指针作为形参问题

void swap1(int *p1,int *p2)
{
    int *temp;
    temp = p1;
    p1 = p2;
    p2 = p_temp;
}

int main()
{

    int a = 10,b = 20;
    printf("交换之前：%d,%d\n",a,b);
    printf("swap1交换a-b之前a和b的地址：%p,%p\n",&a,&b);

    swap1(&a,&b);
    printf("交换后：%d,%d\n",a,b);
    printf("swap1交换a-b之后a和b的地址：%p,%p\n",&a,&b);

}

void swap2(int *p1,int *p2)
{
    int temp;
    temp = *p1;
    *p1 = *p2;
    *p2 = temp;

}



int main()
{

        int c = 3,d = 4;
        printf("swap2交换c-d之前：%d,%d\n",c,d);

        swap2(&c,&d);
        printf("swap2交换c-d之后：%d,%d\n",c,d);

}