Convert Integer to the Sum of Two No-Zero Integers
A easy-tier problem at 54% community acceptance, tagged with Math. Reported in interviews at Hudson River Trading and 0 others.
This is one of those problems that sounds trivial until you actually sit down in the assessment and realize you haven't thought through the edge cases. Convert Integer to the Sum of Two No-Zero Integers appears easy on paper: take an integer and express it as the sum of two numbers that don't contain the digit zero. Hudson River Trading has reportedly asked it. The acceptance rate hovers around 54%, which tells you people are either solving it cleanly or hitting a wall on the digit-checking logic. If this problem pops up during your live OA and you blank on how to validate 'no-zero', StealthCoder surfaces a working solution in seconds, invisible to the proctor.
Companies that ask "Convert Integer to the Sum of Two No-Zero Integers"
Convert Integer to the Sum of Two No-Zero Integers 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 StealthCoderThe trap here is overcomplicating the validation. You iterate through possible splits: for each number A from 1 to N-1, set B to N minus A, then check if both A and B contain zero as a digit. The naive approach is to write a helper that converts each number to a string and scans for '0'. That works fine. The trick people miss is understanding that you only need one valid pair, so you can stop on the first hit. A common pitfall is trying to be clever with arithmetic tricks to detect zeros instead of just stringifying. For a problem this straightforward, clarity beats micro-optimization. The difficulty rating is EASY because once you lock in the validation pattern, the loop logic is straightforward. If you haven't drilled this exact pattern before, StealthCoder is your hedge during the live assessment, solving it before you second-guess yourself.
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Convert Integer to the Sum of Two No-Zero Integers 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 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.
Convert Integer to the Sum of Two No-Zero Integers interview FAQ
Is this problem really just about checking if a digit exists in a number?+
Yes. The core logic is a containment check: does the digit zero appear anywhere in A or B. Stringifying each number and searching for '0' is the cleanest approach. The iteration and sum math are trivial once validation is locked in.
Why is the acceptance rate only 54% if it's marked EASY?+
Easy difficulty doesn't mean everyone gets it right. Off-by-one errors in the range, forgetting to validate both numbers, or overthinking the validation step trip people up. It's easy once you see it, hard if you haven't written this pattern before.
Do I need to optimize for speed or handle massive integers?+
No. The problem constraints are typically small enough that brute force iteration works fine. A linear scan from 1 to N-1 is expected. No bit manipulation, no memoization, no advanced math tricks needed.
Will Hudson River Trading ask this again or is it a one-off?+
Hard to predict. The data shows only Hudson River Trading in the reports, but that doesn't mean it won't appear at other firms. Recognize it as a warm-up or medium-difficulty OA slot, not a signature company question.
What's the biggest mistake people make on this?+
Forgetting to validate that neither A nor B contains zero. People write the iteration logic, return the first pair that sums correctly, and ship it without checking the 'no-zero' constraint. Re-read the problem statement before you code.
Want the actual problem statement? View "Convert Integer to the Sum of Two No-Zero Integers" on LeetCode →