93 lines
2.5 KiB
Java
93 lines
2.5 KiB
Java
/*
|
|
* The MIT License (MIT)
|
|
*
|
|
* Copyright © 2021 xrv <xrv@live.com>
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
* of this software and associated documentation files (the "Software"), to deal
|
|
* in the Software without restriction, including without limitation the rights
|
|
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
* copies of the Software, and to permit persons to whom the Software is
|
|
* furnished to do so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included in
|
|
* all copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
|
* THE SOFTWARE.
|
|
*/
|
|
|
|
package io.github.ehlxr.datastructure.queue;
|
|
|
|
import io.github.ehlxr.datastructure.Node;
|
|
|
|
/**
|
|
* 基于链表实现的队列
|
|
* <p>
|
|
* 入队时间复杂度 O(n)
|
|
*
|
|
* @author ehlxr
|
|
* @since 2021-12-25 16:02.
|
|
*/
|
|
public class LinkedListQueue<T> {
|
|
private Node<T> head;
|
|
|
|
public static void main(String[] args) {
|
|
LinkedListQueue<Integer> queue = new LinkedListQueue<>();
|
|
for (int i = 0; i < 6; i++) {
|
|
System.out.println(queue.enqueue(i));
|
|
}
|
|
|
|
for (int i = 0; i < 6; i++) {
|
|
queue.getData().print();
|
|
System.out.println(queue.dequeue());
|
|
}
|
|
|
|
System.out.println(queue.dequeue());
|
|
}
|
|
|
|
/**
|
|
* 入队（从队尾添加元素）
|
|
* 时间复杂度 O(n)
|
|
*/
|
|
public boolean enqueue(T item) {
|
|
Node<T> node = new Node<T>(item, null);
|
|
if (head == null) {
|
|
head = node;
|
|
return true;
|
|
}
|
|
|
|
// 找到队尾
|
|
Node<T> tail = head;
|
|
while (tail.getNext() != null) {
|
|
tail = tail.getNext();
|
|
}
|
|
|
|
tail.setNext(node);
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* 出队（从队首取出元素）
|
|
*/
|
|
public T dequeue() {
|
|
if (head == null) {
|
|
return null;
|
|
}
|
|
|
|
T val = head.getVal();
|
|
head = head.getNext();
|
|
|
|
return val;
|
|
}
|
|
|
|
public Node<T> getData() {
|
|
return head;
|
|
}
|
|
}
|