两个有序链表合并为一个链表

#include"iostream.h"
#include"string.h"

struct Node
{
 int date;
 Node* next;
};

Node* create();
Node* combin(Node* head1, Node* head2);
void print(Node* head);

void main()
{
 Node* phead1, *phead2,*pcon;
 phead1 = create();
 print(phead1);
 phead2 = create();
 print(phead2);
 pcon = combin(phead1, phead2);
 cout<<"合并后:"<<endl;
 print(pcon);

}

Node* create()  //
{
 Node* head, *phead, *p1;

 head = new Node;
 head->next = NULL;
 head->date = NULL;
 phead = head;
 int data;
 cin>>data;
 while(data)
 {
  p1 = new Node;
  p1->date = data;
  phead->next  = p1;
  phead = p1;
  phead->next = NULL;
  cin>>data;
 }
 return head;
}

Node* combin(Node* head1, Node* head2)//链表合并
{
 Node*p1,*p2,*p,*head,*ptemp;
 if(head1->next ->date <= head2->next ->date )
 {
  head = head1;
  p2 = head2->next;
  p1 = head1->next;
 }
 else
 {
        head = head2;
  p1 = head1->next ;
  p2 = head2->next ;
 }
 p  = head;
    while(p1 != NULL && p2 != NULL)
 {
  if(p1->date > p2->date )
  {
   p->next = p2;
   p = p2;
   p2 = p2->next ;
  }
  else if(p1->date < p2->date )
  {
   p->next = p1;
   p = p1;
   p1 = p1->next ;
  }
  else if(p1->date == p2->date )
  {
   p->next =p1;
   p1=p1->next ;
   p=p->next ;
   ptemp= p2;
   p2=p2->next ;
   delete ptemp;
   ptemp = NULL;
  }
 }
 if(p1 == NULL)
 {
  p->next = p2;
 }
 else
 {
  p->next = p1;
 }
 return head;

}

void print(Node* head)
{
 Node* ptemp = head;
 while(ptemp->next != NULL)
 {
  ptemp = ptemp -> next ;
  cout<<ptemp->date <<" ";
 }
 cout<<endl;
}