c언어 오류 해결이 어렵습니다.

#include <stdio.h>
#include <stdlib.h> 
 
typedef struct listNode *listPointer;
typedef struct {
    int data;
    listPointer link;
}listNode;
 
listPointer search(listPointer ptr, int key)
{  /* determine if key is in the list */
  listPointer temp;
  for (temp = ptr; temp; temp = temp->link) 
        if (temp->item.key == key) return temp;
  return NULL;
}
 
listPointer Deletelist(listPointer ptr, int searchNum, int *found)
{/* search for an  element, delete it if it is in the list
   The pointer to the head of the list is returned in the function name,
   the value of found will be 1, if the entry was deleted, and 0
   otherwise */
 
    listPointer position,temp;
    position = search(ptr,searchNum, found);
    if (*found) {
      if (!position) {
 /* entry was  found at the head of the list, delete
      the current head pointer, and return the link field
      as the new pointer to the head of the list */
 
    	   temp = ptr->link;
    	   free(ptr);
    	   return temp;
       }
       else {
 
 /* entry was not at the head of the list, change the
       link pointers and free the storage */
 
      	   temp = position->link;
      	   position->link =  temp->link;
      	   free(temp);
      	   return ptr;
	}
      }
      else
/* item was not found in the list, return the pointer to
	 the head of the list */
 
      return ptr;
}
 
 
int main (void)
{
int num, found;
listPointer ptr;
 
printf("삭제하고 싶은 숫자를 입력하세요: ");
scanf("%d",&num);
ptr = Deletelist(ptr,num,&found);
if (found)
		  printf("입력한 숫자가 삭제되었습니다.\n");
else
		  printf("입력한 숫자가 리스트에 없습니다.\n");
 
}