All Questions
33 questions
5votes
1answer
158views
Ackermann-Péter function call count using Writer monad
I'm quite new to Monads and I tried add function call counting to the Ackermann function code. The goal was simplicity, not performance. I want to have code review on the ...
4votes
1answer
1kviews
Generate possible combinations by range and length
I am learning Haskell and I implemented a recursive function that generates possible strings by length and array (e.g. ['a'..'z']): ...
- 143
3votes
2answers
2kviews
Haskell Function to get the List representation of an Integral
This is a simple practice problem. The task is to write a function getLR that receives an Integral, ...
1vote
1answer
58views
Equivalent partition sums
I'm looking for feedback on my solution to the following prompt: Given an array of ints, return the index such that the sum of the elements to the right of that index equals the sum of the elements ...
- 185
1vote
1answer
173views
String tokenizer
Objective: Create a function called wordsAndSpaces that splits a string on groups of spaces, preserving each group of space characters as a single token. Example: <...
- 185
1vote
1answer
252views
"Sequence full of colors" challenge on HackerRank
This is the challenge: You are given a sequence of N balls in 4 colors: red, green, yellow and blue. The sequence is full of colors if and only if all of the ...
- 507
2votes
1answer
169views
Berlekamp–Massey Algorithm in Haskell
I was recently tasked to write an implementation of the Berlekamp–Massey algorithm (for GF2) from a given inductional proof and decided to fresh up on my Haskell, since converting a proof by induction ...
- 919
2votes
1answer
142views
Performing an action which may return other actions to be performed, concurrently
I have a program which, at its core, involves repeatedly performing an action on some value, and based on that action also returning a list of new values to perform that action on. The pure version of ...
- 121
1vote
1answer
4kviews
The quicksort algorithm in Haskell
I am learning Haskell programming language mainly from this source. And there I have encouraged with "an elegant" realization of the quicksort sorting algorithm (the Quick, sort! section). ...
- 921
12votes
1answer
222views
Solving alethic modal logic formulas using truth trees
Disclaimer: this first section is about alethic modal logic and truth trees. It's important to the question but significant parts of the code can probably be reviewed without it. You're welcome to ...
- 654
3votes
2answers
299views
Segementing a recursive tree in haskell
Could somebody help me work out how to abstract the recursion from this code for me please? I'm trying to write something that takes a pandoc structure, and subdivides the tree whenever it finds a ...
- 247
5votes
1answer
467views
Haskell limit number of recursions
I want to create a monad which will prevent more than 10 instances of recursion (which I am implementing by preventing more than 10 instances of >>=). My <...
- 153
3votes
1answer
278views
Parsing n lines to count vowels - HackerEarth
I have written a haskell program for the following 'Code Monk' Challenge at HackerEarth. Here is the challenge description. Basically, we are looking for the number of vowels in a string. The first ...
6votes
1answer
18kviews
Filter Duplicate Elements in Haskell
I'm working on HackerRank to try to improve my Haskell skills along side with reading Haskell Programming from first principles. I wrote a program that works, but it seems to time out on large input ...
- 200
3votes
2answers
163views
Count numbers whose digits are only increasing or decreasing
The goal is described here: basically, it is to compute the number of numbers below \$10^n\$ such that its digits are either increasing or decreasing (like 112 or 211, but not like 121). The original ...
- 131
