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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.

Description

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 and 1000000000
  • 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?

PYTHON
OUTPUT
:001 > Cmd/Ctrl-Enter to run, Cmd/Ctrl-/ to comment

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