Tesla·Software Engineer·Technical Phone Screen·Intermediate

Intermediate

May 2026

Summary

Tesla SWE coding round, one algorithmic problem the whole time. Pretty focused session, no fluff.

Questions Asked (1)

Given an array of integers representing network latencies, find all increasing pairs [a, b] where b minus a equals the minimum absolute difference between any two elements in the array. Return the pairs sorted by a, then b. What is the time and space complexity of your solution?

Algorithms & Data StructuresTechnical Trade-offs

Author's notes

Sorting first felt obvious and I went with it.

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AI HintsAI Generated

Suggested Approach

First, sort the array to efficiently find the minimum absolute difference between adjacent elements. Then, scan the sorted array to collect all pairs with that minimum difference, ensuring they are sorted by the first element. Finally, analyze the time and space complexity of your approach.

Pro tip: Mention that sorting is often acceptable in interviews unless the problem explicitly requires preserving the original order or achieving better than O(n log n) time. Also, clarify that the output pairs are naturally sorted by the first element after sorting the array.

1. Understand the problem

Restate the problem to ensure clarity: find all increasing pairs [a, b] where b - a equals the minimum absolute difference between any two elements in the array. The pairs should be sorted by a, then b.

2. Sort the array

Sort the array in ascending order. This allows efficient computation of the minimum difference by checking adjacent elements.

3. Find minimum difference

Iterate through the sorted array and compute the difference between each pair of adjacent elements. Track the minimum difference found.

4. Collect pairs

Iterate again through the sorted array and collect all adjacent pairs whose difference equals the minimum difference. Since the array is sorted, these pairs will automatically be sorted by the first element.

5. Analyze complexity

State the time complexity: O(n log n) due to sorting, and O(n) for the scans. Space complexity: O(n) for the output list (or O(1) extra space if we ignore the output).

Key Points to Mention

Sorting the array simplifies finding the minimum difference and ensures pairs are sorted.
The minimum absolute difference in a sorted array must be between adjacent elements.
Time complexity: O(n log n) due to sorting, which dominates the O(n) scans.
Space complexity: O(n) for the output list, but O(1) auxiliary space if we exclude the output.
Edge cases: arrays with fewer than 2 elements, all elements equal, or multiple pairs with the same minimum difference.
The solution handles duplicates correctly because adjacent equal elements have difference 0, which could be the minimum.

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