Add new R exercises
One of the easiest ways to add new exercises to the R 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 R.
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 R track repository on GitHub.
Create an implementation of the atbash cipher, an ancient encryption system created in the Middle East.
Write a function to convert from normal numbers to Roman Numerals.
Calculate the moment when someone has lived for 10^9 seconds.
Given a person's allergy score, determine whether or not they're allergic to a given item, and their full list of allergies.
We are going to do the `Transform` step of an Extract-Transform-Load.
Manage robot factory settings.
Given students' names along with the grade that they are in, create a roster for the school
Implement a clock that handles times without dates.
Calculate the date of meetups.
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 the `accumulate` operation, which, given a collection and an operation to perform on each element of the collection, returns a new collection containing the result of applying that operation to each element of the input collection.
Implement a binary search algorithm.
Implement the classic method for composing secret messages called a square code.
Given a string of digits, output all the contiguous substrings of length `n` in that string.
Add the numbers to a minesweeper board
Parse and evaluate simple math word problems returning the answer as an integer.
Given the position of two queens on a chess board, indicate whether or not they are positioned so that they can attack each other.
Given a number from 0 to 999,999,999,999, spell out that number in English.
Implement a program that translates from English to Pig Latin
Run Length Encoding
Implement run-length encoding and decoding.
Write a function to determine if a list is a sublist of another list.
Create a custom set type.
Implement basic list operations
Given a 3 x 4 grid of pipes, underscores, and spaces, determine which number is represented, or whether it is garbled.
Implement the `keep` and `discard` operation on collections. Given a collection and a predicate on the collection's elements, `keep` returns a new collection containing those elements where the predicate is true, while `discard` returns a new collection containing those elements where the predicate is false.
Binary Search Tree
Insert and search for numbers in a binary tree.
Take a nested list and return a single list with all values except nil/null
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.
There exists exactly one Pythagorean triplet for which a + b + c = 1000. Find the product a * b * c.
Detect saddle points in a matrix.
Correctly determine change to be given using the least number of coins
A data structure that uses a single, fixed-size buffer as if it were connected end-to-end.
Generate the lyrics of the song 'I Know an Old Lady Who Swallowed a Fly'
Given a string representing a matrix of numbers, return the rows and columns of that matrix.
Implement a simple shift cipher like Caesar and a more secure substitution cipher
Simulate a bank account supporting opening/closing, withdraws, and deposits of money. Watch out for concurrent transactions!
Given a letter, print a diamond starting with 'A' with the supplied letter at the widest point.
Implement an evaluator for a very simple subset of Forth
Output the nursery rhyme 'This is the House that Jack Built'.
Implement a basic reactive system.
Write a function to solve alphametics puzzles.
Compute the result for a game of Hex / Polygon
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.
Parallel Letter Frequency
Count the frequency of letters in texts using parallel computation.
Pick the best hand(s) from a list of poker hands.
Translate RNA sequences into proteins.
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
For want of a horseshoe nail, a kingdom was lost, or so the saying goes. Output the full text of this proverbial rhyme.
Count the rectangles in an ASCII diagram.
Given the size, return a square matrix of numbers in spiral order.
Create a program to solve a word search puzzle.
Diffie-Hellman key exchange.
Search a file for lines matching a regular expression pattern. Return the line number and contents of each matching line.
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.
Create a sentence of the form "One for X, one for me."
Implement various kinds of error handling and resource management
Refactor a Markdown parser
Parsing a Smart Game Format string.
Implement complex numbers.
Write a Domain Specific Language similar to the Graphviz dot language
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.
Report network IO statistics