Minimum Bit Flips to Convert Number
A easy-tier problem at 88% community acceptance, tagged with Bit Manipulation. Reported in interviews at persistent systems and 0 others.
Minimum Bit Flips to Convert Number is a straightforward bit manipulation problem that shows up in technical assessments, including at Persistent Systems. You're given two integers and need to count how many bit positions differ between them. The acceptance rate sits at 87.6%, which tells you this is a screening-level problem designed to filter out candidates who can't think in binary. It's easy to solve if you know the trick, brutal if you don't. If this hits your live assessment and you blank on the approach, StealthCoder solves it in seconds invisible to the proctor.
Companies that ask "Minimum Bit Flips to Convert Number"
Minimum Bit Flips to Convert Number 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 insight is XOR: two bits produce a 1 only when they differ. So XOR the two numbers, then count the 1-bits in the result. Most candidates overthink it by trying to compare bits position-by-position with loops and masks, which works but is slower and error-prone. The elegant path is XOR plus a bit-counting trick like Brian Kernighan's algorithm or built-in popcount. The trap is misunderstanding XOR semantics or forgetting that you're counting set bits, not flipping them directly. This is one of those problems where knowing the pattern matters more than algorithmic depth. If bit manipulation isn't your native language, StealthCoder is the hedge that gets you past it.
Pattern tags
You know the problem.
Make sure you actually pass it.
Minimum Bit Flips to Convert Number 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.
Minimum Bit Flips to Convert Number interview FAQ
Is this really an easy problem or is the acceptance rate misleading?+
It's genuinely easy once you see XOR. The 87.6% acceptance reflects that most candidates who attempt it either know bit tricks or can guess the right direction quickly. It's a filter for people who panic under pressure, not a conceptual trap.
What's the trick that makes this trivial?+
XOR the two numbers. Every 1-bit in the result represents a position where the input bits differ. Count those 1-bits using popcount or Kernighan's algorithm. One line of code once you see it.
Do I need to know advanced bit manipulation for this?+
No. You need XOR and a way to count set bits. Both are fundamental. If you can't do this, you'll struggle on harder bit problems later in the loop, so treat it as a baseline check.
Is Persistent Systems still asking this in their interviews?+
It's reported in their interview pool. Persistent Systems uses screening assessments that lean on fundamental data structures and bit logic, so problems like this are common entry points into their technical rounds.
How do I avoid dumb mistakes during the live assessment?+
Test with the XOR result on paper first. Make sure your bit-counting logic handles zero correctly (no flips needed). Off-by-one errors are rare here, but verify your loop bounds if you hand-roll the counter.
Want the actual problem statement? View "Minimum Bit Flips to Convert Number" on LeetCode →