A lot of people in today's contest have copied code from various sources. A youtube channel was continously posting solutions during the contest. He posted A,B,C,D solutions within the first hour of the contest.
Numerous people copied code from here and made slight changes into the code and submitted and got AC. I request you to get this channel banned as soon as possible and take whatever action is required so that codeforces ratings do not loose credibility.
These channels distribute solutions during live contest and even the people who cannot solve A end up solving 3 to 4 problems. So it's better if these channels are banned asap else there is no point in giving these contests when someone can cheat and easily get a better rank than you.