Reverse Integer
A medium-tier problem at 30% community acceptance, tagged with Math. Reported in interviews at Tech Mahindra and 24 others.
Reverse Integer shows up constantly at Adobe, Apple, Bloomberg, and Intel, but it trips up candidates who don't handle the overflow edge case. About 30% of submissions pass, which tells you most people nail the reversal logic then fail on signed 32-bit boundaries. The problem looks trivial until you hit the wall: your reversed number overflows a signed integer. This is the kind of gotcha that kills an otherwise solid round. If you blank on the constraints during your live OA, StealthCoder runs invisibly and surfaces the solution in seconds.
Companies that ask "Reverse Integer"
Reverse 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 for the engineer who has done the work but might still blank with a webcam pointed at him.
Get StealthCoderThe trick isn't reversing. Any child can reverse digits. The trick is staying within the signed 32-bit integer range: -2^31 to 2^31 - 1. Most candidates build the reversed number first, then check bounds and discard it. That's inefficient and error-prone. The real move is to check bounds before you append each digit. On each iteration, compare your current result against the boundaries and decide if the next digit will overflow. One more trap: the sign. You have to preserve the negative sign through the reversal and handle it cleanly. StealthCoder is your hedge if you freeze on the overflow math during the assessment.
Pattern tags
You know the problem.
Make sure you actually pass it.
Reverse Integer 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. Made for the engineer who has done the work but might still blank with a webcam pointed at him. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Reverse Integer interview FAQ
Is Reverse Integer actually asked at FAANG?+
Yes. It's in the recent ask history at Apple, Bloomberg, Adobe, and Intel. It's especially common in on-site and screening rounds at large-cap tech. The 30% acceptance rate suggests it's still a live problem, not retired.
What's the actual trick everyone misses?+
Overflow checking before you build the number, not after. Most people reverse, then check if the result fits. Real solution: on each digit append, verify the new result won't exceed 2^31 - 1 (or drop below -2^31). Catch it early.
How does the negative sign get handled?+
Strip it at the start, reverse the absolute value, then reapply the sign at the end. Or, keep the sign and reverse only the digits. Either works. The key is consistency so you don't lose the negative during math operations.
Is this a Math topic or just string manipulation?+
It's Math. You're working with digit boundaries and integer constraints, not string operations. Expect modulo and division. The Math label tells you overflow and bit-width reasoning are fair game.
How should I prep for this if I'm going to Adobe or Apple?+
Solve it three times: once with string reversal, once with pure math (modulo/division), once with overflow checking built in. Know the 32-bit bounds by heart: -2147483648 to 2147483647. Test on negative numbers and boundary cases.
Want the actual problem statement? View "Reverse Integer" on LeetCode →