//更换a b的值，而p1和p2 的 值不变

void swap(int *p1, int *p2)
{
    int tmp;
    tmp = *p1;
    *p1 = *p2;
    *p2 = tmp;

}

 

int main() {

    int a, b;
    int *pointer_1, *pointer_2;
    printf("please input two numbers\n");
    scanf("%d %d", &a, &b);
    pointer_1 = &a;
    pointer_2 = &b;

    if (a<b)
    {
        swap(pointer_1, pointer_2);
    }

    printf("a = %d , b = %d\n", a, b);
    printf("Max = %d, Min = %d\n", *pointer_1, *pointer_2);

}