c04p193.txt

Data Abstraction & Problem Solving with C++源码

bool List::isEmpty() const
{
   return size == 0;

}  // end isEmpty

int List::getLength() const
{
   return size;
}  // end getLength

List::ListNode *List::find(int index) const
// --------------------------------------------------
// Locates a specified node in a linked list.
// Precondition: index is the number of the
// desired node.
// Postcondition: Returns a pointer to the desired
// node. If index < 1 or index > the number of
// nodes in the list, returns NULL.
// --------------------------------------------------
{
   if ( (index < 1) || (index > getLength()) )
      return NULL;

   else  // count from the beginning of the list
   {  ListNode *cur = head;
      for (int skip = 1; skip < index; ++skip)
         cur = cur->next;
      return cur;
   }  // end if
}  // end find