We will hold AtCoder Regular Contest 176.
- Contest URL: https://atcoder.jp/contests/arc176
- Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20240421T2100&p1=248
- Duration: 120 minutes
- Number of Tasks: 6
- Writer: PCTprobability
- Tester: maspy, Nyaan
- Rated range: — 2799
The point values will be 400-400-700-700-800-1000.
We are looking forward to your participation!
Hoping for the best ARC Round!
Good luck to all who are competing!
As a writer,I hope everyone who participates in this contest will enjoy it. Good luck!
Good Luck!Hope C!
I didn't get the question right
A was kinda tricky if you don't get the point :( I spent 30+ min on it :(
what was the idea?
can u please explain the solution of A. I am unable to get (b[i] — a[i] + n) % n , i cant understand it even after looking at the editorial
Maybe you can look at the following cases:
Where
x
andy
means $$$1$$$ ando
means $$$0$$$. You can divide them into $$$n$$$ sets that in each set, the elements has a same $$$(b_i-a_i)\bmod n$$$.Nice Explaination , thankyou so much
Yet another pure math contest. I suck at math, so dislike.
can B be solved using bitmasks? I don't know about it but i reduced it to a point like this where quotient is
but I was unable to solve it as I'm not good enough in bitmasks and stuff
what is the idea behind A?
Does B have no testcase with $$$n = m-1$$$ and $$$k=m-1$$$? I realised this condition a few seconds after submitting, but to my surprise, my code got AC.
Data of problem A is weak. As a result of me and my friends' verification, there is not a single piece of data that is $$$M \ne N < 2M$$$. And this is the evidence.
For example, this code which I submitted during the contest must be wrong. It gives completely wrong answer with this input.
I sent a clarification an hour ago, and I'll update as soon as possible when I see any response. I hope that I can write up a code that will allow me to get Accepted after the data is strengthened.
And I LOVE problem B. Very beautiful problem!
can anyone explain question b solution i did not understand
My First ARC got a 0pts but Rating+26, seems like it does need so many brainstroming instead of a number of algorithms at ahead problems.
Problem B is really a clever problem. I think I will never notice the case k=m-1 until I read the editorials. Hats off to the problem writers!
Data of problem C is also weak
The Editorial of C says:
and I forgot to check this case ($$$X_v < k$$$) during the contest, but my code got AC.
There is an input for this case:
my code during contest will give $$$40320$$$.
My code passed your case, but for this case:
my code will give 4.
I'm not sure whether this is common.
I hacked a lot people when I try to use their codes to check my wrong code. I'm so helpless. Who could help me?
Can someone explain the following code for problem A — 01 Matrix Again ?
There are total of n^2 elements in matrix so each (i-j)%n will occur atmost n times.
(you can draw the matrix of (i-j)%n for some n to see it youself)
since element are occurring on separate row and col we can assign 1 to such element that will increase the sum by n. How many times we need to do this? m times
So at last we just need to select m remainders out of n and assign 1 to those positions.
since some pairs are already given, we can just use remainder of those.
I hope it helps...
can someone explain me the problem problem D in it ,I cant understand how transition states are made.