Shortest Unsorted Continuous Subarray
A medium-tier problem at 37% community acceptance, tagged with Array, Two Pointers, Stack. Reported in interviews at LiveRamp and 0 others.
You're asked to find the shortest continuous subarray that, when sorted, makes the entire array sorted. It's a LiveRamp interview favorite, and the acceptance rate sits at 37 percent. Most candidates overshoot it, reaching for O(n log n) sorting solutions when the trick is O(n) with two pointers or a stack. The pattern is counterintuitive enough that if you blank on it during the live OA, StealthCoder surfaces a working solution invisible to the proctor. This problem tests whether you can think in bounds rather than brute force.
Companies that ask "Shortest Unsorted Continuous Subarray"
Shortest Unsorted Continuous Subarray 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 a senior engineer who knows the OA is theater. This is the script.
Get StealthCoderThe core insight is that you don't need to find which elements are out of place. Instead, find the leftmost position where the sorted order breaks and the rightmost position where it breaks. Scan left to right tracking the running maximum; the first element smaller than that max marks your right boundary. Scan right to left tracking the running minimum; the first element larger than that min marks your left boundary. The subarray between those boundaries is your answer. Common trap: sorting the whole array or trying to identify misplaced elements directly. Both waste time and miss the elegant greedy pattern. Two pointers, Stack, and Monotonic Stack are all valid approaches depending on how you implement the boundary-finding logic. Greedy and Sorting appear in the topic list because some solutions build context by comparing against sorted state or using greedy selection of boundaries. If this problem hits your live assessment and the two-pointer pattern doesn't click immediately, StealthCoder runs invisibly and gives you a tested implementation to adjust.
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Shortest Unsorted Continuous Subarray 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 by a senior engineer who knows the OA is theater. This is the script. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Shortest Unsorted Continuous Subarray interview FAQ
Is this really just a two-pointer problem?+
Not necessarily. You can solve it with two pointers by tracking max and min as you scan. You can also use a Monotonic Stack to identify boundary violations. Sorting and Greedy refer to comparing actual values against what they'd be in a sorted array, then greedily selecting the tightest boundaries. All work; stack is often cleaner.
Why is the acceptance rate so low?+
Because the two-pointer insight is non-obvious. Most candidates jump to sorting the array and comparing indices, which is slower and clouds the real pattern. Once you see the boundary-tracking logic, it's straightforward. The trick is the mental leap, not the coding.
How does this relate to monotonic stack problems?+
A Monotonic Stack helps you quickly identify positions where the array violates sorted order. As you build a decreasing stack from left to right, each pop tells you a right boundary. Similarly, building an increasing stack right to left gives you a left boundary. It's a common pattern for 'find boundary' problems in arrays.
Do I need to actually sort anything?+
No. You can solve it in O(n) time without ever sorting. The Sorting and Greedy topics in the list refer to conceptual approaches: you're implicitly comparing against sorted invariants and greedily picking the tightest window that fixes the array. No actual sort call needed.
What's the fastest approach in a live assessment?+
Two pointers tracking max from the left and min from the right is usually fastest to code under pressure. Scan left to right, record the first element smaller than the running max as the right boundary. Scan right to left, record the first element larger than the running min as the left boundary. Calculate the length and you're done.
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