LRU隊列的實現

標籤：

package Queue;public class LRUQueue<T> {private T[] queue = null;private int num; //隊列中元素的個數/** * 指定大小構造隊列 * @param capacity */public LRUQueue(int capacity) {this.num = 0;queue = (T[]) new Object[capacity];}/** * 判斷隊列是為空白 */public boolean isEmpty() {return num==0? true:false;}/** * 判斷隊列是否已滿 */public boolean isFull() {return num==queue.length? true:false;}/** * 尋找某值在隊列中的索引,沒有則返回-1 */public int searchIndex(T value) {for(int i=0; i<num; i++) {if(queue[i]==value)return i;}return -1;}/** * 進隊列 */public void push(T value) {int Vindex = this.searchIndex(value);//隊列中沒有valueif(Vindex==-1) {//判斷隊列是否滿boolean isfull = this.isFull();if(isfull==false) {queue[num++] = value;}//滿else {this.pop();queue[num++] = value;}}//隊列中有valueelse {T temp = queue[Vindex];for(int i=Vindex; i<num; i++) {queue[i] = queue[i+1];}queue[num-1] = value;}}/** * 出隊列 * @param args */public T pop() {T popValue = queue[0];for(int i=0; i<num; i++) {queue[i] = queue[i+1];}queue[num--] = null;return popValue;}/** * 列印佇列資訊 * @param args */public void print() {for(int i=0; i<this.num; i++) {System.out.print(queue[i] + " ");}System.out.println();}public static void main(String[] args) {LRUQueue<Integer> lru_q = new LRUQueue<Integer>(5);lru_q.push(5);lru_q.print();lru_q.push(3);lru_q.print();lru_q.push(5);lru_q.print();lru_q.push(4);lru_q.print();lru_q.push(3);lru_q.print();}}

LRU是Least Recently Used 近期最少使用演算法。
  LRU隊列即把隊列中最近最少使用的資料淘汰掉。

LRU隊列的實現