数据结构之队列的Java实现

Java代码如下：

package com.ds.list;

/**
 * 队列，先进先出的链式数据结构
 */
public class MyQueue<T> {

    class Node {
        public T data;
        public Node next;
    }

    private Node front; //队头
    private Node rear; //队尾

    public MyQueue() {
        Node node = new Node();
        node.next = null;
        this.rear = this.front = node;
    }

    //元素入队
    public void enQueue(T t) {
        Node node = new Node();
        node.data = t;
        node.next = this.rear;
        this.rear = node;
        log("enqueue data: " + t);
    }

    //元素出队
    public T deQueue() {
        if(this.front == this.rear) {
            return null;
        }
        Node p = this.rear;
        while(p.next != this.front) {
            p = p.next;
        }
        T t = p.data;
        this.front = p;
        return t;
    }

    private static void log(String msg) {
        System.out.println(msg);
    }

    public static void main(String[] args) {
        MyQueue<String> queue = new MyQueue<>();
        for(int i = 0; i < 5; i++) {
            queue.enQueue("item " + i);
        }
        log("dequeue data: " + queue.deQueue());
        log("dequeue data: " + queue.deQueue());
        log("dequeue data: " + queue.deQueue());
        log("dequeue data: " + queue.deQueue());
        log("dequeue data: " + queue.deQueue());
        log("dequeue data: " + queue.deQueue());
    }

}

程序运行的结果如下图所示：