Difficult Apple Coding Interview Question - JavaScript

Solution to a very popular coding interview question asked recently by Apple - Maximum Depth of a Binary Tree.

#softwareengineering #javascript #shorts

[rutvikrana]

int maxDepth(node* root)
{
if ( !root ) return 0;
return max(maxDepth(root->left), maxDepth(root->right) ) + 1;
}

[rammrras]

This is the basic question in every company I'll say

[ejv]

apple asks this. probably for a super warm up question lol very nice lesson!

[paololucchesi]

This is an average Computer Engineering university exercise...

[ShortFilmVD]

10 years in, still haven't needed to code a binary tree...

[TheShri]

ask what they'd like as a no root return values first. usually it's a None or a 0 . let's assume 0 for a simple case
in Python:
def maxDepth(root):
if not root: return 0
return 1 + max(maxDepth(root.left), maxDepth(root.right))

[bChipps]

Honestly thanks man just had this as an interview question today. Haven’t thought about depth it breathe first search since college and wouldn’t have remembered if it wasn’t for this video

[ence]

That really weird to use side effect on recursion.
Instead you can just do this.

const maxDepth = node => node == null ? 0 : 1 + Math.max(maxDepth(node.left), maxDepth(node.right))

[Eknoma]

As soon as you said "global variable" I knew exactly what kind of channel this was

[martoxdlol]

// Option 1
function maxDepth(tree) {
const depthLeft = tree.left ? maxDepth(tree.left) : 0
const depthRight = tree.right ? maxDepth(tree.left) : 0

if(depthLeft > depthRight) {
return depthLeft + 1
}

return depthRight + 1
}

// Option 2
function maxDepth(tree) {
if(!tree) return 0

const depthLeft = maxDepth(tree.left)
const depthRight = maxDepth(tree.left)

if(depthLeft > depthRight) {
return depthLeft + 1
}

return depthRight + 1
}

[AlgoJS]

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[engine_man]

Doing gods work. Never could wrap my head around dfs

[DavidNewmon]

The variable maxDepth was a terrible idea. It's the name of the function.

[skillfulfighter]

I wish this was coding question for apple lol

[MatthewIrizarry-]

BFS algorithm easily solves this in minimum time!

[YamiSuzume]

No need for nested functions, just place a default parameter for the first launch.

[rakeshcs]

I’m a beginner plzz correct my question if wrong since you have assigned max depth zero why have you used the ‘ let’ statement ? Is it bcoz zero also represents false in bool ?

[ericli]

public maxDepth(TreeNode root){
if(root == null){
return 0;
}
int leftH = 1 + maxDepth(root.left);
int rightH = 1 + maxDepth(root.right);
maxDepth(root.left);
maxDepth(root.right);
return Math.max(leftH, rightH);
}

[reydavid]

This is a beginner question, not a difficult one....

[mikhailurmich]

Always try to avoid recursion.
These are better ways to solve it, don't use recursion