Monthly Archives: January 2016

Screen Shot 2016-01-31 at 10.22.46 AM

January Lunchtime 2016 on CodeChef

January Lunchtime 2016 has just finished. The problems used there are so great, that I have to let you know about them! 

The most amazing problem in my opinion is the one involving Dilworth's Theorem, check it out: Table Covering

I wrote all editorials to the problems, they are very descriptive and detailed and are available here: editorials.


Invitation to India Hacks 2015, Qualification Round 3


I want to invite all of you to participate in the last Qualification Round of India Hacks 2016, which is organized by HackerEarth.

This is the third and the last one qualification round. If you missed or didn't qualify in the two previous rounds, this is the last change to advance to the semifinals.

Qualification Round 3 takes place on January 17, 04:30 PM CET (click to check your timezone). Top 1000 participants with non-zero score will advance to the main contest.

The prizes in India Hacks are quite nice, including a trip to San Francisco, many tech gadgets and a lot of goodies for top 50 participants. If you want to grab any of them, or you just like to compete agains a lot of other programmers and you haven't qualified to the main contest yet, reserve a time slot for this round!

Screen Shot 2016-01-16 at 9.22.22 PM

I'm a tester of the problem set and a conductor of the contest. There will be 5 problems in the contest and you'll have 3 hours to solve all of them. In addition, a partial scoring system will be used in all of them, which means that you'll get points for each correctly solved test file in any problem.

Big thanks to tanujkhattar, subway, aditya1495 and hellgeek for creating the problems, to belowthebelt for technical assistance and to I_love_Tanya_Romanova and Errichto for proofreading and solving the problems, and for all their suggestions.

Since this is the last qualification round, problems won't be very hard, so if you're going to participate, you may assume that submission time might be a big factor in the final standings.

As a small hint, I can tell you that you should be prepared with number theory, computing optimal subsequences of some types, and techniques used with computation on trees.

Have fun and good luck to all of you!

See you on the leaderboard, hopefully at the top of it :)

Screen Shot 2016-01-06 at 4.57.03 PM

HackerRank Regular Expresso Contest

Tomorrow a new type of contest will be hosted on HackerRank. It's going to be all about regular expressions - a concept that all software engineers should be aware of.

Register for the contest

The contest duration is set to 24 hours and top 10 participants will be awarded with HackerRank T-Shirts. I created two problems there and I'm going to take care of user questions during the contest. As a hint, I can tell you that most problems are not hard if you are familiar with regular expressions already, so speed will be a big factor here.

Have fun with it and see you on leaderboard!