I was reading a solution for PSHTBRTH and found a referrence to following StackOverflow link. Note that this question was asked on March 6, 2017 (during the contest).
Therefore, all those contestants whose code is similar to the code given on StackOverflow should be counted as cheaters and it should be added to rules that if any contestant is caught asking or using StackOverflow to ask contest question during the contest then he would be counted as cheater.