kostka's blog

By kostka, 10 years ago, In English

Welcome in Bayan 2015 Contest Warm Up hacks description. This round was pretty good for hackers, but again there were nearly two times more unused opportunities for hack than the used ones. Let's look at them.

If you want to share your hack (or mistake) -- we're waiting for your comments.

Previous posts can be found here.

Stats

Problem Successful hacks Unsuccessful hacks Other Sum Solutions which can be hacked Accepted solutions All solutions on final tests
475A - Bayan автобус 243 (53.06%) 205 (44.76%) 10 (2.18%) 458 349 (15.73%) 1869 (84.27%) 2218
475B - Сильно связный город 94 (50.81%) 72 (38.92%) 19 (10.27%) 185 192 (10.35%) 1663 (89.65%) 1855
475C - Картина Камаль оль-Молька 6 (14.63%) 26 (63.41%) 9 (21.95%) 41 113 (25.80%) 325 (74.20%) 438
475D - CGCDSSQ 3 (8.82%) 16 (47.06%) 15 (44.12%) 34 53 (12.27%) 379 (87.73%) 432
475E - Сильно связный город 2 0 0 0 0 1 (3.03%) 32 (96.97%) 33
475F - Мультивселенная 0 0 0 0 26 (76.47%) 8 (23.53%) 34
Here should be graph.
Here should be graph.
Here should be graph.

Hacks and possible hacks describtion

475A - Bayan автобус

The task was pretty simple, the solution could be, so why there were so many fails? In the graph below we can see that test #5 was quite bad. What was that? Simple 0. Many hacks was simply the numbers lower than 3. Why so many people failed on this? They forgot about the middle place, instead of this:

+------------------------+
|#.#.#.#.#.#.#.#.#.#.#.|D|)
|#.#.#.#.#.#.#.#.#.#.#.|.|
|#.......................|
|#.#.#.#.#.#.#.#.#.#.#.|.|)
+------------------------+

they were printing this:

+------------------------+
|#.#.#.#.#.#.#.#.#.#.#.|D|)
|#.#.#.#.#.#.#.#.#.#.#.|.|
|........................|
|#.#.#.#.#.#.#.#.#.#.#.|.|)
+------------------------+
Here should be graph.

475B - Сильно связный город

There are two types of killer tests:

2 2
<>
^v

and

20 20
anything
anything

The pretests weren't really big, so the second test was killing slow solutions or the one with bad memory allocation.

Solutions which was failing the first test were checking mostly if the first and last character in each line were equal, if yes -- then the answer was NO, if no -- then YES. Pretty bad, wasn't it?

Here should be graph.

475C - Картина Камаль оль-Молька

There were only 6 successful hacks and nearly all of them were really big tests, which were giving TLE, so unfortunately there is nothing special to talk about here.

Here should be graph.

475D - CGCDSSQ

Here should be graph.

475E - Сильно связный город 2

Here should be graph.

475F - Мультивселенная

Here should be graph.

Fastest hackers

Problem Time Hacker Defender Hack
475A - Bayan автобус 0:16:49 Killever PERNEKHAN 116880
475B - Сильно связный город 0:45:47 abuka atul_agnihotri 116959
475C - Картина Камаль оль-Молька 2:21:39 CA72 MarioYC 117410
475D - CGCDSSQ 1:15:27 sdya NFF 117081

Best hackers

Hacker Stats Successful hacks Unsuccessful hacks
ho-jo-bo-ro-lo +8-0 (800) A: 117063 117069 117150 117260 117380 117465
B: 117317 117342


KMnO4 +7-0 (700) A: 116943 116965 117118 117157 117186 117209 117232

david942j +7-0 (700) A: 117110 117204 117247 117264 117279 117310 117319

Gassa +7-0 (700) A: 116957 117005 117030 117073
B: 116983 117066 117371


EG0R +5-0 (500) A: 117011 117032 117050 117175 117194

Dixtosa +5-0 (500) A: 117087 117106 117141 117181 117217

proitm +6-3 (450) A: 117245 117248 117251 117337
B: 117079 117165

B: 117083 117402 117416
namdev102 +5-1 (450) A: 117112 117164 117206 117230 117294
A: 117178
phantom11 +5-1 (450) A: 116941 116976 116998 117080
B: 117473
A: 117152

minimario +7-5 (450) A: 116960 117021 117429
B: 117099 117113 117203 117314
A: 116898 116899 116940
B: 117368 117491

