java实现的顺序队列

定义接口

package 队列;
/*
 * 
 */
public interface Queue<E> {
	public int getSize();
	public boolean isEmpty();
	public void enqueue(E e);
	public E dequeue();
	public E getFront();
	public E getRear();
	public void clear();
}

接口的实现

package 队列;
/*
 * 特殊的顺序表，
 * 先进先出，在表尾入队，表头出队。
 */
import 顺序表.ArrayList;

public class ArrayQueue<E> implements Queue<E> {
	private ArrayList<E> queue;

	public ArrayQueue(int Capacity) {
		queue = new ArrayList<>(Capacity);
	}

	public ArrayQueue() {
		this(10);
	}

	@Override
	public String toString() {
		StringBuilder str = new StringBuilder("[");
		if (isEmpty()) {
			str.append(String.format("]*%d/%d", getSize(), getCapacity()));
		} else {
			for (int i = 0; i < getSize(); i++) {
				if (i != getSize() - 1) {
					str.append(queue.get(i) + ",");
				} else {
					str.append(queue.get(i) + "]");
				}

			}
			str.append(String.format("*%d/%d", getSize(), getCapacity()));
		}

		return str.toString();
	}

	@Override
	public int getSize() {
		// TODO Auto-generated method stub
		return queue.getSize();
	}

	@Override
	public boolean isEmpty() {
		// TODO Auto-generated method stub
		return queue.isEmpty();
	}

	@Override
	public void enqueue(E e) {
		// TODO Auto-generated method stub
		queue.addLast(e);
	}

	@Override
	public E dequeue() {
		// TODO Auto-generated method stub
		return queue.removeFirst();
	}

	@Override
	public E getFront() {
		// TODO Auto-generated method stub
		return queue.getFirst();
	}

	@Override
	public E getRear() {
		// TODO Auto-generated method stub
		return queue.getLast();
	}

	@Override
	public void clear() {
		// TODO Auto-generated method stub
		queue.clear();
	}

	public int getCapacity() {
		return queue.getCapacity();
	}

}

测试

package 队列;

public class TestArrayQueue {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		ArrayQueue<Integer> q = new ArrayQueue<Integer>();
		System.out.println(q);
		q.enqueue(886);
		q.enqueue(888);
		q.enqueue(888);
		q.enqueue(888);
		q.enqueue(888);
		q.enqueue(888);
		q.enqueue(888);
		q.enqueue(885);
		q.enqueue(888);
		q.enqueue(854);
		q.enqueue(128);
		System.out.println(q);
		q.dequeue();
		System.out.println(q);
	}
}

测试结果

[]*0/10
[886,888,888,888,888,888,888,885,888,854,128]*11/20
[888,888,888,888,888,888,885,888,854,128]*10/20