java 任务 队列 java实现队列功能

队列

1. 定义：队列是一种有序的列表。
2. 实现形式：可以用数组或者链表实现队列
3. 模拟图
4. 代码实现

package com.xc.queue;

import java.util.Scanner;

public class ArrayQueue {
    public static void main(String[] args) {
        ArrayQueue arrayQueue = new ArrayQueue(3);
        Scanner scanner = new Scanner(System.in);
        while (true){
            System.out.println("-------------1-入队--------------");
            System.out.println("-------------2-出队--------------");
            System.out.println("-------------3-队首元素-----------");
            System.out.println("-------------4-显示队列元素--------");
            System.out.println("-------------5-退出---------------");
            System.out.print("请选择您的操作：");
            int choose = scanner.nextInt();
            switch (choose){
                case 1:
                    System.out.print("请输入一个元素入队：");
                    int data = scanner.nextInt();
                    arrayQueue.offer(data);
                    System.out.println("当前队列：");
                    arrayQueue.show();
                    break;
                case 2:
                    try {
                        arrayQueue.poll();
                        System.out.println("当前队列：");
                        arrayQueue.show();
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                    break;
                case 3:
                    System.out.println("当前队列：");
                    arrayQueue.show();
                    break;
                case 4:
                    try {
                        System.out.println(arrayQueue.peek());
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                    break;
                case 5:
                    System.exit(0);
            }
        }


    }
    private int font;
    private int rear;
    private int maxSize;
    private int [] data;
    //初始化队列
    public ArrayQueue(int maxSize){
        data = new int[maxSize];
        this.maxSize = maxSize;
        font = -1;
        rear = -1;
    }
    //是否对空
    public boolean isEmpty(){
        if(font == rear){
            return true;
        }
        return false;
    }
    //是否队满
    public boolean isFull(){
        if(rear == maxSize-1){
            return true;
        }
        return false;
    }
    //入队操作
    public void offer(int date){
        if(isFull()){
            System.out.println("队满无法添加数据");
            return ;
        }
        this.rear ++;
        this.data[rear] = date;
    }
    //出队操作
    public int poll() throws Exception {
        if(isEmpty()){
            System.out.println("对空,出对失败");
            throw new Exception("队列为空");
        }
        int info = this.data[++font];
        this.data[font] = 0;
        return info;

    }
    //打印数据
    public void show(){
        if(isEmpty()){
            System.out.println("对列中没有数据");
        }
        for (int i = 0;i<this.data.length;i++) {
            System.out.println("data"+"["+i+"]"+"="+data[i]);
        }
    }
    //取出对头数据
    public int peek() throws Exception {
        if(isEmpty()){
            throw new Exception("队列中没有数据");
        }
        return this.data[font];
    }

}