Author Archives: Brent

About Brent

Assistant Professor of Computer Science at Hendrix College. Functional programmer, mathematician, teacher, pianist, follower of Jesus.

Competitive programming in Haskell: BFS, part 4 (implementation via STUArray)

Posted on November 17, 2021 by Brent

In a previous post, we saw one way to implement our BFS API, but I claimed that it is not fast enough to solve Modulo Solitaire. Today, I want to demonstrate a faster implementation. (It’s almost certainly possible to make … Continue reading →

Posted in competitive programming, haskell | Tagged , , , , , , | 3 Comments

Competitive programming in Haskell: Enumeration

Posted on November 15, 2021 by Brent

I’m in the middle of a multi-part series on implementing BFS in Haskell. In my last post, we saw one implementation, but I claimed that it is not fast enough to solve Modulo Solitaire, and I promised to show off … Continue reading →

Posted in competitive programming, haskell | Tagged , , , , | 1 Comment

Competitive programming in Haskell: BFS, part 3 (implementation via HashMap)

Posted on October 29, 2021 by Brent

In a previous post, I showed how we can solve Modulo Solitaire (and hopefully other BFS problems as well) using a certain API for BFS, and we also explored some alternatives. I had a very interesting discussion with Andrey Mokhov … Continue reading →

Posted in competitive programming, haskell | Tagged , , , , , | 4 Comments

Competitive programming in Haskell: BFS, part 2 (alternative APIs)

Posted on October 18, 2021 by Brent

In my last post, I showed how we can solve Modulo Solitaire (and hopefully other BFS problems as well) using a certain API for BFS, which returns two functions: one, level :: v -> Maybe Int, gives the level (i.e. … Continue reading →

Posted in competitive programming, haskell | Tagged , , , , | 6 Comments

Competitive programming in Haskell: BFS, part 1

Posted on October 14, 2021 by Brent

In a previous post, I challenged you to solve Modulo Solitaire. In this problem, we are given a starting number and are trying to reach in as few moves as possible. At each move, we may pick one of up … Continue reading →

Posted in competitive programming, haskell | Tagged , , , , | 5 Comments

Swarm: a lot can happen in a week

Posted on October 1, 2021 by Brent

It’s been about a week since I put out an announcement and call for collaboration on a new game, Swarm. Since then, the response has been fantastic: lots of people have tried it out, a few have even streamed themselves … Continue reading →

Posted in haskell, projects | Tagged , , , , | Leave a comment

Swarm: preview and call for collaboration

Posted on September 23, 2021 by Brent

For about a month now I have been working on building a game1, tentatively titled Swarm. It’s nowhere near finished, but it has at least reached a point where I’m not embarrassed to show it off. I would love to … Continue reading →

Posted in haskell, projects | Tagged , , , , | 6 Comments

Competitive programming in Haskell: Codeforces Educational Round 114

Posted on September 21, 2021 by Brent

Yesterday morning I competed in Educational Round 114 on codeforces.com, using only Haskell. It is somewhat annoying since it does not support as many Haskell libraries as Open Kattis (e.g. no unordered-containers, split, or vector); but on the other hand, … Continue reading →

Posted in competitive programming, haskell | Tagged , | 2 Comments

Automatically updated, cached views with lens

Posted on September 17, 2021 by Brent

Recently I discovered a nice way to deal with records where certain fields of the record cache some expensive function of other fields, using the lens library. I very highly doubt I am the first person to ever think of … Continue reading →

Posted in haskell | Tagged , , , | 10 Comments

Competitive programming in Haskell: Kadane’s algorithm

Posted on September 9, 2021 by Brent

I will be giving a talk on competitive programming in Haskell tomorrow, September 10, at Haskell Love. You should attend! It’s free! In my last competitive programming post, I challenged you to solve Purple Rain. We are presented with a … Continue reading →

Posted in competitive programming, haskell | Tagged , , , , | 1 Comment