http://www.acmerblog.com/leetcode-lru-cache-lru-5745.html https://oj.leetcode.com/discuss/1188/java-is-linkedhashmap-considered-cheating http://docs.oracle.com/javase/6/docs/api/java/util/LinkedHashMap.html#removeEldestEntry(java.util.Map.Entry)…

同 HashMap 一样,LinkedHashMap 也是对 Map 接口的一种基于链表和哈希表的实现.实际上, LinkedHashMap 是 HashMap 的子类,其扩展了 HashMap 增加了双向链表的实现.相较于 HashMap 的迭代器中混乱的访问顺序,LinkedHashMap 可以提供可以预测的迭代访问,即按照插入序 (insertion-order) 或访问序 (access-order) 来对哈希表中的元素进行迭代. public class LinkedHashMap<K…

Redis(八)-- LRU Cache 在计算机中缓存可谓无所不在,无论还是应用还是操作系统中,为了性能都需要做缓存.然缓存必然与缓存算法息息相关,LRU就是其中之一.笔者在最先接触LRU是大学学习操作系统时的了解到的,至今已经非常模糊.在学习Redis时,又再次与其相遇,这里将这块内容好好梳理总结. LRU(Least Recently Used)是缓存算法家族的一员--最近最少使用算法,类似的算法还有FIFO(先进先出).LIFO(后进先出)等.因为缓存的选择一般都是用内存(RAM)或者计…

Design and implement a data structure for Least Recently Used (LRU) cache. It should support the following operations: get and set. get(key) - Get the value (will always be positive) of the key if the key exists in the cache, otherwise return -1. set…

esign and implement a data structure for Least Recently Used (LRU) cache. It should support the following operations: get and set. get(key) - Get the value (will always be positive) of the key if the key exists in the cache, otherwise return -1.set(k…

Problem Design and implement a data structure for Least Recently Used (LRU) cache. It should support the following operations: get and set. get(key) - Get the value (will always be positive) of the key if the key exists in the cache, otherwise return…

题目: Design and implement a data structure for Least Recently Used (LRU) cache. It should support the following operations: get and set. get(key) - Get the value (will always be positive) of the key if the key exists in the cache, otherwise return -1.…

http://www.acmerblog.com/leetcode-lru-cache-lru-5745.html acm之家的讲解是在是好,丰富 import java.util.LinkedHashMap; public class LRUCache { private int capacity; private LinkedHashMap<Integer,Integer> map=null; public LRUCache(int capacity) { this.capacity=ca…

设计并实现最近最久未使用(Least Recently Used)缓存. 题目描述: Design and implement a data structure for Least Recently Used (LRU) cache. It should support the following operations: get and set. get(key) - Get the value (will always be positive) of the key if the key ex…

update1:第二个实现,读操作不必要采用独占锁,缓存显然是读多于写,读的时候一开始用独占锁是考虑到要递增计数和更新时间戳要加锁,不过这两个变量都是采用原子变量,因此也不必采用独占锁,修改为读写锁.update2:一个错误,老是写错关键字啊,LRUCache的maxCapacity应该声明为volatile,而不是transient.      最简单的LRU算法实现,就是利用jdk的LinkedHashMap,覆写其中的removeEldestEntry(Map.Entry)方法即可,如下所…