public int Dequeue()
{
if (head == null)
{
throw new InvalidOperationException();
}
var result = head.Value;
head = head.Next;
if (head == null)
{
tail = null;
}
return(result);
}
public void Enqueue(int value)
{
var item = new MyQueueItem {
Value = value
};
if (head == null)
{
head = tail = item;
}
else
{
tail.Next = item;
tail = item;
}
}