In codeforces rounf #212 (Div.2) users HoGho and HosseinYousefi cheated.I know that they are not same people(Hossein Ghotboddini and Hossein Yousefi).
They just did find and replace for preventing "Skipped".
Submissions : 5099927 ~= 5100361 (the differences : indents , v=st) 5104961 ~= 5104402 (the differences : aol=vis , gl=dx , ggk=dy , chcheck=check , acccc=ok).
You can easily see that they've cheated and should be banned !
Well,I'm not sure but that 212A had exactly 1 simple solution (the splution using DFS is obviously "unsimple") , so it's possible that 2 solutions are nearly the same.but since the submissions are consecutive, I'm not sure if they don't cheated.
But with exactly 5 "find and replace"s HoGho's code becomes Yousefi's.You can check their codes for contest round #211(Div.2) to !