public void Put(int key, int value)
{
if (capacity == 0)
{
return;
}
var node = GetNode(key);
if (node == null)
{
if (count == capacity)
{
var exHeadKey = head.key;
head = head.next;
if (head == null)
{
tail = null;
}
else
{
head.prev = null;
if (head == tail)
{
tail.prev = null;
}
}
dic.Remove(exHeadKey);
count--;
}
node = new DoublyListNode(key, value);
if (head == null && tail == null)
{
head = node;
tail = node;
}
else
{
tail.next = node;
node.prev = tail;
tail = node;
}
dic.Add(key, node);
count++;
}
else
{
node.val = value;
dic[key] = node;
MoveToTail(node);
}
}
private void MoveToTail(DoublyListNode node)
{
if (node == null || node.next == null)
{
return; //it is tail already
}
if (node.prev == null)
{
head = node.next;
node.next.prev = null;
}
else
{
node.prev.next = node.next;
node.next.prev = node.prev;
}
tail.next = node;
node.prev = tail;
tail = node;
}
