关于产生随机数
程序代码：# 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;
}srand ((unsigned)time (NULL));放在循环外能产生10个不同的随机数，放在循环内确是10个相同的随机数，这是为啥？