Best rooms

Room #hacks Hackers
117 10 KMnO4 [7], Stratonov [2], poopi [1]
32 9 minimario [7], somag [2]
8 8 mohamednabil00000 [5], FlaminRage [3]
18 8 ho-jo-bo-ro-lo [8]
44 8 simulator [4], killa_vanilla [3], dreamoon_love_AA [1]
50 8 wyxourlove [4], ffao [2], ainu7 [2]
19 7 proitm [6], the_redback [1]
29 7 Gassa [7]
38 7 david942j [7]
102 7 nhatminh2947 [4], mhadih [3]

Best countries

Country #hacks Hackers
China 35 wyxourlove [4], Bobgy [3], Dwayne [3], CA72 [2], mwc123 [2], Starzxy [2], Napoleon_cn [2], kuangbin [1], wust_youji [1], Spark001 [1], yanaz [1], HaibaraAi [1], RoundDog [1], CHEATBEATER [1], zhu081607 [1], Silence_Walker [1], JimmyCHW [1], JOHNKRAM [1], greatwall1995 [1], last_one [1], liympanda [1], shigule [1], mstczuo [1], lxw [1]
Russia 34 Gassa [7], gridnevvvit [4], DimaPhil [3], PavelKunyavskiy [2], Petruchcho [2], Sehnsucht [2], HellKitsune [2], ifsmirnov [1], Dmitry_Egorov [1], redoak [1], dzhenakov [1], Misha100896 [1], knst [1], Zool [1], SC_pRo_ION [1], ItsLastDay [1], el_sanchez [1], SlavaSSU [1], savinov [1]
India 26 namdev102 [5], phantom11 [5], shank_punk [3], harrypotter192 [3], kuldeepfouzdar [2], yellow1 [2], StoneCold_ [2], gorv [1], MoritakaMashiro [1], noah07 [1], rishabh.nsit [1]
Bangladesh 24 ho-jo-bo-ro-lo [8], ndatta [3], sahedsohel [3], FlaminRage [3], bhadra [2], ShockProof [1], nfssdq [1], prophet_ov_darkness [1], the_redback [1], MKGAURAB [1]
Ukraine 22 EG0R [5], Programist [4], sdya [2], adamant [2], aangairbender [2], Stratonov [2], Fdg [1], BigBag [1], RomaWhite [1], fiter [1], T0RRES [1]
Iran 21 mhadih [3], PAP [3], Reza_H [2], somag [2], MamZi [2], Kianoosh [1], ArtinTD [1], Fazel [1], BENYAM1N [1], poopi [1], Amirkasra [1], IMAN_GH [1], SAKT [1], NADAF [1]
  • Vote: I like it
  • +61
  • Vote: I do not like it

| Write comment?
»
10 years ago, # |
  Vote: I like it -51 Vote: I do not like it

DmitriyH and you are so annoying!

  • »
    »
    10 years ago, # ^ |
      Vote: I like it 0 Vote: I do not like it

    :( Why do you think so? I thought that bunch of stats won't hurt anyone.

    • »
      »
      »
      10 years ago, # ^ |
        Vote: I like it -18 Vote: I do not like it

      Accept that you're doing that for contribution, ok?

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

Fastest hacker for second time :D

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

What does "other" mean?! Is there any thing between successful and unsuccessful hack?!

  • »
    »
    10 years ago, # ^ |
      Vote: I like it 0 Vote: I do not like it

    It is one of the: INVALID_INPUT, GENERATOR_INCOMPILABLE, GENERATOR_CRASHED, IGNORED, OTHER.