求大神，这个程序最后多输出了一次，想了很久也没想出来[em06]请问如何改呀

#include<iostream>
using namespace std;
typedef int Elem;
typedef struct aaaa
{
    Elem data;
    struct aaaa *next;
}lian;
void main()
{

    lian *head,*s,*p;
    int x;
    head=(lian*)malloc(sizeof(lian));
    p=head;
    while(x!=0)
    {
        cin>>x;
        s=(lian*)malloc(sizeof(lian));
        s->data=x;
        p->next=s;
        p=s;
   
    }
    head=head->next;
    free(p);
    while(head->next!=NULL)
    {
          cout<<head->data<<endl;
               head=head->next;
   
    }
   
}