Add new Erlang exercises

One of the easiest ways to add new exercises to the Erlang track is to translate them from other language tracks on Exercism. This page lists all of the problem specifications in the common pool of exercises which have not yet been implemented in Erlang.

The icon links to the language-independent description of the problem.

The icon links to the canonical test data.

We also link to all the implementations of each exercise in other languages, which you can use for inspiration.

Once you've picked an exercise, follow the instructions in this guide and submit your pull request to the Erlang track repository on GitHub.

Exercises

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Examples

Pascals Triangle

Compute Pascal's triangle up to a given number of rows.

Nth Prime

Given a number n, determine what the nth prime is.

Perfect Numbers

Determine if a number is perfect, abundant, or deficient based on Nicomachus' (60 - 120 CE) classification scheme for natural numbers.

Prime Factors

Compute the prime factors of a given natural number.

Bracket Push

Make sure the brackets and braces all match.

Crypto Square

Implement the classic method for composing secret messages called a square code.

Say

Given a number from 0 to 999,999,999,999, spell out that number in English.

Pig Latin

Implement a program that translates from English to Pig Latin

Queen Attack

Given the position of two queens on a chess board, indicate whether or not they are positioned so that they can attack each other.

Run Length Encoding

Implement run-length encoding and decoding.

Secret Handshake

Given a decimal number, convert it to the appropriate sequence of events for a secret handshake.

Flatten Array

Take a nested list and return a single list with all values except nil/null

Minesweeper

Add the numbers to a minesweeper board

Sublist

Write a function to determine if a list is a sublist of another list.

Wordy

Parse and evaluate simple math word problems returning the answer as an integer.

Diamond

Given a letter, print a diamond starting with 'A' with the supplied letter at the widest point.

Binary Search Tree

Insert and search for numbers in a binary tree.

List Ops

Implement basic list operations

Ocr Numbers

Given a 3 x 4 grid of pipes, underscores, and spaces, determine which number is represented, or whether it is garbled.

Saddle Points

Detect saddle points in a matrix.

Change

Correctly determine change to be given using the least number of coins

Isbn Verifier

Check if a given string is a valid ISBN-10 number.

Palindrome Products

Detect palindrome products in a given range.

Pythagorean Triplet

There exists exactly one Pythagorean triplet for which a + b + c = 1000. Find the product a * b * c.

Food Chain

Generate the lyrics of the song 'I Know an Old Lady Who Swallowed a Fly'

Kindergarten Garden

Given a diagram, determine which plants each child in the kindergarten class is responsible for.

Protein Translation

Translate RNA sequences into proteins.

Matrix

Given a string representing a matrix of numbers, return the rows and columns of that matrix.

React

Implement a basic reactive system.

Simple Cipher

Implement a simple shift cipher like Caesar and a more secure substitution cipher

Simple Linked List

Write a simple linked list implementation that uses Elements and a List

Transpose

Take input text and output it transposed.

Forth

Implement an evaluator for a very simple subset of Forth

Alphametics

Write a function to solve alphametics puzzles.

Connect

Compute the result for a game of Hex / Polygon

House

Output the nursery rhyme 'This is the House that Jack Built'.

Twelve Days

Output the lyrics to 'The Twelve Days of Christmas'

Dominoes

Make a chain of dominoes.

Rail Fence Cipher

Implement encoding and decoding for the rail fence cipher.

Reverse String

Reverse a string

Tournament

Tally the results of a small football competition.

Book Store

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.

Poker

Pick the best hand(s) from a list of poker hands.

Proverb

For want of a horseshoe nail, a kingdom was lost, or so the saying goes. Output the full text of this proverbial rhyme.

Two Bucket

Given two buckets of different size, demonstrate how to measure an exact number of liters.

Rectangles

Count the rectangles in an ASCII diagram.

Armstrong Numbers

Determine if a number is an Armstrong number

Diffie Hellman

Diffie-Hellman key exchange.

Variable Length Quantity

Implement variable length quantity encoding and decoding.

Markdown

Refactor a Markdown parser

Pov

Reparent a graph on a selected node

Word Search

Create a program to solve a word search puzzle.

Grep

Search a file for lines matching a regular expression pattern. Return the line number and contents of each matching line.

Scale Generator

Generate musical scales, given a starting note and a set of intervals.

Zebra Puzzle

Solve the zebra puzzle.

Error Handling

Implement various kinds of error handling and resource management

Dot Dsl

Write a Domain Specific Language similar to the Graphviz dot language

Go Counting

Count the scored points on a Go board.

Sgf Parsing

Parsing a Smart Game Format string.

Tree Building

Refactor a tree building algorithm.

Hangman

Implement the logic of the hangman game using functional reactive programming.

Ledger

Refactor a ledger printer.

Rational Numbers

Implement rational numbers.

Paasio

Report network IO statistics