Good morning! Here's our prompt for today.
Given a binary tree, write a method to return an array containing the largest (by value) node values at each level. In other words, we're looking for the max per level
.

So for instance, given the following binary tree, we'd get [2, 7, 9]
if the method grabbed the correct maxes.
JAVASCRIPT
1/*
2 2
3 / \
4 3 7
5 / \ \
6 5 8 9
7*/
8
9maxValPerLevel(root);
10// [2, 7, 9]
Assuming the standard tree node definition of:
JAVASCRIPT
1function Node(val) {
2 this.val = val;
3 this.left = this.right = null;
4}
Can you fill it out via the following function signature?
JAVASCRIPT
1function maxValPerLevel(root) {
2 // if (!root) { return []; }
3
4 return;
5};
Constraints
- The number of nodes in the given tree <=
100000
- The nodes will always contain integer values between
-1000000000
and1000000000
- Expected time complexity :
O(n)
- Expected space complexity :
O(n)
Try to solve this here or in Interactive Mode.
How do I practice this challenge?
xxxxxxxxxx
92
​
class Node:
def __init__(self, val):
self.val = val
self.left = None
self.right = None
​
​
def max_per_level(root):
# fill this in
return root
​
​
# root = Node(2)
# root.left = Node(3)
# root.right = Node(7)
# root.left.left = Node(5)
# root.left.right = Node(8)
# root.right.right = Node(9)
# print(maxValPerLevel(root))
​
​
# Node definition
class Node:
def __init__(self, val):
self.val = val
self.left = None
self.right = None
​
​
OUTPUT
:001 > Cmd/Ctrl-Enter to run, Cmd/Ctrl-/ to comment
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