package DataStructure;

import java.util.Arrays;

/**
 * @author: Inki
 * @email: inki.yinji@qq.com
 * @create: 2020 1022
 * @last_modify: 2020 1023
 */

public class MyArrayQueue<AnyType> {

 /**
  * The default max size of my array queue.
  */
 private final int DEFAULT_MAX_SIZE = 10;

 /**
  * The max size of my array queue.
  */
 private int maxSize;

 /**
  * The front of my array queue.
  */
 private int front;

 /**
  * The rear of my array queue.
  */
 private int rear;

 /**
  * Using array to simulate queue.
  */
 private AnyType[] arrQueue;

 /**
  * The first constructor.
  */
 public MyArrayQueue() {
  this(DEFAULT_MAX_SIZE);
 }//Of the first constructor

 /**
  * The second constructor.
  */
 public MyArrayQueue(int paraMaxSize) {
  maxSize = paraMaxSize + 1;
  arrQueue = (AnyType[]) new Object[maxSize];
  front = 0;
  rear = 0;
 }//Of the second constructor

 /**
  * Queue is full?
  * @return:
  *  True if full else false.
  */
 public boolean isFull() {
  return (rear + 1) % maxSize == front;
 }//Of isFull

 /**
  * Queue is empty?
  * @return:
  *  True if empty else false.
  */
 public boolean isEmpty() {
  return front == rear;
 }//Of isEmpty

 /**
  * Add element.
  * @param:
  *  paraVal:
  *   The given value.
  */
 public void add(AnyType paraVal) {
  if(isFull()) {
   System.out.println("The queue is full.");
   return;
  }//Of if
  arrQueue[rear] = paraVal;
  rear = (rear + 1) % maxSize;
 }//Of add

 /**
  * Pop element.
  */
 public AnyType pop() {
  if (isEmpty()) {
   throw new RuntimeException("The queue is full.");
  }//Of if
  AnyType retVal = arrQueue[front];
  front = (front + 1) % maxSize;
  return retVal;
 }//of pop

 /**
  * Display array queue.
  */
 public void display() {
  if (isEmpty()) {
   System.out.println("The queue is empty.");
   return;
  }//Of if

  System.out.print("The queue is: [");
  int i = front;
  while (i != (rear + maxSize- 1) % maxSize) {
   System.out.printf("%s, ", arrQueue[i]);
   i = (i + 1) % maxSize;
  }//Of while
  System.out.printf("%s]", arrQueue[rear - 1]);
 }//Of display

 /**
  * Get current size of my array queue.
  */
 public int getSize() {
  return (rear - front + maxSize) % maxSize + 1;
 }//Of getSize

 /**
  * The main
  **/
 public static void main(String[] args) {
  MyArrayQueue <Integer> testArrayQueue = new MyArrayQueue<>(3);
  testArrayQueue.add(1);
  testArrayQueue.add(2);
  testArrayQueue.add(4);
  testArrayQueue.pop();
  testArrayQueue.display();
 }//Of main

}//Of MyArrayQueue