指针计算（C语言程序设计：现代方法第12章练习2）

#include 

int main() {
	int *high, *middle, *low;
	int a[3] = {1, 2, 3};
	high  = &a[2];
	middle = &a[1];
	low   = &a[0];

	middle = (high - low) / 2 + low;
	

	printf("high=%p  n",   high);
	printf("*high=%d n",  *high);
	printf("middle=%pn", middle);
	printf("middle=%dn", *middle);
	printf("low=%p   n",    low);
	printf("*low=%d  n",   *low);
}

两个指向相同类型变量的指针不能相加，可以相减，差不再为指针变量