Yes you are right that you normally wouldn't change the input vector. I wanted to keep it as simple as possible with this one, that's why I didn't make it constant. But I will change it :)

You are right. It should be fixed now... Thank you for telling me!

I have removed unnecessary test cases and added random cases. I also changed the sample test and added the one for one task. Is that what you meant?

I have added random test cases, thanks for the feedback!