public void AddFront(DLLNode node)
{
node.next = DummyTail;
node.prev = DummyTail.prev;
DummyTail.prev.next = node;
DummyTail.prev = node;
}
public LRUCache(int capacity)
{
Size = 0;
Capacity = capacity;
DummyHead = new DLLNode(0, 0);
DummyTail = new DLLNode(0, 0);
DummyTail.prev = DummyHead;
DummyHead.next = DummyTail;
map = new Dictionary <int, DLLNode>();
}
public int GetValue(int key)
{
if (!map.ContainsKey(key))
{
return(-1);
}
DLLNode node = map[key];
RemoveLast(node);
AddFront(node);
return(node.val);
}
public void SetValue(int key, int value)
{
if (map.ContainsKey(key))
{
DLLNode node = map[key];
node.val = value;
RemoveLast(node);
AddFront(node);
}
else
{
if (Size == Capacity)
{
map.Remove(DummyHead.next.key);
RemoveLast(DummyHead.next);
Size--;
}
DLLNode node = new DLLNode(key, value);
map.Add(key, node);
AddFront(node);
Size++;
}
}
public void RemoveLast(DLLNode node)
{
node.next.prev = node.prev;
node.prev.next = node.next;
}