# ---
# title: 637. Average of Levels in Binary Tree
# id: problem637
# author: Tian Jun
# date: 2020-10-31
# difficulty: Easy
# categories: Tree
# link: <https://leetcode.com/problems/average-of-levels-in-binary-tree/description/>
# hidden: true
# ---
# 
# Given a non-empty binary tree, return the average value of the nodes on each
# level in the form of an array.
# 
# **Example 1:**  
# 
#     
#     
#     Input:
#         3
#        / \
#       9  20
#         /  \
#        15   7
#     Output: [3, 14.5, 11]
#     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].
#     
# 
# **Note:**  
# 
#   1. The range of node's value is in the range of 32-bit signed integer.
# 
# 
## @lc code=start
using LeetCode

## add your code here:
## @lc code=end
