数组实现循环队列

/**
 * 使用size控制 end 和 start
 * @author 小纸人
 *
 */
public class MyLoopQueue {

	private Integer[] arr;
	private Integer start;
	private Integer end;
	private Integer size;
	
	public MyLoopQueue(int initSize) {
		arr = new Integer[initSize];
		start = end = size = 0;
	}
	
	public void push(int num) {
		if(size == arr.length)
			throw new RuntimeException("循环队列已满");
		size++;
		arr[end] = num;
		end = end == arr.length - 1 ? 0 : end + 1;
	}
	
	public Integer pop() {
		if(size == 0)
			throw new RuntimeException("循环队列已空");
		size--;
		int temp = start;
		start = start == arr.length - 1 ?  0 : start + 1;
		return arr[temp];
	}
	//获取队头
	public Integer peek() {
		if(size == 0)
			return null;
		return arr[start];
	}
	
	public static void main(String[] args) {
		int[] arr = {3,2,5,8,4,7};
		MyLoopQueue loopQueue = new MyLoopQueue(arr.length);
		for (int i = 0; i < arr.length; i++) {
			loopQueue.push(arr[i]);
		}
		//
		System.out.println("循环队列输出为：");
		for (int i = 0; i < arr.length; i++) {
			System.out.print(loopQueue.pop()+" ");
		}
		//System.out.println("peek："+loopQueue.peek());
	}
	
}