kostka's blog

By kostka, 9 years ago, In English

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
Here should be graph.
Here should be graph.

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. :)

Here should be graph.

495B - Modular Equations

The most popular hack was pretty simple:

1000000000 1

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

Here should be graph.

495C - Treasure

The hacks were simple strings with no solutions like:

(#(
(((#)((
(#(()

It was also test #14 (look below):

((#)(

Pretty and deadly :)

Here should be graph.

495D - Obsessive String

Here should be graph.

495E - Helping People

Here should be graph.

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]
  • Vote: I like it
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9 years ago, # |
Rev. 3   Vote: I like it +5 Vote: I do not like it

How do you detect the country of contestants? I think there is something wrong.

For example hakeem is from Kazakhstan, not Iran.

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    9 years ago, # ^ |
    Rev. 2   Vote: I like it +1 Vote: I do not like it

    Thanks for mentioning. I used to check everyone's country, but it looks like it is quite bugged. I will take a look.

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9 years ago, # |
  Vote: I like it +1 Vote: I do not like it

thanks kostka for this information :)

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9 years ago, # |
  Vote: I like it 0 Vote: I do not like it

I know this was probably asked before but I don't know where to look for, so what is other? Wrong inputs?

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    9 years ago, # ^ |
      Vote: I like it +1 Vote: I do not like it

    Also. One of the: INVALID_INPUT, GENERATOR_INCOMPILABLE, GENERATOR_CRASHED, IGNORED, OTHER.

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      9 years ago, # ^ |
        Vote: I like it 0 Vote: I do not like it

      And still, what is OTHER? (and ignored) :)

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        9 years ago, # ^ |
          Vote: I like it +1 Vote: I do not like it

        You have to ask Codeforces Team — I have never seen such thing :)

        It is just in possibilities.

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9 years ago, # |
  Vote: I like it 0 Vote: I do not like it

very nice...

wish to continue it...

and so nice to see Iran in top countries( I'm in the list too :) )