leetcode--003 LRU cache

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" alt="" />
 1 package leetcode;

 import java.util.HashMap;
 import java.util.Map;

 class Node{
     int key;
     int value;
     Node pre;
     Node next;
     Node(int key,int value){
         this.key=key;
         this.value=value;
         this.pre=null;
         this.next=null;
     }
 }
 class CacheList{
     private Node head;
     private Node tail;
     CacheList(int capacity){
         head = new Node(0,0);
         tail = new Node(0,0);
         head.next=tail;
         tail.pre=head;
     }
     public void insertFirst(Node n){
         n.next=head.next;
         head.next.pre=n;
         head.next=n;
         n.pre=head;

     }
     public Node removeLast(){
         Node re = tail.pre;
         tail.pre.pre.next=tail;
         tail.pre=tail.pre.pre;
         return re;
     }
     public void shiftToFirst(Node n){
         n.pre.next=n.next;
         n.next.pre=n.pre;
         insertFirst(n);
     }
 }

 public class LRUCache {
      Map<Integer,Node> map;
      CacheList cacheList;
      int capacity;
     public LRUCache(int capacity) {
         map = new HashMap<Integer,Node>();
         cacheList= new CacheList(capacity);
         this.capacity=capacity;
     }

     public int get(int key) {
         if(map.get(key)==null)
         return -1;
         else {
             Node n= (Node) map.get(key);
             cacheList.shiftToFirst(n);
             return n.value;
         }
     }

     public void set(int key, int value) {
         if(map.containsKey(key)){
              Node come= (Node) map.get(key);
              come.value=value;
              cacheList.shiftToFirst(come);;
         }else{
             if(map.size()==capacity){
                 Node old=cacheList.removeLast();
                 map.remove(old.key);

             }
             Node nn=new Node(key,value);
             cacheList.insertFirst(nn);
             map.put(key, nn);
         }

     }
     public static void main(String[] args){
         LRUCache l = new LRUCache(1);
         l.set(2, 1);
         System.out.println(l.get(2));
         l.set(3, 2);
         System.out.println(l.get(2));
         System.out.println(l.get(3));

     }
 }