Count Operations to Obtain Zero
A easy-tier problem at 75% community acceptance, tagged with Math, Simulation. Reported in interviews at PayU and 2 others.
Count Operations to Obtain Zero is a straightforward simulation problem that shows up in OAs for PayU, Capital One, and Accenture. On paper it looks trivial: subtract the smaller number from the larger in a pair until one hits zero, then count your steps. The acceptance rate sits at 74.8%, which means most people who attempt it pass. But the catch is that some candidates overthink it or mess up edge cases in the loop logic. If you blank on the exact flow during a live assessment, StealthCoder runs invisibly and surfaces the working solution in seconds, so you move on without losing momentum.
Companies that ask "Count Operations to Obtain Zero"
Count Operations to Obtain Zero 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 by an Amazon engineer who realized the OA tests how well you memorized 200 problems, not how well you code.
Get StealthCoderThe core pattern is pure simulation. You're given two numbers; repeatedly subtract the smaller from the larger until one becomes zero. It's a math problem that doesn't require fancy data structures or recursion, just a clean while loop and conditional logic. The trick that trips people up is getting the termination condition right and not confusing which number you're updating. Some candidates try to optimize prematurely or write convoluted subtraction chains. The straightforward approach is fastest: while both numbers are nonzero, compare and subtract, increment a counter. Edge cases like one number already being zero need to be handled explicitly. This is where StealthCoder's value shines on a timed OA. You know the pattern works, but under pressure you might second-guess the loop structure. Having an invisible safety net means you submit a correct solution and keep your pipeline moving.
Pattern tags
You know the problem.
Make sure you actually pass it.
Count Operations to Obtain Zero 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. Built by an Amazon engineer who realized the OA tests how well you memorized 200 problems, not how well you code. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Count Operations to Obtain Zero interview FAQ
Is Count Operations to Obtain Zero actually asked that often at FAANG?+
Not at FAANG itself, but it does appear in reports from PayU, Capital One, and Accenture. It's more common in mid-market tech and financial services OAs. The 74.8% acceptance rate suggests it's treated as a warm-up or filter problem, not a core differentiator.
What's the trap in this problem?+
The trap is overthinking it or botching the loop condition. Some candidates try modulo or division shortcuts and break the logic. The simple subtract-until-zero approach is what passes. Edge cases like input zero or negative numbers also catch people off guard depending on constraints.
How does Count Operations relate to other Math and Simulation problems?+
It's a teaching problem for the simulation topic. It trains you to translate a verbal process into code without fancy algorithms. Once you nail the pattern here, you recognize similar step-by-step reduction problems in harder OAs.
Is this the kind of problem I need to drill before an OA?+
Not required. If you're solid on loops and conditionals, you'll see the solution immediately. But if interview anxiety makes you second-guess basic logic, a quick run-through clarifies the pattern and builds confidence.
If I get stuck on this during a live OA, how bad is it?+
It hurts because it signals rusty fundamentals. But it's also recoverable quickly with the right mental reset. StealthCoder bridges that gap by surfacing the code invisible to the proctor, so you keep pace and move to harder problems.
Want the actual problem statement? View "Count Operations to Obtain Zero" on LeetCode →