new和delete的使用

一维数组：
----------alloc-----------
int *array;
array = new int [num];
----------delete---------
delete []array;

二维数组：
----------alloc-----------
int **array;
array = new int *[rows];
for(int i=0; i<rows; i++)
    array[i] = new int [cols];
----------delete---------
for(int i=0; i<rows; i++)
    delete []array[i];
delete []array;
array = NULL;