Hack me! (Codeforces Round #282 (Div. 2))

#	User	Rating
1	tourist	3856
2	jiangly	3747
3	orzdevinwang	3706
4	jqdai0815	3682
5	ksun48	3591
6	gamegame	3477
7	Benq	3468
8	Radewoosh	3462
9	ecnerwala	3451
10	heuristica	3431

#	User	Contrib.
1	cry	167
2	-is-this-fft-	162
3	Dominater069	160
4	Um_nik	158
5	atcoder_official	157
6	Qingyu	156
7	djm03178	151
7	adamant	151
9	luogu_official	150
10	awoo	147

Quite delayed, but here we have stats about hacks in Codeforces Round 282 (Div. 2).

Previous posts can be found here, including div1.

Stats

Problem	Successful hacks	Unsuccessful hacks	Other	Sum	Solutions which can be hacked	Accepted solutions	All solutions on final tests
495A - Digital Counter	623 (85.58%)	76 (10.44%)	29 (3.98%)	728	47 (2.65%)	1727 (97.35%)	1774
495B - Modular Equations	274 (79.42%)	60 (17.39%)	11 (3.19%)	345	232 (27.17%)	622 (72.83%)	854
495C - Treasure	103 (56.59%)	75 (41.21%)	4 (2.20%)	182	426 (64.06%)	239 (35.94%)	665
495D - Obsessive String	0	0	0	0	3 (27.27%)	8 (72.73%)	11
495E - Helping People	0	0	0	0	0	0	0

Hacks and possible hacks description

495A - Digital Counter

That was an interesting problem, but the hacks were pretty simple — the pretests weren't checking every digits, so when someone made a mistake, we can make use of it.

Congratulation to all hackers, because only 47 solutions (2.65%) didn't pass final tests. :)

495B - Modular Equations

The most popular hack was pretty simple:

1000000000 1

Solutions with complexity O(|b - a|) resulted with TLE.

495C - Treasure

The hacks were simple strings with no solutions like:

(#(

(((#)((

(#(()

It was also test #14 (look below):

((#)(

Pretty and deadly :)

495D - Obsessive String

495E - Helping People

Fastest hackers

Problem	Time	Hacker	Defender	Hack
495A - Digital Counter	0:11:52	roiti46	miloserd	127885
495B - Modular Equations	0:34:08	gerelteiblog	YoChinezu	128171
495C - Treasure	0:49:03	iphone	god_of_pain	128488

Best hackers

Hacker	Stats	Successful hacks	Unsuccessful hacks
IDont_love_TanyaRomanova	+15-2 (1400)	A: 127886 127890 128042 128048 128053 128151 128316 128632 128816 129149 B: 128304 128341 128952 129196 129665	A: 127931 B: 129103
hakeem	+13-0 (1300)	A: 128468 128482 128510 128556 128573 128597 128617 128666 128717 128748 128774 128794 128890
deemem26	+13-1 (1250)	A: 128583 128622 128663 128689 128713 128837 B: 128989 C: 129510 129544 129573 129679 129700 129737	B: 129105
ImagineWarrior	+13-1 (1250)	A: 128278 128327 128360 128398 128426 128437 128446 128489 128498 128521 128568 128599 128624	A: 128470
diegoPenguino	+12-0 (1200)	A: 128625 128655 128720 128784 128797 128821 128831 128842 129059 129069 129111 129481
Eldor_Zoirov	+12-1 (1150)	A: 127962 127984 127991 128008 128033 128045 128063 128339 129248 B: 129133 129161 129206	A: 128987
gerelteiblog	+12-1 (1150)	A: 128334 128351 128365 128376 128382 128430 129575 B: 128171 128190 128499 129025 129045	B: 129073
konmaj	+11-0 (1100)	A: 128833 128856 128869 128877 B: 129112 129132 129387 129484 129774 C: 129684 129734
anhphi257	+11-0 (1100)	A: 128152 128181 128308 128357 128412 B: 128670 128701 128731 128758 129476 129495
P_Quantum	+11-0 (1100)	A: 129516 129540 129564 129577 129605 129627 B: 129325 129355 129368 129393 129692
roiti46	+11-0 (1100)	A: 127885 127889 127891 127935 127944 B: 129372 129391 129416 129517 129677 129699
Bek13t	+11-1 (1050)	A: 128057 128066 128098 128107 128119 128207 128313 128799 129208 129509 B: 129751	A: 128087
ezkatka	+10-0 (1000)	A: 128933 128939 129004 129011 129017 129022 129051 129079 129096 129110
GaryWong	+10-0 (1000)	A: 128916 128942 128992 129003 129451 B: 129222 129242 129261 129270 129283
bonyisrail	+10-1 (950)	A: 128920 128966 129043 129082 129092 129148 129169 129184 129197 129228	A: 129475
komendart	+10-1 (950)	A: 127894 127904 127912 127947 127951 128164 128380 B: 128873 128908 128929	B: 128970

