MathWorks OA Speedrun Guide: Solved in 15 Minutes

This morning, I helped one of my students complete the latest MathWorks Online Assessment (OA). He solved both coding problems in just 15 minutes — the difficulty level was quite low, mainly testing basic logic and implementation skills. Here’s the full breakdown of the problems, solutions, and key takeaways for anyone preparing for it!

Problem 1: Valid Parentheses String

Problem description:

You are given several strings, each containing only six types of brackets: “(”, “)”, “{”, “}”, “[”, and “]”. For each string, determine whether it’s valid.

A string is considered valid if every opening bracket has a corresponding closing bracket, and the order of brackets is correct.

For example:

“()[]{}” → valid

“([)]” → invalid

Solution idea: Use a stack.

This is a classic stack problem. The logic is straightforward and easy to follow:

1. Iterate through each character in the string.
2. If the character is an opening bracket (“(”, “[”, “{”), push it onto the stack.
3. If it’s a closing bracket (“)”, “]”, “}”), check the top of the stack:
   • If the top matches the corresponding opening bracket, pop it.
   • If it doesn’t match or the stack is empty, the string is invalid.
4. After processing all characters, if the stack is empty, the string is valid; otherwise, it’s invalid.

This problem is essentially the same as LeetCode’s “Valid Parentheses”. It’s a great warm-up exercise and perfect for testing your basic coding rhythm.

Problem 2: Find the Maximum Number of Teams Working Simultaneously

Problem description:

You’re given n time intervals, where each interval represents a team’s working period. For example, [9, 12] means a team works from 9 AM to 12 PM.

The goal is to determine the maximum number of teams that are working at the same time — in other words, the largest overlap between intervals.

Solution idea: Classic interval overlap problem (two approaches).

This problem is similar to LeetCode’s “Meeting Rooms II”. Both approaches below work well.

Approach 1: Split start and end times

1. Extract all start and end times. Example: [9, 12], [10, 15] → starts: 9, 10; ends: 12, 15.
2. Mark each start as +1 (a new team starts working) and each end as -1 (a team finishes). So the events list looks like: 9 (+1), 10 (+1), 12 (-1), 15 (-1).
3. Sort all events by time.
4. Traverse the sorted list, maintaining a running count:
   • Add 1 for +1, subtract 1 for -1.
   • Track the maximum value reached during traversal — that’s the answer.

Using the example above:

• At 9: count = 1
• At 10: count = 2
• At 12: count = 1
• At 15: count = 0 The maximum count = 2 → meaning two teams worked simultaneously at most.

Approach 2: Prefix count or sweep line

Same logic, different implementation. Track the number of active intervals across the timeline using prefix sums or an ordered map.

Overall OA Experience

The MathWorks OA this time was very standard — two typical algorithmic coding problems, comparable to easy or medium LeetCode problems.

The interface is clean, and input/output formatting is simple. You get 60 minutes, which is more than enough.

The student I guided had practiced similar logic + implementation problems with us before, so during the OA he was basically on “autopilot mode” — stable and efficient.

In general, MathWorks doesn’t focus on tricky algorithms. It tests your clarity, code structure, and the ability to write bug-free code under time pressure. A stable rhythm and clean logic matter far more than fancy techniques.

Common OA Questions

Q1: Which platform is the OA hosted on?

It’s MathWorks’ own platform — clean, stable, and no extra installations required.

Q2: Is there camera monitoring during the test?

No live camera, but screen recording is enabled. Avoid switching tabs to prevent flagging or disqualification.

Q3: What’s the style of the questions?

Mostly logic and basic algorithm problems. Write simple, clear code; you don’t need any complex tricks.

Q4: How does it compare to other companies’ OAs?

Much easier than finance firms like Citadel or IMC, and simpler than Amazon’s OA. It mainly tests clean code implementation.

Want to Pass the OA Smoothly?

MathWorks-type OAs (logic + implementation) often cause candidates to lose points over small details — forgetting edge cases, incorrect I/O formats, or poor time management.

At Programhelp, we offer a remote invisible assistance solution to help you handle these challenges:

• Real-time voice cues to remind you about I/O formats so you don’t lose points.
• Pre-simulation of the OA environment to get used to the platform and timing.
• Invisible real-time collaboration to keep your logic and typing rhythm steady.
• Post-test review and pattern summary to prepare you for similar problems next time.

Many students have already used this setup to secure interviews at MathWorks, NVIDIA, and Stripe.

If you want to practice the OA flow and avoid small mistakes that cost offers, feel free to reach out — we’ll help you prepare confidently and secure that interview invite!