SET 1
if you see these solution, they are IDENTICAL
the hilarious part is that they have the same comments everywhere!!
http://www.codechef.com/viewsolution/2811693
http://www.codechef.com/viewsolution/2811742
http://www.codechef.com/viewsolution/2812230
This guy was smart enough to remove unwanted parts but i guess he is caught too
http://www.codechef.com/viewsolution/2812315
SET 2
identitcal solutions
http://www.codechef.com/viewsolution/2790619
http://www.codechef.com/viewsolution/2793316
http://www.codechef.com/viewsolution/2790711
this looks (to me) edited variable version of the above
http://www.codechef.com/viewsolution/2796890
i am sorry if i am wrong but there is almost zero doubt about the cheating here as well (including identical solution in other problems)
I think there are many other out there…i just checked the first page of submissions with identical time and memory