Add new Ruby exercises

One of the easiest ways to add new exercises to the Ruby 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 Ruby.

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 Ruby track repository on GitHub.





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

Bank Account

Simulate a bank account supporting opening/closing, withdraws, and deposits of money. Watch out for concurrent transactions!


Implement a basic reactive system.


Implement an evaluator for a very simple subset of Forth

Reverse String

Reverse a string

Spiral Matrix

Given the size, return a square matrix of numbers in spiral order.

Armstrong Numbers

Determine if a number is an Armstrong number

Variable Length Quantity

Implement variable length quantity encoding and decoding.

Parallel Letter Frequency

Count the frequency of letters in texts using parallel computation.


Count the rectangles in an ASCII diagram.


Creating a zipper for a binary tree.

Diffie Hellman

Diffie-Hellman key exchange.


Refactor a Markdown parser


Reparent a graph on a selected node

Word Search

Create a program to solve a word search puzzle.

Error Handling

Implement various kinds of error handling and resource management


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

Zebra Puzzle

Solve the zebra puzzle.

Go Counting

Count the scored points on a Go board.

Rational Numbers

Implement rational numbers.

Dot Dsl

Write a Domain Specific Language similar to the Graphviz dot language

Sgf Parsing

Parsing a Smart Game Format string.

Tree Building

Refactor a tree building algorithm.


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


Refactor a ledger printer.

Lens Person

Use lenses to update nested records (specific to languages with immutable data).


Report network IO statistics


Score a single throw of dice in the game Yacht