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Meta·Software Engineer·Technical Phone Screen·Intermediate

Intermediate
Apr 2026

Summary

Meta coding screen, one question about arrays. Short session, nothing else to report.

Questions Asked (1)

Q1

Given an array of integers, determine whether the elements form a sequence of consecutive integers.

Algorithms & Data Structures
Author's notes

Seems easy until you start thinking about edge cases.

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AI HintsAI Generated

Suggested Approach

Clarify the problem constraints (e.g., duplicates, empty array, negative numbers) and then propose an efficient solution. A common optimal approach is to check if the array contains consecutive integers by verifying that max - min == length - 1 and all elements are unique, which can be done using a hash set or by sorting.

Pro tip: Always discuss trade-offs between sorting (O(n log n)) and hash set (O(n) time, O(n) space), and mention edge cases like duplicates and large ranges to show thoroughness.

1. Clarify requirements

Ask about input constraints: Can the array be empty? Are duplicates allowed? Can numbers be negative? What should be returned for an empty array?

2. Discuss brute force

Mention that sorting the array and checking consecutive elements is a straightforward O(n log n) approach, but note its inefficiency for large inputs.

3. Propose optimal solution

Use a hash set to check for duplicates and track min/max. If no duplicates and max - min == length - 1, the array is consecutive.

4. Analyze complexity

State that the hash set approach runs in O(n) time and O(n) space, which is optimal for unsorted input.

5. Test with examples

Walk through edge cases: empty array, single element, duplicates, negative numbers, and large consecutive sequences.

Key Points to Mention

  • Handling duplicates: if any duplicate exists, the array cannot be consecutive.
  • Using min and max to quickly check the range: max - min == n - 1 is necessary but not sufficient without uniqueness.
  • Hash set for O(1) lookups to detect duplicates and verify all numbers in range.
  • Trade-offs: sorting is simpler but slower; hash set is faster but uses extra space.
  • Edge cases: empty array (often considered consecutive), single element (always consecutive), negative numbers.
  • Time and space complexity analysis for each approach.

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.