There is a possibility of dataset contamination on the competitive programming benchmark. A nice discussion on the page where AlphaCode2 was solving the problem

There is a possibility of dataset contamination on the competitive programming benchmark. A nice discussion on the page where AlphaCode2 was solving the problems https://codeforces.com/blog/entry/123035 https://codeforces.com/blog/entry/123035 Problem showed in the video was reused in a recent competition (so could have been available in the dataset).