Wow - one of the problems that caused me grief on the programming challenges web site was 110104 LC-Display. Today when I logged in I noticed it was now marked as solved, yet I haven’t submitted that problem for 3 years. It also appears that I had 5 different correct solutions, that were originally marked wrong.
So someone has reviewed that problem, and found the judge solution was wrong, and re-evaluated all submissions. It’s good to see the site is still alive.
Pity they don’t have a forum as this was a good place to discus tricky problems, and give clues for the easier problems.
My 110206 Erdös Numbers solution is now showing as Compilation error (for all 160 submissions), so I might try and track that down…