private static Cup Initialize(IEnumerable <int> values, Dictionary <int, Cup> cache)
{
Cup head = null;
Cup prev = null;
foreach (int value in values)
{
var current = new Cup(value);
if (head == null)
{
head = current;
}
if (prev != null)
{
current.AttachAfter(prev);
}
prev = current;
if (cache != null)
{
cache.Add(value, current);
}
}
if (prev != null)
{
head.AttachAfter(prev);
}
return(head);
}