Hello Codeforces,

Manthan, Codefest'18 will take place on Sep/02/2018 17:35 (Moscow time) with a duration of 2 hours (tentative). The round is rated for both Div1 and Div2 participants and will consist of 8 problems.

The Department of Computer Science and Engineering, IIT (BHU) is conducting Codefest from 31st August-2nd September. Manthan (मंथन in Hindi, meaning Brainstorming), the algorithmic programming contest under the banner of Codefest, is being held as a special Codeforces round. The round follows regular Codeforces rules.

The round has been prepared by hitman623, karansiwach360, GT_18, Ezio07, Enigma27, csgocsgo and me (dhirajfx3). Special thanks to TooDumbToWin and DeshiBasara for their contribution in the preparation of the round.

We express our heartiest thanks to KAN, vintage_Vlad_Makeev, 300iq, isaf27 and cdkrot for their help in preparing the contest and MikeMirzayanov for the awesome Codeforces and Polygon platforms!

Prizes

Overall 1st place: INR 25000, Overall 2nd place: INR 18000, Overall 3rd place: INR 12000

1st place in India: INR 10,000

1st place in IIT(BHU) Varanasi: INR 4,000 1st place in freshman/sophomore year, IIT(BHU) Varanasi: INR 1,000

About Codefest: Codefest is the annual coding festival of the Department of Computer Science and Engineering, IIT (BHU) Varanasi, which is held online and is open to participation by all! Register on the Codefest website now! Total prizes worth ₹500,000/- up for grabs with events covering domains from Math, Machine Learning, Natural Language Processing and Capture The Flag style competitions. Go to the Codefest website to find out more!

As usual, the scoring distribution will be announced just before the round.

UPD1: Scoring 500-750-1000-1500-2250-3000-3500-4000

UPD2: Following are the winners of the contest

1. tourist

2. DearMargaret

3. LHiC

Best in India

amit_swami

Good luck and have fun!

UPD3: Link to editorial

In solution of http://mirror.codeforces.com/problemset/problem/375/D

consider struct qry { int l,r,id,val; int block; }; vector<qry> Q; vector<int> q_idx;

http://mirror.codeforces.com/contest/375/submission/26098047 this solution got AC , it used

sort(Q.begin(),Q.end(),[](qry &A,qry &B)
{  
       if( A.block == B.block )
		return A.r < B.r;
	return A.block < B.block;	
});

whereas

http://mirror.codeforces.com/contest/375/submission/26097714 this solution got TLE using

bool operator()(int x,int y) 
{
	if( Q[x].block == Q[y].block )
		return Q[x].r < Q[y].r;
	return Q[x].block < Q[y].block;	
}
sort(q_idx.begin(),q_idx.end(),*this); // q_idx is vector<int> containing indices

Can anyone explain why this happened ?