Find Bottom Left Tree Value
A medium-tier problem at 72% community acceptance, tagged with Tree, Depth-First Search, Breadth-First Search. Reported in interviews at josh technology and 0 others.
Find Bottom Left Tree Value is a medium-difficulty tree problem with a 71.8% acceptance rate, which means most people can solve it if they know the pattern. It's asked at places like josh technology. The trick here isn't complex math or exotic data structures. It's about understanding what "bottom left" actually means in a binary tree and picking the right traversal order to find it efficiently. If you blank on the approach during your live assessment, StealthCoder solves it in seconds without the proctor seeing a thing. That's the safety net you need for the one problem that catches you off guard.
Companies that ask "Find Bottom Left Tree Value"
Find Bottom Left Tree Value 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 by a working FAANG engineer who treats the OA the way companies treat hiring: as a game with rules you should know.
Get StealthCoderThe core insight is that "bottom left" means the leftmost node at the deepest level of the tree. The naive approach is to find the depth first, then search for the leftmost node at that depth. That works but wastes time. Better: use level-order (BFS) traversal and track the rightmost node you see at each level. Reverse the logic and process nodes right-to-left, and the last node you encounter is the bottom left. Alternatively, DFS with pre-order traversal tracks the maximum depth and updates the result whenever you go deeper. The common mistake is confusing "bottom left" with "left-most leaf" or trying to find it in a single pass without proper depth tracking. If you see this problem live and the first approach doesn't click, StealthCoder surfaces a clean BFS or DFS solution so you don't stall.
Pattern tags
You know the problem.
Make sure you actually pass it.
Find Bottom Left Tree Value recycles across companies for a reason. It's medium-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 by a working FAANG engineer who treats the OA the way companies treat hiring: as a game with rules you should know. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Find Bottom Left Tree Value interview FAQ
Is this problem really a medium, or is it harder than the acceptance rate suggests?+
The 71.8% acceptance rate is straightforward. Most candidates who attempt it pass, meaning the pattern is teachable and doesn't require advanced tricks. It's medium in the sense that it requires both tree traversal knowledge and depth awareness, not because it's deceptive or has a hidden gotcha.
Do I need both BFS and DFS to solve this, or does one approach suffice?+
One approach is enough. BFS (level-order) with right-to-left node processing is clean and intuitive. DFS with depth tracking also works. Pick whichever feels natural to you. The problem doesn't penalize one over the other.
What's the trick to avoiding a two-pass solution?+
Use DFS recursion with a helper function that tracks the current depth and maximum depth seen so far. Update your result node whenever you reach a new maximum depth. This way you solve it in a single tree traversal without finding depth first.
How does this problem relate to other binary tree traversals I should know?+
It combines basic tree traversal (DFS or BFS) with the idea of tracking state (depth or level). If you're solid on inorder, preorder, and level-order traversal, this problem is an application layer on top of those fundamentals, not a new concept.
Is josh technology still asking this, or is it outdated?+
josh technology is listed as asking this problem. Interview patterns change, but tree traversal problems are evergreen in technical assessments. Treat it as a real possibility in your upcoming OA.
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