Monthly Archives: September 2015


CodeChef September Lunchtime

September Lunchtime starts in under 2 hours, and I am the editorialist for the whole contest.

Problems are exceptionally interesting - big thanks to Sergey Kulik. You will have to deal with fancy pattern matching, some palindroms, maintain a collections of sets, and decide when is it best time to drink a cup o coffee :)

This lunchtime will be probably slightly harder than usual, so I advice to read all the problems very carefully, and stick to the details. Remember, as always on CodeChef, each problem has a few subtasks, and if you do not know how to solve it for the original constraints, we encourage you to solve as many subtasks as you can.

Techniques used it the problems are extremely useful, and I strongly recommend to solve all of them, even after the contest. I hope that my editorial will be helpful to explain intended solutions as well as solutions to each subtask. They will be published just after the contest, so stay tuned :)

UPDATE: All editorials are available here: September Lunch Time Editorials

One more thing worth to mention is that, AngryBacon, who is a tester in the contest, solved one of the problems faster than the indented solution was, so we decided to add another subtask to this problem, with even higher constraints. I am curious if you can spot that subtask during the contest ;)

See you on leaderboards!


Code Monk (Number Theory II) for HackerEarth

I am happy to announce the upcoming Code Monk (Number Theory II) contest on HackerEarth. I am the author of one problem there and the editorialist for the whole problem set.

The contest is scheduled for September 23rd. You can expect great problems covering combinatorics and probabilities - very useful topics in competitive programming.

See you on leaderboards!

My article for HackerEarth Codemonk

HackerEarth just published my first article prepared in purpose of Codemonk series.

This article is a comprehensive tutorial to the most basic graph algorithms, especially useful if you want an overview of the shortest paths problem. In addition, I explained topological sorting also, which is a great property of directed acyclic graphs.

The article is available here: Codemonk: Graph Theory Part II


My contest // Codemonk Revision for HackerEarth

I am very happy to announce my first contest prepared for HackerEarth. It is a part of Codemonk series, which is very popular recently.

The contest is available here: Codemonk Revision

So far, each contest from that series has covered some particular category of algorithms and data structures, not only with problems, but also with an educative article which helped to solve the problems. We have seen graph algorithms, number theory and many more.

My contest is the revision of all Codemonks prepared so far, so you can expect a variety of different problems with cool stories :)

I also want to thank Bohdan Pryshchenko (lebronI_love_Tanya_Romanova) for testing the problems in extreme conditions ;)

Cheers and see you on leaderboards.