//remove a node from LinkedList
private void removeNode(Node node){
Node curr = node;
Node pre = curr.pre;
Node post = curr.next;
if (pre != null)
pre.next = post;
else
head = post;
if (post != null)
post.pre = pre;
else
end = pre;
}
//set a new node to the head of LinkedList
private void setHead(Node node){
node.next = head;
node.pre = null;
if (head != null)
head.pre = node;
head = node;
if (end == null) //if this node is the first of list
end = node;
}
//set key/value pair
public void Set(int key, int value)
{
if (dic.ContainsKey (key)) {
Node curr = dic [key];
curr.value = value;
removeNode (curr);
setHead (curr);
} else {
Node newNode = new Node (value,key);
if (len == capacity) {
Node last = end;
removeNode (last);
dic.Remove (last.key);
dic.Add (key, newNode);
setHead (newNode);
} else {
dic.Add (key, newNode);
setHead (newNode);
len++;
}
}
}