Maximum Strong Pair XOR I
A easy-tier problem at 75% community acceptance, tagged with Array, Hash Table, Bit Manipulation. Reported in interviews at ZScaler and 0 others.
Maximum Strong Pair XOR I shows up in assessments as a trap for candidates who rush. It's easy enough to brute force, but the trick is understanding what makes a pair "strong" and whether your solution actually respects that constraint. ZScaler has asked it. The acceptance rate of 75% means most people pass, but that often means they're not optimizing the right way, or they're missing edge cases in the strength check. If you hit this live and blank on the efficient path, StealthCoder surfaces a working solution in seconds, invisible to the proctor.
Companies that ask "Maximum Strong Pair XOR I"
Maximum Strong Pair XOR I 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 problem asks you to find maximum XOR of two array elements where the pair is "strong", meaning the absolute difference between them is small enough. Most candidates write a nested loop, compute XOR for every pair, filter by strength, and call it done. That's O(n^2) and it works for small inputs. The real optimization lives in sliding window or hash table approaches, depending on whether you sort first. Bit Manipulation and Trie topics hint at more elegant solutions, but the constraint of strength severely limits candidate pairs, so brute force doesn't always lose here. The pitfall is overthinking the bit-level trick when the actual blocker is the strength condition itself. If you understand that, the rest is mechanical.
Pattern tags
You know the problem.
Make sure you actually pass it.
Maximum Strong Pair XOR I 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 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.
Maximum Strong Pair XOR I interview FAQ
What does 'strong pair' actually mean and why does it matter?+
A strong pair has a small absolute difference between its elements, the exact threshold is given in the problem. This constraint massively prunes the search space. Many candidates ignore or misread this constraint, leading to wrong answers or unnecessary complexity. It's what makes an otherwise trivial XOR problem actually solvable efficiently.
Is brute force O(n^2) acceptable here?+
For an easy problem at 75% acceptance, yes. The strength constraint limits your candidate pairs, so nested-loop solutions often pass without timeout. However, the gap between passing and optimal is where interviews separate candidates. Understand why sorting and sliding window beats brute force, even if you don't code it under time pressure.
Does this really need a Trie or is that overkill?+
Trie is one optimization path for maximum XOR queries, but it's not mandatory here. The strength constraint makes the problem smaller than general XOR-maximization. Hash table or even a sorted approach may be simpler and still fast. Trie is the interviewer's way of testing whether you recognize the pattern, not a requirement for passing.
How does Bit Manipulation help here?+
Bit Manipulation is relevant when you're trying to build the maximum XOR greedily, bit by bit. This applies if you use a Trie or similar structure. For brute force, you just XOR and compare. Understand the greedy bit-building trick if you have time, but don't let it distract you from the strength constraint logic.
Will I see this at ZScaler or is it a one-off?+
ZScaler has asked it. XOR and pair-finding patterns are common in systems and networking interviews. If you've drilled similar problems, the structure is familiar. If not and you hit it live, StealthCoder hedges the gap between "I know XOR" and "I know this specific strong-pair trick."
Want the actual problem statement? View "Maximum Strong Pair XOR I" on LeetCode →