【算法导论】用两个堆实现栈

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好久没写java了，用java实现一个吧；

用两个堆实现栈：

import java.util.Queue;import java.util.concurrent.ArrayBlockingQueue;interface Stacked<E> {void push(E newElement);E pop();}class OutofRangeException extends RuntimeException {/** *  */private static final long serialVersionUID = 1L;public OutofRangeException(String message) {        super(message);    }}// 用队列实现栈public class Stack<E> implements Stacked<E> {protected static final int QUEUE_SIZE = 100;protected static final int TOTAL_SIZE = 2 * QUEUE_SIZE;public static final int STACK_SIZE = QUEUE_SIZE;protected Queue<E> queue = new ArrayBlockingQueue<E>(QUEUE_SIZE);protected Queue<E> backupQueue = new ArrayBlockingQueue<E>(QUEUE_SIZE);public Stack() { }@Overridepublic void push(E newElement) {if (this.queue.size() >= QUEUE_SIZE) throw new OutofRangeException("Out of Range");this.queue.add(newElement);}@Overridepublic E pop() {E result = popQueueToBackupQueue();;popBackupQueueToQueue();return result;}// 以倒序复制到backupQueue中protected E popQueueToBackupQueue() {while (queue.size() != 1) {backupQueue.add(queue.remove());}return queue.remove();}// 以倒序复制到queue中protected void popBackupQueueToQueue() {while (!backupQueue.isEmpty()) {queue.add(backupQueue.remove());}}}

用两个栈实现堆的做法类似上面；

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