Reversing a Linked List in C

#include <stdio.h>
#include <conio.h>
#include <malloc.h>
#include <windows.h>
/* structure containing a data part and link part */
struct node
{
 int data ;
 struct node *link ;
} ;
void addatbeg ( struct node **, int ) ;
void reverse ( struct node ** ) ;
void display ( struct node * ) ;
int count ( struct node * ) ;
int main( )
{
 struct node *p ;
 p = NULL ;  /* empty linked list */
 addatbeg ( &p, 7 ) ;
 addatbeg ( &p, 43 ) ;
 addatbeg ( &p, 17 ) ;
 addatbeg ( &p, 3 ) ;
 addatbeg ( &p, 23 ) ;
 addatbeg ( &p, 5 ) ;
 system ( "cls" ) ;
 display ( p ) ;
 printf ( "No. of elements in the linked list = %d\n", count ( p ) ) ;
 reverse ( &p ) ;
 display ( p ) ;
 printf ( "No. of elements in the linked list = %d\n", count ( p ) ) ;
 return 0 ;
}
/* adds a new node at the beginning of the linked list */
void addatbeg ( struct node **q, int num )
{
 struct node *temp ;
 /* add new node */
 temp = ( struct node * ) malloc ( sizeof ( struct node ) ) ;
 temp -> data = num ;
 temp -> link = *q ;
 *q = temp ;
}
void reverse ( struct node **x )
{
 struct node *q, *r, *s ;
 q = *x ;
 r = NULL ;
 /* traverse the entire linked list */
 while ( q != NULL )
 {
  s = r ;
  r = q ;
  q = q -> link ;
  r -> link = s ;
 }
 *x = r ;
}
/* displays the contents of the linked list */
void display ( struct node *q )
{
 /* traverse the entire linked list */
 while ( q != NULL )
 {
  printf ( "%d ", q -> data ) ;
  q = q -> link ;
 }
 printf ( "\n" ) ;
}
/* counts the number of nodes present in the linked list */
int count ( struct node * q )
{
 int c = 0 ;
 /* traverse the entire linked list */
 while ( q != NULL )
 {
  q = q -> link ;
  c++ ;
 }
 return c ;
}