average-of-levels-in-binary-tree

java

python

python3

mysql

mssql

oraclesql

csharp

javascript

typescript

bash

swift

kotlin

dart

golang

ruby

scala

rust

racket

erlang

elixir

pythondata

postgresql

cangjie

Algorithms

Given the <code>root</code> of a binary tree, return the average value of the nodes on each level in the form of an array. Answers within <code>10-5</code> of the actual answer will be accepted.
&nbsp;
Example 1:
<img alt="" src="https://assets.leetcode.com/uploads/2021/03/09/avg1-tree.jpg" style="width: 277px; height: 302px;" />
<pre>
Input: root = [3,9,20,null,null,15,7]
Output: [3.00000,14.50000,11.00000]
Explanation: The average value of nodes on level 0 is 3, on level 1 is 14.5, and on level 2 is 11.
Hence return [3, 14.5, 11].
</pre>

Example 2:
<img alt="" src="https://assets.leetcode.com/uploads/2021/03/09/avg2-tree.jpg" style="width: 292px; height: 302px;" />
<pre>
Input: root = [3,9,20,15,7]
Output: [3.00000,14.50000,11.00000]
</pre>

&nbsp;
Constraints:

<ul>
	<li>The number of nodes in the tree is in the range <code>[1, 104]</code>.</li>
	<li><code>-231 &lt;= Node.val &lt;= 231 - 1</code></li>
</ul>

averageOfLevels

Average of Levels in Binary Tree

Binary Tree Level Order Traversal

binary-tree-level-order-traversal

二叉树的层序遍历

Binary Tree Level Order Traversal II

binary-tree-level-order-traversal-ii

二叉树的层序遍历 II

Tree

Depth-First Search

Breadth-First Search

Binary Tree

给定一个非空二叉树的根节点<meta charset="UTF-8" />&nbsp;<code>root</code>&nbsp;, 以数组的形式返回每一层节点的平均值。与实际答案相差&nbsp;<code>10-5</code> 以内的答案可以被接受。

&nbsp;

示例 1：

<img alt="" src="https://assets.leetcode.com/uploads/2021/03/09/avg1-tree.jpg" />

<pre>
输入：root = [3,9,20,null,null,15,7]
输出：[3.00000,14.50000,11.00000]
解释：第 0 层的平均值为 3,第 1 层的平均值为 14.5,第 2 层的平均值为 11 。
因此返回 [3, 14.5, 11] 。
</pre>

示例 2:

<img alt="" src="https://assets.leetcode.com/uploads/2021/03/09/avg2-tree.jpg" />

<pre>
输入：root = [3,9,20,15,7]
输出：[3.00000,14.50000,11.00000]
</pre>

&nbsp;

提示：

<meta charset="UTF-8" />

<ul>
	<li>树中节点数量在&nbsp;<code>[1, 104]</code> 范围内</li>
	<li><code>-231&nbsp;&lt;= Node.val &lt;= 231&nbsp;- 1</code></li>
</ul>