#include<iostream.h>
void swap(int *p1,int *p2)
{
    int p=0;
    p=*p1;
    *p1=*p2;
    *p2=p;
   
}
main()
{
   
    int a,b;
    int *pointer_1,*pointer_2;
    cin>>a>>b;
    pointer_1=&a;
    pointer_2=&b;
    if(a<b)
        swap(pointer_1,pointer_2);
    cout<<*pointer_1<<" "<<*pointer_2;
}

求高手指点，以上程序为何无法达到交换的效果