Merge pull request wangzheng0822#403 from hkui/master

添加php 树的层级遍历，中序后续遍历，以及修改之前堆的提交author信息

Author: wangzheng0822

php/10_heap/Heap.php

@@ -5,6 +5,7 @@
  * Date: 2019/9/5
  * Time: 9:01
  * 堆的基本操作(大顶堆，小顶堆 几种堆化方式，堆排序，动态数据流查top k ,查中位数)
+ *
  */
 namespace Algo_10;
 

php/10_heap/findmiddle.php

@@ -1,4 +1,9 @@
 <?php
+/**
+ * Created by PhpStorm.
+ * User: [email protected]
+ * 动态数据流实时获取中位数
+ */
 namespace Algo_10;
 
 require_once '../vendor/autoload.php';

php/10_heap/main.php

@@ -1,4 +1,10 @@
 <?php
+/**
+ * Created by PhpStorm.
+ * User: [email protected]
+ * 堆的基本操作
+ */
+
 namespace Algo_10;
 
 require_once '../vendor/autoload.php';

php/10_heap/topn.php

@@ -1,6 +1,9 @@
 <?php
 /**
- *2.动态数据集合求top n
+ * Created by PhpStorm.
+ * User: [email protected]
+
+ *动态数据集合求top n
  */
 namespace Algo_10;
 

php/24_tree/Tree.php

@@ -149,4 +149,61 @@ public function preOrder($node)
         $this->preOrder($node->left);
         $this->preOrder($node->right);
     }
+
+    /**中序遍历
+     * @param $node
+     *
+     */
+    public function inOrder($node){
+        if(empty($node)){
+            return;
+        }
+        $this->inOrder($node->left);
+        echo $node->data . ' ';
+        $this->inOrder($node->right);
+
+    }
+
+    /**
+     * @param $node
+     * 后续遍历
+     */
+    public function postOrder($node){
+        if(empty($node)){
+            return;
+        }
+        $this->postOrder($node->left);
+        $this->postOrder($node->right);
+        echo $node->data . ' ';
+
+    }
+    /**
+     * @param $queue
+     * @param int $index 从队列(数组)的那个位置开始处理
+     * 层级遍历
+     * 首先把节点放入数组，记录放入数组的根节点个数index，把节点的左右子放入数组
+     * 开始遍历数组queue(从index开始,子节点已经入队列的节点元素不再处理)，把左右子节点放入queue,index++
+     * 持续上述过程，当节点没有子节点时，入队列过程结束，queue里节点的顺序即为层级遍历元素节点的顺序
+     *
+     * 完全二叉树
+     */
+    public function levelOrder($queue, $index = 0)
+    {
+        for ($i = $index; $i < count($queue); $i++) {
+            $node = $queue[$i];
+            if ($node->left) {
+                $queue[] = $node->left;
+            } else {
+                return $queue;
+            }
+            if ($node->right) {
+                $queue[] = $node->right;
+            } else {
+                return $queue;
+            }
+            $index++;
+        }
+        return $queue;
+
+    }
 }

php/24_tree/levelOrder.php

@@ -0,0 +1,34 @@
+<?php
+/**
+ * Created by PhpStorm.
+ * User: [email protected]
+ * Date: 2019/9/22
+ * Time: 23:30
+ *
+ *二叉树的层级遍历
+ */
+
+
+namespace Algo_24;
+
+require_once '../vendor/autoload.php';
+
+$tree=new Tree(20);
+$tree->insert(16);
+$tree->insert(30);
+$tree->insert(12);
+$tree->insert(19);
+
+$tree->insert(10);
+$tree->insert(15);
+$tree->insert(18);
+$tree->insert(21);
+$tree->insert(38);
+
+
+$q=$tree->levelOrder([$tree->head]);
+
+foreach ($q as $n){
+    echo $n->data." ";
+}
+echo PHP_EOL;

php/24_tree/main.php

@@ -9,14 +9,22 @@
 
 $tree->insert(20);
 $tree->insert(30);
+$tree->insert(40);
 $tree->insert(10);
 $tree->insert(21);
 $tree->insert(22);
 
 $tree->preOrder($tree->head);
 echo PHP_EOL;
 
-var_dump($tree->find(30));
+$tree->inOrder($tree->head);
+echo PHP_EOL;
+
+$tree->postOrder($tree->head);
+echo PHP_EOL;
+
+
+print_r($tree->find(30));
 echo PHP_EOL;
 
 

php/README.md

@@ -25,3 +25,6 @@
 * main 堆的基本操作,堆排序
 * findmiddle  动态数据流求中位数
 * topn 动态数据流求top k
+#### 24_tree
+* main 二叉树的基本操作 前中后序遍历
+* levelOrder 二叉树的层级遍历