I honestly feel like the first Java coding question in this OA is designed in a very frustrating way.
The issue is not just that the question is hard. The real problem is that the provided starter code seems to contain some very hidden trap that makes the solution fail to compile, and the platform gives almost no useful compiler feedback. You only have around 20 minutes, but you are expected to not only write the actual logic, but also somehow identify the intentionally confusing issue inside the provided code without a proper IDE or clear error message.
That makes the question feel less like a Java coding assessment and more like a blind debugging challenge. Unless you are very strong at debugging Java syntax and environment issues under pressure, it is extremely easy to get stuck forever even if your actual idea is correct.
I understand that companies want to test attention to detail, but hiding a subtle compile issue in the source code and giving no clear feedback feels unnecessarily punishing. In a real development environment, nobody debugs this way. You would normally have IDE hints, compiler logs, stack traces, or at least enough information to locate the problem.
For an entry-level or graduate-style OA, this feels especially rough because the assessment is supposed to test basic coding ability, not whether you can reverse-engineer a hidden trap in a broken template within 20 minutes.