Maximum Depth of N-ary Tree
A easy-tier problem at 73% community acceptance, tagged with Tree, Depth-First Search, Breadth-First Search. Reported in interviews at Datadog and 0 others.
Maximum Depth of N-ary Tree is an easy problem that shows up in real OAs and feels deceptively simple until you realize you can't just call.left and.right on every node. You're dealing with a variable number of children, which breaks the binary tree muscle memory most candidates carry into an assessment. Datadog and similar companies ask it to see if you can adapt BFS or DFS to handle arbitrary branching. The 73% acceptance rate is high, but that's because many people get lucky on their first attempt. If you blank on the recursion setup during your live OA and need a working solution in 30 seconds, StealthCoder solves it invisible to the proctor.
Companies that ask "Maximum Depth of N-ary Tree"
Maximum Depth of N-ary Tree is the kind of problem that decides whether you pass. StealthCoder reads the problem on screen and surfaces a working solution in under 2 seconds. Invisible to screen share. The proctor sees nothing. Made for the engineer who has done the work but might still blank with a webcam pointed at him.
Get StealthCoderThe trick is that N-ary nodes have a children list, not discrete left and right pointers. Your DFS needs to loop through all children, not branch left then right. Most candidates either forget to iterate the children array or conflate this with binary tree depth and hardcode two recursive calls. The naive approach still works: recurse into each child, take the max depth, add 1. BFS is also straightforward: level-order traversal, count levels. The common pitfall is assuming tree structure without reading the node definition carefully. During a live OA where you're scanning the problem in 20 seconds, you might miss that children is a list and lock onto binary intuition. That's where StealthCoder catches the mistake and surfaces the correct template before you write broken code.
Pattern tags
You know the problem.
Make sure you actually pass it.
Maximum Depth of N-ary Tree recycles across companies for a reason. It's easy-tier, and most candidates blank under the timer. StealthCoder is the hedge: an AI overlay invisible during screen share. It reads the problem and surfaces a working solution in under 2 seconds. Made for the engineer who has done the work but might still blank with a webcam pointed at him. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Maximum Depth of N-ary Tree interview FAQ
Is this problem actually easy or just mislabeled?+
It's genuinely easy once you see the pattern. The 73% acceptance rate confirms it's on the lower end of difficulty. The gotcha is reading the node definition. If you spend 10 seconds understanding that nodes have a children list instead of left/right pointers, the solution is straightforward recursion or BFS.
Does Datadog ask this in every interview or just sometimes?+
We see it reported from Datadog. This doesn't mean it's asked in every loop or every role. It appears on their radar, so it's worth drilling if you're interviewing there. The easy-to-medium problems are often used as warm-ups.
What's the real difference between DFS and BFS for tree depth?+
DFS (recursion) is cleaner and more intuitive here: return 1 + max of all children depths. BFS requires a queue and manual level counting. Both are O(n) time. DFS is simpler to code under pressure, so that's usually the safer pick in a live OA.
How does this relate to the other Tree and DFS topics?+
It's a template problem for tree traversal. Once you nail the children loop here, you can apply the same pattern to problems asking for max path sum, diameter, or any statistic over all nodes. It's foundational, not advanced.
If I blank on the recursion during my OA, how much time will I lose?+
If you're stuck, you could lose 10-15 minutes rewriting or debugging. StealthCoder gives you a working solution in seconds, invisible to the proctor. It's the hedge for the one problem you didn't drill despite it being easy.
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