I have solved some of the problems in the challenge. Today I have been experiencing that the submission hangs up (i.e., it appears to be running but never finishes). I took one of the problems that I had previously solved and resubmitted it and had the same thing happen (appeared to be running but never finishes). Has anyone else encountered this?
Yes, I had the same experience yesterday. But when the running time exceeded the usual 2 minutes duration, I checked the My Submissions page and found that the automatic judge had finished testing the submitted code, and the result was reported. It seems that the problem is not with the automatic judge, but that the browser for some reason did not receive and display the results in the completed submission page after the automatic judge had finished.