int main(void)
{
	int array[] = {1, 2, 3};
	int *pa = array;
	int *pb = array + 3;
	printf("sizeof(pa)...%d\n", sizeof(pa));
	printf("pb-pa...%d\n", pb - pa);
	printf("((unsigned)pb-(unsigned)pa)/sizeof(pa)...%d\n", ((unsigned)pb - (unsigned)pa) / sizeof(pa));
	return 0;
}