You are welcome. Short term student programmers may be more likely to write buggy code, but even those with experience make mistakes. Doing some QA helps, code review helps more - but both are not always sufficient.
If the code was subjected to more use - bugs would probably get discovered and fixed sooner... Contributing problems to the OPL is one way to get them more widely used and thus tested and debugged. (Though I should not be the one to say this as my university is not rushing to share the locally developed content, at least not yet.)
I noticed that the solution text is also not totally accurate... You want to state that the rest of the diagonal entries should be set to 1.
If the code was subjected to more use - bugs would probably get discovered and fixed sooner... Contributing problems to the OPL is one way to get them more widely used and thus tested and debugged. (Though I should not be the one to say this as my university is not rushing to share the locally developed content, at least not yet.)
I noticed that the solution text is also not totally accurate... You want to state that the rest of the diagonal entries should be set to 1.