指针的定义、初始化和引用

#include
int main()
{
	int *p1, *p2, *p, a, b;
	scanf("%d %d", &a, &b);
	p1 = &a;
	p2 = &b;
	if (a
		p = p1;
		p1 = p2;
		p2 = p;
	}
	printf("a = %d, b= %d\n", a, b);
	printf("max=%d, min=%d\n", *p1, *p2);
	return 0;
}

#include
int main(){
	void swap(int * p1, int *p2);
	int a, b;
	int *point_1, *point_2;
	printf("Please input two numbers:\n");
	scanf("%d %d", &a, &b);
	point_1 = &a; 
	point_2 = &b;
	printf("a=%d, b=%d\n", a, b);
	printf("point1===%d, point2===%d\n",point_1,point_2);
	if (a
		swap(point_1, point_2);
	}
	printf("After exchanged:\n");
	printf("a=%d, b=%d\n", a, b);
	return 0;
}
 
void swap(int *p1, int *p2)
{
	int tmp;
	printf("function start: p1===%d, p2===%d\n",p1, p2);
	printf("function start: *p1===%d, *p2===%d\n",*p1, *p2);
	printf("tmp=%d\n",tmp);
	tmp = *p1;
	printf("tmp=%d\n",tmp);
	*p1 = *p2;
	*p2 = tmp;
	printf("function end: p1===%d, p2===%d\n",p1, p2);
	printf("function end: *p1===%d, *p2===%d\n",*p1, *p2);
}