package Queue;

public interface Queue<E> {
  //獲取隊(duì)列中元素個(gè)數(shù)
  int getSize();

  //隊(duì)列中元素是否為空
  boolean isEmpty();

  //入隊(duì)列
  void enqueue(E e);

  //出隊(duì)列
  E dequeue();

  //獲取隊(duì)首元素
  E getFront();
}

package Queue;

public class ArrayQueue<E> implements Queue<E> {
  private DynamicArray<E> array;


  //構(gòu)造函數(shù)，傳入隊(duì)列的容量capacity構(gòu)造函數(shù)
  public ArrayQueue(int capacity) {
    array = new DynamicArray<E>(capacity);
  }

  //無(wú)參構(gòu)造函數(shù)，默認(rèn)隊(duì)列的容量capacity=10
  public ArrayQueue() {
    array = new DynamicArray<E>();
  }

  //獲取隊(duì)列中元素?cái)?shù)據(jù)是否為空
  @Override
  public boolean isEmpty() {
    return array.isEmpty();
  }

  //獲取隊(duì)列中元素個(gè)數(shù)
  @Override
  public int getSize() {
    return array.getSize();
  }

  //獲取隊(duì)列的容量
  public int getCapacity() {
    return array.getCapacity();
  }

  //入隊(duì)操作
  @Override
  public void enqueue(E e) {
    array.addLast(e);
  }

  //出隊(duì)操作
  @Override
  public E dequeue() {
    return array.removeFirst();
  }

  //獲取隊(duì)首元素
  @Override
  public E getFront() {
    return array.getFirst();
  }

  //重寫(xiě)object類(lèi)的toString方法
  @Override
  public String toString() {
    StringBuilder res = new StringBuilder();
    res.append("Queue:");
    res.append("front [");//體現(xiàn)左側(cè)為隊(duì)首
    for (int i = 0; i < array.getSize(); i++) {
      res.append(array.get(i));
      if (i != array.getSize() - 1) {
        res.append(",");
      }
    }
    res.append("] tail");//體現(xiàn)右側(cè)為隊(duì)尾
    return res.toString();
  }
}

package Queue;

public class TestMain {
  public static void main(String[] args) {
    ArrayQueue<Integer> queue = new ArrayQueue<Integer>();
    for (int i = 0; i < 10; i++) {
      queue.enqueue(i);
      System.out.println(queue);

      if(i%3==2){//每添加3個(gè)元素出隊(duì)列一個(gè)
        queue.dequeue();
        System.out.println(queue);
      }

    }

  }
}