Invitation to Insomnia 2020 Qualifier

Hello Codechef!

Tonight gear up to get Insomniac!

Computer Club, MNNIT Allahabad, India is glad to invite you to the annual programming competition of MNNIT, ɪɴᴤᴏᴍɴɪᴀ, which is an ACM-ICPC style team programming contest of 3 hours duration held on CodeChef during its annual technical fest Avishkar. The team can consist up to 3 members.

Contest Details:

For the online round, top few global and top few MNNIT teams will get Codechef laddus. For the onsite round, prizes worth 31000 INR to be won. Top Indian teams from the online round will be called for the onsite round to be held at MNNIT Allahabad.

Problem setting panel includes Chinmay Pani ,Shakti Tripathi and Keshav Sharma

Past year’s problemset: 2019 , 2018 , 2017

We have an exciting problemset awaiting for you. Good luck and have fun!


Last year problem set was quite challenging and interesting. Much excited for the one this year.


Looking forward to this year’s problemset.


Very excited for the contest.

I hope you provide quick editorials.


what’s the criteria to qualify for the next round?

Top 15 Indian teams will be selected for the onsite round.


How do you solve Musical Chairs? We spent the last hour on this problem but were unable to think of any way to cleanly code it. It felt like just maintaining the segments but it didn’t feel like there was a simple way to eliminate the case work.


growing xor tree question is copied from cf (icm technex):laughing:

Can you share the link? Please check once again :upside_down_face:
There is difference in both the questions. Here operation is XOR whereas there operation is addition which totally changes the direction of solution towards persistent trie.


Right, the whole approach is different.Kindly check again.


Please move the problems to practice section.


This conversation is probably gonna happen here, for anyone interested :

i know , but idea is same , instead of binary search we are required to use presistent trie. I hope there will be original problems in next round.

Very true … Instead of persistent Segtree persistent Trie is used … :rofl: :rofl: :rofl: :rofl:

Please give the editorials for the contest. The problems are so nice and I really want to up-solve them.

1 Like

I was author of the problem Growing Xor Tree and here is the technex problem I think u r talking about and yes after solving this I got idea of growing xor tree … … but does solving This one helps in solving other or vice versa ? I think technex problem is easier to solve then this… technex uses LCA (I solved via using LCA twice) and ours use Persistent Trie… Language is same but that doesnt qualify as copying as multiple questions can be based on same assumptions. And atlast, its just hard at this level to make questions… I am weak theory wise and just good-good in cp… Most of the hardest problem are created by changing few of things and thinking if is it solvable? btw nice observation there.