Minimum One Bit Operations to Make Integers Zero
A hard-tier problem at 73% community acceptance, tagged with Dynamic Programming, Bit Manipulation, Memoization. Reported in interviews at Expedia and 2 others.
Minimum One Bit Operations to Make Integers Zero is a hard problem that looks like brute-force bit manipulation but hides a pure math trick underneath. You've probably seen it show up in Expedia, McKinsey, and ServiceNow assessments. The acceptance rate is 73%, which sounds high until you realize most of those passes come from people who either already knew the Gray code pattern or spent three hours dry-running examples. If this problem hits your live OA and you don't recognize the pattern, you're staring at a blank editor for 20 minutes. That's where StealthCoder solves it in seconds, invisible to the proctor.
Companies that ask "Minimum One Bit Operations to Make Integers Zero"
Minimum One Bit Operations to Make Integers 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. Made by a working Amazon engineer who got tired of watching qualified friends bomb OAs they'd solve cold in an IDE.
Get StealthCoderThe naive approach is tempting: simulate turning off bits one at a time, count operations, submit. It fails on large numbers because the state space explodes. The real solution has nothing to do with simulation. This is a Gray code problem disguised as a bit manipulation problem. Gray code is an ordering of binary numbers where consecutive numbers differ by exactly one bit. The key insight is that the minimum operations to zero any number n is n XOR (n >> 1), a direct formula. Most candidates see 'operations' and 'bits' and miss that this is actually asking for an invariant property of Gray code sequences. Dynamic Programming and Memoization are red herrings. When you hit this live and the obvious approach fails, StealthCoder surfaces the formula instantly.
Pattern tags
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Minimum One Bit Operations to Make Integers Zero recycles across companies for a reason. It's hard-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 a working Amazon engineer who got tired of watching qualified friends bomb OAs they'd solve cold in an IDE. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Minimum One Bit Operations to Make Integers Zero interview FAQ
Is this really a hard problem or does it just feel hard?+
It's genuinely hard because the solution isn't an algorithm, it's a math identity. The 73% acceptance rate is misleading. Most passes come from candidates who either knew Gray code going in or researched the pattern after failing. First attempt, most people fail.
Do I actually need Dynamic Programming for this?+
No. The topics listed (DP, Bit Manipulation, Memoization) describe common approaches people try, not what the optimal solution needs. The answer is a one-line formula. If you're writing DP, you're on the wrong track.
What's the actual trick?+
The minimum operations to make any integer n zero is n XOR (n >> 1). This comes from Gray code properties. Gray code is a binary numbering system where consecutive values differ by exactly one bit, which matches the operation constraint.
Will this appear in other interviews?+
Expedia, McKinsey, and ServiceNow have all asked it. It's not super common across the board, but it shows up at companies that value bit-level thinking. If your target company is in that space, this is worth knowing.
How do I prepare for this if I don't know Gray code?+
Study Gray code construction and the XOR formula for converting between binary and Gray code. Don't grind test cases. Understand why consecutive Gray code values differ by one bit. That insight alone unlocks the solution.
Want the actual problem statement? View "Minimum One Bit Operations to Make Integers Zero" on LeetCode →