关于产生随机数

代码如下：

# include <stdio.h># include <stdlib.h># include <time.h>int main ( ){    int i;    srand ((unsigned)time (NULL));    for (i = 0;i < 10;i++)    {        //srand ((unsigned)time (NULL));       int a = rand ( );       printf ("%d ", a);    }    printf ("\n");    getchar ( );    return 0;}