There are some users who do not attempt to solve a problem, but have instead have found a hack the solver to create a so called "best" solution. Ignore these.
Cody admins and mods are trying to make sure that such cheats are no longer allowed and the ones that are already been implemented are no longer valid. You can check and see the solution you mentioned in your question and see that it is no longer an accepted or a valid answer.
See related posts -
A very common hack, which is now not usable A general discussion (includes comments from Cody and MATLAB Central advisors)