(int i = 0; i < m; i++)             delete []ga[i];      delete []ga;3.//用一维数组来模拟 A* ga = new A[m*n];    ...    delete []ga;

对应的用malloc 和free 函数进行操作的方法是：1.int (*p)[4] = (int *[])malloc(sizeof(int) *n * m);free(p);2. int **p;for(int i = 0; i < n; i ++){    p[i] = (int *)malloc(sizeof(int) * m);}for(int i = 0; i < n; i ++)   free(p[i]);free(p); 3.int *p  = (int *) malloc(sizeof(int) * n *m);free(p);