### maroonrk's blog

By maroonrk, history, 2 months ago,

We will hold AtCoder Regular Contest 149.

The point values will be 300-500-500-700-700-900.

We are looking forward to your participation!

• +105

 » 2 months ago, # | ← Rev. 2 →   +9 hope all of you have fun!(upd: What an interesting contest! the solution of B is very interesting!)
 » 2 months ago, # |   +14 Hope you all have a good time in this competition！
 » 2 months ago, # |   0 Hope to solve 3 problems
•  » » 2 months ago, # ^ |   0 Succeeded!
 » 2 months ago, # |   +6 thanks
 » 2 months ago, # | ← Rev. 2 →   -8 Problems were interesting.
•  » » 2 months ago, # ^ |   0 Hey i have never participated in ARC rounds. Are they harder than normal beginner contests?What is the minimum codeforces rating one should have to solve 2 problems in most of the contests?
•  » » » 2 months ago, # ^ |   0 Yes ARCs are harder than ABC contests and it's rating range is until 2799 but ABC's rated range is until 1999, Also I don't think CF rating is a good criterion for atcoder contests so I can't answer your second question.
 » 2 months ago, # |   +3 C was a good problem, but my algorithm only works with $n \geq 9$. therefore, i have to calculate all the situations for $n \in [3, 8]$ and add it to my code :(
•  » » 2 months ago, # ^ |   +6 I am luckier than you.I have to calculate the situations for n=3&&n=5.
•  » » » 2 months ago, # ^ |   0 I'm even luckier, I only need to calculate the situation for $n=3$.
 » 2 months ago, # |   +11 D harder than normal, but it's still a great contest. Hope a more banlanced contest next time!
 » 2 months ago, # |   +13 Problem D is similar to this problem.
 » 2 months ago, # |   0
 » 2 months ago, # |   +3 It is difficult for me to understand the official solution of problem D, especially the "symmetry" part and the "spanning a directed edge" part. Would anyone like to share your editorial of this problem? Thank you so much.
 » 2 months ago, # |   +57
 » 2 months ago, # |   0 Such testcase does not exist in D, where the last move will put something to coordinate 0. Example case: 1 1 5 5
 » 2 months ago, # |   -10
 » 2 months ago, # |   0 In problem A, X is a positive integer less than 10^N and N can go upto 10^5 which means X is a positive integer less than 10^(10^5). What should I conclude from this?
•  » » 2 months ago, # ^ |   +8 It means X is a string of digits with string length <= 10^5.
 » 2 months ago, # |   0 In Problem C, instead of looking for multiples of 3, I looked for getting the sum of n^2 (for n = odd cases because n^2 is odd, so the sum of 2 numbers means one of them is odd) and n^2-1 (for n = even cases because n^2-1 is odd.)Both n^2 and n^2-1 are NOT prime.
 » 2 months ago, # |   0 I am so happy that I've got a rating rise of more than 900 points.(As my surprise, Atcoder's discuss in in Codeforces.)