php 09_queue

Author: Hkesd

php/09_queue/QueueOnLinkedList.php

@@ -0,0 +1,115 @@
+<?php
+/**
+ * User: Hkesd
+ * Date: 2018/10/13 11:26
+ * Desc:
+ */
+
+namespace Algo_09;
+
+use Algo_06\SingleLinkedListNode;
+
+/**
+ * 队列 链表实现
+ *
+ * Class QueueOnLinkedList
+ */
+class QueueOnLinkedList
+{
+ /**
+ * 队列头节点
+ *
+ * @var SingleLinkedListNode
+ */
+ public $head;
+
+ /**
+ * 队列尾节点
+ *
+ * @var null
+ */
+ public $tail;
+
+ /**
+ * 队列长度
+ *
+ * @var int
+ */
+ public $length;
+
+ /**
+ * QueueOnLinkedList constructor.
+ */
+ public function __construct()
+ {
+ $this->head = new SingleLinkedListNode();
+ $this->tail = $this->head;
+
+ $this->length = 0;
+ }
+
+ /**
+ * 入队
+ *
+ * @param $data
+ */
+ public function enqueue($data)
+ {
+ $newNode = new SingleLinkedListNode();
+ $newNode->data = $data;
+
+ $this->tail->next = $newNode;
+ $this->tail = $newNode;
+
+ $this->length++;
+ }
+
+ /**
+ * 出队
+ *
+ * @return SingleLinkedListNode|bool|null
+ */
+ public function dequeue()
+ {
+ if (0 == $this->length) {
+ return false;
+ }
+
+ $node = $this->head->next;
+ $this->head->next = $this->head->next->next;
+
+ $this->length--;
+
+ return $node;
+ }
+
+ /**
+ * 获取队列长度
+ *
+ * @return int
+ */
+ public function getLength()
+ {
+ return $this->length;
+ }
+
+ /**
+ * 打印队列
+ */
+ public function printSelf()
+ {
+ if (0 == $this->length) {
+ echo 'empty queue' . PHP_EOL;
+ return;
+ }
+
+ echo 'head.next -> ';
+ $curNode = $this->head;
+ while ($curNode->next) {
+ echo $curNode->next->data . ' -> ';
+
+ $curNode = $curNode->next;
+ }
+ echo 'NULL' . PHP_EOL;
+ }
+}

php/09_queue/main.php

@@ -0,0 +1,29 @@
+<?php
+/**
+ * User: Hkesd
+ * Date: 2018/10/13 11:46
+ * Desc:
+ */
+
+namespace Algo_09;
+
+require_once "../vendor/autoload.php";
+
+$queue = new QueueOnLinkedList();
+$queue->enqueue(1);
+$queue->enqueue(2);
+$queue->enqueue(3);
+$queue->enqueue(4);
+$queue->enqueue(5);
+$queue->printSelf();
+var_dump($queue->getLength());
+
+$queue->dequeue();
+$queue->printSelf();
+$queue->dequeue();
+$queue->dequeue();
+$queue->dequeue();
+$queue->printSelf();
+
+$queue->dequeue();
+$queue->printSelf();

php/README.md

@@ -17,4 +17,7 @@
 * findMiddleNode 求链表的中间结点
 
 #### 08_stack
-* 链栈实现
+* 链栈实现
+
+#### 09_stack
+* 队列链表实现

php/composer.json

@@ -7,7 +7,8 @@
  "psr-4": {
  "Algo_06\\": "06_linkedlist/",
  "Algo_07\\": "07_linkedlist/",
- "Algo_08\\": "08_stack/"
+ "Algo_08\\": "08_stack/",
+ "Algo_09\\": "09_queue/"
  }
  }
 }