Good Bye 2015! (review, pt. 1)

#	User	Rating
1	ecnerwala	3649
2	Benq	3581
3	orzdevinwang	3570
4	Geothermal	3569
4	cnnfls_csy	3569
6	tourist	3565
7	maroonrk	3531
8	Radewoosh	3521
9	Um_nik	3482
10	jiangly	3468

#	User	Contrib.
1	maomao90	174
2	awoo	164
3	adamant	162
4	TheScrasse	159
5	nor	158
6	maroonrk	156
7	-is-this-fft-	151
8	SecondThread	147
9	orz	146
10	pajenegod	145

Hey there, I couldn't sleep, so I spend almost an hour to play with some Python and answering some questions about "who was... in 2015 on Codeforces" (also checking if I still remember anything :)). So — have you ever wondered who was the best in this year on Codeforces? I will try to answer to your (and mostly mine) questions. Here is the first part (and maybe the last :)) of this year review. In this year, there were 105 contests on Codeforces, 12 of them were not on CF rules, so there were removed from the rest of review (i,e, Educational Rounds, some ACM contests and so on).

Most problems solved

Handle	Contests	Sum of tasks solved	Average
20171231	52	112	2.153846
alex_bucevschi	53	106	2.000000
Shavkat_Aminov	54	105	1.944444
ershov.stanislav	31	100	3.225806
Endagorion	30	99.5	3.316667

Wait, what? Half of the problem? There were some rounds where teams were allowed (for example VK Cup Rounds). I decided that the most fair way is to split all solved problems between all team members. That's why there could be some not integral numbers.

I was also really surprised that people from div. 1. made it here. Kudos to them!

Largest mean of solved problems during official contests

(with more than 10 contests in this year)

Handle	Contests	Sum of tasks solved	Average
jqdai0815	21	89.5	4.261905
kcm1700	12	51	4.250000
Petr	15	62.5	4.166667
rng_58	13	53	4.076923
Egor	15	61	4.066667

Number of contests

(kudos for all people there, I want to really congratulate all "veterans")

Handle	Contests	Sum of tasks solved	Average
Iskandarov_Islom	57	86	1.508772
Shavkat_Aminov	54	105	1.944444
alex_bucevschi	53	106	2.000000
CMaster	52	92	1.769231
20171231	52	112	2.153846

And now my favorite part of Codeforces contests :)

Hacks

Most "hacked" points

	Hacked points	Succ hacks	Succ hacks per contest	Unsucc hacks
ErzhaNN	8150	97	2.06383	31
suigingin	6950	82	1.782609	25
ndatta	5900	70	1.891892	22
shank_punk	5800	70	1.707317	24
Adhambek	5700	70	2.413793	26

Most successful hacks

	Hacked points	Succ hacks	Succ hacks per contest	Unsucc hacks
ErzhaNN	8150	97	2.06383	31
alex_bucevschi	5000	87	1.641509	74
suigingin	6950	82	1.782609	25
CMaster	3550	79	1.519231	87
Shavkat_Aminov	4950	72	1.333333	45

And?

Well, I was thinking about finding out who had the biggest rating change (both during year and after one contest), and to narrow some things just to Div. 1. (who took part in nearly all rounds, who was the best hacker and so on). Any other thoughts? Do you like such kind of posts? (Right now I think I will go to sleep properly :)).

Anyway, Happy New Year to everyone!