Guess Number Higher or Lower
A easy-tier problem at 56% community acceptance, tagged with Binary Search, Interactive. Reported in interviews at Samsung and 0 others.
Guess Number Higher or Lower is an easy binary search problem that's deceptively straightforward. You're given a number between 1 and n, and you need to guess it in the minimum number of attempts by receiving feedback on whether your guess is too high, too low, or correct. Samsung has asked this problem. The acceptance rate hovers around 55%, which sounds high until you realize half the people solving it are either brute-forcing or implementing a naive linear search. The real trick is recognizing this as a textbook binary search setup where you can find the answer in log(n) time, not linear time.
Companies that ask "Guess Number Higher or Lower"
Guess Number Higher or Lower 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 used it to pass JPMorgan's OA and system design loop.
Get StealthCoderThe pattern here is pure binary search, but the interactive nature trips up candidates who haven't drilled it. You're not searching an array; you're searching a range. Start at the midpoint between 1 and n, get feedback, and shrink your search space by half each round. The pitfall is overthinking it. Some people try to optimize the guess selection with some formula or try to track state in weird ways. That's noise. Just implement standard binary search logic, adjusting your low and high bounds based on feedback. If you freeze on the binary search template during the live assessment, StealthCoder surfaces the solution instantly so you move on to harder problems.
Pattern tags
You know the problem.
Make sure you actually pass it.
Guess Number Higher or Lower 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 used it to pass JPMorgan's OA and system design loop. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Guess Number Higher or Lower interview FAQ
Is this problem actually asked in real interviews?+
Yes. Samsung has reportedly asked it, and it shows up in screening assessments. It's often a warm-up before harder problems, so nailing the binary search pattern here matters for momentum.
What's the time complexity I need to hit?+
O(log n) worst case. That's the entire point. Linear search or brute force will technically work for small n but signals you don't know the pattern. Binary search is the expected solution.
Why is the acceptance rate only 55% if it's easy?+
People either misunderstand the binary search bounds, implement it with off-by-one errors, or miss that it's interactive, not a static search. Implementation details matter even on easy problems.
How does this relate to other binary search problems I should know?+
This is the purest form of binary search. It trains the mental model you'll use for harder variants like finding rotated arrays or boundary conditions. Master the template here first.
Should I study this if I already know binary search?+
If you can code it cold in under 5 minutes without errors, skip deep study. If you hesitate on the bounds or feedback logic, spend 10 minutes on it. It's the confidence check before the assessment.
Want the actual problem statement? View "Guess Number Higher or Lower" on LeetCode →