### Pages

### Categories

- AC
- algorithm
- announcement
- applicative
- art
- axiom of choice
- balanced
- Beeminder
- bijection
- BlogLiterately
- category
- challenge
- collaborative editing
- combinatorial species
- combinatorics
- competitive
- constructive
- contest
- darcs
- data
- design
- diagrams
- dissertation
- drawing
- DSL
- EDSL
- enumeration
- feedback
- functional
- functional programming
- functor
- geometry
- GHC
- ghci
- graphics
- hackathon
- Hac φ
- haskell
- ICFP
- isomorphism
- Kattis
- library
- log
- monad
- monads
- monoid
- multiset
- music
- paper
- parsing
- partitions
- patch theory
- pedagogy
- Philadelphia
- pictures
- productivity
- programming
- QuickCheck
- random
- release
- sampling
- sets
- species
- talk
- teaching
- theory
- translation
- tree
- tutorial
- type
- type-level
- Typeclassopedia
- types
- virtual
- workshop

### Archives

- February 2021 (1)
- July 2020 (2)
- June 2020 (3)
- May 2020 (4)
- April 2020 (2)
- March 2020 (2)
- February 2020 (4)
- December 2019 (1)
- November 2019 (1)
- October 2019 (1)
- July 2019 (1)
- May 2019 (2)
- April 2019 (2)
- March 2019 (1)
- February 2019 (3)
- November 2018 (1)
- October 2018 (3)
- June 2018 (1)
- May 2018 (4)
- April 2018 (1)
- March 2018 (2)
- February 2018 (3)
- January 2018 (1)
- November 2017 (1)
- September 2017 (1)
- June 2017 (1)
- May 2017 (1)
- April 2017 (1)
- March 2017 (1)
- February 2017 (4)
- January 2017 (3)
- November 2016 (2)
- October 2016 (2)
- September 2016 (3)
- August 2016 (4)
- July 2016 (1)
- June 2016 (1)
- May 2016 (3)
- April 2016 (2)
- March 2016 (3)
- February 2016 (1)
- November 2015 (2)
- October 2015 (1)
- August 2015 (2)
- July 2015 (1)
- June 2015 (3)
- May 2015 (2)
- April 2015 (1)
- March 2015 (1)
- August 2014 (3)
- June 2014 (2)
- May 2014 (2)
- January 2014 (2)
- October 2013 (1)
- August 2013 (1)
- July 2013 (1)
- May 2013 (1)
- April 2013 (3)
- March 2013 (2)
- January 2013 (2)
- December 2012 (2)
- November 2012 (4)
- October 2012 (3)
- August 2012 (4)
- July 2012 (5)
- June 2012 (1)
- March 2012 (1)
- January 2012 (1)
- November 2011 (4)
- October 2011 (3)
- September 2011 (2)
- August 2011 (2)
- July 2011 (2)
- June 2011 (1)
- May 2011 (6)
- April 2011 (2)
- March 2011 (1)
- February 2011 (3)
- January 2011 (1)
- December 2010 (2)
- November 2010 (3)
- October 2010 (1)
- September 2010 (1)
- August 2010 (3)
- July 2010 (2)
- June 2010 (3)
- May 2010 (3)
- April 2010 (3)
- March 2010 (2)
- February 2010 (1)
- January 2010 (1)
- December 2009 (2)
- October 2009 (3)
- September 2009 (2)
- August 2009 (4)
- July 2009 (7)
- June 2009 (1)
- May 2009 (2)
- April 2009 (1)
- March 2009 (2)
- February 2009 (3)
- January 2009 (3)
- December 2008 (2)
- September 2008 (2)
- August 2008 (1)
- July 2008 (3)
- June 2008 (1)
- April 2008 (4)
- March 2008 (4)
- February 2008 (4)
- January 2008 (2)
- December 2007 (4)
- October 2007 (2)
- September 2007 (2)
- August 2007 (3)
- June 2007 (2)

### Top Posts

### Blogroll

### Fun

### Personal

### Meta

# Tag Archives: haskell

## Competitive programming in Haskell: folding challenge

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

Posted in competitive programming, haskell
Tagged challenge, geometry, haskell, Kattis, origami
3 Comments

## Competitive programming in Haskell: cycle decomposition with mutable arrays

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

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

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

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

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

Posted in competitive programming, haskell
Tagged boxes, cake, coordinates, haskell, intersection, Kattis
7 Comments

## Competitive programming in Haskell: vectors and 2D geometry

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

Posted in competitive programming, haskell
Tagged geometry, haskell, Kattis, robot, vector
2 Comments

## Competitive programming in Haskell: permutations

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

Posted in competitive programming, haskell
Tagged cipher, cycle, decomposition, GCRT, haskell, Kattis, permutation, substitution
5 Comments

## Competitive programming in Haskell: building unordered trees

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

## Competitive programming in Haskell: sorting tree shapes

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

## Competitive programming in Haskell: summer series

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

## Competitive Programming in Haskell: modular arithmetic, part 2

In my last post I wrote about modular exponentiation and egcd. In this post, I consider the problem of solving modular equivalences, building on code from the previous post. Solving linear congruences A linear congruence is a modular equivalence of … Continue reading