How do you check if an array is sorted in a single pass?
This question asks candidates to verify the sorted order of an array efficiently. It tests understanding of linear time complexity and basic iteration logic.
Why Interviewers Ask This
Interviewers ask this to assess fundamental coding skills and the ability to write clean, efficient loops. They want to see if the candidate understands edge cases like empty arrays or single-element arrays. Additionally, it evaluates whether the candidate can optimize for O(n) time complexity without unnecessary nested iterations. This serves as a quick filter for logical thinking and code correctness.
How to Answer This Question
Start by defining the problem clearly: iterate through the array comparing adjacent elements. Handle edge cases first, such as null or empty inputs. Use a simple loop to check if any element is greater than the next one. If found, return false immediately; otherwise, return true after the loop completes. Mention time and space complexity explicitly at the end.
Key Points to Cover
- Iterate once through the array
- Compare adjacent elements
- Handle edge cases like empty input
- Return early on failure
Sample Answer
To check if an array is sorted, I would iterate through the array from the first element to the second-to-last element. For each element, I compare it with the next one. If I find any pair where the current element is gr…
Common Mistakes to Avoid
- Using nested loops unnecessarily
- Forgetting to handle empty arrays
- Incorrect comparison operators
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