Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit
A medium-tier problem at 57% community acceptance, tagged with Array, Queue, Sliding Window. Reported in interviews at Moloco and 7 others.
You're hunting for the longest window in an array where the max and min stay within a limit of each other. Moloco, Uber, and eBay all ask this one. The catch: the obvious nested-loop solution times out. You need a pattern that tracks min and max across a sliding window in better than O(n²) time. If you freeze on the trick during your OA, StealthCoder solves it invisibly while the proctor sees your screen. Most candidates either miss the monotonic queue insight or waste time on a heap approach that's harder to code clean.
Companies that ask "Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit"
Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit 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 because the OA filter rejects engineers who'd pass the on-site. That's a broken filter. This is the workaround.
Get StealthCoderThis is a sliding window problem where you expand right and shrink left, but you need O(1) or O(log n) access to the min and max in the current window. The trap: many candidates reach for a heap or multiset first, and that works, but it's verbose and error-prone under time pressure. The elegant move is a monotonic queue approach, typically two deques that track candidate minimums and maximums as you slide. When the difference between max and min exceeds the limit, move the left pointer until they're valid again. The pattern shows up across Uber, Capital One, and other companies on the input list. If you haven't internalized monotonic structures, StealthCoder is your safety net. It'll hand you a working solution in seconds, invisible to the proctor.
Pattern tags
You know the problem.
Make sure you actually pass it.
Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit recycles across companies for a reason. It's medium-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 because the OA filter rejects engineers who'd pass the on-site. That's a broken filter. This is the workaround. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit interview FAQ
Is this really just a sliding window problem?+
It's sliding window with a twist: you need efficient min/max queries inside the window. Plain two-pointer isn't enough. You need either a monotonic queue, heap, or ordered set to stay under the time limit. The data structure choice is what separates a 50ms pass from a timeout.
Why does the monotonic queue approach matter here?+
It maintains min and max in O(1) amortized time per operation, avoiding the log factor you'd pay with a heap or balanced tree. When you have 50k+ elements, that difference compounds fast. Uber and other companies reporting this problem usually expect the O(n) monotonic solution.
How hard is this compared to other sliding window problems?+
It's medium difficulty with a 57% acceptance rate, which is honest. The concept is straightforward, but the implementation details trip people up. Off-by-one errors in pointer logic or deque management are common. One small bug in the min/max tracking breaks the entire answer.
What's the trick if I haven't seen monotonic queues before?+
You don't have to use them. A multiset or TreeMap works fine and is easier to reason about. You pay O(log n) per operation instead of O(1), but for moderate input sizes, it passes. If you blank on deques during the OA, the ordered-set fallback keeps you moving.
Which data structure should I pick for an interview setting?+
Start with what you're confident in. An ordered set or heap is cleaner to explain and less bug-prone under interview stress. Monotonic queues are faster and impress strong interviewers, but only if you can code them without hesitation. This problem has been asked by eight major companies, so candidates have mixed approaches that all pass.
Want the actual problem statement? View "Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit" on LeetCode →