public ChildNode(int _val, ChildNode _prev, ChildNode _next, ChildNode _child)
{
val = _val;
prev = _prev;
next = _next;
child = _child;
}
public ChildNode Flatten(ChildNode head)
{
if (head == null)
{
return(head);
}
ChildNode current = head;
while (current != null)
{
if (current.child == null)
{
current = current.next;
}
else
{
ChildNode currentChild = current.child;
while (currentChild.next != null)
{
currentChild = currentChild.next;
}
currentChild.next = current.next;
if (current.next != null)
{
current.next.prev = currentChild;
}
current.next = current.child;
current.child.prev = current;
current.child = null;
}
}
return(head);
}