Selling Pieces of Wood
A hard-tier problem at 52% community acceptance, tagged with Array, Dynamic Programming, Memoization. Reported in interviews at Palantir Technologies and 0 others.
Selling Pieces of Wood is a hard DP problem that shows up in Palantir assessments. You're given a wood plank and a list of cutting positions. The trick: each cut costs the length of the current piece, and the order of cuts matters. Most candidates see the problem and start greedy or brute force, then hit a wall when they realize the cut order drastically changes total cost. This is where the DP pattern clicks. If you blank on the approach during the live OA, StealthCoder solves it in seconds, invisible to the proctor.
Companies that ask "Selling Pieces of Wood"
Selling Pieces of Wood 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 Amazon engineer who got tired of watching qualified friends bomb OAs they'd solve cold in an IDE.
Get StealthCoderThe core insight is that this is an interval DP problem, not a greedy one. You need to track all possible ways to partition a segment and memoize the minimum cost. Think of it backward: instead of deciding which cut to make first, decide which cut to make last. When you make the last cut on a segment, all other cuts are already done, so the cost is the segment length plus the sum of optimal costs for left and right subsegments. Common trap: trying to cut left-to-right and forgetting that later cuts inherit the cost of earlier ones. The DP state is (left, right, available cuts), and memoization prevents recomputing overlapping subproblems. Palantir loves this because it tests whether you can recognize a hidden interval structure. StealthCoder surfaces the working solution when the obvious approach fails under time constraints.
Pattern tags
You know the problem.
Make sure you actually pass it.
Selling Pieces of Wood recycles across companies for a reason. It's hard-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 Amazon engineer who got tired of watching qualified friends bomb OAs they'd solve cold in an IDE. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Selling Pieces of Wood interview FAQ
Is this actually asked at Palantir, or is it rare?+
Palantir is the only company listed for this problem in public reports. It's a hard problem, so it's likely a strong signal question for certain roles. Not as frequent as easier problems, but if you're applying there, it's worth understanding the pattern.
What's the actual trick I'm missing?+
Think in reverse. Instead of deciding the first cut, decide the last cut on each segment. The cost of making that last cut is the segment length. All other cuts within that segment are already paid for by smaller subproblems. This flips the problem into interval DP with memoization.
How does memoization help here versus a naive recursive approach?+
Without memoization, you recalculate the same (left, right, cuts) state exponentially. With it, you store results and hit the same state again in O(1). This brings a solution from exponential to roughly O(n^3) for n cuts, which is feasible.
Is greedy ever correct for this problem?+
No. Greedy fails because cutting the shortest segment first doesn't guarantee minimum total cost. The final cost depends on the order of all cuts and how they compound. Dynamic programming is required.
How does this relate to Array and DP topics listed?+
The array holds cutting positions. DP optimizes the order. You'll iterate over subarrays, track intervals, and use a memoization table (often a dictionary or 2D/3D array). It's a textbook interval DP pattern.
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