### Tomah4wk's blog

By Tomah4wk, history, 10 months ago, ,

In the last 2 rated Div1 rounds there were 2 problems with such good points that can be solved by just writing a brute force and figuring out a pattern and then you may kiss the bride.

815B - Karen and Test

809C - Find a car

How does it seem to you?

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 » 10 months ago, # |   -22 By the way how many non-english natives here who know the meaning of "notorious" :'D
•  » » 10 months ago, # ^ |   +145 I came across the word in a comment I read (it was in English) way back.
•  » » 10 months ago, # ^ | ← Rev. 2 →   +10 Although one wouldn't use "notorious" in such a context :3 Edit: Sorry, didn't know about the notorious coincidence you are referring to XD
 » 10 months ago, # |   +36 I hope that in 809C - Find a car you aren't talking about thing that the value in cell (i, j) is (j - 1)xor(i - 1) + 1... If you are, then you should read about Sprague Grundy theorem. If you are talking about that recursion, then you should read about how xor behaves. I can bet that most of participans didn't write brute force to this problem, it's well known that this matrix behaves like this. If it comes to problem 815B - Karen and Test, then yes, it isn't the most interesting sort of problems, but imo it's not so bad on individual contests, where you have computer just for yourself and brute force is easy to implement and gives much.
•  » » 10 months ago, # ^ |   -24 Seems you got aggressive after getting up to top 10 :( (Yeah rating changes people)Anyway, it's a programming contest, I can bet that most of participants would write a brute and recognize the pattern for 5 minutes rather than thinking for > 10 minutes of an interesting solution and fapping after getting the idea. I bet most people fap after getting higher rating more frequently than after getting nice ideas (However I'd fap for nice ideas)Problems alike shouldn't exist in my opinion in a CF round (This comment will be downvoted because you are who you are and I am just a normie but I don't care), It make some get what they may not deserve.
•  » » » 10 months ago, # ^ |   +27 Huh, hold on, your comment looks much more aggresive to me :P. As for me and find a car — I knew that it is i^j with some +-1 instant I saw that picture, I already encountered exactly same matrix at least 3 times and it is not hard to come up with it from scratch (smallest integer not present in some set — sounds pretty familiar, probably has some connection with games theory, xors etc). However I was not able to solve the problem even though I spent a long time on it. As for today's problem, yes, I agree it is kind of problem when you need to write a bruteforce to notice the pattern but I think such problems are completely fine, especially on individual contests.
•  » » » » 10 months ago, # ^ |   -27 I really hate that situation when you sit and boost your brain to come up with an idea. I tried some binomial shit today (but seems I am not experienced enough), anyway in the end couldn't come up with something. But when most of people wrote that it was patterns stuff I was pretty much likeand BTW this post was just for fun and mentioning the notorious coincidence but seems your friend has been so much serious recently :D I hope he hasn't been friendzoned
•  » » » » » 10 months ago, # ^ |   +31 I would say I am rather experienced with binomials and shit but I would say there was no way to concluding how does it look like without writing bruteforce. Problems like that happen from time to time, it is not something extraordinary.
•  » » » » » » 10 months ago, # ^ |   +27 You are stressed so much guys, I think that I should just post it here for you.
•  » » » » » » » 10 months ago, # ^ |   +399 Yo mama waited 9 months for systests and she got WA
•  » » » » » » » » 10 months ago, # ^ |   +42 ;_;
•  » » » » » » » » » 10 months ago, # ^ |   +88 Yo mama so fat she falls on both sides of the bed at the same time.
•  » » » » » » » » » 10 months ago, # ^ | ← Rev. 2 →   +172 deadwingYou started a civil war in Poland :P
•  » » » » » » » » » 10 months ago, # ^ |   +317 When yo mama creates grid problems she gives first number of columns and then number of rows
•  » » » » » » » » » 10 months ago, # ^ |   +65 Yo mama so ugly her face is just one giant presentation error.
•  » » » » » » » » » 10 months ago, # ^ |   +181 When yo mama creates contests she uses dynamic scoring
•  » » » » » » » » » 10 months ago, # ^ |   +40 Yo mama so stupid on Distributed Code Jam she was solving A throughout entire contest.
•  » » » » » » » » » 10 months ago, # ^ |   +138 Yo mama records screencasts
•  » » » » » » » » » 10 months ago, # ^ |   +160 And yo mama watches them.
•  » » » » » » » » » 10 months ago, # ^ |   +95 Yo mama asks if it's rated
•  » » » » » » » » » 10 months ago, # ^ |   +193 Yo mama got compilation error on test 57.
•  » » » » » » » » » 10 months ago, # ^ | ← Rev. 3 →   -127 yo mamas are funnier than chinese
•  » » » » » » » » » 10 months ago, # ^ |   +123 And yo mama got "Can't find file C:\Contesters\Work\invoker-prod\work\codeforces2\b00a58c7139058a693e243e272a449d7\check-aa5f5d80dec38086488721f39ffc5878\run\output.fd0138e687.txt"
•  » » » » » » » » » 10 months ago, # ^ |   +98 Yo mama still wonders who sorry_dreamoon is.
•  » » » » » » » » » 10 months ago, # ^ | ← Rev. 2 →   +16 Yo mama failed a relatively easy problem on a first day
•  » » » » » » » » » 10 months ago, # ^ |   +69 Yo mama's graphs can contain loops and multiple edges.
•  » » » » » » » » » 10 months ago, # ^ |   +65 Sorry man, Swistakk won
•  » » » » » » » » » 10 months ago, # ^ |   +56 Yea, I guess people don't know what was problem A on DCJ about :/
•  » » » » » » » » » 10 months ago, # ^ |   -27 Your mamas read all the comments.
•  » » » » » » » » » 10 months ago, # ^ |   -8 yo mamas are are proud of you both :D
•  » » » » » » » » » 10 months ago, # ^ | ← Rev. 2 →   +115 "When yo mama creates grid problems she gives first number of columns and then number of rows" and square samples. P.S. You guys should create a twitter with jokes.
•  » » » » » » » » » 10 months ago, # ^ |   -43 Seems there are so many chinese here such that my comment got -115. I guess all of them were like: Calm down it's just a joke.
•  » » » » » 10 months ago, # ^ |   +17 I think brute-forcing is just another idea to try during contest, neither better, nor worse.However, my way to find the solution was to draw some pyramids for some short sequences like a b c, a b c d. When you notice a+c b+d in the third row of pyramid beginning with a b c d, you can smell something interesting, when you extend the first row with e f then magically a+2c+e b+2d+f in the fifth row appears, you can continue that process, prove it or start believing it works and code it. Some may say that it's essentialy brute-forcing but it shows that this problem really can be solved without using PC, which could be important during team competitions (for example your teammates have some easier problems to code in the first hour). Sometimes solving small cases can help you understand the structure of the problem better ;)
•  » » 10 months ago, # ^ |   +37 I think opposite. It is OK on ACM contests because you can implement bruteforce in 2 minutes, print this triangles and look at them while your teammate coding another problem.
•  » » » 10 months ago, # ^ |   -21 You can get yourself a printer and print these triangles at home too :)
 » 10 months ago, # |   +27
•  » » 10 months ago, # ^ |   -15 Such a classic !