Category Archives: competitive programming

Competitive programming in Haskell: folding folds

Posted on June 19, 2021 by Brent

Now that the semester is over—and I will be on sabbatical in the fall!—you can expect a lot more competitive programming in Haskell posts. In a previous post, I challenged you to solve Origami. j0sejuan took me up on the … Continue reading →

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Competitive programming in Haskell: folding challenge

Posted on February 23, 2021 by Brent

As of this writing, I am the only person who has solved Origami on Open Kattis (see the problem statistics here). This is a shame since it is a very nice problem! Of course, I solved it in Haskell. I … Continue reading →

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Competitive programming in Haskell: cycle decomposition with mutable arrays

Posted on July 18, 2020 by Brent

In my previous post I I challenged you to solve Chair Hopping: if a bunch of people permute themselves according to the same rule twice, how many different rules could they be following which would result in the observed final … Continue reading →

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Competitive programming in Haskell: 2D cross product, part 1

Posted on July 10, 2020 by Brent

Time for some more geometry! In my previous post I challenged you to solve Cookie Cutters, which asks us to scale the vertices of a polygon so that it has a certain prescribed area. It’s possible to solve this just … Continue reading →

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Competitive programming in Haskell: data representation and optimization, with cake

Posted on June 29, 2020 by Brent

In my previous post I challenged you to solve Checking Break, which presents us with a cake in the shape of a rectangular prism, with chocolate chips at various locations, and asks us to check whether a proposed division of … Continue reading →

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Competitive programming in Haskell: vectors and 2D geometry

Posted on June 24, 2020 by Brent

In my previous post (apologies it has been so long!) I challenged you to solve Vacuumba, which asks us to figure out where a robot ends up after following a sequence of instructions. Mathematically, this corresponds to adding up a … Continue reading →

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Competitive programming in Haskell: permutations

Posted on May 30, 2020 by Brent

In my previous post I challenged you to solve The Power of Substitution. This problem presents us with a substitution cipher, and asks how many times we would have to iterate the encoding process in order to turn a given … Continue reading →

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Competitive programming in Haskell: building unordered trees

Posted on May 22, 2020 by Brent

In my previous post I challenged you to solve Subway Tree System, which encodes trees by recording sequences of steps taken away from and towards the root while exploring the whole tree, and asks whether two such recordings denote the … Continue reading →

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Competitive programming in Haskell: sorting tree shapes

Posted on May 19, 2020 by Brent

In my previous post I challenged you to solve this problem, which essentially asks how many distinct binary tree shapes are created when we take lists of numbers and build a tree from each by repeated binary search tree insertion. … Continue reading →

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Competitive programming in Haskell: summer series

Posted on May 16, 2020 by Brent

Now that this weird and crazy semester is finally over, I’d like to get back to doing some blogging (among other things). I’m going to return to my series on competitive programming in Haskell (previous posts here: basic setup; code … Continue reading →

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