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Early-stage Startup·Software Engineer·Online Assessment (OA)·Intermediate

Intermediate
May 2026

Summary

90-minute OA for a quant engineer role, just one coding problem in Python. Not a brutal experience but the problem had some tricky state management that I didn't fully appreciate until I was already halfway through a wrong approach.

Questions Asked (1)

Q1

Given an array of integers, two players alternate picking numbers from it. If a picked number is even, player 1 gets a point; if odd, player 2 gets a point and the array is reversed. Write a function to compute the final score difference between the two players.

Algorithms & Data Structures
Author's notes

The reversal mechanic is what got me.

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AI HintsAI Generated

Suggested Approach

Clarify the rules and edge cases first, then simulate the game step-by-step while tracking the score difference. Optimize by recognizing that reversing the array only changes the direction of traversal, so you can use two pointers or a deque to avoid actual reversal.

Pro tip: Mention that the reversal can be handled by toggling the direction of traversal, which keeps the solution O(n) time and O(1) extra space. Also, discuss how to handle ties or empty arrays.

1. Clarify the rules

Ask questions to confirm: Who picks first? Is the array reversed immediately after an odd pick? Does the reversal affect the next pick? What if the array is empty?

2. Simulate the game

Walk through a small example to understand the mechanics. Track the score difference and the current direction of traversal.

3. Design an efficient algorithm

Use two pointers (left and right) to represent the current ends of the array. When an odd number is picked, swap the pointers to simulate reversal without actually reversing the array.

4. Implement and test

Write the function, handling edge cases like empty array, single element, and all even/odd numbers. Test with the example and additional cases.

5. Analyze complexity

State that the time complexity is O(n) since each element is processed once, and space complexity is O(1) as only pointers and a score variable are used.

Key Points to Mention

  • Clarify the rules and edge cases before coding.
  • Use two pointers to simulate reversal without modifying the array.
  • Track the score difference directly instead of separate scores.
  • Handle the direction toggle when an odd number is picked.
  • Discuss time and space complexity: O(n) time, O(1) space.
  • Consider alternative approaches like using a deque, but note the overhead.

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