IIRC the Coursera class autograder used actual code, and offered _some_ design improvement suggestions - about code correctness, edge cases, speed. Of course, i

IIRC the Coursera class autograder used actual code, and offered _some_ design improvement suggestions - about code correctness, edge cases, speed. Of course, it couldn't point out other design flaws. I think that the Java used in that class was a good approach. By limiting the packages you could use, they prevented leveraging builtin facilities (e.g. Java collections) and forced people to write their own data structures.