// CircularQueue
public class CircularQueue {
  private int[] queue;
  private int front;
  private int rear;
  private int size;
  private int capacity;

  // 원형 큐 초기화
  public CircularQueue(int capacity) {
    this.capacity = capacity;
    queue = new int[capacity];
    front = 0;
    rear = -1;
    size = 0;
  }

  // 큐에 요소 추가
  public void enqueue(int element) {
    if (isFull()) {
      System.out.println("Queue is full");
      return;
    }

    rear = (rear + 1) % capacity;
    queue[rear] = element;
    size++;
  }

  // 큐에서 요소 제거 및 반환
  public int dequeue() {
    if (isEmpty()) {
      System.out.println("Queue is empty");
      return -1;
    }
    int element = queue[front];
    front = (front + 1) % capacity;
    size--;
    return element;
  }

  // 큐의 앞쪽 요소 반환
  public int peek() {
    if (isEmpty()) {
      System.out.println("Queue is empty");
      return -1;
    }
    return queue[front];
  }

  // 큐가 비어 있는지 확인
  public boolean isEmpty() {
    return size == 0;
  }

  // 큐가 가득 찼는지 확인
  public boolean isFull() {
    return size == capacity;
  }

  // 큐의 크기 반환
  public int getSize() {
    return size;
  }
}

// Main
public class Main {

  public static void main(String[] args) {
    CircularQueue circularQueue = new CircularQueue(5);

    circularQueue.enqueue(1);
    circularQueue.enqueue(2);
    circularQueue.enqueue(3);
    circularQueue.enqueue(4);
    circularQueue.enqueue(5);

    System.out.println("Dequeue: " + circularQueue.dequeue());
    System.out.println("Dequeue: " + circularQueue.dequeue());

    circularQueue.enqueue(6);
    circularQueue.enqueue(7);

    System.out.println("Peek: " + circularQueue.peek());

    while (!circularQueue.isEmpty()) {
      System.out.println("Dequeue: " + circularQueue.dequeue());
    }
  }
}

// 출력
/*
Dequeue: 1
Dequeue: 2
Peek: 3
Dequeue: 3
Dequeue: 4
Dequeue: 5
Dequeue: 6
Dequeue: 7
 */