用数组实现队列

第一个只能用一次先是创造数据结构（最大值，俩索引，存数据的），用构造器初始化，判断空或者满，增加，取出

package com.sparseArray.queue;

//使用数据模拟队列
class ArrayQueue{
    private int maxSize;
    private int front;
    private int rear;
    private int arr[];

    //创建构造器(用来初始化)
    public ArrayQueue(int arrmaxSize){
        maxSize = arrmaxSize;
        arr = new int[maxSize];
        front = -1;//指向队列头的前一个位置
        rear = -1;//指向队尾
    }

    public boolean isFull(){
        return  rear == maxSize - 1;
    }
    public  boolean isEmpty(){
        return rear  == front;
    }

    public void addQueue(int n){
        if (isFull()){
            System.out.println("队列已满");
            return;
        }
        rear++;//rear后移
        arr[rear] = n;
    }
    //获取队列数据，出队列
    public int getQueue(){
        if(isEmpty()){
            throw new RuntimeException("队列空，无数据");
        }
        front++;//front后移
        return arr[front];
    }
    //显示队列所有数据
    public void showQueue(){
        if(isEmpty()){
            System.out.println("队列空，无数据");
            return;
        }
        for (int i = 0; i 

测试

package com.sparseArray.queue;

import java.util.Scanner;

/**
 * @Auther: 大哥的叔
 * @Date: 2019/7/25 08:44
 * @Description:
 */
public class ArrayQueueDemo {
    public static void main (String[] args) {
    //测试
        ArrayQueue queue = new ArrayQueue(3);
        char key = ' ';//接收用户输入
        Scanner scanner = new Scanner(System.in);
        boolean loop = true;
        while (loop){
            System.out.println("s(show):显示队列");
            System.out.println("e:退出");
            System.out.println("a:添加");
            System.out.println("g:取出");
            System.out.println("h:查看队列头的数据");
            key = scanner.next().charAt(0);//接收一个字符
            switch (key){
                case 's':
                    queue.showQueue();break;
                case 'a':
                    System.out.println("输出一个数");
                    int value = scanner.nextInt();
                    queue.addQueue(value);break;
                case 'g':
                    try {
                        int res = queue.getQueue();
                        System.out.printf("取出的数据是%d\n",res);
                    } catch (Exception e) {
                        System.out.println(e.getMessage());
                    }break;

                case 'h':
                    try {
                        int res = queue.headQueue();
                        System.out.printf("头数据是%d\n",res);
                    } catch (Exception e) {
                        System.out.println(e.getMessage());
                    }break;
                case 'e':
                    scanner.close();
                    loop = false;
                    break;
                    default:
                        break;
            }

        }
        System.out.println("退出");
    }
}