数据结构及算法之队列（基于链表）讲解

1，具体实现

package com.dream21th.algorithmicdatastructure.linkedlist; /** * @Auther: hp * @Date: 2019/9/13 20:52 * @Description: */ public class LinkedListQueue implements Queue { private class Node{ public E e; public Node next; public Node(E e,Node next) { this.e = e; this.next = next; } public Node(E e){ this(e,null); } public Node(){ this(null,null); } @Override public String toString() { return e.toString(); } } private Node head; private Node tail; private int size; public LinkedListQueue(){ head=null; tail=null; size=0; } @Override public int getSize() { return size; } @Override public void enquene(E e) { if(tail==null){ tail=new Node(e); head=tail; }else { tail.next=new Node(e); tail=tail.next; } size++; } @Override public E dequene() { if(isEmpty()){ throw new IllegalArgumentException("illeage operator"); } Node current = this.head; head=head.next; current.next=null; if(head==null){ tail=null; } size--; return current.e; } @Override public E getfornt() { if(isEmpty()){ throw new IllegalArgumentException("illeage operator"); } return head.e; } @Override public boolean isEmpty() { return size==0; } @Override public String toString() { StringBuilder builder=new StringBuilder(); builder.append("Queue head"); builder.append("["); for(Node cur=head;cur!=null;cur=cur.next){ builder.append(cur+"->"); } builder.append("Null ] tail"); return builder.toString(); } public static void main(String[] args) { LinkedListQueue linkedListStack = new LinkedListQueue<>(); for(int i=0;i<10;i++){ linkedListStack.enquene(i); } linkedListStack.dequene(); linkedListStack.dequene(); System.out.println(linkedListStack); } }