ItemType BinaryNodeTree<ItemType>::getRootData() const throw(PrecondViolatedExcep)
{
if (isEmpty())
throw PrecondViolatedExcep("getRootData() called with empty tree.");
return rootPtr->getItem();
} // end getRootData
ItemType ArrayMaxHeap<ItemType>::peekTop() const throw(PrecondViolatedExcep)
{
if (isEmpty())
throw PrecondViolatedExcep("Attempted peek into an empty heap.");
return items[0];
} // end peekTop
ItemType LinkedQueue<ItemType>::peekFront() const throw(PrecondViolatedExcep)
{
if (isEmpty())
throw PrecondViolatedExcep("getFront() called with empty queue.");
// Queue is not empty; return front
return frontPtr->getItem();
} // end peekFront
void LinkedList<ItemType>::setEntry(int position, const ItemType& newEntry) throw(PrecondViolatedExcep)
{
// Enforce precondition
bool ableToSet = (position >= 1) && (position <= itemCount);
if (ableToSet)
{
Node<ItemType>* nodePtr = getNodeAt(position);
nodePtr->setItem(newEntry);
}
else
{
string message = "setEntry() called with an invalid position.";
throw(PrecondViolatedExcep(message));
} // end if
} // end setEntry
ItemType LinkedList<ItemType>::getEntry(int position) const throw(PrecondViolatedExcep)
{
// Enforce precondition
bool ableToGet = (position >= 1) && (position <= itemCount);
if (ableToGet)
{
Node<ItemType>* nodePtr = getNodeAt(position);
return nodePtr->getItem();
}
else
{
string message = "getEntry() called with an empty list or ";
message = message + "invalid position.";
throw(PrecondViolatedExcep(message));
} // end if
} // end getEntry
