SOURCE FILE: createList.cpp
// Creates a linked list from the data in a text
// file. The pointer variables Head and Tail are
// initially NULL. FileName is a string that names
// an existing external text file.
ifstream F(FileName);
int NextItem;
if (F >> NextItem) // is file empty?
{ // file not empty:
Head = new node;
// add the first integer to the list
Head->Item = NextItem;
Head->Next = NULL;
Tail = Head;
// add remaining integers to linked list
while (F >> NextItem)
{ Tail->Next = new node;
Tail = Tail->Next;
Tail->Item = NextItem;
Tail->Next = NULL;
} // end while
} // end if
F.close();
// Assertion: Head points to the first node of the
// created linked list; Tail points to the last
// node. If the file is empty, Head and Tail are
// NULL (list is empty).