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 other implementations.

For example take a look at the following problems:

2057A - MEX Table — just print max(n, m) + 1

2044A - Easy Problem — just print n - 1

2009A - Minimize! — just print b - a

1445C - Division — just print x - 1 and y

Although these problems are fun to solve and sometimes tricky, being disqualified because you accidentally write the same code with other unlucky contestant it's pretty annoying. I think the plagiarism detector should be less strict for the simple enough problems.