Linked List error!

Hi, I have the following code which compiles fine but does not produce any output..

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using namespace std;

#include<iostream>
#include<cstdio>
#include<conio.h>

struct node
{
  int data;
  struct node *link;
};

void append(struct node *,int);
void addatbeg(struct node *,int);
void addafter(struct node *,int,int);
void display(struct node *);
int count(struct node *);
void Delete(struct node *,int);

int main(void)
{
   struct node *p;
   p=NULL;
   cout<<"No of elements in the linked list:"<<count(p);
   append(p,14);
   append(p,30);
   append(p,25);
   append(p,42);
   append(p,17);
   
   display(p);
   
   addatbeg(p,999);
   addatbeg(p,888);
   addatbeg(p,777);
   
   display(p);
   
   addafter(p,7,0);
   addafter(p,2,1);
   addafter(p,5,99);
   
   display(p);
   
   cout<<"\nNo of elements in the linked list:"<<count(p);
   
   Delete(p,99);
   Delete(p,1);
   Delete(p,10);
   
   display(p);
   
   cout<<"\nNo of elements in the linked list:"<<count(p);
   cin.get();
   getch();
   return 0;
}

void append(struct node *q,int num)
{
     struct node *temp,*r;
     if(q==NULL)
     {
      temp= new struct node; 
      temp->data=num;
      temp->link=NULL;
      q=temp;
     }
     else
     {
      temp=q;
      
      while(temp->link!=NULL)
       temp=temp->link;
       
      r= new struct node;;
      r->data=num;
      r->link=NULL;
      temp->link=r;
     }
}

void addatbeg(struct node *q,int num)
{ 
     struct node *temp;
     
     temp= new struct node;;
     temp->data=num;
     temp->link=q;
     q=temp;
}

void addafter(struct node *q,int loc,int num)
{
     struct node *temp,*r;
     int i;
     
     temp=q;
     
     for(i=0;i<loc;i++)
     {
      temp=temp->link;
      if(temp==NULL)
      {
       cout<<"\nThere are less than"<<loc<<"elements in the list";
       return;
      }
     }
     r= new struct node;;
     r->data=num;
     r->link=temp->link;
     temp->link=r;
}

void display(struct node *q)
{
     cout<<"\n";
     
     while(q!=NULL)
     {
       cout<<q->data;
       q=q->link;
     }
}

int count(struct node *q)
{
    int c=0;
    
    while(q!=NULL)
    {
      q=q->link;
      c++;
    }
    return c;
}

void Delete(struct node *q,int num)
{
     struct node *old,*temp;
     
     temp=q;
     while(temp!=NULL)
     {
       if(temp->data==num)
       {
         if(temp==q)
          q=temp->link;
         else
          old->link=temp->link;
          
         delete temp;
         return;
        }
        
        else
        {
          old=temp;
          temp=temp->link;
        }
      }
      cout<<"\nElement"<<num<<"not found";
}


Please help me out!!!
The problem is that p keep pointing to NULL. Try this
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//void append(struct node *q,int num)
void append(struct node * &q,int num)
node *append(struct node *q,int num)
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