Recently, I've participated in Educational Codeforces Round 173 (Rated for Div. 2) and I've got a system message reporting that my submission 298211934 for the problem 2043B - Digits significantly coincides with Alexandr_White's submission 298213898. All other submissions from that contest got skipped, thus I got disqualified and my rating got rolled back. I checked both submissions and indeed are almost identical! Now I think this problem was caused by the fact that there aren't other solutions to solve the problem and the only solution isn't so complex to generate many differences in implementations.