数组实现环形队列

import java.util.Scanner;



public class RingQueue {
    public static void main(String[] args) {
        RingQueue integerRingQueue = new RingQueue(3);
        Scanner scanner = new Scanner(System.in);
        System.out.println("a:添加元素,b:获取元素,c:显示队列");
        char key = ' ';
        while (true){
            key = scanner.next().charAt(0);   // 接受第一个字符
            switch (key){
                case 'a':
                    System.out.println("输入一个数据:");
                    integerRingQueue.add(scanner.nextInt());
                    break;
                case 'b':
                    System.out.println(integerRingQueue.get());
                    break;
                case 'c':
                    integerRingQueue.getAll();
                default:
                   break;

            }

        }

    }

    private int leader;  // 起始位置
    private int tail;    // 结束位置,指向有效值的前一个位置
    private int maxSize;
    private int[] arr;

    public RingQueue(Integer maxSize){
        this.maxSize = maxSize;
        arr = new int[maxSize];
    }
    // 添加元素
    public void add(int value){
        if (isFull()){
            System.out.println("队列已满");
            return;
        }
        arr[tail] = value;
        tail = (tail+1)%maxSize;

    }

    // 弹出队列
    public Integer get(){
        if (isEmpty()){
            System.out.println("队列为空");
        }
        int value = arr[leader];
        arr[leader] = 0;
        leader = (leader+1)%maxSize;
        return value;
    }

    // 获取所有元素
    public void getAll(){
        if (isEmpty()){
            System.out.println("队列为空");
        }
        for (int i =leader; i < (tail+maxSize-leader)%maxSize; i++) {
            System.out.println("当前位置："+(i%maxSize)+",值为："+arr[i%maxSize]);
        }
    }

    // 判断队列是否为空
    public Boolean isEmpty(){
        return leader == tail;
    }

    // 判断队列是否满
    public Boolean isFull(){
        if (isEmpty()){
            return false;
        }
        return (tail+1)%maxSize == leader;
    }
}