Let me mention one of the main contributor named Nitin nitin_05 Singh Rawat.
Most important tip
Codeforces Round #748 (Div. 3)
Solution B
Solution C
Solution D1
Solution D2
Solution E
Not only Codeforces Round #748 (Div. 3), every contest in his profile, he uses the same way to contribute to code forces and take "ratings" in return.
If anyone wanted to learn how to add comments in code, contact nitin_05.
MikeMirzayanov have a look at his abilities, how beautifully he adds comments in his code.
You need to start fromToday (anyone get it?), and not wait until later.
Dammed, I Open This Blog to take tips for Expert But Not in that sense :(
Even today also solutions of the first 4 problems were leaked in that same website as evident from the number of submissions and drastic decrease from the 5th problem :(
Can-do's and Can't-do's
Codeforces Contest Rules