Hello codeforces community!
I am happy to invite you to participate in the Aleppo Collegiate Programming Contest 2023 V.2 (V.2 because the first version of the contest was dismissed, so this is version 2) that was held at Damascus University on Aug/22/2023 17:00 (Moscow time). The online training will be on codeforces gyms and will start on Aug/29/2023 14:00 (Moscow time).
Thanks to Kaitokid, AboAbdoMC, Mahmoud_Haddad, Obada_Saleh, Mohanad_Nahhal, YazanAlattar, A.D., Helal_Salloum, Wael_Mchantaf and radi__07 for creating and preparing the contest. Special thanks to Majedh and Anas_Da who did most of the work.
Thanks to Baraa_Armoush and HeMoo for their contribution and constructive feedback.
Thanks to Vectors_Master, TripleM5da, IsaacMoris, BabaVoss, Abdelrahman_Etman, LastDance_NotLastOfMe and Assem_albitar for solo testing.
Thanks to the team testers:
Thanks to Damascus University for hosting the onsite contest.
Thanks to polygon for providing the amazing platform for creating and preparing the problems, and to codeforces for the hosting of the online training.
I hope you enjoy solving the problems. Any feedback will be appreciated.
As a tester, I'd like to say that naseem makes some good matcha.
Agree, the best matcha I've ever tasted in my life.
As a tester , I think I deserve some contribution LOL
Can you give me too??
As a problem setter
Naseem is the greatest chief judge I've ever seen
And give me contribution
You’ve only seen one chief judge
I don't think I will see a better chief judge soon
Excited for this round. It is expected that this round will be enjoyable :)
As a tester, I can say that the authors did a great job on this contest with all the interesting problems.
Thanks, you are the best
Lk 3ashhh <3
Thanks to everyone who contributed to this
Thanks for the nice problem ideas and strong testing :)
As a tester , I'd like to say I'm so proud of you Naseem17
is it team contest?
It’s an ICPC style contest, so a team is recommended, but you can register as a person if you want
Great I join as a team
Are the problems provided in English?
Yes
Editorial?
which problem do you need ?
want G and M
let's calculate for each number
how many subsequence that have the mex i
first we make frequency array for element less than n
we don't really care about numbers greater than n
for i from 1 to n
for each element less than i , we have to include at least one of its occurences
and for each element greater than i , we don't care about what we take of them
Don't forget to MOD
As a tester I am too late to write comment.
How do you solve problem A?
As $$$x \lt = 10^9$$$ You can replace every $$$a_i$$$ with $$$g = gcd(x, a[i])$$$ because you can't get more contribution than $$$g$$$ from $$$a_i$$$. Now all integers are the divisors of $$$x$$$. So, there will be about $$$10^3$$$ distinct integers. You can store maximum $$$q$$$ duplicates from each of them where $$$q$$$ is maximum power of a prime factor of $$$x$$$. Now, try using dp to find a proper subset.
How did you know that there will be at most 1000 distinct numbers ?
Maximum number of divisor of x can be $$$10^3$$$
Hints on H?
Someone please provide Editorial for problem D
I have tried Binary search to find b.. assuming a = x;
but getting WA on test 4
bool check(ll x, ll y, ll mid){
// if(left==0 or right == 0) return false;
}
void __jaiShreeRam() {
ll x,y; cin>>x>>y;
double left = 0, right = 400 + 10;
ll ans = -1, red = 1e3 + 10;
while(left<=right){
double mid = left + (right - left)/2; if(check(x,y,mid)){ ans = mid; right = mid-1; } else left = mid+1; red--; if(red==0) break;}
if(ans == -1){ print(-1) return; }
cout<<ans+x<<"\n";
}