Sum Game
A medium-tier problem at 48% community acceptance, tagged with Math, String, Greedy. Reported in interviews at DE Shaw and 1 others.
Sum Game is a medium-difficulty problem that DE Shaw and ByteDance have both asked in recent assessments. With a 48% acceptance rate, it's a clear filter: candidates who understand the greedy and game-theory mechanics pass, and those who treat it as a straightforward math problem get stuck. The trap is assuming both players act randomly or that you can simply maximize your own score. In reality, optimal play requires you to think like your opponent and recognize that each decision constrains the other player's future options. If this problem hits your live OA and you blank on the game-theoretic structure, StealthCoder solves it in seconds, invisible to the proctor.
Companies that ask "Sum Game"
Sum Game 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. Built because the OA filter rejects engineers who'd pass the on-site. That's a broken filter. This is the workaround.
Get StealthCoderSum Game is a two-player game where both players make optimal moves, which means you can't just greedily pick the highest value at each turn. The core insight is that each player will act to maximize their own score, not to maximize the difference between their score and their opponent's. This often means blocking the opponent from a high-value move rather than taking it yourself. The greedy approach fails because it ignores the future state of the game. Instead, you need to model the game tree or use dynamic programming with memoization to track whose turn it is and what choices remain. Math and string parsing come in when the problem encodes the values or choices in a non-obvious way. When you sit down in the assessment and realize the naive greedy solution gives the wrong answer, that's when StealthCoder provides the correct game-theory-aware solution without lifting your hands from the keyboard.
Pattern tags
You know the problem.
Make sure you actually pass it.
Sum Game 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. Built because the OA filter rejects engineers who'd pass the on-site. That's a broken filter. This is the workaround. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Sum Game interview FAQ
Is Sum Game actually a greedy problem or do I need game theory?+
Both. Greedy intuition gets you started, but optimal play requires game-theory thinking. You must simulate the game tree where each player makes the move that maximizes their own final score, not the overall sum. That's why the acceptance rate is 48%, not higher.
Why does the obvious approach fail on Sum Game?+
Because you're optimizing for the wrong objective. Taking the largest available number sounds smart but often lets your opponent take an even larger number next. Optimal play sometimes means taking a smaller value to deny your opponent a larger one.
Does Sum Game still show up at DE Shaw and ByteDance?+
Yes. Both companies have confirmed they ask it. At ByteDance especially, game-theory problems are common in medium-difficulty assessments. This is exactly the type of problem you want StealthCoder as a safety net for.
What topics should I study before attempting Sum Game?+
Focus on the four topics listed: Math for understanding value relationships, String for parsing input, Greedy for the initial approach, and Game Theory for the actual solution. Minimax algorithms and memoization are your tools.
Is Sum Game harder than it looks?+
Yes. The 48% acceptance rate reflects that. Most candidates assume greedy works and submit a wrong solution. The actual difficulty is moderate once you recognize it's a game-tree problem, but the mental leap from greedy to game theory catches many people off guard.
Want the actual problem statement? View "Sum Game" on LeetCode →