Best rooms

Room	#hacks	Hackers
67	22	ImagineWarrior [13], biltharesatyendra [7], mR_zohir [2]
44	19	ivan.sachkovski [9], smallling [9], D05T0N [1]
48	18	Bek13t [11], sxczf [4], aman_cold [3]
8	17	komendart [10], dinepo [5], zjwoody [2]
29	17	gerelteiblog [12], underSpirit [2], deleteeeeeeeeed [2], r3gz3n [1]
59	17	IDont_love_TanyaRomanova [15], Khairy [1], compilation_error [1]
61	16	deemem26 [13], shadow_crawler [3]
4	15	bulat.s [6], ruvamu [6], GreatDice [2], aloksharma [1]
50	15	sanzhar_001 [7], arystan_kalimov [5], M.Aladdin [3]
68	15	bonyisrail [10], zyaad [3], bes4etnov [2]
72	15	ezkatka [10], Rafiq_SEC [3], Arento [1], Alimol [1]

Best countries

Country	#hacks	Hackers
India	140	P_Quantum [11], hell_raiser [9], ksaurav [9], kuldeepfouzdar [8], hariramsvnit [7], kshashank [7], biltharesatyendra [7], pk. [7], PrashantM [7], ddt [6], ksurv [5], grayhathacker [5], Dr.I_m_possible [5], ManikantanV [4], prakhar3agrwal [4], venki421 [4], yashkumar18 [3], vishwacs111 [3], shank_punk [3], abbas [3], Skr379 [3], ShekharNain [3], rohitnandani3118 [3], sysadmin [2], conspirator [2], tusharg1993 [2], aloksharma [1], achaitanyasai [1], onecoder [1], kaushik_iiitd [1], gupta_shvm [1], av.driftking [1], kalpjain [1], r3gz3n [1]
Bangladesh	87	ImagineWarrior [13], bonyisrail [10], Baridcse [9], MRoy [7], Emruz_Hossain [6], joker00 [6], musa.cse12 [5], aliakber [4], aerofoil.kite [4], Rafiq_SEC [3], shadow_crawler [3], dipta007 [3], Abinash [3], Najmuzzaman [2], adnanSharif [2], imtiaz_iu [2], underSpirit [2], ashiquzzaman33 [1], ivplay [1], Mohtasim [1]
Russia	60	ZharkovGK [8], Sehnsucht [6], bulat.s [6], sultazat [5], MagAlex [5], desdolganov [5], favstovol [3], NevstruevDmitriy [3], gars [3], Alexp239 [3], bes4etnov [2], Vesbat [2], bunos [2], Kirito.LVL99 [1], Loremon [1], iphone [1], mayorovmp [1], Arento [1], EasyRider [1], Fritz_97 [1]
Iran	58	hakeem [13], kj.1998 [9], TheOverlord [8], mosiomohsen [6], Majid [4], DaneshvarA [4], R4mt1n [4], taki [3], ITDOI [2], oofldw289 [1], ashkan_d13 [1], Alimol [1], SaDDaS [1], Batman [1]
China	53	smallling [9], I_Love_Balabala [9], Defined [8], biu [6], ChouUn [6], zjbztianya [4], quakerzyq [4], luminous11 [3], akxxsb [3], xiaowei [1]
Kazakhstan	51	Bek13t [11], qwertyuiop [8], sanzhar_001 [7], arystan_kalimov [5], SmallBoy [5], chrome [5], CMaster [3], ErzhaNN [3], dangerOff [1], aspiring_man [1], TimaMetiss [1], ZzZZzzzZZZZZzzzzzzzz [1]
Uzbekistan	40	Eldor_Zoirov [12], Shavkat_Aminov [9], Yura_Sultonov [8], rng__58 [4], Rasulbek [3], Valixon [2], D05T0N [1], mehmed_77 [1]
Egypt	38	Druid [8], A__H [6], waleed [5], Raoof [5], ahmedameen [4], Mohamed_Ayman [3], M.Aladdin [3], Amr-Alaa [1], mohamednabil00000 [1], Mostafa_Hamdy [1], Khairy [1]
Belarus	30	IDont_love_TanyaRomanova [15], MSPU_Pikun [5], chiselko6 [4], sazas [3], Scrat [1], aandrukhovich [1], Dovgal [1]