In the Python book 15.10 computing a Gray code, I am thinking whether it is necessary to add three lines of codes after
so it becomes:
This is because if you have checked that the recursively called function returns False, it means at the end of the day, the first and last element will not satisfy the requirement, so the candidate is not valid to be added. Rather, you need to try other candidate in the for loop, and you need to clear what was done in the previous round.
I know that as a result, the original code also outputs the correct answer. This is because in fact, the first-last element check alway passes. But logically, I think it is necessary to add the lines of codes.
Am I correct?