java实现队列的练习

java用数组实现队列

package com.fanmzdj.tools;

public class Test17 {
    
    public static void main(String[] args) {    
        ArrayQueue queue = new ArrayQueue(4);
        queue.insert(10);
        queue.insert(20);
        queue.insert(30);
        queue.insert(40);
        queue.insert(50);// 队列已满，再插入时，不会插入没有提示
        queue.remove();// 删除，并返回删除的数据
        queue.insert(60);
        while(!queue.isEmpty()) {
            print(queue.remove());
        }
    }
    
    public static void print(Object o) {
        System.out.println(o);
    }
}
// 用数组实现队列
class ArrayQueue {
    private int front;// 取数据的下标
    private int rear;// 存数据的下标
    private int nItems;// 记录队列存的数据个数
    private int maxSize;// 表示队列的大小
    private int[] queArr;// 用数组来存放队列数据
    
    public ArrayQueue(int size) {// 队列为空时，front、rear、nItems都是0，
        maxSize = size;
        queArr = new int[maxSize];
        front = 0;
        rear = 0;
        nItems = 0;
    }
    
    public void insert(int j) {
        if(isFull()) {
            return;
        }
        if(rear == maxSize) {
            rear = 0;
        }
        queArr[rear++] = j;
        nItems++;
    }
    
    public int remove() {
        int temp = queArr[front++];
        if(front == maxSize) {
            front = 0;
        }
        nItems--;
        return temp;        
    }
    
    public int peekFront() {
        return queArr[front];
    }

    private boolean isFull() {
        return (nItems == maxSize);
    }

    public boolean isEmpty() {
        return (nItems == 0);
    }
}