Good morning! Here's our prompt for today.

We are given a binary tree and are tasked with writing a method that determines the average of every level in the tree. So for instance, given the following binary tree, we'd get [2, 5, 7] if the method grabbed the correct means.

1/*
2       2
3      / \
4     3   7
5    / \   \  
6   4   8   9 
7*/
8
9meanOfLevels(root);
10// [2, 5, 7]

You may assume the standard tree node definition of:

1function Node(val) {
2  this.val = val;
3  this.left = this.right = null;
4}
5
6const root = new Node(2);
7root.left = new Node(3);
8root.right = new Node(7);
9root.left.left = new Node(4);
10root.left.right = new Node(8);
11root.right.right = new Node(9);
12console.log(meanOfLevels(root));

Constraints

• The nodes will always contain integer values between -1000000000 and 1000000000
• In case the division is not proper, add the quotient to the list and ignore the remainder
• You may assume that while adding the numbers, the sum will not overflow the integer range
• Expected time and space complexity : O(n) for both
• In case the tree is null, return an empty list

Try to solve this here or in Interactive Mode.

How do I practice this challenge?

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​

def mean_of_levels(root):

    # fill in

    return root

​

​

# Node definition

class Node:

    def __init__(self, val):

        self.val = val

        self.left = None

        self.right = None

​

​

# Regular binary trees

tree1 = Node(4)

tree1.left = Node(1)

tree1.right = Node(3)

​

tree2 = Node(5)

tree2.left = Node(10)

tree2.left.left = Node(17)

tree2.left.right = Node(3)

tree2.right = Node(8)

​

# Binary search trees

tree3 = Node(6)

tree3.left = Node(3)

​

tree4 = Node(5)

We'll now take you through what you need to know.

How do I use this guide?