public object First()
{
_iter = null;
if (_head == null) // Liste ist Leer
{
return(null);
}
_iter = _head;
return(_iter.data);
}
public void AddHead(object aObj)
{
CsLink elem = new CsLink(aObj);
// im allgemeinen Fall passt das mit der _tail
if (_head == null) // spezialfall Liste ist leer
{
_head = _tail = elem;
}
else
{
elem.next = _head;
_head = elem;
}
}
public object Next()
{
if (_iter == null)
{
return(null);
}
_iter = _iter.next;
if (_iter == null)
{
return(null);
}
return(_iter.data);
}
public object At(int aPos)
{
CsLink it = _head;
for (int i = 1; i <= aPos; i++)
{
if (i == aPos)
{
return(it.data);
}
it = it.next;
}
return(null);
}
public void AddTail(object aObj)
{
CsLink it = new CsLink(aObj);
CsLink elem = _tail;
if (_tail == null)
{
_tail = _head = it;
}
else
{
elem.next = it;
_tail = elem.next;
}
}
public object RemoveHead()
{
if (_head == null) // Liste ist leer
{
return(null);
}
if (_head == _tail) // Nur ein Elemt
{
_tail = null;
}
//head und tail müssen nach dem Remove wieder stimmen
_head = _head.next;
return(null);
}
public object RemoveTail()
{
CsLink it = _head;
if (_head == _tail)
{
_head = _tail = null;
}
while (true)
{
if (it.next == _tail) // Vorgänger gefunden
{
break;
}
it = it.next; // iter++
}
_tail = it;
it.next = null;
return(_tail);
}
public void InsertSorted(object aObj, IComparer aCmp)
{
CsLink iter;
CsLink prev;
CsLink elem = new CsLink(aObj);
iter = prev = _head;
if (First() == null)
{
iter = elem;
_head = prev = _tail = elem;
return;
}
while (iter != null)
{
if (aCmp.Compare(iter.data, aObj) > 0)
{
if (iter == _head)
{
elem.next = _head;
_head = elem;
}
else
{
prev.next = elem;
elem.next = iter;
}
return;
}
prev = iter;
iter = iter.next;
}
_tail.next = elem;
_tail = elem;
}
public object Find(Object aTestObject, IComparer aCmp)
{
CsLink it = _head;
int sol;
while (First() != null)
{
sol = aCmp.Compare(it.data, aTestObject);
if (sol == 0)
{
return(it.data);
}
if (it.next == null)
{
return(null);
}
it = it.next; // iter++
}
return(null);
}
public void Clear()
{
_iter = _head = _tail = null;
}