Add new exercises to Lisp Flavoured Erlang (LFE)
One of the easiest ways to add new exercises to the Lisp Flavoured Erlang (LFE) track is to translate them from other language tracks on Exercism. This page lists all of the exercises that exist on Exercism, but have not yet been implemented in Lisp Flavoured Erlang (LFE).
icon links to the generic, language-independent problem description
icon links to the canonical test data
The language icons link to each existing implementation of the problem.
Once you've picked an exercise, follow the instructions in the Contributing Guide and submit your pull request to the Lisp Flavoured Erlang (LFE) track repository on GitHub.
The classical introductory exercise. Just say "Hello, World!"
Convert a number to a string, the contents of which depend on the number's factors.
Write a function to convert from normal numbers to Roman Numerals.
Given a word, compute the scrabble score for that word.
Determine if a triangle is equilateral, isosceles, or scalene.
Manage robot factory settings.
Determine if a sentence is a pangram.
Use the Sieve of Eratosthenes to find all the primes from 2 up to a given number.
Compute Pascal's triangle up to a given number of rows.
Given a number n, determine what the nth prime is.
Convert a long phrase to its acronym
All Your Base
Convert a number, represented as a sequence of digits in one base, to any other base.
Make sure the brackets and braces all match.
Implement a binary search algorithm.
Implement the classic method for composing secret messages called a square code.
Determine if a word or phrase is an isogram.
Determine if a number is perfect, abundant, or deficient based on Nicomachus' (60 - 120 CE) classification scheme for natural numbers.
Compute the prime factors of a given natural number.
Given the position of two queens on a chess board, indicate whether or not they are positioned so that they can attack each other.
Parse and evaluate simple math word problems returning the answer as an integer.
Add the numbers to a minesweeper board
Given a decimal number, convert it to the appropriate sequence of events for a secret handshake.
Implement a program that translates from English to Pig Latin
Given a number from 0 to 999,999,999,999, spell out that number in English.
Create a custom set type.
Given a 3 x 4 grid of pipes, underscores, and spaces, determine which number is represented, or whether it is garbled.
Run Length Encoding
Implement run-length encoding and decoding.
Binary Search Tree
Insert and search for numbers in a binary tree.
Given a diagram, determine which plants each child in the kindergarten class is responsible for.
Implement a doubly linked list
Detect palindrome products in a given range.
Implement basic list operations
Given a string representing a matrix of numbers, return the rows and columns of that matrix.
There exists exactly one Pythagorean triplet for which a + b + c = 1000. Find the product a * b * c.
Detect saddle points in a matrix.
Implement a simple shift cipher like Caesar and a more secure substitution cipher
Write a function to determine if a list is a sublist of another list.
Take a nested list and return a single list with all values except nil/null
Generate the lyrics of the song 'I Know an Old Lady Who Swallowed a Fly'
Correctly determine change to be given using the least number of coins
Given a letter, print a diamond starting with 'A' with the supplied letter at the widest point.
Implement a basic reactive system.
Compute the result for a game of Hex / Polygon
Output the nursery rhyme 'This is the House that Jack Built'.
Tally the results of a small football competition.
Write a function to solve alphametics puzzles.
Implement an evaluator for a very simple subset of Forth
Translate RNA sequences into proteins.
Simple Linked List
Write a simple linked list implementation that uses Elements and a List
Take input text and output it transposed.
Output the lyrics to 'The Twelve Days of Christmas'
Make a chain of dominoes.
Pick the best hand(s) from a list of poker hands.
Create an implementation of the rotational cipher, also sometimes called the Caesar cipher.
Variable Length Quantity
Implement variable length quantity encoding and decoding.
To try and encourage more sales of different books from a popular 5 book series, a bookshop has decided to offer discounts of multiple-book purchases.
Rail Fence Cipher
Implement encoding and decoding for the rail fence cipher.
Creating a zipper for a binary tree.
Reparent a graph on a selected node
Count the rectangles in an ASCII diagram.
Create a program to solve a word search puzzle.
Search a file for lines matching a regular expression pattern. Return the line number and contents of each matching line.
For want of a horseshoe nail, a kingdom was lost, or so the saying goes. Output the full text of this proverbial rhyme.
Generate musical scales, given a starting note and a set of intervals.
Given two buckets of different size, demonstrate how to measure an exact number of liters.
Calculate the number of steps to reach 1 using the Collatz conjecture
Diffie-Hellman key exchange.
Refactor a Markdown parser
Parsing a Smart Game Format string.
Write a Domain Specific Language similar to the Graphviz dot language
Implement various kinds of error handling and resource management
Count the scored points on a Go board.
Implement the logic of the hangman game using functional reactive programming.
Refactor a ledger printer.
Use lenses to update nested records (specific to languages with immutable data).
Refactor a tree building algorithm.
Create a sentence of the form "One for X, one for me."
Report network IO statistics