Check if Array Is Sorted and Rotated
A easy-tier problem at 55% community acceptance, tagged with Array. Reported in interviews at SoundHound and 2 others.
You walk into an assessment and see this problem. It sounds trivial until you actually code it and realize there's a gotcha that tanks half the candidates. Check if Array Is Sorted and Rotated is asked by SoundHound, TCS, and Bloomberg. The twist isn't detecting sorted order or rotation alone, it's handling the specific mechanics of a rotated sorted array in a single pass without false positives. Most people either overthink it or miss an edge case. If you blank on the exact condition during your live OA, StealthCoder runs invisibly and surfaces the working solution in seconds.
Companies that ask "Check if Array Is Sorted and Rotated"
Check if Array Is Sorted and Rotated 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 pattern here is that a sorted-then-rotated array has exactly one 'break' point where a larger element comes before a smaller one. Your job is counting those breaks and validating the endpoints wrap correctly. The obvious approach fails because you need to check that rotation point against both the start and end of the array, not just scan for decreasing pairs. Most people write the condition once, test on an easy case, and move on. They hit a rotated array with a rotation point at index 0, or one that's not rotated at all, and their logic collapses. The acceptance rate sits around 55 percent, which signals a real trick to it. When the actual assessment hits and you can't quite nail the condition, StealthCoder catches it and shows you exactly what you missed.
Pattern tags
You know the problem.
Make sure you actually pass it.
Check if Array Is Sorted and Rotated 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.
Check if Array Is Sorted and Rotated interview FAQ
What's the actual trick to this problem.+
The trick is counting exactly one 'break' where an element is greater than the next, then verifying that the last element is less than or equal to the first. One break means rotation, zero means fully sorted, two or more means invalid. Most people miss the second check.
Why is acceptance rate only around 55 percent if it's marked easy.+
Because candidates either miss the rotation endpoint validation or fail to account for arrays with no rotation at all. The problem is easy to state but the edge cases catch a lot of people off guard under time pressure.
Is this still asked at Bloomberg and other top companies.+
Yes. It shows up at SoundHound, TCS, and Bloomberg. It's typically an early-round filter problem used to weed out people who rush through array logic without thinking through all cases.
How does this relate to array rotation problems in general.+
This is the validation side of rotation problems. While others ask you to rotate or find a target in a rotated array, this one forces you to understand the structure of rotation itself. That pattern knowledge is foundational.
Can I solve this in one pass without extra space.+
Yes. Iterate once, count the break points where arr[i] > arr[i+1], check the wrap condition at the end. O(n) time, O(1) space. That's the expected solution.
Want the actual problem statement? View "Check if Array Is Sorted and Rotated" on LeetCode →