Subtract the Product and Sum of Digits of an Integer
A easy-tier problem at 87% community acceptance, tagged with Math. Reported in interviews at Quora and 0 others.
You get an integer, extract its digits, compute the product of all digits and the sum of all digits, then return product minus sum. Sounds trivial, and it is, but it's still live in Quora interviews and shows up across assessment platforms. The acceptance rate sits at 86.6 percent, which means most candidates who see it pass, but the ones who fail usually overthink the digit extraction or make an off-by-one error in the loop. If you blank on how to isolate each digit during a live OA, StealthCoder surfaces a clean solution in seconds.
Companies that ask "Subtract the Product and Sum of Digits of an Integer"
Subtract the Product and Sum of Digits of an Integer 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 an Amazon engineer who watched the leaked-problem repo become an industry secret. He decided you should have it too.
Get StealthCoderThe core trick is digit extraction: convert the number to a string, iterate through each character, convert back to int, and accumulate both product and sum. The trap is handling single-digit numbers (product stays that digit, sum stays that digit, difference is zero), negative numbers (clarify whether input is always positive), and making sure you don't mutate state across test cases. Most candidates write this in under two minutes because there's no dynamic programming, no graph traversal, no bit manipulation. The real hazard isn't the algorithm, it's careless bugs: forgetting to initialize product to 1 instead of 0, or sum to 0 instead of 1, or misreading the order (product minus sum, not sum minus product). If this problem appears in your live assessment and you hit a wall on the implementation details, StealthCoder runs invisibly and hands you a working answer.
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Subtract the Product and Sum of Digits of an Integer 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. Made by an Amazon engineer who watched the leaked-problem repo become an industry secret. He decided you should have it too. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Subtract the Product and Sum of Digits of an Integer interview FAQ
Is this problem actually asked at FAANG or just easier companies?+
Quora has confirmed asking it. It's an easy problem, so it lands as a warm-up question or a quick screen, not a main event. If you see it live, treat it as a gimme and move fast. The acceptance rate of 86.6 percent backs this: most people who attempt it pass.
What's the most common mistake on this problem?+
Initializing product to 0 instead of 1. If you start with 0 and multiply, every digit turns the result to 0. Another frequent error: parsing digits from a negative number without handling the sign first. Always clarify input constraints with the problem statement.
Do I need a helper function or can I write this inline?+
You can write this inline in most languages. Convert to string, loop through characters, convert each back to int, accumulate both totals. No recursion, no complex state. Most solutions are 5 to 10 lines. Keep it simple.
How does Math relate to the other topics in live coding interviews?+
Math problems on their own are rare as full interview questions. They often appear as sub-problems inside strings, arrays, or bit manipulation tasks. This one is pure Math, so if it lands in your OA, it's meant to be a confidence boost before harder problems.
Is there any edge case I should test before submitting?+
Test single digits (0 to 9): product and sum are the same, difference is zero. Test numbers with zeros in them (101, 1001): zeros in the product make it zero. Test large numbers to confirm your language doesn't overflow. That covers most edge cases here.
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