public kiwinode(kiwinode <T> childl, kiwinode <T> childr, T key, kiwinode <T> parent)
{
this.childl = childl;
this.childr = childr;
this.key = key;
this.parent = parent;
}
public void insert(T value)
{
count++;
kiwinode <T> current = root;
if (root == null)
{
root = new kiwinode <T>(null, null, value, null);
}
while (current != null)
{
if (value.CompareTo(current.key) < 0)
{
if (current.childl == null)
{
current.childl = new kiwinode <T>(null, null, value, current);
break;
}
current = current.childl;
}
else
{
if (current.childr == null)
{
current.childr = new kiwinode <T>(null, null, value, current);
break;
}
current = current.childr;
}
}
}
private kiwinode <T> max(kiwinode <T> node)
{
while (node.childr != null)
{
node = node.childr;
}
return(node);
}
private kiwinode <T> min(kiwinode <T> node)
{
while (node.childl != null)
{
node = node.childl;
}
return(node);
}
public bool deletion(T val)
{
kiwinode <T> todel = finder(val);
if (todel == null)
{
return(false);
}
delete(todel);
count--;
return(true);
}
private void delete(kiwinode <T> node)
{
if (node.childcount() == 2)
{
kiwinode <T> candy = min(node.childr);
node.key = candy.key;
node = candy;
}
if (node.childcount() == 1)
{
kiwinode <T> child;
if (node.childl == null)
{
child = node.childr;
}
else
{
child = node.childl;
}
if (node == root)
{
root = child;
}
else if (node.ischildr())
{
node.parent.childr = child;
}
else if (!node.ischildr())
{
node.parent.childl = child;
}
}
if (node.childcount() == 0)
{
if (node == root)
{
root = null;
}
else if (node.ischildr())
{
node.parent.childr = null;
}
else if (!node.ischildr())
{
node.parent.childl = null;
}
}
}
public IEnumerable <T> preorder()
{
LinkedList <T> nodes = new LinkedList <T>();
bool finished = false;
bool same;
while (true)
{
kiwinode <T> current = root;
same = false;
for (int i = 0; i < nodes.Count; i++)
{
LinkedListNode <T> node = nodes.First;
if (node.Value.CompareTo(current.key) == 0)
{
same = true;
}
}
if (current.childl != null && !same)
{
nodes.AddLast(current.key);
current = current.childl;
}
else if (current.childr != null && !same)
{
nodes.AddLast(current.key);
current = current.childr;
}
else if (current.parent == null)
{
break;
}
else
{
current = current.parent;
}
}
return(nodes);
}
private kiwinode <T> finder(T key)
{
kiwinode <T> current = root;
while (current != null)
{
int comp = key.CompareTo(current.key);
if (comp < 0)
{
current = current.childl;
}
if (comp > 0)
{
current = current.childr;
}
if (comp == 0)
{
return(current);
}
}
return(null);
}